Deep-learning computer vision can identify increased nuchal translucency in the first trimester of pregnancy.

OBJECTIVE: Many fetal anomalies can already be diagnosed by ultrasound in the first trimester of pregnancy. Unfortunately, in clinical practice, detection rates for anomalies in early pregnancy remain low. Our aim was to use an automated image segmentation algorithm to detect one of the most common fetal anomalies: a thickened nuchal translucency (NT), which is a marker for genetic and structural anomalies. METHODS: Standardized mid-sagittal ultrasound images of the fetal head and chest were collected for 560 fetuses between 11 and 13 weeks and 6 days of gestation, 88 (15.7%) of whom had an NT thicker than 3.5 mm. Image quality was graded as high or low by two fetal medicine experts. Images were divided into a training-set (n = 451, 55 thick NT) and a test-set (n = 109, 33 thick NT). We then trained a U-Net convolutional neural network to segment the fetus and the NT region and computed the NT:fetus ratio of these regions. The ability of this ratio to separate thick (anomalous) NT regions from healthy, typical NT regions was first evaluated in ground-truth segmentation to validate the metric and then with predicted segmentation to validate our algorithm, both using the area under the receiver operator curve (AUROC). RESULTS: The ground-truth NT:fetus ratio detected thick NTs with 0.97 AUROC in both the training and test sets. The fetus and NT regions were detected with a Dice score of 0.94 in the test set. The NT:fetus ratio based on model segmentation detected thick NTs with an AUROC of 0.96 relative to clinician labels. At a 91% specificity, 94% of thick NT cases were detected (sensitivity) in the test set. The detection rate was statistically higher (p = 0.003) in high versus low-quality images (AUROC 0.98 vs. 0.90, respectively). CONCLUSION: Our model provides an explainable deep-learning method for detecting increased NT. This technique can be used to screen for other fetal anomalies in the first trimester of pregnancy.

Impact of first-trimester anomaly scan on health-related quality of life and healthcare costs: a scoping review.

IMPORTANCE: The first-trimester anomaly scan (FTAS) has the potential to detect major congenital anomalies in an early stage of pregnancy. Due to this potential early detection, there is a trend to introduce FTAS in regular care. Data regarding the impact of FTAS on the patient's perspective are limited. OBJECTIVE: To provide an overview of the literature assessing the impact of the FTAS on health-related quality of life (HRQoL) and healthcare costs. EVIDENCE ACQUISITION: Literature search was performed in Embase, PubMed, Medline Ovid, Cochrane Library database, Web-of-Science, and Google Scholar were searched. All studies that reported the performance of a nuchal translucency measurement with a basic fetal assessment HRQoL or healthcare costs of FTAS were included. Studies solely describing screening of chromosomal anomalies were excluded. Three authors independently screened the studies and extracted the data. Results were combined using descriptive analysis. PROSPERO registration number: CRD42016045190. RESULTS: The search yielded 3242 articles and 16 were included. Thirteen articles (7045 pregnancies) examined the relationship between FTAS and HRQoL. Anxiety scores were raised temporarily before FTAS and returned to early pregnancy baseline following the absence of anomalies. Depression scores did not change significantly as a result of FTAS. Three articles studied healthcare costs. These studies, published before 2005, found a combination of FTAS and second-trimester anomaly scan (STAS) resulted in an increased amount of detected anomalies when compared to a STAS-only regimen. However, the combination would also be more costly. CONCLUSIONS: Women experience anxiety in anticipation of the FTAS result and following a reassuring FTAS result, anxiety returns to the baseline level. FTAS seems to be a reassuring experience. The included studies on costs showed the addition of FTAS is likely to increase the number of detected anomalies against an increase in healthcare costs per pregnancy.Review registration: PROSPERO CRD42016045190.

[NUCHAL TRANSLUCENCY CONCURRENT WITH EARLY ANOMALY SCAN: TIME TO RECONSIDER].

INTRODUCTION: During the last decades, a major achievement was reported in detecting Down's syndrome in the first trimester of pregnancy. This is attributed to the use of high-resolution accurate ultrasound machine allowing the detection of a "nuchal translucency" in the back of the fetus during 11-14 weeks' gestation. This is considered to be a physiologic finding, but when increased, may alert for chromosomal abnormality (mainly Down's syndrome), cardiac and other organ anomalies and other genetic syndromes. Later additional sonographic findings were found, including nasal bone assessment, and Doppler flow studies of the ductus venosus and tricuspid regurgitation Technology advancement accompanied by sonographers' skills enhancement allows (at the time frame of the nuchal scan) a detailed anomaly scan. Additional screening for pregnancy complication was achieved using first trimester multi marker assessment, alerting for preeclamptic toxemia or placenta accreta. Currently, many national and international professional organizations recommend performing the nuchal scan concurrent with an early anomaly scan both at the same time of gestation. This approach is different than the one performed in Israel, whereas the nuchal scan is conducted separately and 2-3 weeks later an anomaly scan is offered. We call for reconsideration of the sequential approach and performing all the tests in a comprehensive first trimester clinic.

Ultrasonographic Fetal Nuchal Translucency Measurements and Cytogenetic Outcomes.

Importance: Ultrasonographic measurement of fetal nuchal translucency is used in prenatal screening for trisomies 21 and 18 and other conditions. A cutoff of 3.5 mm or greater is commonly used to offer follow-up investigations, such as prenatal cell-free DNA (cfDNA) screening or cytogenetic testing. Recent studies showed a possible association with chromosomal anomalies for levels less than 3.5 mm, but extant evidence has limitations. Objective: To evaluate the association between different nuchal translucency measurements and cytogenetic outcomes on a population level. Design, Setting, and Participants: This population-based retrospective cohort study used data from the Better Outcomes Registry & Network, the perinatal registry for Ontario, Canada. All singleton pregnancies with an estimated date of delivery from September 1, 2016, to March 31, 2021, were included. Data were analyzed from March 17 to August 14, 2023. Exposures: Nuchal translucency measurements were identified through multiple-marker screening results. Main Outcomes and Measures: Chromosomal anomalies were identified through all Ontario laboratory-generated prenatal and postnatal cytogenetic tests. Cytogenetic testing results, supplemented with information from cfDNA screening and clinical examination at birth, were used to identify pregnancies without chromosomal anomalies. Multivariable modified Poisson regression with robust variance estimation and adjustment for gestational age was used to compare cytogenetic outcomes for pregnancies with varying nuchal translucency measurement categories and a reference group with nuchal translucency less than 2.0 mm. Results: Of 414 268 pregnancies included in the study (mean [SD] maternal age at estimated delivery date, 31.5 [4.7] years), 359 807 (86.9%) had a nuchal translucency less than 2.0 mm; the prevalence of chromosomal anomalies in this group was 0.5%. An increased risk of chromosomal anomalies was associated with increasing nuchal translucency measurements, with an adjusted risk ratio (ARR) of 20.33 (95% CI, 17.58-23.52) and adjusted risk difference (ARD) of 9.94% (95% CI, 8.49%-11.39%) for pregnancies with measurements of 3.0 to less than 3.5 mm. The ARR was 4.97 (95% CI, 3.45-7.17) and the ARD was 1.40% (95% CI, 0.77%-2.04%) when restricted to chromosomal anomalies beyond the commonly screened aneuploidies (excluding trisomies 21, 18, and 13 and sex chromosome aneuploidies). Conclusions and Relevance: In this cohort study of 414 268 singleton pregnancies, those with nuchal translucency measurements less than 2.0 mm were at the lowest risk of chromosomal anomalies. Risk increased with increasing measurements, including measurements less than 3.5 mm and anomalies not routinely screened by many prenatal genetic screening programs.

Automatic measurement of fetal anterior neck lower jaw angle in nuchal translucency scans.

This study aims at suggesting an end-to-end algorithm based on a U-net-optimized generative adversarial network to predict anterior neck lower jaw angles (ANLJA), which are employed to define fetal head posture (FHP) during nuchal translucency (NT) measurement. We prospectively collected 720 FHP images (half hyperextension and half normal posture) and regarded manual measurement as the gold standard. Seventy percent of the FHP images (half hyperextension and half normal posture) were used to fit models, and the rest to evaluate them in the hyperextension group, normal posture group (NPG), and total group. The root mean square error, explained variation, and mean absolute percentage error (MAPE) were utilized for the validity assessment; the two-sample t test, Mann-Whitney U test, Wilcoxon signed-rank test, Bland-Altman plot, and intraclass correlation coefficient (ICC) for the reliability evaluation. Our suggested algorithm outperformed all the competitors in all groups and indices regarding validity, except for the MAPE, where the Inception-v3 surpassed ours in the NPG. The two-sample t test and Mann-Whitney U test indicated no significant difference between the suggested method and the gold standard in group-level comparison. The Wilcoxon signed-rank test revealed significant differences between our new approach and the gold standard in personal-level comparison. All points in Bland-Altman plots fell between the upper and lower limits of agreement. The inter-ICCs of ultrasonographers, our proposed algorithm, and its opponents were graded good reliability, good or moderate reliability, and moderate or poor reliability, respectively. Our proposed approach surpasses the competition and is as reliable as manual measurement.

Nuchal Translucency and Congenital Heart Defects.

Nuchal translucency comprises a temporary accumulation of fluid in the subcutaneous tissue on the back of a fetus's neck, which accompanies the crown-rump length and is observed through an ultrasound performed between 11 and 13 weeks + 6 days gestation. Nuchal translucency is considered to be above normal when values are higher than the 95th/99th percentile or equal to or higher than 2.5/3.5 mm. The first connection between increased nuchal translucency and the presence of congenital heart defects is described in the study of Hyett et al., who observed that they are directly proportional. Since that time, several studies have been conducted to understand if nuchal translucency measurements can be used for congenital heart defect screening in euploid fetuses. However, there is great variability in the estimated nuchal translucency cutoff values for congenital heart defect detection. The purpose of this review was to understand how increased nuchal translucency values and congenital heart defects are related and to identify which of these defects are more frequently associated with an increase in these values.

Diagnostic yield of copy number variation sequencing in fetuses with increased nuchal translucency: a retrospective study.

OBJECTIVE: To assess the efficacy of copy number variation sequencing (CNV-seq) and karyotyping for prenatal detection of chromosomal abnormalities in fetuses with increased nuchal translucency. METHODS: Amniotic fluid samples were extracted from 205 fetuses with increased nuchal translucency (NT ≥ 2.5 mm), diagnosed by ultrasound between gestational ages of 11 and 13 + 6 weeks. Karyotyping and CNV-seq were performed for detecting chromosomal abnormalities. RESULTS: There are 40 fetuses (19.51%) showing increased NT detected with chromosomal abnormalities in karyotyping, and trisomy 21 was found to be the most common abnormalities. There are 50 fetuses (24.39%) identified with chromosomal abnormalities by CNV-seq. The detection of the applied techniques indicated that CNV-seq revealed higher chromosomal aberrations. The risk of chromosomal abnormalities was significantly increased with NT thickening, from 13.64% in the NT group of 2.5-3.4 mm, 38.64% in the NT group of 3.5-4.4 mm, and to 51.72% in the NT group of over 4.5 mm (P < 0.05). The investigated cases with increased NT with presence of soft markers in ultrasound or high risk in non-invasive prenatal testing presented chromosomal abnormalities in higher rates, comparing with those with isolated NT or low risk (P < 0.05). CONCLUSION: The results indicated that the risk of chromosomal abnormalities was associated with the NT thickness, detected by karyotype or CNV-seq. The combination application of two analysis was efficient to reveal the possible genetic defects in prenatal diagnosis. The finding suggested that the detection should be considered with ultrasonographic soft markers, and the NT thickness of 2.5-3.4 mm could be a critical value for detecting chromosomal abnormalities to prevent the occurrence of missed diagnosis.

Identification of Fetuses at Increased Risk of Trisomies in the First Trimester Using Axial Planes.

INTRODUCTION: The measurement of nuchal translucency (NT) is crucial for assessing risk of aneuploidies in the first trimester. We investigate the ability of NT assessed by a transverse view of the fetal head to detect fetuses at increased risk of common aneuploidies at 11-13 weeks of gestation. METHODS: We enrolled a nonconsecutive series of women who attended our outpatient clinic from January 2020 to April 2021 for aneuploidy screening by means of a first trimester combined test. All women were examined by operators certified by the Fetal Medicine Foundation. In each patient, NT measurements were obtained both from the median sagittal view and transverse view. We calculated the risk of aneuploidy using NT measurements obtained both with sagittal and axial scans, and then we compared the results. RESULTS: A total of 1,023 women were enrolled. An excellent correlation was found between sagittal and transverse NT measurements. The sensitivity and specificity of the axial scan to identify fetuses that were deemed at risk of trisomy 21 using standard sagittal scans were 40/40 = 100.0% (95% confidence interval [CI]: 91.2-100.0) and 977/983 = 99.4% (95% CI: 98.7-99.7), respectively. The sensitivity and specificity of the axial scan to identify fetuses at risk of trisomy 13 or 18 were 16/16 = 100.0% (95% CI: 80.6-100.0) and 1,005/1,007 = 99.8% (95% CI: 99.3-99.9). CONCLUSIONS: When the sonogram, a part of combined test screening, is performed by an expert sonologist, axial views can reliably identify fetuses at increased risk of trisomies without an increase in false negative results.

Decoding 22q11.2: prenatal profiling and first-trimester risk assessment in Danish nationwide cohort.

OBJECTIVES: To examine the distribution of nuchal translucency thickness (NT), free ß-human chorionic gonadotropin (ß-hCG) and pregnancy-associated plasma protein-A (PAPP-A) in pregnancies with a fetal 22q11.2 aberration. Furthermore, the performance of combined first-trimester screening (cFTS) and a new risk algorithm targeting 22q11.2 deletions in detecting affected pregnancies was evaluated. Finally, prenatal malformations and pregnancy outcome were assessed. METHODS: This was a nationwide registry-based cohort study of all pregnancies that underwent prenatal screening with a due date between January 2008 and December 2018 in Denmark. All cases with a fetal 22q11.2 deletion or duplication (hg19 chr22:18.9mio-25.0mio) diagnosed pre- or postnatally or following pregnancy loss or termination of pregnancy were retrieved from the Danish Cytogenetic Central Register and linked with pregnancy data from the Danish Fetal Medicine Database. Fetal and maternal characteristics, including cFTS results and pregnancy outcome, of pregnancies with any 22q11.2 deletion or duplication (LCR22-A to -H) and pregnancies with a classic deletion or duplication (LCR22-A to -D) diagnosed by chromosomal microarray were compared with those of a chromosomally normal reference group. A risk algorithm was developed for assessing patient-specific risks for classic 22q11.2 deletions based on NT, PAPP-A and ß-hCG. Detection rates and false-positive rates at different risk cut-offs were calculated. RESULTS: We included data on 143 pregnancies with a fetal 22q11.2 aberration, of which 97 were deletions (54 classic) and 46 were duplications (32 classic). NT was significantly increased in fetuses with a classic deletion (mean, 1.89 mm), those with any deletion (mean, 1.78 mm) and those with any duplication (mean, 1.86 mm) compared to the reference group (mean, 1.65 mm). ß-hCG multiples of the median (MoM) was decreased in all 22q11.2 subgroups compared with the reference group (mean, 1.02) and reached significance in pregnancies with a classic deletion and those with any deletion (mean, 0.77 and 0.71, respectively). PAPP-A MoM was significantly decreased in pregnancies with a classic duplication and those with any duplication (mean, 0.57 and 0.63, respectively), and was significantly increased in pregnancies with a classic deletion and those with any deletion (mean, 1.34 and 1.16, respectively), compared to reference pregnancies (mean, 1.01). The screen-positive rate by cFTS was significantly increased in pregnancies with a classic deletion (13.7%), any deletion (12.5%), a classic duplication (46.9%) or any duplication (37.8%) compared to the reference group (4.5%). A risk algorithm targeting classic 22q11.2 deletions more than doubled the prenatal detection rate of classic 22q11.2 deletions, but with a substantial increase in the false-positive rate. Structural malformations were detected in 41%, 35%, 17% and 25% of the pregnancies with a classic deletion, any deletion, classic duplication or any duplication, respectively. Pregnancy loss occurred in 40% of pregnancies with a classic deletion and 5% of those with a classic duplication diagnosed prenatally or following pregnancy loss. CONCLUSIONS: The distribution of cFTS markers in pregnancies with a classic 22q11.2 duplication resembles that of the common trisomies, with decreased levels of PAPP-A. However, classic 22q11.2 deletions are associated with increased levels of PAPP-A, which likely limits early prenatal detection using the current cFTS risk algorithm. The scope for improving early detection of classic 22q11.2 deletions using targeted risk algorithms based on NT, PAPP-A and ß-hCG is limited. This demonstrates the capability, but also the limitations, of cFTS markers in detecting atypical chromosomal anomalies, which is important knowledge when designing new prenatal screening programs. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Analysis of factors affecting ultrasound examination time: A quantitative study.

BACKGROUND: Numerous studies have focused on reducing patient absences and effectively scheduling exams. However, very few studies have analyzed the factors influencing examination time and predicted examination time. OBJECTIVES: To investigate the factors affecting ultrasound examination visit length and provide a reference for interventions to optimize ultrasound appointments. METHODS: This cross-sectional study was conducted at a fertility clinic in China. Ultrasound examination time and clinical characteristics were obtained from the electronic records. Univariate and multivariate analyses used 33,432 patients who attended our clinic center between August 1 and October 30, 2018. A quantile regression model was constructed to examine associations between ultrasound examination time and statistically significant variables in the univariate analysis. RESULTS: Of the 33,432 patients included in this study, 29,085 (87%) were female and 4,347 (13%) were male. Their mean examination time was 6 ± 3 minutes. The doctor's title and gender, equipment, and patient's age, examination site, gender, and origin were all statistically significant. Physical examination and outpatient clinic patients had shorter examination times than inpatients. Female physicians had longer examination times than male physicians. Examination time was positively correlated with thyroid, breast, liver, gallbladder, spleen, pancreas, kidney, heart, vascular, adrenal, gynecological, early pregnancy, nuchal translucency, prostate, scrotum, and mid-to-late pregnancy fetal sites. Moreover, NT and mid-to-late pregnancy fetal sites showed a clear and continuous positive trend with increasing examination time. CONCLUSION: The length of the ultrasound examination was correlated with the examination site, physician title, physician gender, patient age, patient gender, patient origin, and instrumentation. The reliability of inspection time predicted by variables such as the physicians' title, sex, sites examined, and the number of sites examined was higher when they were longer.

Early Diagnosis of 46,XX Testicular Difference of Sexual Development: Unusual Presentation with Increased Nuchal Translucency.

INTRODUCTION: 46,XX testicular disorder of sexual development (DSD) may present prenatally as a mismatch between phenotype and karyotype. Enlarged nuchal translucency is an abnormal sign of many disorders. We present a first trimester fetus with increased nuchal translucency that was later determined to be a 46,XX testicular DSD. CASE PRESENTATION: A first-trimester pregnancy ultrasound revealed enlarged nuchal translucency. Chorionic villous sampling documented a 46,XX karyotype. Subsequent ultrasounds identified male external genitalia. FISH analysis documented a SRY gene translocation. At birth, the infant had normal male internal and external genitalia. CONCLUSIONS: 46,XX testicular DSD may present in the first trimester with an enlarged nuchal translucency.

Current controversies in prenatal diagnosis: Noninvasive prenatal testing should replace other screening strategies for fetal trisomies 13, 18, 21.

This is a written summary of the oral debate presented at the International Society for Prenatal Diagnosis annual conference in Edinburgh in 2023. The topic under debate is whether noninvasive prenatal testing (NIPT) using cell-free fetal DNA should replace other screening strategies for the detection of fetal trisomies 13, 18, 21. There is no disagreement that NIPT is far more sensitive and has better positive predictive values for identifying trisomies 13, 18, and 21 than traditional screening approaches using biochemical markers and measurement of nuchal translucency. The major issue lies in the potential adverse consequences associated with abandoning traditional screening methods. The source of disagreement stems primarily from whether you consider the role of ultrasound in the context of screening to be strictly for nuchal translucency measurement or whether it should be combined with a fetal anatomy scan. The debate featured two experts who presented evidence in favor of each argument.

A new contingent screening strategy increased detection rate of trisomy 21 in the first trimester.

BACKGROUND: Although the traditional contingent screening strategy is effective, there are still undetected low-risk trisomy 21. This study aims to define appropriate cut-off values of serum biochemical markers at low-risk and develop a strategy for sequential prenatal testing associated with first-trimester screening to increase the detection rate of trisomy 21. METHODS: This was a 9-year retrospective analysis of singleton pregnant women who underwent serum biochemical screening or combined first-trimester screening (CFTS) in the first trimester. For the low-risk group, the cut-off values of the serum biochemical markers were adjusted to determine the appropriate detection efficiency. Gravidas with abnormal serum biochemical markers at low-risk were advised to undergo further non-invasive prenatal screening (NIPS), whereas others continued with routine prenatal care. RESULTS: When cut-off values of free beta subunit of human chorionic gonadotropin (free ß-hCG) multiples of the median (MoM) or pregnancy-associated plasma protein A (PAPP-A) MoM were defined with ≥ 2.75 or ≤ 0.5, 7.72% (2,194/28,405) in the serum biochemical screening group and 12.36% (4,005/32,403) in CFTS group could be detected as abnormal results for further NIPS. Finally, 55.56% (5/9) and 85.71% (6/7) of trisomy 21 cases with false-negative results were detected, and the overall detection rate for trisomy 21 was improved by 10.64% (5/47) and 12.77% (6/47), respectively. CONCLUSIONS: The new contingent screening strategy can increase the detection rate of trisomy 21 compared with the traditional contingent screening strategy.

Risk factors for delayed termination of pregnancy following increased nuchal translucency.

OBJECTIVES: Termination of pregnancy after increased nuchal translucency (NT) is a common occurrence. This study aimed to identify characteristics of a cohort with a NT ≥3.0 mm who underwent a pregnancy termination ≥15 weeks compared with those who terminated <15 weeks. METHODS: All NT ≥3.0 mm identified within our department over an 11-year period (2010-2021) (n = 689) were retrospectively examined and characteristics of the cohort of increased NTs ending in termination were further categorized. RESULTS: There were 221 (32.1%) individuals with an increased NT (≥3 mm) who underwent a termination of pregnancy within our study period (2010-2021). Pregnancy termination occurred at a gestational age <15 weeks in 162 (73.3%) and ≥15 weeks in 59 individuals. Pregnant individuals without positive NIPT for aneuploidy were at a higher risk for a ≥15-week termination (p = 0.004). In 29% (17/59) of late terminations, there were additional imaging findings after the NT scan (ultrasound, echocardiogram, magnetic resonance imaging) that ultimately triggered the decision to pursue termination. CONCLUSIONS: As the options for workup of an increased NT expand, potential delays in decision-making surrounding termination increase. This study identifies multiple reasons for delayed termination and proposes several approaches to care aimed at maximizing diagnostic information by imaging and diagnostic testing in an expedited manner.

Prenatal diagnosis of autosomal recessive Noonan syndrome associated with biallelic LZTR1 variants presented with thick nuchal translucency and cardiac abnormalities.

Noonan syndrome (NS) is a common clinical variable disease characterized by a number of features, mainly including congenital heart defects, short stature, and a variable degree of developmental delay. This disorder is transmitted mostly in an autosomal dominant manner and is genetically heterogeneous. We report three prenatal cases of LZTR1-related recessive NS. One case had a recurrent cystic hygroma at 13 weeks gestation and the pregnancy was terminated. Two cases had an increased nuchal translucency at 12 weeks' gestation, but a normal second trimester ultrasound; both presented with hypertrophic cardiomyopathy in the third trimester. The two infants were diagnosed with NS after birth. All of the three cases had invasive genetic investigations during pregnancy, and trio exome sequencing revealed biallelic likely pathogenic or pathogenic LZTR1 variants in the fetuses. All parents were LZTR1 variant carriers. Our report further strengthens the association of LZTR1 with an autosomal recessive form of NS. The affected fetuses are more likely to have cardiac anomalies. Clarification of molecular diagnosis has important implications in these families because they carry a 25% recurrence risk.

[First trimester ultrasound: beyond nuchal translucency]. / Examen échographique du premier trimestre : au-delà de la clarté nucale.

Pregnancy care has gradually evolved over the last two decades, with a trend towards earlier detection and diagnosis of both maternal and fetal pathologies. At the core of this process, antenatal ultrasound allows to identify a large number of congenital malformations as early as the end of the first trimester. It has also become an increasingly specialized procedure, requiring considerable material and human resources. In this article, we review the basic principles of first-trimester ultrasound, focusing on most recent screening recommendations.

La prise en charge des grossesses a progressivement changé au cours des deux dernières décennies, avec une tendance à dépister et diagnostiquer de plus en plus précocement ls pathologies tant maternelles que fœtales. L'échographie prénatale, au centre du processus de soins, permet d'identifier un grand nombre de malformations congénitales dès la fin du premier trimestre. Au cours du temps, elle est également devenue un examen toujours plus spécialisé nécessitant des ressources matérielles et humaines importantes. Dans cet article, nous revenons sur les principes de base de l'échographie du premier trimestre en intégrant les nouvelles recommandations en matière de dépistage.

Intertwin nuchal translucency difference predicts the chance of co-twin death after fetal reduction in dichorionic triplet pregnancies: a retrospective analysis study.

OBJECTIVES: To compare the clinical outcomes of different multifetal pregnancy reduction (MFPR) programs in dichorionic (DC) triplets, and explore the association between early ultrasound characteristics and co-twin death after potassium chloride (KCl) injection into one monochorionic (MC) twin. METHODS: We retrospectively reviewed the data of DC triplets who underwent MFPR at our center during 2012-2021. Patients were grouped as follows: intracardiac KCl injection into one MC twin (group A), intracardiac KCl injection into both MC twins simultaneously (group B), and reduction of the singleton fetus (group C) and pregnancy outcomes were compared. Logistic regression was used to determine whether ultrasound measurements at 11-13+6 weeks predicted co-twin death and the receiver operator characteristic (ROC) analysis was conducted to assess the predictive performance. RESULTS: Finally, we enrolled 184 patients. 153 cases were in group A, and 18, 13 cases were in group B and C respectively. Gestational age at the time of MFPR did not differ among the 3 groups (median: [Formula: see text] weeks). The survival rate was 89.6%, 88.9%, and 92.3% in group A, B, and C respectively, which was comparable among groups. Preterm birth was more common in group C (10/12, 83.3%). After KCl injection into one MC twin, co-twin death occurred in 86.3% cases (132/153) within 1 day; however, 3 patients had 2 live births each, with normal postnatal development. Intertwin nuchal translucency (NT) difference/discordance significantly predicted co-twin death within 1 day after MFPR, and the areas under the ROC curve were 0.694 and 0.689, respectively. CONCLUSIONS: For MFPR in DC triplet pregnancies, reduction of the MC twins results in less preterm birth, and women with KCl injection into either one or both MC twins had similar outcomes. Large intertwin NT difference/discordance was associated with co-twin death within 1 day after KCl injection into one of the MC twins.

Prenatal diagnosis of 15q11.2 microdeletion fetuses in Eastern China: 21 case series and literature review.

OBJECTIVE: 15q11.2 microdeletion can lead to syndromes affecting the nervous system. However, 15q11.2 microdeletion has large phenotypic differences and incomplete penetrance, which brings challenges to prenatal diagnosis. We reported 21 cases of 15q11.2 microdeletion fetuses in Eastern China and reviewed literature on the prenatal clinical characteristics related to the deletion variants to provide a basis for prenatal genetic counseling. METHODS: The clinical data of 21 cases of 15q11.2 microdeletion fetuses collected from June 2018 to September 2021 were retrospectively analyzed, and chromosomal microarray analysis was performed. The reported prenatal clinical features of 15q11.2 microdeletion fetuses were reviewed and summarized. A meta-analysis of 20 studies was performed to test heterogeneity, data integration, and sensitivity on the correlation between 15q11.2 microdeletion and neuropsychiatric diseases. RESULTS: The median age of the women was 29.5 years. The median gestational age at interventional examination was 24 weeks. All fetuses showed deletion variants of the 15q11.2 fragment, and the median deletion range was approximately 0.48 MB. Ultrasound of five cases showed no abnormalities; however, four of them showed a high risk of Down's syndrome (risk values were 1/184, 1/128, 1/47, and 1/54, respectively). The remaining 16 fetuses showed congenital heart disease (7/16), elevated nuchal translucency (5/16), abnormal brain structure (2/16) and renal disease (2/16). In a literature review of 82 prenatal cases, 44% (36/82) had abnormal ultrasound features, 31% (11/36) showed abnormal nuchal translucency, approximately 28% (10/36) showed abnormal cardiac structure, and 14% (5/36) had brain structural abnormalities. The meta-analysis revealed that the frequency of the 15q11.2 microdeletion mutation in patients with schizophrenia and epilepsy was significantly higher (odds ratio 2.04, 95% confidence interval: 1.78-2.33, p < 0.00001; odds ratio 5.23, 95% confidence interval: 2.83-9.67, p < 0.00001) than that in normal individuals. CONCLUSION: More than half of the 15q11.2 microdeletion cases presented no abnormalities in prenatal ultrasound examination. The cases with ultrasound features mainly showed isolated malformations such as elevated nuchal translucency, congenital heart disease, and brain structural abnormalities. Postpartum 15q11.2 microdeletion patients are at an increased risk of suffering from schizophrenia, epilepsy, and other neurological and mental diseases from 15q11.2 microdeletion. Therefore, prenatal diagnosis of 15q11.2 microdeletion not only depends on molecular diagnostic techniques but also requires cautious genetic counseling.