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===Morphological and molecular characteristics of living human fetuses between Carnegie stages 7 and 23: developmental stages in the post-implantation embryo===
Hum Reprod Update. 1997 Jan-Feb;3(1):3-23.
Harkness LM, Baird DT.
Source
Department of Obstetrics and Gynaecology, University of Edinburgh, UK.
Abstract
Determination of embryonic age groups or stages has been based on the Carnegie Institute collection started in 1887. Improved technology has enabled the building of a new collection of embryos of < 9 weeks gestation; these were then used to compare with the original Carnegie collection. The results suggest that in providing definitive stages that are rigidly bound by developmental events, limitations are placed on categorizing the embryo. Allocation of embryos to a specific stage can assist in identifying post-ovulatory age but overlaps between stages could lead to classification into an incorrect stage.
PMID 9193935
===The rate of growth in young human embryos of Streeter's horizons. 13 to 23===
===The rate of growth in young human embryos of Streeter's horizons. 13 to 23===


Line 1,169: Line 1,181:
Acta Anat (Basel). 1967;66(2):178-86.
Acta Anat (Basel). 1967;66(2):178-86.


PMID 6050342  
PMID 6050342


===Report Upon the Collection of Human Embryos at the John Hopkins University===
===Report Upon the Collection of Human Embryos at the John Hopkins University===

Revision as of 23:01, 21 November 2013

Carnegie Stage Table 1

Stage
Days (approx)
Size
(mm)
Images
(not to scale)
Events
1
1
(week 1)
0.1 - 0.15
Link=Carnegie_stage_1

fertilized oocyte, pronuclei

2
2 - 3
0.1 - 0.2
Link=Carnegie_stage_2

cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

3
4 - 5
0.1 - 0.2
Link=Carnegie_stage_3

loss of zona pellucida, free blastocyst

4
5 - 6
0.1 - 0.2

attaching blastocyst

5
7 - 12
(week 2)
0.1 - 0.2

implantation

6
13 - 15
0.2

extraembryonic mesoderm, primitive streak

7
15 - 17
(week 3)
0.4
Link=Carnegie_stage_7

gastrulation, notochordal process

8
17 - 19
1.0 - 1.5
Link=Carnegie_stage_8

primitive pit, notochordal canal

9
19 - 21
1.5 - 2.5
Link=Carnegie_stage_9

Somite Number 1 - 3 neural folds, cardiac primordium, head fold

10
22 - 23
(week 4)
2 - 3.5
Link=Carnegie_stage_10

Somite Number 4 - 12 neural fold fuses

11
23 - 26
2.5 - 4.5
Link=Carnegie_stage_11

Somite Number 13 - 20 rostral neuropore closes

12
26 - 30
3 - 5
Link=Carnegie_stage_12

Somite Number 21 - 29 caudal neuropore closes

13
28 - 32
(week 5)
4 - 6
Link=Carnegie_stage_13

Somite Number 30 leg buds, lens placode, pharyngeal arches

Stage 13/14 shown in serial embryo sections series of Embryology Program
14
31 - 35
5 - 7
Link=Carnegie_stage_14

lens pit, optic cup

15
35 - 38
7 - 9
Link=Carnegie_stage_15

lens vesicle, nasal pit, hand plate

16
37 - 42
(week 6)
8 - 11
Link=Carnegie_stage_16

nasal pits moved ventrally, auricular hillocks, foot plate

17
42 - 101
11 - 14
Link=Carnegie_stage_17

finger rays

18
101 - 48
(week 7)
13 - 17
Link=Carnegie_stage_18

ossification commences

19
48 - 51
16 - 18
Link=Carnegie_stage_19

straightening of trunk

20
51 - 53
(week 8)
18 - 22
Link=Carnegie_stage_20

upper limbs longer and bent at elbow

21
53 - 54
22 - 24
Link=Carnegie_stage_21

hands and feet turned inward

Stage 22 shown in serial embryo sections series of Embryology Program
22
54 - 56
23 - 28
Link=Carnegie_stage_22

eyelids, external ears

23
56 - 60
27 - 31
Link=Carnegie_stage_23

rounded head, body and limbs

Following this stage Fetal Development occurs until birth (approx 40 weeks)


Carnegie Stage Table 2

Stage
Days (approx)
Size
(mm)
Images
(not to scale)
Events
1
1
(week 1)
0.1 - 0.15
Link=Carnegie_stage_1

fertilized oocyte, pronuclei

2
2 - 3
0.1 - 0.2
Link=Carnegie_stage_2

cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

3
4 - 5
0.1 - 0.2
Link=Carnegie_stage_3

loss of zona pellucida, free blastocyst

4
5 - 6
0.1 - 0.2

attaching blastocyst

5
7 - 12
(week 2)
0.1 - 0.2

implantation

6
13 - 15
0.2

extraembryonic mesoderm, primitive streak

7
15 - 17
(week 3)
0.4
Link=Carnegie_stage_7

gastrulation, notochordal process

8
17 - 19
1.0 - 1.5
Link=Carnegie_stage_8

primitive pit, notochordal canal

9
19 - 21
1.5 - 2.5
Link=Carnegie_stage_9

Somite Number 1 - 3 neural folds, cardiac primordium, head fold

10
22 - 23
(week 4)
2 - 3.5
Link=Carnegie_stage_10

Somite Number 4 - 12 neural fold fuses

11
23 - 26
2.5 - 4.5
Link=Carnegie_stage_11

Somite Number 13 - 20 rostral neuropore closes

12
26 - 30
3 - 5
Link=Carnegie_stage_12

Somite Number 21 - 29 caudal neuropore closes

13
28 - 32
(week 5)
4 - 6
Link=Carnegie_stage_13

Somite Number 30 leg buds, lens placode, pharyngeal arches

Stage 13/14 shown in serial embryo sections series of Embryology Program
14
31 - 35
5 - 7
Link=Carnegie_stage_14

lens pit, optic cup

15
35 - 38
7 - 9
Link=Carnegie_stage_15

lens vesicle, nasal pit, hand plate

16
37 - 42
(week 6)
8 - 11
Link=Carnegie_stage_16

nasal pits moved ventrally, auricular hillocks, foot plate

17
42 - 101
11 - 14
Link=Carnegie_stage_17

finger rays

18
101 - 48
(week 7)
13 - 17
Link=Carnegie_stage_18

ossification commences

19
48 - 51
16 - 18
Link=Carnegie_stage_19

straightening of trunk

20
51 - 53
(week 8)
18 - 22
Link=Carnegie_stage_20

upper limbs longer and bent at elbow

21
53 - 54
22 - 24
Link=Carnegie_stage_21

hands and feet turned inward

Stage 22 shown in serial embryo sections series of Embryology Program
22
54 - 56
23 - 28
Link=Carnegie_stage_22

eyelids, external ears

23
56 - 60
27 - 31
Link=Carnegie_stage_23

rounded head, body and limbs

Following this stage Fetal Development occurs until birth (approx 40 weeks)

Carnegie Stage Table 3

Stage
Days (approx)
Size
(mm)
Images
(not to scale)
Events
1
1
(week 1)
0.1 - 0.15
Link=Carnegie_stage_1

fertilized oocyte, pronuclei

2
2 - 3
0.1 - 0.2
Link=Carnegie_stage_2

cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

3
4 - 5
0.1 - 0.2
Link=Carnegie_stage_3

loss of zona pellucida, free blastocyst

4
5 - 6
0.1 - 0.2

attaching blastocyst

5
7 - 12
(week 2)
0.1 - 0.2

implantation

6
13 - 15
0.2

extraembryonic mesoderm, primitive streak

7
15 - 17
(week 3)
0.4
Link=Carnegie_stage_7

gastrulation, notochordal process

8
17 - 19
1.0 - 1.5
Link=Carnegie_stage_8

primitive pit, notochordal canal

9
19 - 21
1.5 - 2.5
Link=Carnegie_stage_9

Somite Number 1 - 3 neural folds, cardiac primordium, head fold

10
22 - 23
(week 4)
2 - 3.5
Link=Carnegie_stage_10

Somite Number 4 - 12 neural fold fuses

11
23 - 26
2.5 - 4.5
Link=Carnegie_stage_11

Somite Number 13 - 20 rostral neuropore closes

12
26 - 30
3 - 5
Link=Carnegie_stage_12

Somite Number 21 - 29 caudal neuropore closes

13
28 - 32
(week 5)
4 - 6
Link=Carnegie_stage_13

Somite Number 30 leg buds, lens placode, pharyngeal arches

Stage 13/14 shown in serial embryo sections series of Embryology Program
14
31 - 35
5 - 7
Link=Carnegie_stage_14

lens pit, optic cup

15
35 - 38
7 - 9
Link=Carnegie_stage_15

lens vesicle, nasal pit, hand plate

16
37 - 42
(week 6)
8 - 11
Link=Carnegie_stage_16

nasal pits moved ventrally, auricular hillocks, foot plate

17
42 - 101
11 - 14
Link=Carnegie_stage_17

finger rays

18
101 - 48
(week 7)
13 - 17
Link=Carnegie_stage_18

ossification commences

19
48 - 51
16 - 18
Link=Carnegie_stage_19

straightening of trunk

20
51 - 53
(week 8)
18 - 22
Link=Carnegie_stage_20

upper limbs longer and bent at elbow

21
53 - 54
22 - 24
Link=Carnegie_stage_21

hands and feet turned inward

Stage 22 shown in serial embryo sections series of Embryology Program
22
54 - 56
23 - 28
Link=Carnegie_stage_22

eyelids, external ears

23
56 - 60
27 - 31
Link=Carnegie_stage_23

rounded head, body and limbs

Following this stage Fetal Development occurs until birth (approx 40 weeks)

Carnegie Stage Table v2

Stage
Days (approx)
Size (mm)
Images
(not to scale, click image to see original)
Events
1
1
(week 1)

0.1-0.15

Link=Carnegie_stage_1

fertilized oocyte, pronuclei

2
2 - 3

0.1-0.2

Link=Carnegie_stage_2

cell division with reduction in cytoplasmic volume, formation of inner and outer cell mass

3
4 - 5

0.1-0.2

Link=Carnegie_stage_3

loss of zona pellucida, free blastocyst

4
5 - 6

0.1-0.2

attaching blastocyst

5
7 - 12
(week 2)
0.1-0.2

implantation

6
13 - 15
0.2

extraembryonic mesoderm, primitive streak

7
15 - 17
(week 3)
0.4
Link=Carnegie_stage_7

gastrulation, notochordal process

8
17 - 19
1.0 - 1.5
Link=Carnegie_stage_8

primitive pit, notochordal canal

9
19 - 21
1.5 - 2.5
Link=Carnegie_stage_9

Somite Number 1 - 3neural folds, cardiac primordium, head fold

10
22 - 23
(week 4)
2 - 3.5
Link=Carnegie_stage_10

Somite Number 4 - 12neural fold fuses

11
23 - 26
2.5 - 4.5
Link=Carnegie_stage_11

Somite Number 13 - 20rostral neuropore closes

12
26 - 30
3 - 5
Link=Carnegie_stage_12

Somite Number 21 - 29caudal neuropore closes

13
28 - 32
(week 5)
4 - 6
Link=Carnegie_stage_13

Somite Number 30leg buds, lens placode, pharyngeal arches

Stage 13/14 shown in serial embryo sections series of Embryology Program
14
31 - 35
5 - 7
Link=Carnegie_stage_14

lens pit, optic cup

15
35 - 38
7 - 9
Link=Carnegie_stage_15

lens vesicle, nasal pit, hand plate

16
37 - 42
(week 6)
8 - 11
Link=Carnegie_stage_16

nasal pits moved ventrally, auricular hillocks, foot plate

17
42 - 44
11 - 14
Link=Carnegie_stage_17

finger rays

18
44 - 48
(week 7)
13 - 17
Link=Carnegie_stage_18

ossification commences

19
48 - 51
16 - 18
Link=Carnegie_stage_19

straightening of trunk

20
51 - 53
(week 8)
18 - 22
Link=Carnegie_stage_20

upper limbs longer and bent at elbow

21
53 - 54
22 - 24
Link=Carnegie_stage_21

hands and feet turned inward

Stage 22 shown in serial embryo sections series of Embryology Program
22
54 - 56
23 - 28
Link=Carnegie_stage_22

eyelids, external ears

23
56 - 60
27 - 31
Link=Carnegie_stage_23

rounded head, body and limbs

Following this stage Fetal Development occurs until birth (approx 40 weeks)

Embryo Stages

Developmental stages in human embryos: revised and new measurements

Cells Tissues Organs. 2010;192(2):73-84. doi: 10.1159/000289817. Epub 2010 Feb 26.


O'Rahilly R, Müller F. Source School of Medicine, University of California, Davis, Calif., USA.

Abstract

The staging of human embryos, as distinct from seriation, depends on a morphological scheme devised by Streeter and completed by O'Rahilly, who proposed the term Carnegie stages. To avoid misconceptions and errors, and to place new findings in perspective, it is necessary to summarize the essentials of the Carnegie system: (1) Twenty-three stages cover the embryonic period, i. e. the first 8 postfertilizational weeks of development. (2) The system is based on internal as well as external features, and the use of only external criteria is subject to serious limitations. For example, precise delineation of stages 19-23 and of the embryonic-fetal transition depends on histological examination. (3) Prenatal measurements are not an integral component of the staging system, and hence a stage should never be assigned merely on the basis of embryonic length. A 20-mm embryo, for example, could belong to any of three stages. Measurements, however, are important for the assessment of age, and very few measurements are available for staged embryos. Presented here and based on accurate staging are the maximum diameter of the chorionic sac, the crown-heel length, the greatest length exclusive of the lower limbs, the biparietal diameter, the head circumference, the length of the hindbrain, the total length of the brain, and the lengths of the limbs as well as of their segments, including the foot length. (4) Prenatal ages are also not an integral part of the staging system and hence a stage should never be assigned merely on the basis of prenatal age. Ages, however, are of clinical importance and their estimate has been rendered more precise by accurate timing of fertilization followed by ultrasonography. Prenatal age is postfertilizational and hence some 2 weeks less than the postmenstrual interval. The term gestational age is ambiguous and should be discarded. Presented here is a new graph showing proposed estimates of age in relation to stages and based on current information. Copyright 2010 S. Karger AG, Basel. PMID 20185898


A standard system to study vertebrate embryos

PLoS One. 2009 Jun 12;4(6):e5887.

Werneburg I.

Paläontologisches Museum und Institut der Universität Zürich, Zürich, Switzerland. ingmar_werneburg@yahoo.de

Abstract

Staged embryonic series are important as reference for different kinds of biological studies. I summarise problems that occur when using 'staging tables' of 'model organisms'. Investigations of developmental processes in a broad scope of taxa are becoming commonplace. Beginning in the 1990s, methods were developed to quantify and analyse developmental events in a phylogenetic framework. The algorithms associated with these methods are still under development, mainly due to difficulties of using non-independent characters. Nevertheless, the principle of comparing clearly defined newly occurring morphological features in development (events) in quantifying analyses was a key innovation for comparative embryonic research. Up to date no standard was set for how to define such events in a comparative approach. As a case study I compared the external development of 23 land vertebrate species with a focus on turtles, mainly based on reference staging tables. I excluded all the characters that are only identical for a particular species or general features that were only analysed in a few species. Based on these comparisons I defined 104 developmental characters that are common either for all vertebrates (61 characters), gnathostomes (26), tetrapods (3), amniotes (7), or only for sauropsids (7). Characters concern the neural tube, somite, ear, eye, limb, maxillary and mandibular process, pharyngeal arch, eyelid or carapace development. I present an illustrated guide listing all the defined events. This guide can be used for describing developmental series of any vertebrate species or for documenting specimen variability of a particular species. The guide incorporates drawings and photographs as well as consideration of species identifying developmental features such as colouration. The simple character-code of the guide is extendable to further characters pertaining to external and internal morphological, physiological, genetic or molecular development, and also for other vertebrate groups not examined here, such as Chondrichthyes or Actinopterygii. An online database to type in developmental events for different stages and species could be a basis for further studies in comparative embryology. By documenting developmental events with the standard code, sequence heterochrony studies (i.e. Parsimov) and studies on variability can use this broad comparative data set.

PMID 19521537

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2693928

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005887

A history of normal plates, tables and stages in vertebrate embryology

Int J Dev Biol. 2007;51(1):1-26.

Hopwood N.

Department of History and Philosophy of Science, University of Cambridge, UK. ndh12@cam.ac.uk Abstract Developmental biology is today unimaginable without the normal stages that define standard divisions of development. This history of normal stages, and the related normal plates and normal tables, shows how these standards have shaped and been shaped by disciplinary change in vertebrate embryology. The article highlights the Normal Plates of the Development of the Vertebrates edited by the German anatomist Franz Keibel (16 volumes, 1897-1938). These were a major response to problems in the relations between ontogeny and phylogeny that amounted in practical terms to a crisis in staging embryos, not just between, but (for some) also within species. Keibel's design adapted a plate by Wilhelm His and tables by Albert Oppel in order to go beyond the already controversial comparative plates of the Darwinist propagandist Ernst Haeckel. The project responded to local pressures, including intense concern with individual variation, but recruited internationally and mapped an embryological empire. Though theoretically inconclusive, the plates became standard laboratory tools and forged a network within which the Institut International d'Embryologie (today the International Society of Developmental Biologists) was founded in 1911. After World War I, experimentalists, led by Ross Harrison and Viktor Hamburger, and human embryologists, especially George Streeter at the Carnegie Department of Embryology, transformed Keibel's complex, bulky tomes to suit their own contrasting demands. In developmental biology after World War II, normal stages-reduced to a few journal pages-helped domesticate model organisms. Staging systems had emerged from discussions that questioned the very possibility of assigning an embryo to a stage. The historical issues resonate today as developmental biologists work to improve and extend stage series, to make results from different laboratories easier to compare and to take individual variation into account.

PMID 17183461

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1885287

http://www.ijdb.ehu.es/web/paper.php?doi=10.1387/ijdb.062189nh


Morphological and molecular characteristics of living human fetuses between Carnegie stages 7 and 23: developmental stages in the post-implantation embryo

Hum Reprod Update. 1997 Jan-Feb;3(1):3-23.

Harkness LM, Baird DT. Source Department of Obstetrics and Gynaecology, University of Edinburgh, UK.

Abstract

Determination of embryonic age groups or stages has been based on the Carnegie Institute collection started in 1887. Improved technology has enabled the building of a new collection of embryos of < 9 weeks gestation; these were then used to compare with the original Carnegie collection. The results suggest that in providing definitive stages that are rigidly bound by developmental events, limitations are placed on categorizing the embryo. Allocation of embryos to a specific stage can assist in identifying post-ovulatory age but overlaps between stages could lead to classification into an incorrect stage.

PMID 9193935

The rate of growth in young human embryos of Streeter's horizons. 13 to 23

Iffy L, Shepard TH, Jakobovits A, Lemire RJ, Kerner P.

Acta Anat (Basel). 1967;66(2):178-86.

PMID 6050342

Report Upon the Collection of Human Embryos at the John Hopkins University

Mall, F.P.

The Anatomical Record Volume 5, Issue 7, pages 343–357, July 1911