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Cite this page: Hill, M.A. (2021, September 18) Embryology Ultrasound. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Ultrasound
Characterization of Thermal and Mechanical Indices from Serial Ultrasound Exams and Associations with Neonatal Anthropometry: The NICHD Fetal Growth Studies
Am J Perinatol. 2018 Jun;35(7):632-642. doi: 10.1055/s-0037-1608926. Epub 2017 Nov 30.
Smarr MM1, Louis GMB1, Albert PS2, Kim S2, Fuchs KM3, Grewal J1, D'Alton ME3, Grantz KL4.
OBJECTIVE: This article aims to determine if the number of maternal ultrasound scans where the highest thermal (TI) or mechanical (MI) indices recorded during obstetrical ultrasound exceed 1.0 were associated with neonatal anthropometric measurements. STUDY DESIGN: A prospective cohort of 2,334 nonobese low-risk pregnant women from 12 U.S. clinical sites underwent a total of six ultrasound scans, for which the highest TI and MI values were recorded. Neonatal anthropometric measurements were obtained within 12 to 24 hours of delivery. Multiple linear regression models adjusted for maternal race/ethnicity, body mass index, weight gain, and gestational age were used to examine associations between the number of maternal ultrasounds during gestation with a TI or MI exceeding 1.0 and the mean change in neonatal anthropometry. RESULTS: Ultrasounds with TI or MI >1.0 were not associated with birth weight, neonatal length, nor head, chest, and abdominal circumferences. TI >1.0 was negatively associated with neonatal mid-upper arm and mid-upper thigh circumferences. MI >1.0 was negatively associated with neonatal skinfold measurements of the anterior thigh and triceps, and neonatal circumferences of the mid-upper thigh and umbilicus. CONCLUSION: Prenatal ultrasound examinations in which TI or MI intermittently exceeded 1.0 did not identify a pattern of alterations of birth size. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA. PMID: 29190846 DOI: 10.1055/s-0037-1608926
Diagnosis of Fetal Structural Anomalies at 11 to 14 Weeks
J Ultrasound Med. 2018 Feb 24. doi: 10.1002/jum.14561. [Epub ahead of print]
Vayna AM1, Veduta A1, Duta S1, Panaitescu AM1,2, Stoica S1, Buinoiu N1, Nedelea F1,2, Peltecu G1,2. Author information Abstract OBJECTIVES: To assess the performance of first-trimester ultrasound (US) in identifying major fetal structural abnormalities in an unselected population. METHODS: We conducted a retrospective analysis of all pregnancies that underwent the 11- to 14-week scan in the Fetal Medicine Department of Filantropia Hospital in Bucharest, which were prospectively examined within our screening program. The purpose of the first-trimester US was to evaluate the risk for chromosomal abnormalities and to conduct fetal anatomic examination using a detailed protocol. RESULTS: Our population consisted of 7480 pregnant patients (7576 fetuses). The follow-up was completed for 6045 patients (6114 fetuses). The prevalence of major structural anomalies was 1.89%. In the first trimester, we identified 79% of all major structural anomalies. The highest detection rates were achieved for abdominal wall defects (100%), major central nervous system anomalies (88%), cardiac defects (74%), and skeletal anomalies (71%). The nuchal translucency was increased in 35% of the cases with structural anomalies, and 95% of these were diagnosed in the first trimester. Seventy percent of the patients who presented with structural anomalies and a normal nuchal translucency were diagnosed in the first trimester. CONCLUSIONS: Our results emphasize the importance of performing a detailed US examination at 11 to 14 weeks' gestation in identification of fetal structural defects. © 2018 by the American Institute of Ultrasound in Medicine. KEYWORDS: cardiac defects; echocardiography; fetal anomalies; first trimester; nuchal translucency; spina bifida; ultrasound PMID: 29476550 DOI: 10.1002/jum.14561
CRL GA Table
Table adapted from Westerway (2015) PDF and <pubmed>11065037</pubmed>
|Gestational Age and Crown-Rump Length (measured by ultrasound)|
PMID 20843340 Heart images.
PMID 17374167 Ductus venosus.
PMID 16308909 Virtual reality 2005
Dating of Pregnancy in First versus Second Trimester in Relation to Post-Term Birth Rate: A Cohort Study
PLoS One. 2016 Jan 13;11(1):e0147109. doi: 10.1371/journal.pone.0147109. eCollection 2016.
Näslund Thagaard I1, Krebs L1, Lausten-Thomsen U2, Olesen Larsen S3, Holm JC2, Christiansen M3, Larsen T1. Author information Abstract OBJECTIVES: To evaluate in a national standardised setting whether the performance of ultrasound dating during the first rather than the second trimester of pregnancy had consequences regarding the definition of pre- and post-term birth rates. METHODS: A cohort study of 8,551 singleton pregnancies with spontaneous delivery was performed from 2006 to 2012 at Copenhagen University Hospital, Holbæk, Denmark. We determined the duration of pregnancy calculated by last menstrual period, crown rump length (CRL), biparietal diameter (1st trimester), BPD (2nd trimester), and head circumference and compared mean and median durations, the mean differences, the systematic discrepancies, and the percentages of pre-term and post-term pregnancies in relation to each method. The primary outcomes were post-term and pre-term birth rates defined by different dating methods. RESULTS: The change from use of second to first trimester measurements for dating was associated with a significant increase in the rate of post-term deliveries from 2.1-2.9% and a significant decrease in the rate of pre-term deliveries from 5.4-4.6% caused by systematic discrepancies. Thereby 25.1% would pass 41 weeks when GA is defined by CRL and 17.3% when BPD (2nd trimester) is used. Calibration for these discrepancies resulted in a lower post-term birth rate, from 3.1-1.4%, when first compared to second trimester dating was used. CONCLUSIONS: Systematic discrepancies were identified when biometric formulas were used to determine duration of pregnancy. This should be corrected in clinical practice to avoid an overestimation of post-term birth and unnecessary inductions when first trimester formulas are used.
see earlier 2000 paper
Ultrasonic fetal measurements: new Australian standards for the new millennium. Westerway SC, Davison A, Cowell S. Aust N Z J Obstet Gynaecol. 2000 Aug;40(3):297-302. PMID 11065037
Ultrasonic Fetal Measurement Standards for an Australian Population
Australasian Society for Ultrasound in Medicine - Ultrasonic Fetal Measurement Standards for an Australian Population Compiled by Dr Susan Campbell Westerway
University of Sydney
2017 Charles Sturt University, New South Wales, Australia
Sonographic fetal sex determination in the first trimester: study in 2314 pregnancies and literature review
Ginecol Obstet Mex. 2015 Apr;83(4):207-12.
[Article in Spanish]
González Ballano I, Savirón Cornudella R, Puertas DL, Luis Jde L.
OBJECTIVE: To evaluate the success rate and reliability of fetal sex determination in first trimester between 11-13+ 6 weeks and make a comparative study with other studies. MATERIAL AND METHODS: A cohort study was performed. 2314 first trimester pregnancy ultrasounds were examined. For fetal sex estimation, the method of a sagittal section and the relation between the angle formed by the genital tubercle and spinal column was used. RESULTS: Diagnosis of fetal sex was issued in 1986 cases with 90.1% success rate. In 328 cases (14.2%) no gender assignment was achieved. A directly proportional relationship between success rate in fetal sex diagnosis and crown-rump length (CRL) (p < 0.001) was described; with CRL over 65 mm, the prediction of fetal sex is above 95% and from 77 mm is close to 100%. With CRL < 51 mm, the success rate is less than 80% in both sexes. CONCLUSION: The simplest and best performing technique is the relation between the angle formed by the genital tubercle and spinal column. Success rate below 60 mm is less than 90% overall, so it would have to be wary of establishing the fetal sex, especially if it involves a decision as to avoid an invasive test. PMID 26727753
Transvaginal three-dimensional sonographic assessment of the embryonic brain: a pilot study
Clujul Med. 2015;88(2):152-8. doi: 10.15386/cjmed-437. Epub 2015 Apr 15.
Boitor-Borza D1, Kovacs T1, Stamatian F1.
AIMS: A very good knowledge of human embryology is mandatory not only for the correct sonographic assessment of the developing brain, but also for better understanding the origins of congenital anomalies involving the central nervous system. 3D transvaginal sonography may be an effective technique for imaging the developing brain. The aims of this explorative study are to demonstrate the feasibility of imaging the embryonic brain between 7 and 10 weeks of gestation for clinical studies by using a 3D high-frequency vaginal ultrasound transducer and to provide a reference for the morphology of the brain in the embryonic period. MATERIALS AND METHODS: Four embryos of 9 mm, 17 mm, 23 mm and 31 mm crown-rump length respectively were assessed in vivo by transvaginal sonography. We gave a special attention to the embryonic brain. All patients were examined with a Voluson E10, BT 15 ultrasound scanner (GE Healthcare, Zipf, Austria), using a high-frequency 6-12 MHz/ 256-element 3D/4D transvaginal transducer. Three-dimensional sonography was performed routinely as the patients were scanned. The multiplanar display was used after selecting the best volume. The Omni view® software was used for digitally slicing the selected volumes. RESULTS: We describe the morphological details of the developing brains of four embryos ranging from 7 to 10 gestational weeks. In the human embryo 9 mm CRL the hypoechogenic cavities of the three primary vesicles (prosencephalon, mesencephalon, rhombencephalon) could be observed on a sagittal section. In the human embryo 17 mm CRL the prosencephalon was divided into the median diencephalon and two telencephalic vesicles, which were partially separated by the falx cerebri. In the human embryo 23 mm CRL the cerebral hemispheres developed and they were completely separated by the falx cerebri. The choroid plexus was evident inside the lateral ventricles and the fourth ventricle. In the human embryo 31 mm CRL the ventral thalamus was evident, and the ganglionic eminence, as the precursor of the basal ganglia, was well seen on the floor of the cerebral hemispheres. CONCLUSIONS: Studies of embryology are still needed for a complete understanding of the developing brain. 3D sonography using a high-frequency vaginal ultrasound transducer is feasible for imaging the embryonic brain with an acceptable quality for clinical studies. KEYWORDS: 3D transvaginal ultrasound; developing brain; human embryo
Ganglionic eminence within the early developing brain visualized by 3D transvaginal ultrasound
Med Ultrason. 2015 Sep;17(3):289-94. doi: 10.11152/mu.2013.2066.173.rbb.
Boitor-Borza D1, Kovacs T2, Stamatian F2.
Abstract AIM: Early diagnosis of cerebral congenital anomalies requires a profound knowledge of the anatomy of the developing human brain. The ganglionic eminences (GE) are crucial structures of the brain, giving rise mostly to the basal nuclei. The aim of this explorative study is to assess the GE within the embryonic and early fetal brain by using 3D transvaginal US. MATERIAL AND METHODS: From March 2015 to May 2015, a total of 18 singleton non-malformed embryos and fetuses at 9-13 weeks of gestation were assesed in vivo by transvaginal ultrasound using a Voluson E10, BT 15 scanner (GE Healthcare, Zipf, Austria). The 3D sonography was performed routinely as the subjects were scanned. Inter-observer agreement (concordance) was calculated using the Cohen's kappa statistics. RESULTS: At 9 gestational weeks, no GE was identified. At 10 gestational weeks the GE were identified as mere thickenings in the lateral wall of the cerebral hemispheres, well depicted by 3D transvaginal ultrasound using the HDlive rendering mode and the OmniView® software. Starting with 11 gestational weeks the GE are evident. The results of inter-observer agreement for ganglionic eminences identification were as follows: observed agreement Po=0.94, expected agreement Pe=0.76, kappa coefficient=0.83, which means a very good agreement between the observers. CONCLUSIONS: The GE can be clearly visualized by 3D transvaginal sonography, and especially by HDlive rendering mode. This method has become the "golden standard" for in vivo morphological studies of the embryonic and early fetal brain. PMID 26343075
International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown-rump length in the first trimester of pregnancy
Ultrasound Obstet Gynecol. 2014 Dec;44(6):641-8. doi: 10.1002/uog.13448. Epub 2014 Nov 2.
Papageorghiou AT, Kennedy SH, Salomon LJ, Ohuma EO, Cheikh Ismail L, Barros FC, Lambert A, Carvalho M, Jaffer YA, Bertino E, Gravett MG, Altman DG, Purwar M, Noble JA, Pang R, Victora CG, Bhutta ZA, Villar J; International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st). Collaborators (237)
OBJECTIVES: There are no international standards for relating fetal crown-rump length (CRL) to gestational age (GA), and most existing charts have considerable methodological limitations. The INTERGROWTH-21(st) Project aimed to produce the first international standards for early fetal size and ultrasound dating of pregnancy based on CRL measurement. METHODS: Urban areas in eight geographically diverse countries that met strict eligibility criteria were selected for the prospective, population-based recruitment, between 9 + 0 and 13 + 6 weeks' gestation, of healthy well-nourished women with singleton pregnancies at low risk of fetal growth impairment. GA was calculated on the basis of a certain last menstrual period, regular menstrual cycle and lack of hormonal medication or breastfeeding in the preceding 2 months. CRL was measured using strict protocols and quality-control measures. All women were followed up throughout pregnancy until delivery and hospital discharge. Cases of neonatal and fetal death, severe pregnancy complications and congenital abnormalities were excluded from the study. RESULTS: A total of 4607 women were enrolled in the Fetal Growth Longitudinal Study, one of the three main components of the INTERGROWTH-21(st) Project, of whom 4321 had a live singleton birth in the absence of severe maternal conditions or congenital abnormalities detected by ultrasound or at birth. The CRL was measured in 56 women at < 9 + 0 weeks' gestation; these were excluded, resulting in 4265 women who contributed data to the final analysis. The mean CRL and SD increased with GA almost linearly, and their relationship to GA is given by the following two equations (in which GA is in days and CRL in mm): mean CRL = -50.6562 + (0.815118 × GA) + (0.00535302 × GA(2) ); and SD of CRL = -2.21626 + (0.0984894 × GA). GA estimation is carried out according to the two equations: GA = 40.9041 + (3.21585 × CRL(0.5) ) + (0.348956 × CRL); and SD of GA = 2.39102 + (0.0193474 × CRL). CONCLUSIONS: We have produced international prescriptive standards for early fetal linear size and ultrasound dating of pregnancy in the first trimester that can be used throughout the world. © 2014 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. KEYWORDS: crown-rump length; dating; gestational age; global health; growth; pregnancy
© 2014 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Sequential cranial ultrasound and cerebellar diffusion weighted imaging contribute to the early prognosis of neurodevelopmental outcome in preterm infants
PLoS One. 2014 Oct 20;9(10):e109556. doi: 10.1371/journal.pone.0109556. eCollection 2014.
Brouwer MJ1, van Kooij BJ1, van Haastert IC1, Koopman-Esseboom C1, Groenendaal F1, de Vries LS1, Benders MJ2.
OBJECTIVE: To evaluate the contribution of sequential cranial ultrasound (cUS) and term-equivalent age magnetic resonance imaging (TEA-MRI) including diffusion weighted imaging (DWI) to the early prognosis of neurodevelopmental outcome in a cohort of very preterm infants (gestational age [GA] <31 weeks). STUDY DESIGN: In total, 93 preterm infants (median [range] GA in weeks: 28.3 [25.0-30.9]) were enrolled in this prospective cohort study and underwent early and term cUS as well as TEA-MRI including DWI. Early cUS abnormalities were classified as normal, mild, moderate or severe. Term cUS was evaluated for ex-vacuo ventriculomegaly (VM) and enlargement of the extracerebral cerebrospinal fluid (eCSF) space. Abnormalities on T1- and T2-weighted TEA-MRI were scored according to Kidokoro et al. Using DWI at TEA, apparent diffusion coefficients (ADCs) were measured in four white matter regions bilaterally and both cerebellar hemispheres. Neurodevelopmental outcome was assessed at two years' corrected age (CA) using the Bayley Scales of Infant and Toddler Development, third edition. Linear regression analysis was conducted to explore the correlation between the different neuroimaging modalities and outcome. RESULTS: Moderate/severe abnormalities on early cUS, ex-vacuo VM and enlargement of the eCSF space on term cUS and increased cerebellar ADC values on term DWI were independently associated with worse motor outcome (p<.05). Ex-vacuo VM on term cUS was also related to worse cognitive performance at two years' CA (p<.01). CONCLUSION: These data support the clinical value of sequential cUS and recommend repeating cUS at TEA. In particular, assessment of moderate/severe early cUS abnormalities and ex-vacuo VM on term cUS provides important prognostic information. Cerebellar ADC values may further aid in the prognostication of gross motor function.
Determination of gestational age by ultrasound
J Obstet Gynaecol Can. 2014 Feb;36(2):171-83.
Butt K1, Lim K2; Society of Obstetricians and Gynaecologists of Canada. Collaborators (10)
Abstractin English, French OBJECTIVE: To assist clinicians in assigning gestational age based on ultrasound biometry. OUTCOMES: To determine whether ultrasound dating provides more accurate gestational age assessment than menstrual dating with or without the use of ultrasound. To provide maternity health care providers and researchers with evidence-based guidelines for the assignment of gestational age. To determine which ultrasound biometric parameters are superior when gestational age is uncertain. To determine whether ultrasound gestational age assessment is cost effective. EVIDENCE: Published literature was retrieved through searches of PubMed or MEDLINE and The Cochrane Library in 2013 using appropriate controlled vocabulary and key words (gestational age, ultrasound biometry, ultrasound dating). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies written in English. There were no date restrictions. Searches were updated on a regular basis and incorporated in the guideline to July 31, 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. VALUES: The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). BENEFITS, HARMS, AND COSTS: Accurate assignment of gestational age may reduce post-dates labour induction and may improve obstetric care through allowing the optimal timing of necessary interventions and the avoidance of unnecessary ones. More accurate dating allows for optimal performance of prenatal screening tests for aneuploidy. A national algorithm for the assignment of gestational age may reduce practice variations across Canada for clinicians and researchers. Potential harms include the possible reassignment of dates when significant fetal pathology (such as fetal growth restriction or macrosomia) result in a discrepancy between ultrasound biometric and clinical gestational age. Such reassignment may lead to the omission of appropriate-or the performance of inappropriate-fetal interventions. Summary Statements 1. When performed with quality and precision, ultrasound alone is more accurate than a "certain" menstrual date for determining gestational age in the first and second trimesters (≤ 23 weeks) in spontaneous conceptions, and it is the best method for estimating the delivery date. (II) 2. In the absence of better assessment of gestational age, routine ultrasound in the first or second trimester reduces inductions for post-term pregnancies. (I) 3. Ideally, every pregnant woman should be offered a first-trimester dating ultrasound; however, if the availability of obstetrical ultrasound is limited, it is reasonable to use a second-trimester scan to assess gestational age. (I) 4. Notwithstanding Summary Statements 1, 2, and 3, women vary greatly in their awareness of their internal functions, including ovulation, and this self-knowledge can sometimes be very accurate. (III) Recommendations 1. First-trimester crown-rump length is the best parameter for determining gestational age and should be used whenever appropriate. (I-A) 2. If there is more than one first-trimester scan with a mean sac diameter or crown-rump length measurement, the earliest ultrasound with a crown-rump length equivalent to at least 7 weeks (or 10 mm) should be used to determine the gestational age. (III-B) 3. Between the 12th and 14th weeks, crown-rump length and biparietal diameter are similar in accuracy. It is recommended that crown-rump length be used up to 84 mm, and the biparietal diameter be used for measurements > 84 mm. (II-1A) 4. Although transvaginal ultrasound may better visualize early embryonic structures than a transabdominal approach, it is not more accurate in determining gestational age. Crown-rump length measurement from either transabdominal or transvaginal ultrasound may be used to determine gestational age. (II-1C) 5. If a second- or third-trimester scan is used to determine gestational age, a combination of multiple biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) should be used to determine gestational age, rather than a single parameter. (II-1A) 6. When the assignment of gestational age is based on a third-trimester ultrasound, it is difficult to confirm an accurate due date. Follow-up of interval growth is suggested 2 to 3 weeks following the ultrasound. (III-C). KEYWORDS: dating; gestational age; ultrasound
Uterine Doppler velocimetry of the uterine arteries in the second and third trimesters for the prediction of gestational outcome
Rev Bras Ginecol Obstet. 2014 Jan;36(1):35-9. doi: 10.1590/S0100-72032014000100008.
Afrakhteh M1, Moeini A1, Taheri MS2, Haghighatkhah HR2, Fakhri M3, Masoom N4. Author information
PURPOSE: The aim of this longitudinal study was to investigate the value of uterine artery Doppler sonography during the second and third trimesters in the prediction of adverse pregnancy outcome in low-risk women. METHODS: From July 2011 to August 2012, a total of 205 singleton pregnant women presenting at our antenatal clinic were enrolled in this prospective study and were assessed for baseline demographic and obstetric data. They underwent ultrasound evaluation at the time of second and third trimesters, both included Doppler assessment of bilateral uterine arteries to determine the values of the pulsatility index (PI) and resistance index (RI) and presence of early diastolic notch. The endpoint of this study was assessing the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Doppler ultrasonography of the uterine artery, for the prediction of adverse pregnancy outcomes including preeclampsia, stillbirth, placental abruption and preterm labor. RESULTS: The mean age of cases was 26.4±5.11. The uterine artery PI and RI values for both second (PI: 1.1±0.42 versus 1.53±0.59, p=0.002; RI: 0.55±0.09 versus 0.72±0.13, p=0.000 respectively) and third-trimester (PI: 0.77±0.31 versus 1.09±0.46, p=0.000; RI: 0.46±0.10 versus 0.60±0.14, p=0.010 respectively) evaluations were significantly higher in patients with adverse pregnancy outcome than in normal women. Combination of PI and RI >95th percentile and presence of bilateral notch in second trimester get sensitivity and specificity of 36.1 and 97% respectively, while these measures were 57.5 and 98.2% in third trimester. CONCLUSIONS: According to our study, it seems that uterine artery Doppler may be a valuable tool for the prediction of a variety of adverse outcomes in second and third trimesters.
Third-trimester abnormal uterine artery Doppler findings are associated with adverse pregnancy outcomes
J Ultrasound Med. 2013 Dec;32(12):2107-13. doi: 10.7863/ultra.32.12.2107.
Shwarzman P1, Waintraub AY, Frieger M, Bashiri A, Mazor M, Hershkovitz R. Author information
OBJECTIVES: To evaluate the association between third-trimester abnormal uterine artery Doppler findings and pregnancy outcomes. METHODS: A prospective study was designed, including 198 consecutive singleton pregnancies between 27 and 41 weeks' gestation. In the study population, 144 had normal uterine artery Doppler waveforms, 37 had unilateral pathologic waveforms, and 17 had bilateral pathologic waveforms. Eighty patients had intrauterine growth restriction (IUGR), preeclampsia toxemia, or both, and 118 had no complications and served as a control group. The uterine artery Doppler waveform was considered abnormal when a notch or pulsatility index above the 90th percentile was noted. RESULTS: In patients with bilateral pathologic uterine artery Doppler waveforms, the rates of cesarean delivery, small-for-gestational-age (SGA) neonates, preterm delivery, and low Apgar scores were increased compared to patients with normal or pathologic unilateral waveforms (P = .009; P > .001; P = .007; P > .001, respectively). The incidence rates for SGA neonates, cesarean delivery, and preterm delivery were significantly higher among patients without IUGR or preeclampsia toxemia when associated with pathologic bilateral waveforms in comparison to normal waveforms (P = .01 for all). A bilateral pathologic waveform was found to be an independent risk factor for cesarean delivery and SGA neonates. The incidence rates for SGA neonates and preterm delivery were significantly higher among patients with IUGR and/or preeclampsia toxemia when associated with bilateral abnormalities in comparison to normal waveforms (P = .01 for both). CONCLUSIONS: Third-trimester abnormal uterine artery Doppler findings are associated with worse perinatal outcomes among patients both with and without pregnancy complications. KEYWORDS: Doppler sonography, perinatal outcomes, pregnancy, third trimester, uterine artery
Sonographic markers for early diagnosis of fetal malformations
World J Radiol. 2013 Oct 28;5(10):356-371.
Renna MD, Pisani P, Conversano F, Perrone E, Casciaro E, Renzo GC, Paola MD, Perrone A, Casciaro S. Source Maria Daniela Renna, Paola Pisani, Francesco Conversano, Ernesto Casciaro, Marco Di Paola, Sergio Casciaro, National Council of Research, Institute of Clinical Physiology, c/o Campus Universitario Ecotekne, 73100 Lecce, Italy.
Fetal malformations are very frequent in industrialized countries. Although advanced maternal age may affect pregnancy outcome adversely, 80%-90% of fetal malformations occur in the absence of a specific risk factor for parents. The only effective approach for prenatal screening is currently represented by an ultrasound scan. However, ultrasound methods present two important limitations: the substantial absence of quantitative parameters and the dependence on the sonographer experience. In recent years, together with the improvement in transducer technology, quantitative and objective sonographic markers highly predictive of fetal malformations have been developed. These markers can be detected at early gestation (11-14 wk) and generally are not pathological in themselves but have an increased incidence in abnormal fetuses. Thus, prenatal ultrasonography during the second trimester of gestation provides a "genetic sonogram", including, for instance, nuchal translucency, short humeral length, echogenic bowel, echogenic intracardiac focus and choroid plexus cyst, that is used to identify morphological features of fetal Down's syndrome with a potential sensitivity of more than 90%. Other specific and sensitive markers can be seen in the case of cardiac defects and skeletal anomalies. In the future, sonographic markers could limit even more the use of invasive and dangerous techniques of prenatal diagnosis (amniocentesis, etc.). KEYWORDS: Chromosome abnormalities, Fetal echocardiography, Nuchal translucency, Prenatal diagnosis, Prenatal sonography, Skeletal dysplasia
Ultrasound evaluation of fetal gender at 12-14 weeks
Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2012 Dec;156(4):324-9. doi: 10.5507/bp.2012.022. Epub 2012 Apr 19.
Lubusky M1, Studnickova M, Skrivanek A, Vomackova K, Prochazka M.
AIMS: The aim of this study was to assess the feasibility and accuracy of fetal gender assignment by transabdominal ultrasound at 12-14 weeks of gestation. METHODS: Fetal gender assessment was performed in 1222 singleton pregnancies. In all fetuses the crown-rump length (CRL) was measured and the genital area of the fetus was examined in the mid-sagittal plane. The result of ultrasound examination was compared to the phenotypic sex of the newborn after delivery. RESULTS: The feasibility as well as accuracy in determining gender increased with growing fetal CRL. At CRL < 50 mm (gestational age < 11+4) the feasibility was 39.1% and accuracy 30.5% (40.9% in male gender vs 24.3% in female gender). At CRL 50-54.9 mm (gestational age 11+4 to 12+0) the feasibility was 63.5% and accuracy 75.0% (89.1% in male gender vs 66.7% in female gender). At CRL 55-59.9 mm (gestational age 12+0 to 12+2) the feasibility was 90.5% and accuracy 96.6% (99.1% in male gender vs 93.5% in female gender). At CRL ≥ 60 mm (gestational age ≥ 12+2) the feasibility was 97.4% and accuracy 100.0% (100.0% in male gender vs 100.0% in female gender). CONCLUSIONS: Fetal gender may reliably be determined when CRL ≥ 60 mm (gestational age ≥ 12+2). Male gender may already be reliably determined when CRL ≥ 55 mm (gestational age ≥ 12+0). If CRL < 50 mm (gestational age < 11+4) the gender cannot be reliably predicted.
Three- and four-dimensional HDlive rendering images of normal and abnormal fetuses: pictorial essay
Arch Gynecol Obstet. 2012 Dec;286(6):1431-5. doi: 10.1007/s00404-012-2505-1. Epub 2012 Aug 7.
Hata T, Hanaoka U, Tenkumo C, Sato M, Tanaka H, Ishimura M. Source Department of Perinatology and Gynecology, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa, 761-0793, Japan. email@example.com
BACKGROUND: Our objective is to present our experience of normal embryonic development and fetal anatomy and fetal anomalies reconstructed employing the three-dimensional (3D) and four-dimensional (4D) HDlive rendering mode. METHODS: A total of 18 normal embryos and fetuses and 21 abnormal fetuses (one case each of thoracic meningocele, thickened nuchal translucency, multicystic dysplastic kidney, gastroschisis, omphalocele, and ovarian cyst, five of hydrops fetalis, three of skeletal abnormality, three of chromosome abnormality, two of cystic hygroma, and two of amniotic band syndrome) at 7-36 weeks' gestation were studied using the 3D/4D HDlive rendering mode. RESULTS: In normal fetuses, marked embryonic development with advancing gestation was clearly shown in the first trimester of pregnancy, and various realistic facial expressions were noted in the second and third trimesters. In abnormal fetuses, anatomically realistic features such as gross specimens were obtained. In particular, 3D/4D HDlive provides new, realistic sensations for the diagnosis of amniotic band syndrome, skeletal abnormalities, and facial abnormalities. CONCLUSION: 3D/4D HDlive rendering images seem to be more readily discernible than those obtained by conventional 3D/4D sonography. 3D/4D HDlive may be an important modality in future embryonic research, fetal neurobehavioral assessment, and the evaluation of fetal anomalies.
Prenatal ultrasound diagnosis of neural tube defects. Pictorial essay
Med Ultrason. 2012 Jun;14(2):147-53.
Rădulescu M, Ulmeanu EC, Nedelea M, Oncescu A. Source Clinical Emergency Hospital Bucharest, Department of Radiology, Bucharest, Romania; Email: firstname.lastname@example.org.
Neural tube defects (NTD) are a heterogeneous group of malformations resulting from failure of normal neural tube closure before the fourth and fifth week of embryologic development. The three most common forms of NTD are: anencephaly, encephalocele and spinal dysraphism. Less common forms of neural tube defects include iniencephaly, amniotic bands and other types of spinal abnormalities including scoliosis/cyphosis, sacral agenesis, limb-body wall complex, diastematomyelia. The most part of these abnormalities are accessible to the ultrasound diagnosis in the midtrimester and sometimes even in the late first trimester of the pregnancy. This kind of abnormalities can occur in isolation or in association with other anomalies, which can also be characterized with ultrasound. In this pictorial essay the ultrasonographic aspects of the NTD will be discussed.
The Role of 4D Ultrasound in the Assessment of Fetal Behaviour
Maedica (Buchar). 2011 Apr;6(2):120-7.
Lebit DF, Vladareanu PD. Source University of Medicine and Pharmacy "Carol Davila", Elias University Emergency Hospital, Bucharest, Romania.
Fetal behavior is defined as any fetal action seen by the mother or fetus diagnosed by objective methods such as cardiotocography (CTG) or ultrasound. Analysis of the dynamics of the fetal behavior with morphological studies has lead to the conclusion that fetal behavior patterns are directly reflecting development and maturation of the central nervous system. The assessment of fetal behavior by 4D ultrasound could allow distinction between normal and abnormal fetal behavior patterns which might make possible the early recognition of fetal brain impairment.Aim: Assessment of fetal movements throughout the pregnancy using 4D ultrasound.Material and Method: The study group included 144 healthy pregnant women with single pregnancies between 7-38 weeks of gestation. For the first trimester of pregnancy we assessed eight types of fetal movements and for the second and third trimesters 14 types of fetal movements and facial expressions. The analyzed parameters for each trimester of pregnancy can be used for performing antenatal neurodevelopment test, used the first time by Professor Kurjak.Results: After 15-20 minutes 4D ultrasound examination, we found a pattern of fetal behavior for each trimester of pregnancy.Conclusions: Dynamic evaluation of fetal behavior reflects directly the processes of maturation and development of the central nervous system. This can make the difference between normal and abnormal brain development and may be used for early diagnosis of neurological disorders that become manifest in perinatal and postnatal periods. PMID 22205894
Area of Wharton's jelly as an estimate of the thickness of the umbilical cord and its relationship with estimated fatal weight
Reprod Health. 2011 Nov 4;8:32.
Barbieri C, Cecatti JG, Surita FG, Costa ML, Marussi EF, Costa JV. Source Department of Obstetrics and Gynecology, School of Medical Sciences, Universidade Estadual de Campinas-UNICAMP, Campinas, São Paulo, Brazil.
BACKGROUND: To build a reference curve for the area of Wharton's jelly (WJ) in low-risk pregnancies from 13 to 40 weeks and to assess its relationship with estimated fetal weight (EFW). METHODS: 2,189 low-risk pregnancies had the area of WJ estimated by ultrasound and the 10th, 50th and 90th percentiles calculated using a third-degree polynomial regression procedure. EFW by ultrasound was correlated with the measurement of the area of WJ. RESULTS: The area of WJ increased according to gestational age (R² = 0.64), stabilizing from the 32nd week onwards. There was a significant linear correlation between area of WJ and EFW up to 26 weeks (R = 0.782) and after that 5t remained practically constant (R = 0.047). CONCLUSION: The area of WJ increases according to gestational age, with a trend to stabilize at around 32 weeks of gestation. It is also linearly correlated with EFW only up to 26 weeks of gestation.
Ultrasonic fetal measurements: new Australian standards for the new millennium
Aust N Z J Obstet Gynaecol. 2000 Aug;40(3):297-302.
Westerway SC1, Davison A, Cowell S.
In over 30 years of ultrasound assessment of the fetus, Australian researchers have only produced growth curves for the biparietal diameter (BPD) and occipito-frontal diameter (OFD) for general use. The overseas curves used for other fetal parameters are up to 25 years old and based on predominantly white middle class sample populations. In the last decade the ethnicity in Australia has changed significantly, putting into question the accuracy of the existing charts. This 3-year study of 3,800 pregnancies has resulted in the production of fetal measurement charts for the BPD, OFD, head circumference (HC), abdominal circumference (AC), crown rump length (CRL), femur and humerus lengths. Using over 11,600 measurements collected from diverse ethnic, social and economic groups within the Australian population, rigorous statistical analysis was performed. The results showed that statistically significant differences occur between the curves currently in regular use and those for the OFD, HC, AC, CRL and humerus length obtained from our data. PMID 11065037
Eleven fetal echocardiographic planes using 4-dimensional ultrasound with spatio-temporal image correlation (STIC): a logical approach to fetal heart volume analysis
Cardiovasc Ultrasound. 2010 Sep 15;8:41. doi: 10.1186/1476-7120-8-41.
Jantarasaengaram S, Vairojanavong K. Source Maternal-Fetal Medicine Unit and Ultrasound Unit, Rajavithi Hospital, College of Medicine, Rangsit University, Bangkok, Thailand. email@example.com
BACKGROUND: Theoretically, a cross-sectional image of any cardiac planes can be obtained from a STIC fetal heart volume dataset. We described a method to display 11 fetal echocardiographic planes from STIC volumes. METHODS: Fetal heart volume datasets were acquired by transverse acquisition from 200 normal fetuses at 15 to 40 weeks of gestation. Analysis of the volume datasets using the described technique to display 11 echocardiographic planes in the multiplanar display mode were performed offline. RESULTS: Volume datasets from 18 fetuses were excluded due to poor image resolution. The mean visualization rates for all echocardiographic planes at 15-17, 18-22, 23-27, 28-32 and 33-40 weeks of gestation fetuses were 85.6% (range 45.2-96.8%, N = 31), 92.9% (range 64.0-100%, N = 64), 93.4% (range 51.4-100%, N = 37), 88.7%(range 54.5-100%, N = 33) and 81.8% (range 23.5-100%, N = 17) respectively. CONCLUSIONS: Overall, the applied technique can favorably display the pertinent echocardiographic planes. Description of the presented method provides a logical approach to explore the fetal heart volumes. PMID 20843340
13-14-week fetal anatomy scan: a 5-year prospective study
Ultrasound Obstet Gynecol. 2010 Mar;35(3):292-6.
Ebrashy A, El Kateb A, Momtaz M, El Sheikhah A, Aboulghar MM, Ibrahim M, Saad M. Source Fetal Medicine Unit, Cairo University, Cairo, Egypt.
Abstract OBJECTIVES: To assess the potential value of an early (first-trimester) ultrasound examination in depicting fetal anomalies by transabdominal (TAS) and transvaginal (TVS) sonography, to compare it with the traditional mid-trimester anomaly ultrasound examination and to evaluate the degree of patient acceptance of early sonography by the transvaginal route.
METHODS: In this prospective study over a 5-year period (January 2002 to January 2007) 2876 pregnant women underwent a 13-14-week ultrasound examination. The scan was performed by TAS at first and then, if a full fetal anatomical survey was not achieved, by TVS. A mid-trimester fetal anatomy scan was then performed in patients who had not dropped out, miscarried or undergone pregnancy termination (n = 2834).
RESULTS: In the early scan, analyzable data for 2876 TAS and 1357 TVS examinations showed that TVS was significantly better in visualizing the cranium, spine, stomach, kidneys, bladder and upper and lower limbs (P < 0.001). Complete fetal anatomical surveys were achieved by TAS in 64% of cases versus 82% of the cases in which it was attempted by TVS (P < 0.001). Patient body mass index significantly affected the ability of the sonographer to achieve a complete anatomical survey by both TAS and TVS (P < 0.001 and P = 0.004, respectively). The duration of the scan was significantly longer using TVS. The heart and kidneys were not properly visualized in 42% and 27% of cases, respectively, at the 13-week scan compared with 1.6% and 0% at the mid-trimester scan. The total number of cases in which anomalies were detected was 31. At the first-trimester scan, anomalies were detected in 21 fetuses and in 14 of these cases the parents chose pregnancy termination. At the second-trimester scan, anomalies were detected in 17 fetuses: 10 new anomalous cases along with seven cases already detected in the first-trimester scan.
CONCLUSION: Besides its importance in screening for chromosomal abnormalities, the early scan has great potential in visualizing with precision fetal anatomy. TVS can be used to compliment difficult TAS examinations; however, patients do not always agree to undergo TVS. The mid-trimester scan remains crucial for detailed fetal anatomical survey.
(c) 2010 ISUOG. Published by John Wiley & Sons, Ltd.
PMID: 20205205 http://www.ncbi.nlm.nih.gov/pubmed/20205205
Sonographic fetal sex determination
Obstet Gynecol Surv. 2009 Jan;64(1):50-7. doi: 10.1097/OGX.0b013e318193299b.
Odeh M1, Granin V, Kais M, Ophir E, Bornstein J.
Although sonographic fetal sex determination is feasible in most pregnancies, in some cases, it may pose difficulties. An attempt to determine the fetal sex should not be made before 12-weeks' gestation because this early, it is relatively inaccurate. After 13 weeks, it is accurate in 99% to 100% of cases without malformed external genitalia. Sonographic fetal sex determination in the late second trimester is based on direct visualization of the external genitalia, whereas in the late first and early second trimester, it is based mainly on the direction of the genital tubercle (the "sagittal sign"): downward direction of the genital tubercle indicates a female fetus and upward direction a male fetus. Other sonographic landmarks, such as the fetal scrotum, the midline raphe of the penis, the labial lines, the uterus, the descended testis, and the direction and origin of the fetal micturition jet in males may contribute to the correct determination of fetal sex. Inaccurate fetal sex determination may occur when the external genitalia are malformed. Three-dimensional ultrasound, although of generally limited diagnostic value for fetal sex determination, may aid in better definition of congenital malformations of the external genitalia. PMID 19099612
A fast automatic recognition and location algorithm for fetal genital organs in ultrasound images
J Zhejiang Univ Sci B. 2009 Sep;10(9):648-58.
Tang S, Chen SP.
Post-Doctoral Research Station, Shenzhen University, Shenzhen 518060, China. Abstract Severe sex ratio imbalance at birth is now becoming an important issue in several Asian countries. Its leading immediate cause is prenatal sex-selective abortion following illegal sex identification by ultrasound scanning. In this paper, a fast automatic recognition and location algorithm for fetal genital organs is proposed as an effective method to help prevent ultrasound technicians from unethically and illegally identifying the sex of the fetus. This automatic recognition algorithm can be divided into two stages. In the 'rough' stage, a few pixels in the image, which are likely to represent the genital organs, are automatically chosen as points of interest (POIs) according to certain salient characteristics of fetal genital organs. In the 'fine' stage, a specifically supervised learning framework, which fuses an effective feature data preprocessing mechanism into the multiple classifier architecture, is applied to every POI. The basic classifiers in the framework are selected from three widely used classifiers: radial basis function network, backpropagation network, and support vector machine. The classification results of all the POIs are then synthesized to determine whether the fetal genital organ is present in the image, and to locate the genital organ within the positive image. Experiments were designed and carried out based on an image dataset comprising 658 positive images (images with fetal genital organs) and 500 negative images (images without fetal genital organs). The experimental results showed true positive (TP) and true negative (TN) results from 80.5% (265 from 329) and 83.0% (415 from 500) of samples, respectively. The average computation time was 453 ms per image.
PMID: 19735097 http://www.ncbi.nlm.nih.gov/pubmed/19735097
Fetal volume and crown-rump length from 7 to 10 weeks of gestational age in singletons and twins
Martins WP, Nastri CO, Barra DA, Navarro PA, Mauad Filho F, Ferriani RA. Eur J Obstet Gynecol Reprod Biol. 2009 Jul;145(1):32-5. Epub 2009 Apr 21. PMID: 19386409
- "Twins and singletons had similar fetal volume and crown-rump length between the 7th and 10th week of gestational age. Additionally, fetal volume assessed by VOCAL was better than crown-rump length to estimate the gestational age at the evaluated period. However, the improvement was small and probably without clinical significance. CONDENSATION: Fetal volume and crown-rump length were similar between singletons and twins. Fetal volume relative increase was higher and the predicted gestational age was better."
Fetal crown-rump length and estimation of gestational age in an ethnic Chinese population
Sahota DS, Leung TY, Leung TN, Chan OK, Lau TK. Ultrasound Obstet Gynecol. 2009 Feb;33(2):157-60. PMID: 19115262
- "The best-fit equation for the sonographic estimate of gestational age (GA, in days) from CRL (in mm) was GA = 26.643 + 7.822 x CRL(1/2)(R(2) = 0.96). The mean difference between menstrual age and the predicted gestational age was 0.22 days (95% CI, - 0.14 to 0.56), which was lower than that of the three established CRL dating formulae. CONCLUSION: We have derived a formula suitable for the dating of naturally conceived pregnancies between 6 and 15 weeks of gestation that has no systematic prediction error (the 95% CI of mean difference between predicted and menstrual age included zero), comparing favorably with established CRL dating formulae."
Ultrasound screening in pregnancy: test accuracy with regard to detection rates of foetal abnormalities
Executive summary of final report S05-03, Version 1.0.
Source Institute for Quality and Efficiency in Health Care: Executive Summaries [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2005-. 2008 Apr 21.
The aim of this review was to determine the test accuracy of ultrasound screening in pregnancy with regard to the detection of serious foetal abnormalities, depending on examiner qualifications and device quality. Nuchal translucency measurement (NTM) was to be given particular consideration. © IQWiG (Institute for Quality and Efficiency in Health Care). Sections Research question Methods Results Conclusion
New charts for ultrasound dating of pregnancy and assessment of fetal growth: longitudinal data from a population-based cohort study
Ultrasound Obstet Gynecol. 2008 Apr;31(4):388-96.
Verburg BO, Steegers EA, De Ridder M, Snijders RJ, Smith E, Hofman A, Moll HA, Jaddoe VW, Witteman JC.
The Generation R Study Group, Erasmus Medical Center, Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The Netherlands.
OBJECTIVES: Correct assessment of gestational age and fetal growth is essential for optimal obstetric management. The objectives of this study were, first, to develop charts for ultrasound dating of pregnancy based on crown-rump length and biparietal diameter and, second, to derive reference curves for normal fetal growth based on biparietal diameter, head circumference, transverse cerebellar diameter, abdominal circumference and femur length from 10 weeks of gestational age onwards.
METHODS: A total of 8313 pregnant women were included for analysis in this population-based prospective cohort study. All women had repeated ultrasound assessments to examine fetal growth.
RESULTS: Charts for ultrasound dating of pregnancy, based on crown-rump length and biparietal diameter, were derived. Internal validation with the actual date of delivery showed that ultrasound imaging provided reliable gestational age estimates. Up to 92% of deliveries took place within 37-42 weeks of gestation if gestational age was derived from ultrasound data, compared with 87% based on a reliable last menstrual period. The earlier the ultrasound assessment the more accurate the prediction of date of delivery. After 24 weeks of gestation a reliable last menstrual period provided better estimates of gestational age. Reference curves for normal fetal growth from 10 weeks of gestational age onwards were derived.
CONCLUSIONS: Charts for ultrasound dating of pregnancy and reference curves for fetal biometry are presented. The results indicate that, up to 24 weeks of pregnancy, dating by ultrasound examination provides a better prediction of the date of delivery than does last menstrual period. The earlier the ultrasound assessment in pregnancy, preferably between 10 and 12 weeks, the better the estimate of gestational age.
Copyright (c) 2008 ISUOG. Published by John Wiley & Sons, Ltd.
PMID: 18348183 http://www.ncbi.nlm.nih.gov/pubmed/18348183
Fetal age assessment based on 2nd trimester ultrasound in Africa and the effect of ethnicity
BMC Pregnancy Childbirth. 2008 Oct 30;8:48.
Salpou D, Kiserud T, Rasmussen S, Johnsen SL.
Centre for International Health, University of Bergen, Norway. firstname.lastname@example.org Abstract BACKGROUND: The African population is composed of a variety of ethnic groups, which differ considerably from each other. Some studies suggest that ethnic variation may influence dating. The aim of the present study was to establish reference values for fetal age assessment in Cameroon using two different ethnic groups (Fulani and Kirdi).
METHODS: This was a prospective cross sectional study of 200 healthy pregnant women from Cameroon. The participants had regular menstrual periods and singleton uncomplicated pregnancies, and were recruited after informed consent. The head circumference (HC), outer-outer biparietal diameter (BPDoo), outer-inner biparietal diameter and femur length (FL), also called femur diaphysis length, were measured using ultrasound at 12-22 weeks of gestation. Differences in demographic factors and fetal biometry between ethnic groups were assessed by t- and Chi-square tests.
RESULTS: Compared with Fulani women (N = 96), the Kirdi (N = 104) were 2 years older (p = 0.005), 3 cm taller (p = 0.001), 6 kg heavier (p < 0.0001), had a higher body mass index (BMI) (p = 0.001), but were not different with regard to parity. Ethnicity had no effect on BPDoo (p = 0.82), HC (p = 0.89) or FL (p = 00.24). Weight, height, maternal age and BMI had no effect on HC, BPDoo and FL (p = 0.2-0.58, 0.1-0.83, and 0.17-0.6, respectively). When comparing with relevant European charts based on similar design and statistics, we found overlapping 95% CI for BPD (Norway & UK) and a 0-4 day difference for FL and HC.
CONCLUSION: Significant ethnic differences between mothers were not reflected in fetal biometry at second trimester. The results support the recommendation that ultrasound in practical health care can be used to assess gestational age in various populations with little risk of error due to ethnic variation.
PMID: 18973673 http://www.ncbi.nlm.nih.gov/pubmed/18973673
Fetal size in the second trimester is associated with the duration of pregnancy, small fetuses having longer pregnancies
Functional linear discriminant analysis: a new longitudinal approach to the assessment of embryonic growth
Fetal age assessment based on 2nd trimester ultrasound in Africa and the effect of ethnicity
Salpou D, Kiserud T, Rasmussen S, Johnsen SL. BMC Pregnancy Childbirth. 2008 Oct 30;8:48. PMID: 18973673
- Ultrasonic evaluation of fetal limb growth. Jeanty P, Kirkpatrick C, Dramaix-Wilmet M, Struyven J. Radiology. 1981 Jul;140(1):165-8. PMID: 7244221
Nontraditional sonographic pearls in estimating gestational age
Gottlieb AG, Galan HL. Semin Perinatol. 2008 Jun;32(3):154-60. Review. PMID: 18482614
- "This chapter focuses on nontraditional fetal ultrasound measurements, including the transverse cerebellar diameter, fetal foot length, ratios of biometric and nonbiometric measurements, epiphyseal ossification centers, amniotic fluid volume, placental grading, and other miscellaneous markers in the context of evaluating a fetus with possible intrauterine growth restriction."
A virtual reality rendition of a fetal meningomyelocele at 32 weeks of gestation
Ultrasound Obstet Gynecol. 2005 Dec;26(7):799-801.
Groenenberg IA1, Koning AH, Galjaard RJ, Steegers EA, Brezinka C, van der Spek PJ.
Using a virtual reality system to render images obtained with three-dimensional (3D) ultrasound a fetal lumbosacral meningomyelocele (L3–S2) is shown here at 32 weeks' gestation (Figure 1). The defect was originally observed in a 24-year-old primigravida during a routine sonogram at 22 weeks (Figure 2). After extensive counseling the patient decided not to have an amniocentesis and to continue with the pregnancy.
Pant N. Congenital anomalies of foetus-ultrasonographic study (2000). Thesis Bundelkhand University, India. Internet Archive
Pant N. Congenital anomalies of foetus-ultrasonographic study (2000). Thesis Bundelkhand University, India. Internet Archive
Pant N. Congenital Anomalies Of Foetus-ultrasonographic Study by Neeta Pant
Computer analysis of the human embryo growth curve: differences between published ultrasound findings on living embryos in utero and data on fixed specimens
Anat Rec. 1993 Nov;237(3):400-7.
Dickey RP, Gasser RF. Source Fertility Institute, New Orleans, Louisiana.
Accurate information on the normal growth rate of the human embryo is fundamental to a better understanding of the embryonic period of pregnancy. Crown-rump length measured previously in utero (N = 227) with vaginal ultrasound in 107 in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT) singleton pregnancies was compared to the greatest length of fixed human embryos from the Carnegie collection, of known developmental stage whose postovulatory ages were estimated from menstrual histories. Average crown-rump length in utero was 60% of the greatest length of the fixed specimens prior to postovulation day 33, but were equal after postovulation day 40. The growth rate of in utero embryos and fixed specimens, analyzed by computer using exponential equations, was compared to linear and polynomial equations used in previously published embryo growth tables. The exponential equation, length = exp(a + B/age), fit in utero measurements best, while the equation length = exp[a + b/exp(age)] fit the fixed specimens best. Differences between length in utero and in fixed specimens may be related to distortion of the fixed embryos resulting from the formalin fixation, to ultrasound distortion, to curling of the embryo, or to incorrectly estimated ages of the fixed specimens. Study of human embryos in utero is now practical with vaginal ultrasound.
- Crown-Rump Length (CRL)
- Functional linear discriminant analysis (FLDA) - new growth assessment technique using serial measurements to discriminate between normal and abnormal fetal growth.
- Gestational sac (GS) size
- Linear discriminant analysis (LDA) to longitudinal data (James and Hastie, 2001)
- Mean gestation sac diameter (MSD)
- Mean yolk sac diameter (MYD)
- Transvaginal scan (TVS)
- Termination of pregnancy (TOP)