Risk of selected structural abnormalities in infants after increased nuchal translucency measurement

We sought to examine the association between increased first-trimester fetal nuchal translucency (NT) measurement and major noncardiac structural birth defects in euploid infants.

Included were 75,899 singleton infants without aneuploidy or critical congenital heart defects born in California in 2009 through 2010 with NT measured between 11-14 weeks of gestation. Logistic binomial regression was employed to estimate relative risks (RRs) and 95% confidence intervals (CIs) for occurrence of birth defects in infants with an increased NT measurement (by percentile at crown-rump length [CRL] and by ≥3.5 mm compared to those with measurements <90th percentile for CRL).

When considered by CRL adjusted percentile and by measurement ≥3.5 mm, infants with a NT ≥95th percentile were at risk of having ≥1 major structural birth defects (any defect, RR, 1.6; 95% CI, 1.3-1.9; multiple defects, RR, 2.1; 95% CI, 1.3-3.4). Infants with a NT measurement ≥95th percentile were at particularly high risk for pulmonary, gastrointestinal, genitourinary, and musculoskeletal anomalies (RR, 1.6-2.7; 95% CI, 1.1-5.4).

Our findings demonstrate that risks of major pulmonary, gastrointestinal, genitourinary, and musculoskeletal structural birth defects exist for NT measurements ≥95th percentile. The ≥3-fold risks were observed for congenital hydrocephalus; agenesis, hypoplasia, and dysplasia of the lung; atresia and stenosis of the small intestine; osteodystrophies; and diaphragm anomalies.