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.