Utility of fetal facial markers on a second trimester genetic sonogram in screening for Down syndrome in a high-risk Thai population

Background To establish the reference ranges and evaluate the efficacy of the fetal facial sonomarkers prenasal thickness (PT), nasal bone length (NBL), PT/NBL ratio and NBL/PT ratio for Down syndrome screening in the second trimester of high-risk pregnancies using two-dimensional (2D) ultrasound. Methods A prospective study was done in Thai pregnant women at high risk for structural and chromosomal abnormalities between May 2018 and May 2019. The main exclusion criteria were any fetal anatomical anomaly detected on ultrasonography or postpartum examination, abnormal chromosome or syndrome other than Down syndrome. Ultrasounds were performed in 375 pregnant women at 14 to 22 weeks’ gestation and the fetal facial parameters were analyzed. Down syndrome results were confirmed by karyotyping. The reference ranges of these facial ultrasound markers were constructed based on the data of our population. The Down syndrome screening performance using these facial ultrasound markers was evaluated. Results In total, 340 euploid fetuses and 11 fetuses with Down syndrome met the inclusion criteria. The PT, NBL, and PT/NBL ratios in the euploid fetuses gradually increased with gestation progression while the NBL/PT ratio gradually decreased between 14–22 weeks’ gestation. The NBL, PT/NBL ratio, and NBL/PT ratio all had 100% sensitivity and PT had 91% sensitivity. These facial markers had 100% negative predictive value for Down syndrome screening in the second trimester. The Bland–Altman analysis showed the intra- and inter-observer variations of PT and NBL had high intraclass correlation coefficients (ICC) in both operators, with ICCs of 0.98 and 0.99 and inter-observer ICCs of 0.99 for both operators. Conclusion The facial ultrasound markers are very useful for second trimester Down syndrome screening in our population. These facial ultrasound markers were easily identifiable and highly consistent either intra- or inter-operator by using widely-available 2D ultrasound. However, the reference ranges for these markers need to be constructed based on individual populations. Trial registration Registration number: REC 61–029-12–3. Date of registration: 18 May 2018.

Does women’s place of birth affect their opportunity for an informed choice about Down syndrome screening? A population-based study in France

Background To examine disparities by maternal place of birth in the opportunity to make an informed choice about Down syndrome screening, in France, where the national guidelines recommend that physicians offer it to all pregnant women. Methods We used population-based data from the nationally representative French Perinatal Surveys in 2010 and 2016 (N=24,644 women) to analyze the opportunity for an informed choice for prenatal screening, measured by a composite indicator. Results Among the 24 644 women in the study, 20 612 (83.6%) were born in France, 861 (3.5%) elsewhere in Europe, 1550 (6.3%) in North Africa, and 960 (3.9%) in sub-Saharan Africa. The probability of screening was lower for women born outside France. After adjustment for survey year, maternal age, parity, education level, and the maternity unit’s level of perinatal care, women born outside France had the opportunity to make an informed choice less often than women born in France. This association remained essentially the same even after excluding women without adequate prenatal care. Conclusions Women born outside France, including those with adequate prenatal care, had less opportunity than women born in France to make an informed choice about prenatal screening for Down syndrome.

Testing Times: The Social Life of Non-invasive Prenatal Testing

Non-invasive prenatal testing (NIPT) is a genomic technology used to predict the chance of a foetus having a genetic condition. Despite the immediacy of this technology’s integration into clinical practice, there is a dearth of evidence outlining how both patients and professionals experience NIPT on the ground. In this article, we draw upon our collective empirical research—specifically on earlier screening technologies (BKR), Down syndrome screening (GT), genetic screening/testing (JL) and NIPT (HS)—to outline the most pressing and often controversial issues which, we argue, remain unresolved and vital to consider regarding NIPT. We begin with a brief introduction to NIPT as a prenatal technology and the bodies of literature which unpack its ‘social life’. In what follows, BKR discusses NIPT within the context of her research on ‘the tentative pregnancy’ and diagnostic testing in the USA. In the following sections, GT, HS and JL identify different, but related, concerns with respect to NIPT, particularly around routinisation, commercialisation, choice, abortion, and configurations of disability and ‘normalcy’.

Does women’s place of birth affect their opportunity for an informed choice about Down syndrome screening? A population-based study in France.

Background To examine disparities in the opportunity to make an informed choice about Down syndrome screening by maternal place of birth, in France, where the French national authority for health (HAS) recommends that physicians offer it to all. We used population-based data from the nationally representative French Perinatal Surveys in 2010 and 2016 (N=24,644 women) to analyze the opportunity for an informed choice for prenatal screening, measured by a composite indicator. Results Among the 24 644 women in the study, 20 612 (83.6%) were born in France, 861 (3.5%) elsewhere in Europe, 1550 (6.3%) in North Africa, and 960 (3.9%) in Sub-Saharan Africa. The probability of screening was lower for women born outside France. After adjustment for survey year, maternal age, parity, education level, and level of perinatal care of the maternity, women born outside France had less often the opportunity to make an informed choice as compared with women born in France. This association remained essentially the same even after excluding women without adequate prenatal care. Conclusions Women born outside France, including those with adequate prenatal care, had less opportunity than women born in France to make an informed choice about prenatal screening for Down syndrome.