Impact of new definitions of preeclampsia at term on identification of adverse maternal and perinatal outcomes

Any definition of preeclampsia should identify women and babies at greatest risk of adverse outcomes. This study aimed to investigate the ability of the American College of Obstetricians and Gynecologists and International Society for the Study of Hypertension in Pregnancy definitions of preeclampsia at term gestational age (≥37 0/7 weeks) to identify adverse maternal and perinatal outcomes. In this prospective cohort study at 2 maternity hospitals in England, women attending a routine hospital visit at 35 0/7 to 36 6/7 weeks’ gestation underwent assessment that included history; ultrasonographic estimated fetal weight; Doppler measurements of the pulsatility index in the uterine, umbilical, and fetal middle cerebral arteries; and serum placental growth factor–to–soluble fms-like tyrosine kinase-1 ratio. Obstetrical records were examined for all women with chronic hypertension and those who developed new-onset hypertension, with preeclampsia (de novo or superimposed on chronic hypertension) defined in 5 ways: traditional, based on new-onset proteinuria; American College of Obstetricians and Gynecologists 2013 definition; International Society for the Study of Hypertension in Pregnancy maternal factors definition; International Society for the Study of Hypertension in Pregnancy maternal factors plus fetal death or fetal growth restriction definition, defined according to the 35 0/7 to 36 6/7 weeks’ gestation scan as either estimated fetal weight 95th percentile, umbilical artery pulsatility index >95th percentile, or middle cerebral artery pulsatility index