Chronic hypertension and risk of placental abruption: is the association modified by ischemic placental disease?

Objective The purpose of this study was to evaluate whether the increased risk of placental abruption among women with chronic hypertension is modified by ischemic placental disease, specifically pregnancy-induced hypertension (PIH) and fetal growth restriction (FGR). Study Design We used the US linked natality and fetal death data files (1995-2002) and restricted the analysis to women who had a singleton birth at ≥22 weeks of gestation and to fetuses who weighed ≥500 g (n = 30,189,949). Fetal growth was defined both on a continuum (