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

Abstract

Objective: To determine the relative burdens of maternal and perinatal complications for preterm and term pre-eclampsia. Design: Prospective observational cohort study. Setting: Two English maternity units. Population: Unselected women with singleton pregnancies who developed pre-eclampsia (International Society for the Study of Hypertension in Pregnancy definition). Methods: Outcomes were ascertained by health record review and compared between pregnancies with preterm (versus term) pre-eclampsia. Main outcome measures: Severe maternal hypertension, maternal mortality or major maternal morbidity, perinatal mortality or major neonatal morbidity, neonatal unit (NNU) admission ≥48 hours, and birthweight <3rd percentile. Results: Among 40 241 singleton pregnancies, 298 (0.7%, 95% confidence interval [CI] 0.66–0.83) and 1194 (3.0%, 95% CI 2.8–3.1) developed preterm and term pre-eclampsia, respectively. Women with preterm (versus term) pre-eclampsia more commonly experienced adverse maternal or perinatal events: severe hypertension 18.5% (95% CI 14.5–23.3) versus 13.6% (95% CI 11.7–15.6); maternal mortality/major morbidity 7.4% (95% CI 4.9–10.9) versus 2.2% (95% CI 1.5–3.2); perinatal mortality/major neonatal morbidity 29.5% (95% CI 24.6–34.9) versus 2.2% (95% CI 1.5–3.2); and birthweight <3rd percentile 54.4% (95% CI 48.7–59.9) versus 14.2% (95% CI 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% (95% CI 68.5–80.0); maternal mortality/major morbidity 54.2% (95% CI 40.3–67.4); perinatal mortality/major neonatal morbidity 22.8% (95% CI 16.1–31.3); NNU admission ≥48 hours 38.1% (95% CI 32.4–44.1); and birthweight <3rd percentile 51.2% (95% CI 45.8–56.5). Conclusions: Although adverse event risks are greater with preterm (versus 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.