Early Fetal Anatomy Research Articles

Technical Update No. 352: The Role of Early Comprehensive Fetal Anatomy Ultrasound Examination

Tweetable AbstractMost detectable fetal anomalies are present in early pregnancy. Early fetal anatomy at 13-16 weeks, performed by trained operator, should be considered for women at high risk for fetal anomalies or when the routine mid-trimester anatomy scan may be technically challenging. SUMMARY STATEMENTS1.Development of fetal organs begins early in the first trimester, with the majority of organs visible by ultrasound evaluation towards the end of the first trimester of pregnancy (high).2.The majority of significant and sonographically detectable fetal anomalies can be detected on early fetal anatomic ultrasound assessment (high).3.Early detection of fetal anomalies allows patients to obtain counselling consultations, and genetic testing at an earlier gestational age, as well as more time to consider options for pregnancy management (high). RECOMMENDATIONS1.Medical personnel (physicians, technologists, or ultrasound practitioners) who have substantial experience or training in the assessment and interpretation of early comprehensive fetal anatomic scanning should be performing the examination (strong, high).2.The examination can be performed transvaginally, transabdominally, or by both approaches, and the choice for each mode depends on the fetal position, the gestational age, and the experience of the operator (strong, high).3.Early comprehensive fetal anatomic scanning at 13–16 weeks’ gestation should be considered for women who have higher risk for significant fetal anomalies or in whom it is anticipated that a midtrimester transabdominal scan will be technically challenging (strong, high). This scan does not replace the routine 18- to 22-week anatomy scan.

A Nonimmune Hydrops Case.

A Nonimmune Hydrops Case.

Fetal anatomy scan with integrated nuchal translucency and combination of PAPP-A and fβhCG for prediction of aneuploidy.

Nuchal translucency (NT) is an important finding of early fetal anatomy scan because of the association with genetic and structural anomalies. Enlarged nuchal translucency can be easily detected even without measurement on fetal anatomy scan as a neck pathology. Because of demanding criteria for measurning NT in established prenatal aneuploidy screening we came with an idea of improvement and simplification with availabe methods. The aim of this study is to compare established screening methods with new model of screening composed of fetal anatomy scan with integrated nuchal translucency and combination of PAPP-A and fβhCG. A prospective one center study analyzed atotal of 351 pregnancies between January 2017 and December 2020. Sonographic measurement of NT and fetal anatomy scan (FAS) were performend with biochemical testing from blood sample in the first trimester. Combined screening and fetal anatomy scan was performed. Patients with a pathological screening or with structural defects underwent an invasive procedure. In patient with positive screenining who missed the first trimester invasive procedure, amniocentesis was performed. Fetuses were divided into two groups according to positive or negative karyotype and to calculate sensitivity and specificity of screening methods. From statistical methods regression analysis, significance p of individual predictor, sensitivity and specificity with graphic drawing of ROC charts were used. Data were analyzed using statistical tools of Microsoft Excel 365 and BESH stat. Four models for aneuploidy screening were tested. 1) Model of "Age at the time of diagnosis" was slightly significant predictor with insignificant odds ratio (P=0.04, OR=1). 2) Model of" First trimester biochemical screening" (age, free beta human chorionic gonadotropine - fβhCG and pregnancy associated plasmatic protein A -PAPP-A) were significant (P=0.0001; LR=21) with sensitivity of 87.5 % and specificity of 65.7 %. 3) Model of "First trimester combined test" (age of patients at the time of diagnosis, fβhCG, PAPP-A, NT) was significant (P=7.9 x10-14, LR=67, sensitivity 87 %, specificity 80 %). 4) Model of "Fetal anatomy scan with biochemistry" (structural abnormality finding with combination including age, fβhCG and PAPP-A) was significant (P=4.9x10-18, LR=87, sensitivity 95 %, specificity 80 %). Fetal anatomy scan combined with age, fβhCG and PAPP-A has the highest sensitivity and specificity for both, the detection of fetal aneuploidies and structural abnormalities. Our study shows that fetal anatomy scan is the best possible option for first trimester diagnostics (Tab. 4, Fig. 5, Ref. 16).

First Trimester Screening for Fetal Aneuploidies Using Placental Growth Factor: The Great Obstetrical Syndrome (GOS) Study

ObjectiveThis study sought to estimate the ability of first trimester maternal serum placental growth factor (PlGF) to identify fetal aneuploidies. MethodsA prospective cohort study of singleton pregnancy at 11 to 13 weeks was conducted. Maternal serum PlGF concentration was measured using BRAHMS PlGF plus KRYPTOR automated assays (Thermo Scientific BRAHMS, Hennigsdorf, Germany). PlGF and nuchal translucency were log-transformed and reported as multiples of the median (MoM) adjusted for crown-rump length. Detection rates were calculated using receiver-operator characteristic curves. ResultsThe study observed 21 cases of fetal aneuploidies (0.4%) out of 4765 participants. Trisomy 21 (13 cases; 0.85 MoM; interquartile range [IQR] 0.80–0.93), trisomy 18 (two cases; 0.77 MoM; IQR 0.66–0.87) and trisomy 13 (two cases; 0.68 MoM; IQR 0.61–0.75) were associated with low PlGF concentrations. The low PlGF values observed in the cases of monosomy X (two cases; 0.85 MoM; IQR 0.82–0.88, P = 0.05), triploidy (0.78 MoM, P = 0.11), and 47,XX,i(22)(p10) (0.18 MoM, P = 0.08) were not statistically different from the controls. A model including maternal age, nuchal translucency, and PlGF could have identified all (95% CI 83%–100%) cases of trisomy 21 and six of the other fetal aneuploidies (75%) at a false-positive rate of 9%. ConclusionLow first trimester PlGF is associated with an increased risk of fetal aneuploidy. PlGF combined with first trimester ultrasound (nuchal translucency, uterine artery Doppler, and early fetal anatomy) could identify not only women at high risk for preeclampsia, but also fetuses at high risk of aneuploidy for optimal further testing (non-invasive testing for common aneuploidy screening or chorionic villus sampling for full screening and diagnosis).

The added value of detailed early anomaly scan in fetuses with increased nuchal translucency.

This study aims to assess the utility of a detailed early fetal anatomy scan prior to karyotyping in the management of pregnancies with an increased nuchal translucency (NT). The study included fetuses with NT above the 99th centile. These women were offered the option of an early detailed fetal anatomy scan prior to genetic evaluation. The presence or absence of major sonographic findings was analyzed for its predictive value for fetal aneuploidy. An increased NT >99th centile was detected in 43 fetuses (1.8%). Mean NT was 4.5mm (range 3.4-9.0), and gestational age at the early fetal anatomy survey was 12.4weeks (12-13.6). Major sonographic findings were present in 30 fetuses (69.8%); 24 of them underwent karyotyping, and it was abnormal in 14. Among the 13 fetuses without major sonographic findings, 12 had normal karyotype results, and 1 had aneuploidy, yielding a positive predictive value of 58.3% of early fetal anatomy scan for abnormal karyotype results. Multivariate logistic regression analysis showed that the presence of major sonographic findings was as an independent predictor of fetal aneuploidy (adjusted odds ratio 8.15). A detailed early anatomy scan upon detection of increased NT has an important value in the prediction of fetal aneuploidy. © 2016 John Wiley & Sons, Ltd.

What are the most common first-trimester ultrasound findings in cases of Turner syndrome?

Objectives: To identify the most common first-trimester ultrasound findings in Turner syndrome (TS). To evaluate which first-trimester findings can be best used to predict the likelihood of TS.Methods: This was a prospective study, based on singleton pregnancies. The referrals included 6210 patients. Scan protocol covered a review of the early fetal anatomy and markers of aneuploidy.Results: Study population comprised 5644 pregnancies: 5613 with a normal karyotype and 31 cases of TS. Statistically significant differences (p < 0.05) were found between euploidy and TS groups in terms of nuchal translucency (NT; 1.7 mm versus 8.8 mm) and fetal heart rate (FHR; 160 versus 171 beats per minute). None of the TS cases demonstrated absent markers of aneuploidy as opposed to 5133 (91.4%) cases of euploidy. NT and abnormal DV flow (aDV or revDV) were the most common markers found in combination in TS cases (n = 17; 54.8%). 27 (0.5%) cases of euploidy and 17 (54.8%) cases of TS revealed congenital heart defects. Fetal hydrops was observed in 14 cases of TS (43.8%) and in 5 of euploidy (0.1%). In backward regression model, NT > 3.5 mm and right dominant heart (RDH) augmented the risk of TS risk by 991 and 314 times, respectively.Conclusions: First-trimester sonography is a feasible method to identify the most characteristic features of TS fenotype. When the first-trimester pattern of TS is considered, a highly thickened NT, FHR above the 95th percentile, abnormal ductus venosus velocimetry, fetal hydrops, and RDH should be specifically searched for.

Early fetal anatomy screening: who, what, when and why?

This article reviews the potential benefits and downsides of early anatomy screening. There is increasing evidence that about 50% of severe fetal anomalies can be diagnosed prior to 14 weeks of gestation. 'Red flags' such as an increased nuchal or intracranial translucency, tricuspid valve regurgitation, a small biparietal diameter, a single umbilical artery or an abnormal retronasal triangle should raise the sonographer's suspicion of a congenital defect and warrant a more thorough fetal assessment, which often includes transvaginal scanning. Care should, however, be taken not to overinterpret first-trimester findings as false-positive rates of 3-4% have been reported. With more subtle findings, and especially if a heart defect is suspected, a sonographic reassessment after 15 weeks' gestation is indicated. Patients should be counseled that findings could worsen but also improve with time. Basic fetal anomaly screening should be recommended, piggybacked on the routine first-trimester (aneuploidy screening) ultrasound, both for low and high-risk populations. First-trimester anatomy screening seems particularly useful in obese women, whose fetuses are difficult to screen at the midtrimester ultrasound and in multiple gestation. Noninvasive prenatal testing using cell-free fetal DNA can complement but should not replace first-trimester ultrasound.

How effective is ultrasound-based screening for trisomy 18 without the addition of biochemistry at the time of late first trimester?

Trisomy 18 (T18) remains the second most common aneuploidy. It is associated with multiple congenital anomalies and causes intrauterine fetal demise in the most severe cases. To examine the screening performance of ultrasound-based protocols for detecting T18, we aimed to determine the most common signs and their prevalence in fetuses with T18 to develop logistic regression model. This was a prospective study based on singleton pregnancies examined at gestation 11+0 to 13+6. The referrals constituted 6210 patients. Scan protocol enclosed a systematic review of the entire early fetal anatomy, including fetal cardiac evaluation and sonographic signs of aneuploidy. Our study population comprised 5650 pregnancies: 5613 cases with a normal karyotype and 37 cases with T18. The mean nuchal translucency (NT) thickness in the subgroup of euploidy was 1.7 and in the subgroup of T18 it was 5.4. No statistically significant differences were found in terms of maternal age. One case of T18 (2.7%) demonstrated no markers of aneuploidy as opposed to 5111 cases of euploidy (91.1%). Extracardiac malformations were identified in 13 cases of T18 (35.1%) and in 48 cases of euploidy (0.8%). Congenital heart defects were observed in 26 cases of T18 (70.3%) and in 27 cases of euploidy (0.5%). Our results showed good screening performance of ultrasound-based risk calculation models. When the first trimester pattern of T18 is considered, an increased NT, tricuspid regurgitation, single umbilical artery, omphalocele and right dominant heart should be specifically searched for.

155: Assessment of the number of umbilical cord vessels at the time of nuchal translucency screening

Objective: To investigate feasibility of identifying the number of vessels in umbilical cord during nuchal translucency screening. Methods: We performed a prospective study in patients undergoing nuchal translucency screening at 11.0-13.9 weeks’ from 2011-2012. An oblique transverse view of fetal abdomen utilizing Doppler flow and a cross section view of free loop of umbilical cord were obtained. Maternal characteristics, technical aspects of first trimester ultrasound, and number of umbilical cord vessels identified in the second trimester were collected. McNemar’s test and kappa analysis were used to compare quantification of umbilical cord vessels in the first vs. second trimesters. Results: Total of 123 women were included. The number of umbilical cord vessels was successfully visualized in 95.9% of patients utilizing the bladder view, and 65.0% of patients on cross sectional cord views. Three-vessel cord was correctly identified in 99.2% of patients; one case was incorrectly diagnosed with a two two-vessel cord. McNemar’s test indicated that overall, first and second trimester ultrasounds have the same propensity to detect umbilical cord vessels (p=0.414), with moderate agreement (kappa=0.226). Conclusions: Identification of umbilical cord vasculature is possible in the first trimester and can be used as an adjunct to early fetal anatomy evaluation.

First‐trimester detection of structural abnormalities and the role of aneuploidy markers

To determine the sensitivity of first-trimester ultrasound for diagnosing different structural anomalies in chromosomally normal pregnancies, and to establish the role of aneuploidy markers in the detection of abnormalities. This was a retrospective study of chromosomally normal singleton pregnancies with an 11-14-week scan performed in our center during 2002-2009. The ultrasound examination included an early fetal anatomy survey and assessment of nuchal translucency, ductus venosus blood flow and nasal bone. Among 13 723 scanned first-trimester pregnancies with no genetic anomalies and complete follow-up, 439 fetuses (3.2%) were found to present with structural anomalies (194 with major anomalies and 245 with only minor anomalies). Forty-nine per cent of major structural anomalies were detected during the first-trimester scan, the highest rates corresponding to acrania (17/17), holoprosencephaly (three of three), hypoplastic left heart syndrome (10/10), omphalocele (six of six), megacystis (seven of eight) and hydrops (eight of nine). Higher than expected detection rates were obtained for skeletal (69%) and cardiac (57%) defects, coincidentally showing the highest presence of an increased nuchal translucency or abnormal ductus venosus blood flow (38% and 52%, respectively). The finding of an absent nasal bone did not appear to be associated with structural defects. About half of major structural abnormalities can be diagnosed in the first trimester. Increased nuchal translucency or abnormal ductus venosus blood flow appear to be associated with cardiac and skeletal defects and may facilitate early detection.

713: Accuracy and utility of the early fetal anatomy ultrasound

713: Accuracy and utility of the early fetal anatomy ultrasound

Significance of early prenatal diagnosis of fetal hepatic cyst

: To summarize our experience of early prenatal diagnosis of fetal hepatic cysts. : We reviewed all cases of fetal hepatic cyst detected in our institution between 13 and 17 weeks' gestation over the last 20 years. All scans were initially performed transvaginally to improve image quality. Most of the scans were performed as a routine fetal anatomy scan in a low-risk population. : Seven fetal hepatic cysts were detected out of 54,500 fetal anatomy scans performed between 13 and 17 weeks' gestation. Five peripheral cysts measuring 3-5 mm disappeared during the follow-up period, between 18 and 24 weeks' gestation. Two hilar cysts appeared on sonography as choledochal cysts; one disappeared at 22 weeks' gestation, and the other diminished in size during the postnatal follow-up. : Based on our experience, when hepatic cysts are diagnosed during an early fetal anatomy scan, disappearance of these cysts can be expected, especially when the cysts are initially small and peripheral. (c) 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009.

Screening for structural fetal anomalies during the nuchal translucency ultrasound examination

The purpose of this study was to evaluate the ability to screen for structural fetal anomalies during the nuchal translucency (NT) ultrasound examination, without performing a complete anatomic fetal scan, by using the sagittal views of the fetus. In a prospective study, we evaluated all the suspected structural findings observed during the NT examinations performed in our Division of Maternal-Fetal Medicine in 2004-2005. The purpose of the examination was to screen for fetal chromosome abnormalities by using the fetal NT measurements. However, the sonographers were instructed to pay attention to any abnormality observed while obtaining the sagittal views of the fetus. Other views were not to be obtained and fetal anatomy scan was performed only if a structural fetal anomaly was suspected when viewing the fetus in sagittal planes. When a structural fetal anomaly was suspected, a fetal anatomy scan was performed, and then a diagnosis was established at 14-16 weeks' gestation or later. We performed 1723 NT examinations during the study period. The sonographers suspected structural fetal anomalies in 22 cases (1.3%), most of them performed between 11.2 and 13 weeks' gestation. Further evaluation of these cases diagnosed 9 fetuses (0.52%) with structural anomalies including: acrania, holoprosencephaly, Dandy-Walker syndrome, cerebellar agenesis, prune belly syndrome, 2 cases of omphalocele, and 2 cases of cleft lip. The NT was abnormal (greater than 3 mm) in only 1 case (omphalocele). None of the additional 8 cases diagnosed with structural anomalies had a positive maternal serum screening result for trisomy 21. Eight of these 9 fetal structural anomalies were sonographically confirmed at 14-16 weeks' gestation and the remaining 1 was confirmed at 20 weeks' gestation. An additional 13 noncardiac structural anomalies were detected in the study group during routine fetal anatomy scan performed at 14-16 or at 18-24 weeks' gestation. Four of these 9 fetal cardiac defects (44%) were diagnosed by an early fetal echocardiography performed for an increased fetal NT. In addition to chromosomal anomalies and congenital cardiac defects, the NT examination can provide an opportunity to screen for structural fetal anomalies when viewing within the sagittal planes of the fetus. The NT examination can be used as a screening test for those who require an early fetal anatomy scan without performing an additional early anatomy scan to all patients.

Qualified and trained sonographers in the US can perform early fetal anatomy scans between 11 and 14 weeks

ObjectivesThe objective of this study was to determine the extent to which normal fetal anatomy can be detected between 11- and 14-week scan by sonographers in the US. Study designIn a prospective cross-sectional study, 223 unselected women underwent a detailed assessment of fetal anatomy at 11 to 13 and 6/7 weeks by sonographers with transabdominal and/or transvaginal transducers. Thirty-seven structures were examined. Two groups were identified: group I: 121 patients between 11 and 12 weeks, and group II: 102 patients between 13 and 14 weeks. ResultsStructures other than the posterior fossa, heart, genitalia, and the sacral spine were seen between 64% to 99% for group I, and 72% to 98% for group II. The following structures were detected with statistically significantly higher rates in group II compared with group I: cerebellum, posterior fossa, face, 4-chamber view left ventricular outflow tract, aortic arch, ductal arch, kidneys, and genitalia. Comparing the patients of group I and group II, the transvaginal scans yielded a higher detection rate of structures than do the transabdominal scans. ConclusionAnatomic surveys between 11 and 14 weeks can be performed by sonographers with good detection rates of most structures. Using the vaginal probe compared with the abdominal probe improved the detection rate at 13 to 14 weeks as well as 11 to 12 weeks. If early fetal structure evaluation is to become customary in the US, the present practice of experienced and trained sonographers to scan such patients can be maintained.