Gestation related karyotype, QF-PCR and CGH-array failure rates in diagnostic amniocentesis

The decline of amniocentesis and the increase of chorionic villus sampling in modern perinatal medicine

Objective The aims of this study were to determine the rate of change by type of diagnosis by transabdominal chorionic villus sampling (TA-CVS) vs. amniocentesis for aneuploidy and to describe a successful and intensive international training program for TA-CVS in ongoing pregnancies. Methods We conducted a retrospective cohort study of all deliveries from 2010 to 2018 in Sardinia. All invasive diagnostic procedures are conducted at a single regional perinatal referral center. Descriptive statistics were used to compare data across groups, and inter-correlations between variables were investigated by Pearson's correlation coefficient. We subsequently describe the international trainee experiences in TA-CVS over a 35-year period. Results A total of 101,025 deliveries occurred over 9 years. The number of deliveries (13,413-9143, P < 0.0001) and total invasive diagnostic procedures (1506-858 per year, P = 0.019) declined over this period. The percentage of deliveries undergoing invasive diagnostic procedures remained steady (mean: 12.2%). In 2010, TA-CVS made up 32.3% of all invasive diagnostic procedures, while amniocentesis made up 67.7%. By 2018, TA-CVS made up 61.3% of the invasive diagnostic procedures, and amniocentesis, only 38.7%. The rate of TA-CVS increased over 9 years, while the rate of amniocentesis declined. A total of 236 trainees from 39 different countries and 5 different continents rotated through this site. The average length of stay was 2.4 weeks. Conclusion We demonstrate an increasing prevalence of TA-CVS vs. amniocentesis in the current era of prenatal testing and underscore the importance of continuing to train specialists skilled in TA-CVS. Our global operative experience is feasible and sustainable and will have a lasting impact on physicians conducting invasive fetal procedures.

Risk factors for failed chorionic villus sampling: results of a 4-year retrospective study

Objectives: Chorionic villus sampling (CVS) allows for earlier results for aneuploidy or genomic abnormalities compared to amniocentesis. Nevertheless, the inability to provide complete results has been described as being more frequent with CVS. This study was conducted in order to identify risk factors for such failures.Study design: A retrospective single-center study was performed from January 2014 to December 2018. Participants were divided into two groups depending on whether complete CVS results were issued ("successful CVS group") or not ("failed CVS group"). Failure affected preliminary short-term cultures, long-term cultures, or both.Results: During the study period, 214 CVS were performed, 73 (34%) of which were classified in the failed CVS group. We observed significant intergroup differences between the successful and failed CVS groups for four variables: BMI (respectively 23.9 [±5.88] and 25.9 [±6.13] kg/m²), term at sampling (12.9 [±1.35] and 12.6 [±1.09] weeks gestation), trophoblastic location (posterior in 49 [40%] and 37 [66%] cases), and sampling approach (transcervical in 54 [43%] and 36 [64%] cases) (p < .05). In a stepwise binary logistic regression analysis, higher BMI, posterior trophoblastic location, and transcervical sampling approach were the only variables negatively influencing CVS success, with respective aOR [95% CI] of 0.947 [0.898; 0.996], 0.322 [0.160; 0.634], and 0.466 [0.238; 0.900].Conclusions: In the presence of CVS failure risk factors, a discussion could be initiated regarding a deferred amniocentesis as a first option.

Analysis of prenatal diagnosis before and after implementation of the two-child policy in northeastern China

The universal two-child policy has now been fully implemented in China. This change requires adaptations to maternal care and childcare systems, but the features of prenatal diagnosis before and after implementation of the policy have not been reported.We conducted a retrospective study of 6736 prenatal cytogenetic diagnoses performed on amniotic fluid cells over a 4-year period, including 2 years before and after implementation of the second child policy. Amniotic fluid cells collected through amniocentesis were cultured, harvested, and stained for chromosome analysis using standard laboratory protocols.The study included 3222 pregnant women referred before implementation of the policy, which we used as a control group, and 3514 pregnant women referred after policy implementation as an investigational study group. There were significantly fewer pregnant women aged <25 years in the investigational group than in the control group (P < .001). There were no significant between-group differences for other pregnant women aged >31 years and 27-28 years old (P > .05). A total of 358 cases with chromosomal abnormalities were diagnosed, including 129 (4%, 129/3222) in the control group which was significantly lower than the 229 (6.5%, 229/3514) in the study group (P < .001). In particular, significantly more trisomy 21 cases were observed in the study group than in the control group (120 vs 59). More pregnant women underwent non-invasive prenatal testing (NIPT) in the study group (46%) than in the control group (20%). In the study group, the average age of pregnant women who underwent NIPT was significantly higher than that of women who did not receive NIPT (P < .05). However, there were no significant between-group differences for the control group (P > .05).The number of cases with chromosomal abnormalities increased in northeastern China in the 2 years after implementation of the two-child policy. The number of pregnant women of advanced maternal age did not increase significantly, perhaps because of the widespread application of NIPT. However, the number of fetuses with Down syndrome increased significantly, suggesting that prenatal screening and diagnosis should be strengthened.

Quantitative analysis of fetal facial morphology using 3D ultrasound and statistical shape modeling: a feasibility study

BACKGROUND

The antenatal detection of facial dysmorphism using 3-dimensional ultrasound may raise the suspicion of an underlying genetic condition but infrequently leads to a definitive antenatal diagnosis. Despite advances in array and noninvasive prenatal testing, not all genetic conditions can be ascertained from such testing.

OBJECTIVES

The aim of this study was to investigate the feasibility of quantitative assessment of fetal face features using prenatal 3-dimensional ultrasound volumes and statistical shape modeling. STUDY DESIGN: Thirteen normal and 7 abnormal stored 3-dimensional ultrasound fetal face volumes were analyzed, at a median gestation of 29⁺⁴ weeks (25⁺⁰ to 36⁺¹). The 20 3-dimensional surface meshes generated were aligned and served as input for a statistical shape model, which computed the mean 3-dimensional face shape and 3-dimensional shape variations using principal component analysis.

RESULTS

Ten shape modes explained more than 90% of the total shape variability in the population. While the first mode accounted for overall size differences, the second highlighted shape feature changes from an overall proportionate toward a more asymmetric face shape with a wide prominent forehead and an undersized, posteriorly positioned chin. Analysis of the Mahalanobis distance in principal component analysis shape space suggested differences between normal and abnormal fetuses (median and interquartile range distance values, 7.31 ± 5.54 for the normal group vs 13.27 ± 9.82 for the abnormal group) (P = .056).

CONCLUSION

This feasibility study demonstrates that objective characterization and quantification of fetal facial morphology is possible from 3-dimensional ultrasound. This technique has the potential to assist in utero diagnosis, particularly of rare conditions in which facial dysmorphology is a feature.