Paper - A comparison of the growth of the body dimensions of anencephalic human fetuses with normal fetal growth as determined by graphic analysis and empirical formulae

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Nañagas JC. A comparison of the growth of the body dimensions of anencephalic human fetuses with normal fetal growth as determined by graphic analysis and empirical formulae. (1925) American J. Anatomy. 455-494.

This historic 1925 paper by Nañagas attempted to quantify differences between the anencephalic and normal fetus growth. Much of the early embryology studies were based around measurements and formulas to describe growth.


See also Frazer JE. Report on an anencephalic embryo. (1921) J Anat. 56(1): 12-9. PMID 17103933

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A Comparison of the Growth of the Body Dimensions of Anencephalic Human Fetuses with Normal Fetal Growth as determined by Graphic Analysis and Empirical Formulae

Juan C. Nanagas Institute of Anatomy, University of Minnesota

Seventeen Figures

Introduction

The teratological condition known as anencephaly is not an uncommon human malformation. It is obvious on the first inspection of anencephalic fetuses that, concomitant with the faulty or even complete suspension of development of the cranial portion of the head, there is a marked departure from the normal proportions of not only the facial region, but also of the other divisions of the body. These disproportions have received little attention in studies of congenital malformations.


This study was undertaken with the object of determining quantitatively the anomalous growth of this type of fetus and the changes in body-form associated with the partial loss or complete absence of the cranial vault and encephalon.


The present report was made possible by the use of the extensive data on normal fetal growth available in the Institute of Anatomy of the University of Minnesota. The writer wishes to express his grateful acknowledgments to Professor Scammon, under whom this investigation was conducted, and to Professor Jackson, Director of the Institute.

General Description of Material

Fifty-seven anencephalic fetuses were available for study.


The sizes of these ranged from 279 to 502 mm. in calculated crown-heel length (p. 466) and from 320 to 2750 co. in body volume. Of these fifty-seven cases forty-three were females, twelve were males, and the sex of two specimens was undetermined. The great majority of these fetuses were born in the last three months of gestation.


These specimens were preserved in 10 per cent formalin for a longer or shorter period of time, but in no instance was this preservation less than six months. All mere well fixed and hardened, and were in good condition for measurement.


Taking into consideration the degree of involvement of the vertebral column and the modifications or the total absence of the brain, the cases in the series may be grouped into five general types, short descriptions of each of which are given below.


1. Anencephalic acrawia (fig. 1,a). In these cases the whole cranial vault, together with the encephalon, is wanting. The flattened base of the cranium is covered by a membrane that varies in texture from a thin semitransparent sheet to an opaque scalp-like epidermal covering. When this covering is thin, it is markedly vascular, closely resembling the cerebral meninges, and the line of union between it and the normal skin of the face and neck is very distinct. When the covering is opaque and epidermal in character there is no such line of transition into the surrounding normal skin. In the former condition this covering is loose and irregularly folded, while in the latter it is generally thick and tense. Fifteen of the fifty-seven cases in the series were of this type (26.3 per cent).


2. Anencephalic cramioirhachisis (fig. 1,b). This type is similar to the preceding, but has an associated involvement of the vertebral column and a characteristic change in the position of the head. The vertebral arches have failed to unite in a varying degree. The open spinal canal may reach from the base of the cranium to any level of the vertebral column, and this defect frequently occupies the middle third of the surface of the back. The external covering or roof of the canal is structurally the same as the thin covering of the anencephalie cranium. This membrane is continuous with the surrounding skin of the back, but is distinctly marked off from it. It is a meningeal-like membrane and not epidermal in structure. In many of these cases the canal is so widely open and the membrane is so transparent that the roots of the spinal nerves are easily seen passing to the intervertebral foramina. In some cases, however, the spinal cord is completely absent and 110 nervous structure is seen through the roof. The vertebral column in these cases is abnormally shortened and bent so that the head is drawn backward with the face directed upward. The convexity of the curvature of the column in many of these iristaiices is most acute in the lumbar region producing an exaggerated posterior prominence of the gluteal regions. Fourteen cases of this type of aiiencephalus were encountered in the series (24.5 per cent).

Nanagas1925-fig01a.jpg Nanagas1925-fig01b.jpg Nanagas1925-fig01c.jpg Nanagas1925-fig01d.jpg Nanagas1925-fig01e.jpg

Fig. 1 Five types of anencephalus encountered in the present series: a, anencephalic acranius; b, anencephalic craniorhachischiis; e, microcephalic acranius; d, microcephalic craniorha.e.11isc.1'1isis, and, e, exocephalic acranius.



3. Microcephalic acmmia (fig. 1, c). This is a condition of acrania with the persistence of a diminutive and imperfectly developed brain. The brain tissue is represented by a soft, flabby of variable size which occupies the flattened base of the vaultless cranium. A meningeal-like membrane covers this structure in all cases. Tn some instances, fluid is present within this tumor-like mass, giving it the form of a cyst with walls of varying thickness. Such cases would more properly come within the subclassification of hydromicrocephalus. There were seven cases of microcephalic acrania in the series (12.3 per cent).


4. Miicrocephriahlc cmmlorhachsisis (fig. 1,d). In this condition the spinal arches are separated by a wide cleft which usually extends to the lumbar region. The imperfectly developed brain in most of the cases is dislocated downward in the cervical region (hernia cerebri cervicalis) arid in a few instances this hernial formation is found in the thoracic region. The covering of the hernial sac is a meningeal-like memhrane continuous with the covering of the flattened internal base of the cranium and that of the open vertebral arches. This type forms the largest number in our series of acrania, there being nineteen cases, or 83.3 per cent of the whole number of anencephalic cases.


5. Easencephvalucs acmmn (fig. 1,e). As the term signifies, specimens of this type show hemiae cerebri, usually pendulous and attached to the back of the head. The cranial vault is likewise absent as in all the preceding groups of cases. The covering of the flattened head is formed by an ordinary scalp continuous with the skin supporting the herniated encephalon. Only one example of this type of exencephalus was encountered in our series. The pendulous mass, suspended by a stalk, was cystic in character, and the hemispheres of the brain were filled with fluid.


The appearance of the face in all these various types of anencephalus is very striking. The eyes are markedly protruded, with a prominent bulging of the upper eyelids — a condition obviously due to the receded superciliary ridges produced by the disappearance of the forehead. The nose appears enlarged. The tongue in many of these cases is considerably protruded.


The neck is abnormally short; so much so, that the head appears to be attached directly to the shoulders and upper end of the thorax. In fetuses with open vertebral canals the head is hyperextended with the face looking upward and its base is set firmly against the back of the shoulders. The trunk region in these specimens is relatively much shorter than in other types. This is partly due to the marked anterior curvature of the vertebral colunm.

Methods of Measurement

The method of external measurement followed in this work is identical with that devised by Calkins and Scammon for the measurement of the normal fetus. A steel vernier caliper, which registered to Im. on the major and 0.1 mm. on the minor scale, was employed for lineal determinations. Lineal measurements were taken to the nearest millimeter in all cases. For volumetric determination the method of immersion and displacement was used. For the determination of circumference a stiff linen thread has been used in preference to the graduated steel tape usually employed. In the measurement of circumference the thread was wound three times about the part measured and the entire length was divided by 3 to obtain the exact circumference. This method gave a more correct expression of circumferences than the usual determination with the steel tape.


For the exact identification of the bony or cartilaginous points from which measurements were taken, fine-pointed needles have been employed. Proper use of these needles allowed a much more accurate determination of measuring points than is otherwise possible by simple palpation.


The measurements taken of the extremities in each case were separately recorded for each side and were then averaged. In general, the measurements taken of the extremities on the two sides correspond very closely. The following are the external measurements taken in connection with this study :

1. UEL, length of the upper extremity; the sum of the separate lengths of the arm, forearm, and hand.

2. AL, arm length; from the tip of the acromium to the olecranon process.

3. FML, forearm length; from the tip of the olecranon process to the middle of the wrist-joint.

4. HL, hand length; from the middle of the wrist to the tip of the middle finger.

5. FrL, finger length; from the metacarpophalangeal joint to the tip of the middle finger.

6. LLE, length of the lower extremity; the sum of the lengths of the thigh and leg, and the height of the foot.

7. TL, thigh length, from the tip of the great trochanter to the lateral condyle of the tibia, in line with the posterior angle of the knee.

8. LL, leg length, from the lateral condyle to the most prominent part of the lateral malleolus.

9. FtH, foot height; from the external malleolus to the sole of the heel, vertically.

10. FtL, foot length; from the posterior surface of the heel to the tip of the big toe.

11. AA, bi—acromial diameter; distance between the tips of the two acromial processes.

12. ETDM, transverse diameter of the thorax at the level of the nipples.

13. BTDR, transverse diameter of the thorax at the level of the tenth rib.

14. BADN, anteroposterior diameter of the thorax at the level of the nipples.

15. BADR, anteroposterior diameter of the thorax at the level of the tenth rib.

16. ICD, intercristal diameter of the pelvis; distance between the most prominent points of the lateral crests of the ilium.

17. CD, conjugate diameter of the pelvis; from the npper margin of the symphysis pubis in front to the dorsum of the sacrum behind.

18. SL, sternal length; from the suprasternal notch to the tip of the xiphoid process, measurement taken as a straight line.

19. SPL, suprasternal—pubic length; from the suprasternal notch to the symphysis pubis.

20. NC, neck circumference.

21. AC, arm circumference; taken about, the middle portion of the arm.

22. TC, thigh circumference; taken about the middle portion of the thigh.

23. BCN, thorax circumference at the level of the nipples.

24. BCR, thorax circumference at the level of the tenth rib.

25. BCU, trunk circumference at the level of the umbilicus.

26. AAD, bi—auricular diameter; distance between the roots of the two ears.

27. MMD, bimalar diameter; distance between the two malar prominences.

28. MND, mentonasal diameter; from the root of the nose to the mental prominence of the mandible.

29, BV, volume of the whole body of the fetus.

30. HV, volume of the head; taken to the middle of the neck.

Analysis of Data

Since the present report is primarily a quantitative study it is essential to outline in detail the graphic and numerical methods employed in the comparison and summation of the data, and in the formulation of conclusions drawn from their application. This is particularly important in this work, since the determination of the degree of abnormality in this material is based upon calculations obtained from empirical formulae for the expression of normal relations.


Five main procedures have been followed in the examination and analysis of our data as follows :

1. Plotting of the measurements of the various dimensions of anencephalic fetuses against one another in field graphs.

2. Construction, on these field graphs, of point-to-point curves of the measurements on the basis of the weighted average values for definite, coiistarit ranges of each dimension.

3. Construction of curves of normal dimensional growth on the corresponding field graphs of the anencephalic material by means of the empirical formulae for the normal.

4. Calculation of results and conversion of increments or decrements into mean values, either as absolute deviations or as percentage deviations from the normal curve.

5. Selection of a standard dimension for the comparison of normal and anencephalic fetuses, and construction of field graphs and curves on the basis of this standard.

1. Plotting of one series of measurements against another on the field graphs

The data obtained for each measurement were first plotted separately on field graphs in which the more standard or convenient value was used for the abscissa or ‘X’ axis and the measurement in question, or under test, was used for the ordinate or ‘Y’ axis. The values used in plotting are always in millimeters or in cubic centimeters for the lineal or volumetric measurements, respectively.

2. Conxstrusction of curves for the a'nenceph»al*u—s on the field graphs

The individual cases having been plotted on the field graph for each measurement, it becomes a simple matter to construct the curve. The weighted mean values are determined for the cases included within certain definite and uniform intervals in the graphs. The points of these mean values being known, they are connected by straight lines to express the observed anencephalic curve for the particular measurement.


For the construction of the anencephalic curve another method has been tried with practically the same results. The mean value for each interval was found by summing all the deviation values of the individual cases without regard to sign, and, after subtracting the sum of the minus values, dividing the remainder by the total number of cases. The mean values were plotted in the graph in their proper positions and connected to express the anencephalic curve. This method is of advantage in that it gives a numerical expression of the increment or decrement from the normal.

3. Construction of the normal curves on the field graphs of the anencephalic measurements

The curves of the normal growth of the various measurements shown in the field graphs were calculated from the empirical formulae of Calkins and Scammon, but since these empirical formulae were all computed to the total or crownheel lengths, it became necessary to calculate from them such substitution formulae as were needed in this work. The Calkins-Scammon formulae are almost all of the simple linear type:

Y = a.X i B. (1) Where (Y) is the given dimension in millimeters, (a) a decimal fraction empirically determined, (X) the body length in

millimeters and (b) a second empirical constant in milli meters. Therefore, if a formula for a given dimension (Y1) ls:

Y1:-a,X —b, (2) and the formula for a second dimension Y2 is:

Y, =-a,X—-—b._, (3)

then X: ' Y_r3;+:_b2 .'." 1 ' 3

and, substituting (5) in (2):

and, substituting (4) in (3) : -....-.._.._...___.._ _ ba

Thus, for example, the empirical formula for the length of the lower extremity (L) is L=:0.43X—7 .0 and the formula for the length of the upper extremity (U) is U =0.40X —4.0, and if the length of the lower extremity in a given instance is, say, 165 the calculated length of the upper extremity would be,

165+?

172 43 ——4, 01' 0.40—4§—4 01' (o.4o><40o)—4 or 156

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4. Calculation of results and conversion of increments or decrements into mean values

The numerical expression of the departure of the anencephalic values from the normal curve is given here in two forms. One is expressed in millimeters and the other is the average percentage deviation of the anencephalic cases from the normal curves traced in the graphs. The expression of deviation in both cases is always the average or the mean value of the increment or decrement. These calculations are given in tables 1,2, and 3.

5. Selection of a standard dimension for the comparison of normal and anencephalic fetuses

It was essential in this study to select some dimension which could be used as a base against which other measurements might be plotted and which could serve as a standard of comparison with the normal. This is particularly difficult because the crown-heel and the crown-rump lengths of anencephalic specimens cannot be determined, and because there are no clinical data available for estimating age.

In the selection of a lineal measurement for a reliable base to be utilized in graphic comparison of dimensions, there are five important conditions which should be fulfilled: 1) It should be a large measurement in which the error involved GROWTH OF ANENCEPHALIC FETUS

in its determination will be relatively small. 2) It should be a measurement in which the natural variability lies within narrow limits, i.e., one in which the individual cases show but slight deviation from the curve of central tendency. 3) It should be in normal agreement with a large proportion of other measurements and in uniform relation with other observed dimensions.‘ 4) It should be a measurement in which the constituent parts or segments are in normal relation to one another and to the dimension as a whole. 5) Finally, it should be a dimension which, when made the base for the calculation of the crown-heel or crown-rump length of the body with empirical formulae, will give values which are within a reasonable range of probability.

After repeated plottings of the more important measurements, it was found that the length of the lower extremity was the one best suited for use as a standard measurement for plotting field graphs in the anencephalic series and for instituting therefrom a comparison with the normal. The use of this measurement in preference to others is based on the following reasons : 1)The length of thelower extremity is one of the longer linear measurements in the anencephalic fetus. The technique of measuring this part is simple and the experimental error small. 2) With repeated observation in direct or transposed plotting of this dimension against other measurements it was found that it had as small a degree of variability in the anencephalic as in tlie normal fetus. 3) It was observed that its component parts, when plotted against its whole or against many of the dimensions of the body, showed close agreement with corresponding normal curves. 4) \Vl1en the crown-heel length of the body is calculated from this measurement by means of the einpirical formula, tlie resulting values range from 279 to 500 mm., whicli may be regarded as within reasonable limits for normal material.


This criterion of normality may be questioned. As a matter of fact, it is only an example of the common test which we constantly apply almost unconsciously in the estimation of normality or abnormality of any material when data regarding exact age are not available, and it is neither more nor less reliable than this test. If, for example, we examine an individual in which one digit is, say, half its usual relative size we do not hesitate to conclude that it is the digit which is undersized and the body as a whole which is normal. Yet it is conceivable that we might be examining an oversized body attached to a normal digit. If one half of the body were proportionate to a given size and the other half proportionate to another size, and we had no further data upon which to base a conclusion, we would be in a quandary to formulate an opinion as to the normal proportions of the individual. What we do in actual practice is to unconsciouslp or tacitly assume that the larger the number of parts showing normal relations among themselves, the greater is the probability that these parts are in themselves of normal dimensions. This is the criterion applied in this instance, and it becomes of much greater significance when considered in connection with the criterion expressed in number 4 as stated in the body of this paper above.


It was possible to make a further test of the normality of the lower extremity by a comparison of some of the centers of ossification, as shown in sections through tlie knee and ankle-joints of the anencephalic specimens, with Adair and Scammon’s findings for normal cases. The state of ossification of the calcaneus, the talus, the cuboid, the inferior epiphysis of the femur and the superior epiphysis of the tibia were determined in fifty-five anencephalic specimens. The ossification of tlie superior epiphysis of the tibia alone proved significant, because the other centers, with the exception of the cuboid, were present in almost all of both the anencephalic and tlie normal specimens. The cuboid, on tlie other hand, showed little ossification in either series. Tlie findings for the superior tibial epiphysis and their relation to the normal are given in table 5. In making this table the percentage frequency of the ossification of the epiphysis was determined for the specimens in each 5-cm. interval of crown-heel length from 35 to 50 cm. The crown-lieel length of the normal material was observed directly, while that of the anencephalus was calculated separately from tlie lengtli of the upper and of the lower extremities by means of the Calkins—Scammon ernpirical formulae (upper extremity length =0.43 CH lengtli —4.0 mm.; lower extremity length =0.43 CH length —7'.() mm.). Comparing the percentage frequency of tlie tibial ossification of the normal mitli that of tlie anencephalic material, when tlie (",1'0W11-l'1('3-el length is calculated from the obseI've(,l lower extremity length, it will be seen that the figures are in fairly close agreement (for the 40- to 50-cm. interval it is 83.8 per cent as compared with 66.7 per cent). The frequency of ossification in the anencephalic material, when the body-length is calculated from the observed length of the upper extremity is, however, widely divergent from the normal. This is a further confirmation of the normality of the lower extremity both as regards body-length and age.

Observations and Findings

1. The dimenisiow/ass of the lower extremity

As previously mentioned, the length of the lower extremity has been observed to closely coincide with the normal. The length of the lower extremity has been plotted against practically all the other dimensions measured. If the curves for both the normal and anencephalic material in one graph are compared with those of other graphs having a measurement in common (for example, fig. 4), an estimate can be made of the degree of normality of this part. The examination of the-tables of the relation of the observed cases to the calculated normal curves (tables 1 and 2) will show more definitely this method of comparison. Taking, for example, the bi-acromial diameter plotted against the lower extremity (fig. 4 C), there is found an absolute average increment of 1.5 mm. and a relative increase of 0.6 per cent above the normal curve for this relation. This indicates a fairly close agreement of the two measurements with the normal. If now, the bi-acromial diameter is taken as a base and the length of the upper extremity plotted against it (fig. 8) there is found to be a very noticeable increment of 20.3 mm., or. of 13.3 per cent. To test this finding, the upper extremity is now plotted against the lower extremity (as presented in figure 9). From this graph it is found that the differences between the upper and lower extremity are 21.8 mm. and 11.9 per cent, which are in close agreement with the values given above, while the lower extremity and the bi-acromial diameter are in fairly normal relationship.


The examination of the field graphs with the curves made by plotting the different segments of the lower extremity against its whole leiigtli shows that the relations existing between these segments in the normal are also characteristic of this series. The curve of tlie length of the thigh plotted against that of the lower extremity as a whole (fig. 2A) is only slightly above the curve for tlie normal. The length of the leg and the height of the foot plotted against the lower extremity (fig. 2 B) show likewise a fairly close fit with the corresponding normal curve. The length of the foot plotted in the same manner (fig. 2 C) also gires a similar result.



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Fig. 2 Graphs illustrating tlie 1i11e:.1.l growth of the different segments of the lower extremity in relation to its entire length. A.hseissa,: length of tlie lower extremity in millimeters. Ordinates: length of the segments in millimeters. A, length of the thigh : eases indicated by solid dots, curve of anencephalic average by broken line, and ealciilated normal curve by solid line. B, lengtli of tlie leg anti height of the foot: eases indicatetl b__\ circled dots, curve of anencepialic material by broken line, c:-1.le11lat.ed normal curve by solid line. C, length of the foot; cases iiidicatetl by open circles, curve of a.I1encepha.]ic average by broken line hml (‘.1-tleuhited normal (tune by solid line.


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Fig. 3 Graphs illustrating the circuniferential growth of the thigh and arm in relation to the length of the loner extremity. Abscissa: length of the inferior extremity in millimeters. Ordinates: circumferences of the thigh and arm in millimeters. A, circumference of the thigh; cases indicated by solid dots, curve of anencephalic averages by broken line, and calculated normal curve by solid line. B, circumference of the arm, cases indicated by circles, curve of anencephalic average by broken line, and calculated normal curve hy solid line.


Figure 17, which shows graphic reconstructions of a normal fetus of an anencephalus of the same leg length, illustrates tllese findings. It is to be noted that the circumference of the thigh in the anencephalus is slightly increased over the

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Fig. 4 Graphs illustrating the growth of the trunk diameters in relation to t_he length of the lower extremity. Abscissa: length of the lower extremity in millimeters. Ordinates: diameters of the trtmk in millimeters. A, transverse diameter of the body at the tenth rib: eases indicated by solid dots, curve of aneneephalic averages by broken line, and calculated normal curve by solid line. B, transverse diameter at the nipples: curve of anencephalic averages by broken line, and culculated normal curve by solid line. C, bi-acromial diameter: eases indicated by solid dots, curve of anencephalic averages by broken line and calculated normal curve by solid line. D, intereristal diameter of the pelvis; curve of anencephalic averages indicated by broken line and calculated normal curve by solid line.

normal measurement. A plotting of this circumference against. the length of the lower extremity (fig. 3) shows a slight increment in the larger specimens which may be due to

the greater accumulation of body fat in the anencephalic fetuses.

2. The dimensioozs of the trunk

The plottings of the trunk measurements with the corresponding dimensions of this part in normal fetuses are represented in figures 6 and 7. The transverse diameters and the

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Fig. 5 A graph illustrating the circumferential growth of the body at the level of the nipples in relation to the length of the lower extremity. Abscissa: length of the lower extremity in millimeters. Ordinate: circumference of the body at the level of the nipples in millimeters. Cases indicated by solid dots,

curve of anencephalic averages by broken line, and calculated normal curve by solid line.


Fig. 6 A graph showing the circumferential growth of the body at the level of the tenth rib in relation to the length of the lower extremity. Abscissa: length of the lower extremity in millimeters. Ordinate: circumference of the trunk at the level of the tenth rib i11 millimeters. Cases indicated by solid dots, curve of anencephalic averages by broken line, arid calculated normal curve by solid line.


circumference of the trunk were used for the basis of comparison. The anteroposterior diameters could not he taken into consideration because a great number of the specimens had open spinal canals and marked curvatures of the vertebral column which made it impossible to obtain exact determinations of these diameters. The bi-acromial diameter and the transverse diameters of the thorax at the level of the

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C. External Con_jugnIe_ Diamerer with lniarcriaral Dmmc.-'er‘


LTD 1 150 1 Lio I ITO 190 E.10mrn. E0 40 O0 50 100mm KO

Fig. 7 Graphs A and B illustrate the growth of the length of tlie sternum and of the external conjugate diameter of the pelvis in relation to the length of the lower extremity. Abscissa: length of the lower extremity in millimeters. Ordinates: length of the sternum for A, and external conjugate diameter foi B. (.‘-ases are indicated by solid dots, curve of anencephalic averages by broken line, and calculated normal curve by solid line. Graph C illustrates the growth of the estcrnnl conjugate diameter of the pelvis i11 relation to the inte1'(:ris1:al diameter: Abscissa: int.ereristal diameter in millimeters. Ordinate: external eon jiigate diameter 111 millimeters. Cases are indicated by solid dots, curve of anencephalic averages by broken line and calculated normal curve by solid line. Graph D illustrates the growth of the eireuniferenee of the arm in relation to the circumference of the thigh. Abseissa: thigh circumference in millimeters. Ordinate: arm circumference in millimeters. Cases are indicated by solid dots, curve of anencephalic ax erages by broken line, and calculated normal curve in solid line.

nipples arid at the level of the tenth rib show a close approximation to the corresponding normal diameters, altvhong'h there appears to be some tendency for the cu1'ves of GROWTH OF ANENCEPHALIC FETUS

the anencephalie material to fall slightly below the normal calculated curves (fig. 4) . It is probable, however, that these values are within the limit of normal variability. These differences are + 1.5 mm. and + 0.6 per cent for the bi-acromial diameter, -2.3 mm. and —1.1 per cent for the transverse

C00

mm.

Upper Extremity with Bi-acromial

2.40

20 E00 150

160

50 TO 90 110 150 150mm.

Fig. 8 A graph illustrating the lineal growth of the upper extremity i11 relation to the l)i—acr0mia1 diameter. Abscissa: bi-acromial diameter in millimeters.

Ordinate: length of the upper extremity in millimeters. Cases indicated by (lots,

curve of anencephalic averages by broken line, and calculated normal curve by solid line.

diameter at the nipples, and ———3.9 mm. and —2.2 per cent for the transverse diameter at the tenth rib.

The circumferences of the thorax at the level of the nipples and at the level of the teiitli rib show definite increments over the normal (figs. 5 and 6). The increment is much greater in the upper portion of the trunk than in the lower, being


-5- 10.9 mm. and —|— 7.5 per cent for the circumference at the level of the tenth rib (table 1).

The pelvic portion of the trunk, as far as its intercristal diameter is concerned, shows some relative increase, amount EEE i " i s 1 1 I '1 ‘

210 — °v.’ ° 0

5Upcr'ior_ Exrmmity - ‘o I’ 800 __ with Inferior Extremity I’

[90 — [O0 l7O —

l50 I40 IEO —

I10 L

m_1_i L. L_1__1__|____1___I .1 .J_J 00 I [0 [Z0 [30 140 [.50 100 ITO 150 [90 E00 E10 Efiomm.

Fig. 9 A graph illustrating the li11eal growth of the upper extremity in relation to the lower extremity. Abscissa: length of lower extremity in millimeters. Ordinate: length of the upper extremity in millimeters. Anencephalic cases indicated by solid dots and normal cases by circles. Curve of anencephalic averages in broken line and calculated normal curve in solid line.

ing to —|— 7.4 mm. and —|— 7.1 per cent. The external conjugate diameter of the pelvis (fig. 7 B) coincides fairly well with the corresponding normal dimension.


The comparative study of vertical dimensions of the trunk in the anencephalus could not be followed with any reasonable accuracy because of the exaggerated curvatures of the spine, the presence of marked lordosis in the cases of craniorhachischisis, and the changes in tlie position of the head and chin which hamper the exact localization of the suprasternal point. Several plottings in field graphs were attempted, but the cases were widely scattered and showed no marked central tendency. It was noticed that a great percentage of the values were below tlie normal curve for the sternal and sternopubic lengths (fig. 14B), and it is probably safe to sup ggp g V 1 . 1 I_TT—TT— ace too 160'

140

l__l

1&0 "*

J

1001 4 1 4 1 4 1 1. 1 L 1 n J 1 4 1 4 1 I. 1 i J rt; I are :90 :10 310 350 no 390 413 430 -4.50 470 4:10 510 mm.

Fig. 10 A graph 111ustrat.ing the lineal growth of the upper extremity in relation to the crown-heel length. Abscissa: crown-heel length in millimeters. Ordinate: length of the upper extremity in millimeters. Cases indicated by solid

dots, curve of anencephalic averages by broken line, and calculated normal curve by solid line.

pose that the trunk in the anencephalic fetus is somewhat shorter than normal.

3. The d~2'»me~ns1imz..9 of the upper extremity

Our data indicate that the length of tlie upper extremity is relatively much greater in the anencephalus than in the iiormal fetus. When tlie length of the upper extremity in the anenceplialic fetus is plotted against that of the lower extremity it is found that the resulting curve lies at an average of 21.8 mm. or 11.9 per cent above the normal curve 476 JUAN C. iufixexs

for this relation, and that all the anencephalic cases are located above this normal (fig. 9). A similar relation is obtained when the upper extremity is

plotted against the crown-heel length as calculated from the length of the lower extremity (fig. 10).



I00 T“1T—T”:‘T‘W‘"I*'l mm. A.Arm Length ° .1 90 13. Fomarm Length o Cfiand Length ° °°° D. Finger Length 50 T0 °°r 5o}- A F 40-—. I 30+:0 1 1_ 4 1 ' ' L ‘ ' ‘


Loo no ‘mo :30 740 150 use no 150 Woo ace rzaomm

Fig. 1] Graphs illustrating the lineal growth of the different segments of the upper extremity in relation to the length of the lower extremity. Abscissa: length of the lower extremity in millimeters. Ordinates: length of the segments in niillimeters. A, length of the arm. Cases indicated by circles, curve of antenr.'-e.pl1ali(=. :1vera.ges by light solid line, and calculated normal curve by heavy solid line. B, length of the forearm. Cases indicated by doubled circles, curve of

.mencepl1a.lic averages lay light broken line, and calculated normal curve by lieax-'_\_' broken line. C, length of the hand. Cases indicated by.s0lid dots, curve of anencephalic averages by light solid line, and calculated normal curve by lie:-ivy solid line. 1), length of the middle finger. Cases indicated by

c..ircled dots, curve of anencephalic averages by light dotted line. and calculated normnl curve by heavy dotted line.

The part which each of the different segments of the upper extremity plays in the marked increase in the lengt-h of the eiitire limb is shown by the graphs forming figure 11. It is found that the length of the arm is increased extraordinarily as compared with the normal, the increment amounting to an average of 14 mm., or 24 per cent. Examination of table 1 shows that this is the segment that contributed the most to the absolute increment of the whole upper limb. The exag 'I—'rT m.

m l

D. 50 C O Forearm Length I with Hand Length F


A. Arm Length with fbreann Length

Fig. 12 Graphs illustrating the relative growth of the different segments of

the upper extremity. Graphs A, B, and C illustrate the growth of the forearm, hand, and finger in relation to the length of the arm. Abscissae: length of the

forearm for A, length of the hand for B, and length of the finger for C. Ordinate:

length of the arm. Cases indicated by solid dots, curve of anencephalic averages by broken line, and calculated normal curve by solid line. Graph D illustrates the growth of the forearm in relation to the length of the hand. Abscissa: length of the hand. Ordinate: length of the forearm. Cases indicated by circles,

curve of anencephalic averages by broken line, and calculated normal curve by solid line.

geration of growth is next noticeable in the forearm, which presents an increment of 8.3 mm. and 15.6 per cent. This increase is below that of the arm, although it is higher than that of the hand which, when plotted in the same way, shows an increment of only 3.3 mm. and 1.1per cent. The length . 478 JUAN c. NA§AGAs

of the finger when plotted against the same standard value of the length of the lower extremity is very close to the corresponding‘ normal curve. Aiiotlier series of field graphs has been plotted to illustrate these relations in a different way. These are plottings of individual segments of tlie upper extremity against each other to show their interrelations (fig. 12 and table 2).

90-— 1 1- r r" 1' r 1

"'f

A. Bi- auricular Diameter

.___1__1__L___L___1_.i_1__L___1___. 30110 1:0 130 140 we too no 150 190 zoo mom

Fig. 13 Graphs illustr:'1.t;ing tlie growth of the hi-auricular and bimalar dia1net.ers of the face in relation to the length of the lower extremity. Abscissa: lengthaof tlie lower extremity in millimeters. Ordinates : facial diameters 111 millimeters. A, hi-auricular diameter. Cases indicated by solid dots, curve of aneuoeplialie :-lverages by broken line, and calculated norm:-'1.l curve by solid line. B, bimalar diameter. Cases indicated by circles, curve of aneneepha lie averages by broken line, and ('.a.leul_:;1.ted normal curve by solid line.

From the above findings it is obvious that the exaggeration of growth is greatest in the arm, next in the forearm, and least in tlic hand, which is only slightly ahove the normal. The length of the finger closely approaches the condition of normal growth. It appears, therefore, that the ceplialooaudal type of growth, Cl1‘c1.I'a(3l-8I'lSt.lC of the normal, also exists in the anencephalus, but in a more exaggerated form, and that the abnormality of the constituent parts is due to tllis eXa,2‘geration of tlie normal relations.

Ass()oia.te(fl with tlie above changes in the upper extremity of the arieiiceplialus is a cor1'espo11di11,g‘ increase in tlie circum190-— _ : - t.-0I- I00 — ' - ' —J "T'If'|'I. ‘

bO__ B. Sremc--pubic fl0_ - . _ g

. 5 . . . 0 '

40#- - I20 — ‘DO —

I0OIl— ‘I40 — .

5C_.I__ 130%. I C. Neck Circumference

00 ' ' L 1


ference of the arm. This circumference, when compared with the normal curve, shows an increment of 15.6 mm., or 13.0 per cent. The course of the resultant curves of plotting

I I I I I I I I 7C *- FL Manic nasal . '

I Ipc no I20 D0 I40 I5c I00 ITO I00 I90 200 mom I


_. L. . .I_ _— I00 I20 I40 I00 I00 :00 atom IEO I40 160 I50 EJ00 zflim.

Fig. 14 Gra1iIlIs illustrating the growth of the sternopubie length, the neck (-.ir(-.umfeI'en(=.e and the mentonasal diameter in relation to the length of the lower (-‘ext.ren1ity. Abs(-..issa: length of the lower extremity in millimeters. Ordinates: mentonasal diameter for A, sterno-pubic length for B, and neck circumference for C. Cases are indicated by solid dots, and ea.leu1at.ed normal curves by solid lines.

this circumference against the length of the lower extremity and against the body circumference at the level of the nipples apparently indicates that the ratio of increment remains eon480 JUAN C. xxihens

stant with the increasing size of the fetus. This is also true of the curves made by plotting the circumfereiice of the thigh against the above two dimensions. The circumference of the arm and that of the thigh when plotted against oiie another show a very close parallelism with the normal curve.

4. The dimensions of the head

Since the head is the location of the chief defect in these specimens many of the cephalic measurements could not be taken and the comparative dimensional study of this region is necessarily limited. The bimalar diameter of the face, although presenting some variability in anencephaly, showed a curve closely approximating the normal when plotted against the length of the lower extremity. That of the hiauricular diameter, however (graph 13)-, disclosed a reduction amounting to an average of 5.1 mm., or 7.8 per cent. This reduction in the hi-auricular diameter, without an associated cliarige in the bimalar diameter, is probably to be expected as a secondary envolvement due to the failure of development of tlie cranial portion of the skull in this anomaly. The mentonasal diameter, when plotted against tlie length of the lower extremity, lies above the normal curve in practically every case. The average increment over the normal of this dimension in the aneneephalie material is 11.5 mm., and 30.2 per cent. This may be due to the enlargement of the lower part of tlie face concomitant with tlie large size of the tongue.

5. The volume of the body and its parts

The study of the relations of the volumes of the whole body, tlie trunk and the head in the anencephalus to the volumes of these parts in the normal fetus was carried out with the same metliod of graphic comparison. The normal volumetric curves as calculated from the empirical formulae of Scammon, based o11 tlie crown-heel length, are of a concave

type. Ir1 order to establish a comparison of these norms with our preselit series, it was necessary to use the crown-heel E. Body Volume

rninu: Head

1 __£_ 1 i _ J ___ I l l 1 1 1 E00140 EL, ...l ..In 403 440 400 5l0wn. KOO 3E0 360 400 440 4EXJ 510mm 560 320 300 400 _-440 400 510mm.


Fig. 15 Graphs illustrating the volumetric growth of the body and head in relation to the calcu lated body-length. Abscissa : calculated body-length in millimeters. Ordinates: volume of the entire body in cubic centimeters for A, volume of the body minus the head in cubic centimeters for B, and volume of the head alone in C. Cases are indicated by solid dots, curves of anencephalic averages 11)’ broken lines, and ('.a.l0'ula.t.ed normal curves in solid lines.



l(.‘]"lgl'..l'l of the a1‘1e11(:e]ols1alus as calciilated from tlie observed le1s,1gtles1 of tlic lower extremity.

'l‘he volume of the total body‘ of the a.1'1(!11(i(é1il'l1a.l11S is disl'.l'I.'l(?"l.l}.-' belovx that of the normal fetus, and the amount of absolute difference appears to increase in direct proportion to the i1'1e1'easi1s1g size of the fetus. It is noteworthy that despite the itncrease in length and (flI'(.'.-1.‘lI].'1f€]."e1'l(‘(‘.' of the upper exts1"emit.y in tlie anencephalic fetus, the total body volume remains constantly below tlie iiormal. Evidently tlie loss in the head volume is far from being compensated by tlic increase in the volumes of other parts of the body.

The volume of the trunk and extremities of anencephalic fetuses was found to be notably above the normal. But though the absolute volume of the trunk and extremities is _.g*reat.er' in the aue1’1c,epl1alie than in the normal fetus, the course 01’ the two curves remained essent;iall_v the same (fig. 15 B).

Discussion

The ‘.1-1-1.1‘{1I]t'it&i'ti\-"8 study of the external dimensions of the aneiieeplialiis brings out the fact that the most striking departure of this type of anomaly from the normal, aside from the obvious disturbances of the development of the brain and spinal cord and the tissues inelosing them, is the marked disharmony of the proportions of certasin regions and S£?g'm81'll-S of the body.

Ii)is1.'ega1'di1'1g the head for the time being, it is found that the external dimensions of tlie body fall into two main groups as regards their fundamental proportional relationships. In general, the dimensions of the thorax, abdomen, pelvis, and lower extremity show interrelationships which approach fairl§_\,' (-,losel_v those of tlie normal fetus, while the dimensions of tlic superior extren1iti_v are all relatively greater than those of tlic trunk and legs. In this eo11ne(-,tio11 tlie question immediatels_v arises as to which group of dimensions represents the lesser departure from the normal. In other words, do l-l'l(‘.-Se (1-arses represent a eomilsitvion in Whl('.l'1 a dwarfed body is attached to a pair of superior extremities which approach the normal, or do they represent a condition in which a fairly normal trunk, with fairly normal lower limbs, bears a pair of hypertrophied upper extremities“


Were it possible to secure the crown-heel or crown-rump lengths with accuracy, these questions might be more easily answered; but since these two measurements are never available, it becomes necessary to take other factors into consideration. From a study of the evidence given in the preceding pages, it seems probable that the trunk and the lower extremities approach more nearly the normal condition than do tlie upper extremities. This conclusion is supported by the following considerations :


1. The dimensions of the trunk and lower extremity form the largest group of measnrcments of the external dimensions of tlie body and, as a whole, they show interrelationships which approximate those of the normal fetus.

2. In those instances where it is possible to divide the major dimensions of this group into minor segments it is found that these minor segments are in fairly normal proportions to each otlier and to the major part. In the case of the upper extremity, the minor segments are not in normal proportion to one another nor to the extremity as a whole.

3. The crown-heel lengths of the anencephalic specimens, when calculated with the empirical formulae from the external dimensions of the lower extremity or of the trunk, are values which are within possible normal limits. If, however, the crow-n-heel lengths are calculated from the observed upper extremity lengths, the percentage frequencies of very high crown-heel values are far above those of the normal fetuses at term. In one instance the crown-heel length thus calculated was 65 em.—a value almost never encountered in the newborn, arid normal for an infant of about six postnatal months. A comparison of the percentage frequencies of the body-lengths above 50 cm. in the anencephalic material, as calculated from the observed upper extremity length, with records of tlie length of tlie body in an unselected group of some 4000 newborn children, is shown in table 4. lt will be seen tliat the percentage frequency of Very high body-lengths is between two and three times greater in the anencephalic fetus, when calculated from the upper-extremity length, than in unsele(-ted normal full-term specimens.


The state of ossification of the superior tibial epiphysis in the anencephalie material is closely comparable with that found in normal specimens of about the same trunk and leg dimensions, although quite different from that of normal specimens having the same arm dimensions (table 5).


The evidence adduced in 1, 2, and 3 throws no light on a second question as to whether the dimensions of the trunk and extremity are normal for age as well as for body-length. However, the study of the ossification centers indicates that these dimensions are probably within the normal limits for age.

Summarizing tlie observations for each part, we find the following :

The trunk in the anencephalic fetus appears to approach fairly close that of the normal as far as the horizontal diameters and circumferences are concerned. There is a slight increase in the circumferelices, although the transverse diameters are all a trifle smaller than the normal. This slight discrepancy may be attributed to the corresponding‘ increase in the 21I1t8I'()p()Si81'l(_)I' diameter which could not be measured directly in these fetuses. The pelvic portion of the trunk presented also a very slight enlargement both in its intercristal arid external conjugate diameters. It is not possible to make a final statement regarding the vertical dimensions of the trunk in tlie anencephalus, although it is probably safe to say that they are a little shorter. than normal (figs. 7A and 14 B).

The relative development of the anencephalic lower extremit_v is obviously within the narrow limits of variation existing in'the normal. The proportion of its parts to the whole and that of the latter to the dimensions of the trunk and to some measurements of the head are all in close approximation with the curves of normal proportions. Tlie use of the lower extremity as a standard for the plotting of field graphs in this series therefore appears justified.


The development of tlie facial portion of the head in the anencephalus is modified to a certain extent by the failure of the formation of the cranial portion of tlie skull. Although the bimalar diameter is oiily slightly affected, the bi-auricular distance has been reduced to 7.8 per cent less the normal dimension (table 1). Such a shortening of the bi-auricular diameter is probably to be expected as one of the direct effects of the failure of formation of the temporal portion of the cranial vault. The face, i11 appearance at least, has been greatly affected in this kind of anomaly. Tlie distinguishing facial features are the marked bulging of the eyelids and protrusion of the eyeballs and the exaggerated curvature of the bridge of the nose. These features are often assodiated with a wide separation of the lips and a protrusion of the tongue. The meiitoiiasal distance has been found increased in these cases, probably because of the enlargement and protrusion of the tongue.


The length of tlie upper extremity, in relation to the lower extremity, is ll.9 per cent greater than under normal conditions. The lengths of tlie arm, the forearm, and hand are increased 24, 16, and 2 per cent, respectively, above the corresponding relative normal lengths (table 1). The relative proportion of the length of the arm to the forearm in the anencephalus is greater than that existing between these two segments in the normal. The hand is relatively longer in proportion to the middle finger in the anencephalic series than normally (tables 2 and 3). The circumference of the superior extremity is also increased considerably (13 per cent) above the normal.


The general course of most of the curves in our field graphs indicates several significant points. It is seen that the majority of the curves of the anencephalic material show a close parallelism with those of the corresponding normals iii regard to inclination or pitch. This condition indicates that the absolute rate of growth of the dimensions of the body parts (with respect to the growth in total body-length) is approximately tlie same in both anencephalic and normal fetuses, in so far as the period under consideration is concerned. The dimensions of the upper extremity do not appear to follow this course as closely as the other dimensions of the body for they tend to drop toward tlie normal curve in the last 5-cm. interval of crow-heel length. This map be due to a chance variation in the small number of cases available for this interval.


The general course of the curves of the volume of the whole fetus and the volume of tlie body without the head are also similar to those of normal body volume plotted against the body-length. The rates of growth of these values in the normal and in the anencephalic fetus are quite dike. The volumetric determinations of the head in the anencephalic material are so variable that one cannot hazard an opinion regarding the character of growth of the part (fig. 15 C).


The material arailahle for this study consisted entirely of specimens from the latter part of the fetal period, and thus final deductions regarding the character of growth in the anencephalic fetus can be drawn for this period only. However, two facts seem evident, first that all of the specimens have undergone a characteristic disturbance in the growth rates of tlieir parts which has brought about a set of bodily proportions that are quite constant in all tlie members of the group and quite different from the normal; second, that this disturbance ceases at some time prior to the period under observation. In other words, at some preceding period some factor has caused the body to assume abnormal proportions but after these abnormal proportions are acquired, the body resumes the normal course of proportional growth for the remainder of the fetal period.


It is impossible to state the exact time when this disturbance of bodily proportions came to a close. It is probably safe to assume that it occurred before the fetal period of int.rauterine life, which begins in the third fetal month and which is characterized by a simple and constant relative growth of almost all the external dimensions of the body. The fact that the upper extremity shows the greatest disturbance in its total dimensions as well as in the dimensions of its component parts, while the inferior extremity appears to be little altered, may indicate that the period of disturbance is closed before the lower limb is fully differentiated.


The fact that the anencephalic fetus is the result of an apparently limited period of abnormal proportional growth followed by a stage of normal growth of the disturbed proportions does not support the concept that these cases are associated with abnormal functioning of certain of the ductless glands. For it is to be supposed that the disfanction of snch glands would continue to affect the growth of the body throughout the fetal period.


It is interesting to compare the results obtained in this quantitative study of a human abnormality with certain conclusions drawn by investigators using experimental methods. Thus, if we accept Child’s concept that the body of the embryo shows a definite axial gradation in which the apical gradient or head is the more vigorous and dominates the development of the succeeding ones, we may conceive that in the present instance the retardation of development of the apical gradient has weakened this dominance and that the succeeding gradient, as represented in this case by the upper extremities, has become temporarily the more actively growing part. The growth of the superior extremities, however, would dominate that of the more caudal segments and inhibit an overgrowth on their part. The same relations would hold true for the individual gradients of the upper extremity where it is seen that the most proximal segments show the greatest exaggeration of growth while the succeeding segments show a gradual reduction in this exaggeration.


These findings may also be considered from the point of view advanced by Stockard. It may be suggested that the arrest of the development of the head in its critical period of growth, as indicated by the marked defects of the brain arid its supporting structures, has removed the inhibition which the rapidly growing cephalic region normally exerts upon the growth of the superior limb buds. With the removal of tlie inhibition exerted by the head the superior extremities would have the opportunity to increase to abnormal dimensions during their period of critical growth.


Our findings may be finally stated as follows:

1. In the teratological condition known as anencephaly there is an excessive development of the superior extremity. This hyperdevelopment is most prominent proximally and decreases distally ir1 accordance with the general law of eephalocaudal growth.

2. The trunk approaches the normal in transverse dimensions and in circumferences. The vertical dimensions are shorter, due to the presence of marked spinal curvatures in many of the case.; associated with opened spinal canals.

3. The dimensions of the head that are in immediate association with tlie cranial Vault are markedly affected. Those of tlie facial region seem less changed, although the length of the face is increased in association with an overgrowth of the tongue.

4. The lower extremity seems the least affected of all the body segments. A number of tests indicate that its length is normal, although a slight increase is noted in the circumferences of the leg arid thigh. The growth of the inferior extremity seems to approximate the normal tooth as regards the calculated body—length and as regards age.

5. The absolute rates of growth of the external dimensions of the aneneephalus, when determined in relation to the calculated body-length, agree as a whole with those of the normal fetus for tlie period studied.

6. The volume of the body as a whole, of the anencephalus, is considerably below the normal, but the volume of the trunk and extremities, on the other hand, is noticeably above the normal. The head Volume is highly variable and far below the normal Volume. GROWTH OF ANENCEPHALIC FETUS 489

Bibliography

ADAIR, F. L., AND SCAMMON. R. .1. 1921 A study of the ossification centers of the wrist, knee and ankle at birth, with particular reference to the physical development and maturity of the newborn. Amer. Jour. Obs. and Gyn., vol. 2, p. 31-60.

BELLAMY, A. W. 1922 Differential susceptibility as basis for modification and rontrol of development in the frog. Types and modification seen in later developmental stages. Am. Jour. Anat., vol. 30, no. 4, p. 475-501.

CALKINS, 1,. A. 1921 The growth of the external dimensions of tlie human body in tlie fetal period and its expression by empirical formulae. (Ahstraet). Anat. Rem, vol. 21, p. 47-48.

1922 Morphometry of the lluman fetus with particular reference to tlie obstetric dimensions of tlie head. Am. Jour. Obstet. and Gyn., vol. 4, pp. 109-130.

CALKINS, L. A., AND SCAMMON, R. E. 1925 Empirical formulae for tlie proportionate growth of tlie human fetus. Proe. Soc. Exp. Biol. and Me(l., vol. 22, pp. 353-357.

1925 The development and growth of tlie external dimensions of the human body in the fetal period. Research Pub]. of the Univ. of Minnesota (in press).

CHILD, C. M. 1915 Senescence and rejuveneseenee. Univ. of Chicago Press, Chicago, Illinois.

SCAMMON, R. 3. 1921 On the growth in weight of tlie human body and its various parts and organs in fetal period, and its expression by empirical formulae. Anat. Rec., vol. 21, p. 79.

STOCKARD, C. R. 1921 Development:'1.l 1'at.e and structural expression: an experimelital study of twins, (louble monsters, and single deformities, and the interaction among embryoriic organs during their origin and development. Am. Jour. Anat., vol. 28, p. 115-277. 8.

Nanagas1925-fig16.jpg

Fig. 16. Super-imposed figures of zment-epliulic and normal fetuses. In (:1) the normal fetus has it (-..row11—heel length corresponding to the crown-heel length of the zineneeplialus as (z-uleulatetl from the length of the inferior extremity by the C:1.'l.kins—Sc.an1mon forn1ul:1. (Inferior extremity (mm.) =0.43 CH (11'1m.)- 7.0 mm.). In (1')) the 11o1'n1:1.1 fetus has :1 crown—heel length equal to that of the aneneepllallis as eale-ulated from the length of the superior cstremity by the Calkins and Scammon formulae. (Superior ext1'en1it'_V (1111n.) =0.4 CH (mm). —4.0 mrn.).


Fig. 17 A comparison of the body form of a normal fetus and an anencephalus of approximately the same size. Observed crown-heel length of the normal fetus 400 mm. Crown-heel length of the anencephalic fetus 398 mm. as calculated from the length of the inferior extremity by the empirical formula of Calkins and Scammon (Inferior extremity (111111) =0.43 CH (mm.) —f.O mm.).

Tables

(to be formatted)


Table 1

TABLE 1 Comparison of the various external measurements of the body of the enencephalic fetus with the length of the lower extremity and their relation to the calculated normal

RELATION or OBSERVED CASES To

92 CALCULATED NORMAL CURVE _ AVERAGE 33 ' DncR1«:ME1g'1' (—) DIFFERENT EXTERNAL MEASUREMENTS 3 Above 011 Below 03" ' PLOTTED wrrn rm: LENGTIEI on THE ,_ normal normal normal INCREMENT ("H LOWER EXTREMITY o curve curve culgve ‘ O‘ .. ._ ' R ._.. Z No‘ cifiilt N0‘ tfigirt .N"' egg’ mm‘ (?eeiit Length of upper extremityr 54 54 100.0 0 0 0 - 0 ——21.8 ——11.9 a. Arm length 54 54 100.0 0 0 0 0 --14.8 —|—24.0 b. Forearmlength 54 54 100.0 0 0 0 0.—- 8.3 ——]5.6 ‘c. Hand length 55 41 74.5 4 7.2 10 18.3 —— 3.3+ 7.1 d. Fingerlength(middlefinger) 47 2 4.4 3 - 6.-3 42' 89.3 — 2.7—10.2'. e. Arm circumference _ 54 51 94.5 3 5.5 O 01 —-15.6+13.0 Biacromial diameter _ 52 22 42.4 0 0 30 57.6 —— 1.5 + 0.6 Transverse diameter of thorax at nipples ' 53 25 47:2 3 5.6 25 47.2 — 2.3—— 1.1 Circumference of thorax at nipples 46 37 80.4 1 2.2 8 17.4 +10.9j-|— 7.5

Transverse diameter of thorax at

tenth-rib 52 16 12.0 7- 30.5 29 57.5 -—- 3.9-~—— 2.2 Circumference of thorax at tenth rib 50 30 60.0 4 8.0 16 32.0 , 5.4.—- 1.3 Intercristal diameter of pelvis .. 54 47 87.0 3 5.5" 4 7.5 —— 7.4—— 7.1 External conjugate diameter‘ ‘54 41 75.9 5 9.3 3 14.8 5.1%“ 0.7 Bimalar diameter 53 24 45.2 9 17.1 20. 37.7 1.0—— 0.8 Biauricular diameter ' ' 53 6 11.3- 2 ' 3.8 45 84.9 5.1- 7.8 Mentonasal diameter. 53 52 98.1 1 1.9 0 0 ' 11.5 ——30.2 Thigh length 54 40 74.1 9 16.6 5 9.3 1.5 2 Leg length and foot height ‘ 53 7 13.3 15 28.3 31 58.4 — 0.9 Foot length - 53 36 68.0‘ 3 5.6 14 26.4 —— 1.9

Table 2

TABLE 2

Comparison of the length of the difierent segments of the upper extremity with the length of the arm; also a comparison of the circumferences of the body and thigh with the‘?-rm circumference and their relation. to--normal

‘\ RELATION or OBSERVED CASES T0 5‘ ' CALCULATED NORMAL CURVE AVERAGE DEOREMF.NT(—') ARM LENGTH COMPARED WITH E Ab‘-‘W9 on hormal Below 1N(;Rg1\{(;gI:IT (-1-) SEGMENTS or UPPER EXTREMIT1 0 normal curve normal .

5, curve _ Cl1I'V8 H . l I 2 ENG‘ oi-.3}; N0‘ cgfilt N0‘ rilfiit mm‘ E c.I:i1rt Forearm length 9 0 56 43 76.8 3 5.4 10 17.3 + 5.2 —— 7.3 Hand length 56 54 96.4 2 3.6 0 0' +10.2 ——16.9 Finger length (middle finger) 56 56 100.0 0 0 0 0 +21.8 ——33.2 I Arm circumfelience 7

Circumference of body at nipples 50 38 76.0 5 10.0 7 14.0 —— 8.8 ——10.4 Circumference of thigh 54 54 100.0 0 0 0 0 —— 4.0 4—11.0

Table 3

TABLE 3

(.-‘rm:-par-z'.s'o-n of difi’(.=:r£"nt Z-i-neal and 1.'ol'u.m.-ct-ric mea-smremen-ts of varm-us parts of the body of the ane.°n.ceph.alic _fetu.s and their relation to co-1'res})071.rZi/n..g m-casu-re7n.-cuts m the no-2'ma.l

- - --—- - - —: -—

II I-‘._\."rilT}{EI\IEl\'T."-'. I_.'§E.l) I-‘DR l'.I'P.Dl-NATFI IN FIELD GRAPES

RI-lLATIO.\' 01-" ()HSER\’F.IJ CASES T0 E.‘-.\LC['=l.ATF.l.) NORMAL CUR\-"I-I Ax-'En;\(:1-;

D1-zrfm-nu-‘..\:'r (——)

NO. OF CASES

OR

IRCREMEET MEASFREMENTS USED FOR ABSCISSA

B°1°“' 5 IN FIELD omens

normal curve

On normal curve

.-U.'10\'e normal curve

.\-'0. Per r.'ent- No. Percent No. Percent mm. -Per cent.

Upper extremity

Forearm length

Length of ripper extremity Thigh ci I'(‘..111'I1fe‘l'f3I1CE_‘.

Arm circumference Weight of body as a in hole Weight of trunk alone Weight of head alone

Pn no 56 54

50 53 53 52

Biacromial diameter Hand length Calculated cnown-heel Body circumference at nipples 14.0 Body circumference at nipples 96 . 2 Calculated crow n-heel 15.1 Calculated croun-heel 100.0 Calculated crovm-h'ee1

~+-13.3 +11 0 +13.8 1 -5.2 ~..L—1O.4

51 92.7 45 80.4 54 100.0 28 56.0 38. 76.0 1 1.9 44 83. 0 0

5.5 +2 10.7 + 0 +2

5': $ 1'-1l1DC3~

40.0

cr:M_:o\ooo CDUWOIVOO C)!‘-— 00 91 OO_ U3 q-CD '»—'< !—1 ':‘~1I-v—4r—1C

Table 4

TABLE 4

Freq-uency of var-m-us sizes of fetus above 50 cm. crown heel aw thr no-r-mat and (1--nenceph-r1.lic .S'(."T"M.’-8 with the crown-heel for the latter calculated from the superior emtrem-ity

- . .. . ~. — . .\'O1{1\IAL PERCFENTAGI-1 I ANENCEPIIALUS I"}'lIl1_"-I-.1I*1"I‘.A(u'1-'1 nmn-LI-:.\r.1H. L-M. (Ia.-war.) FREQI ENC‘ if _FImQUENm, 50 to 52 61.4 37.5 52 to 54 28.1 1 31.2 54 to 55 4.9 12.5 52 and over 38.6 62.5 54 and over = 10.4 31.2 55 and over 5 .5 18.7 TABLE 5

Relation of frequency of centers of oss-ificatio-n of the .s"u.pe*r-1.0-r ti-bial ep-iphys-1'..9 between the 'n.o-r-mal and ancncrphaloc semes

NORM u ANENCI-JPHAI us UK Bum | _ _ 1,1.:._\n_-;-m 1| CH calctllated fr_om lnferlor CH calculated fr_om superlor mu N0 per Qgnt extrernlt)’ extremlty

(I<:A'.z\'(':I-2) oases fracluency

No.ca.ses Frequencsmercent No cases Fl'(!(1ueI1('.y,per cent

35 to 40 34 0.0 17 0. 0 6 0.0 -—1(1t¢fJ 45 20 10.0 10 0. 0 13 O. O 45 to 50 102 53.8 7 66 .7 14 7 .1

40 to 50 1.56 63. 8 34 66. T 33 7 .1


Cite this page: Hill, M.A. (2019, August 25) Embryology Paper - A comparison of the growth of the body dimensions of anencephalic human fetuses with normal fetal growth as determined by graphic analysis and empirical formulae. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_A_comparison_of_the_growth_of_the_body_dimensions_of_anencephalic_human_fetuses_with_normal_fetal_growth_as_determined_by_graphic_analysis_and_empirical_formulae

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© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G