Influence of Body Mass Index on Fetal Fraction Increase With Gestation and Cell-Free DNA Test Failure.

Abstract

OBJECTIVE: To assess the influence of body mass index (BMI) on fetal fraction increase with gestational age and on the rates of test failure. METHODS: We performed a cross-sectional study of consecutive singleton pregnancies in which cell-free DNA screening for fetal aneuploidies was performed from 10 weeks of gestation, between May 2013 and January 2018, at two fetal medicine clinics in Australia using one of two different platforms. Maternal characteristics, fetal fraction, and failure after a first attempt ("no-call") and after resampling ("test failure") were recorded. Body mass index was classified as normal (BMI less than 25.0), overweight (BMI 25.0-29.9), obesity class I (BMI 30.0-34...