Preterm and term pre-eclampsia: relative burdens of maternal and perinatal complications.

To determine the relative burdens of maternal and perinatal complications, for preterm and term pre-eclampsia. Prospective observational cohort study. Two English maternity units. Unselected women with singleton pregnancies who developed pre-eclampsia (International Society for the Study of Hypertension in Pregnancy definition). Outcomes were ascertained by health record review and compared between pregnancies with preterm (vs. term) pre-eclampsia. Severe maternal hypertension, maternal mortality or major maternal morbidity, perinatal mortality or major neonatal morbidity, neonatal unit (NNU) admission ≥48 hours, and birthweight <3 percentile. Among 40,241 singleton pregnancies, 298 (0.7% [95% confidence interval 0.66-0.83]) and 1194 (3.0% [2.8-3.1]) developed preterm and term pre-eclampsia, respectively. Women with preterm (vs term) pre-eclampsia more commonly experienced adverse maternal or perinatal events (severe hypertension: 18.5% [14.5-23.3] vs 13.6% [11.7-15.6]; maternal mortality/major morbidity: 7.4% [4.9-10.9] vs 2.2% [1.5-3.2]; perinatal mortality/major neonatal morbidity: 29.5% [24.6-34.9] vs 2.2% [1.5-3.2]; and birthweight <3 percentile: 54.4% [48.7-59.9] vs 14.2% [12.4-16.3]). However, in absolute terms, most maternal complications occurred in women with term pre-eclampsia, as did a large proportion of perinatal complications: severe hypertension (74.7% [68.5-80.0]); maternal mortality/major morbidity (54.2% [40.3-67.4]), perinatal mortality/major neonatal morbidity (22.8% [16.1-31.3]); NNU admission ≥48 hours (38.1% [32.4-44.1]); and birthweight <3 percentile (51.2% [45.8-56.5]). While adverse event risks are greater with preterm (vs term) pre-eclampsia, term disease is associated with at least equivalent total numbers of maternal, and a significant proportion of perinatal, adverse events. Increased efforts should be made to decrease the incidence of term pre-eclampsia. [Abstract copyright: This article is protected by copyright. All rights reserved.]