Racial disparity in fetal aneuploidy risk in an ultrasound screening population: A result of selection bias?

Abstract

POPULATION: A RESULT OF SELECTION BIAS? DAVID STAMILIO, ANTHONY ODIBO, HARISH SEHDEV, LINDA DUNN, GEORGE MACONES, University of Pennsylvania, Obstetrics and Gynecology, Philadelphia, Pennsylvania, Pennsylvania Hospital, Maternal Fetal Medicine, Philadelphia, Pennsylvania, Chestnut Hill Hospital, Obstetrics and Gynecology, Philadelphia, Pennsylvania OBJECTIVE: There is evidence for racial differences in the incidence of fetal aneuploidy, utilization of prenatal genetic tests, and predictive value of screening markers. Our aim is to compare the risk of fetal aneuploidy across maternal race & to explore potential causes of disparity. STUDY DESIGN: Between 2002 & 2005 we performed a multicenter prospective cohort study of 2900 pregnant patients of variable risk level referred for a fetal ultrasound that included standard aneuploidy markers. A standardized ultrasound was performed between 15 & 22 gestational weeks. Using bivariate and multivariable statistical methods we compared fetal aneuploidy rates across maternal race. We used logistic regression to explore for confounding and sources of racial differences in aneuploidy rates. RESULTS: Patients of African origin were younger, 47% less likely to have an aneuploidy risk factor, underwent a screening ultrasound later in gestation and more commonly received care at the community versus university hospitals than other races. After controlling for multiple confounders, patients of African origin had a fetal aneuploidy rate 80% less than other races.