Effect of placenta previa on fetal growth.

Abstract

To estimate the association between placenta previa and abnormal fetal growth. Retrospective cohort study of consecutive women undergoing ultrasound between 15 and 22 weeks. Groups were defined by the presence or absence of complete or partial placenta previa. The primary outcome was intrauterine growth restriction (IUGR), defined as a birthweight <10th percentile by the Alexander growth standard. Univariable, stratified, and multivariable analyses were used to estimate the effect of placenta previa on fetal growth restriction. Of 59,149 women, 724 (1.2%) were diagnosed with a complete or partial previa. After adjusting for significant confounding factors (black race, gestational diabetes, preeclampsia, and single umbilical artery), the risk of intrauterine growth restriction remained similar (adjusted odds ratio, 1.1; 95% confidence interval, 0.9-1.5). The presence of bleeding did not impact the risk of growth restriction. Placenta previa is not associated with fetal growth restriction. Serial growth ultrasounds are not indicated in patients with placenta previa.