Evaluation of a definition of pre-eclampsia

Objectives To determine: 1. whether an alternative definition of gestational hypertension and preeclampsia stratifies women according to their risk of maternal and fetal complications; 2. whether pregnancy outcome in women with gestational hypertension differs in the presence or absence of '+' proteinuria; and 3. whether a blood pressure rise of greater than or equal to 30/15 mmHg during pregnancy is associated with adverse outcome in women who remain normotensive. Design Prospective, nested case-control study. Setting Community based. Population Healthy, nulliparous women (n = 1496). Methods Women recruited into a study investigating serum markers predictive of pre-eclampsia were classified as having gestational hypertension (systolic blood pressure greater than or equal to 140 mmHg with a rise of greater than or equal to 30 mmHg and/or diastolic blood pressure greater than or equal to 90 mmHg with a rise of greater than or equal to 15 mmHg) or pre-eclampsia (gestational hypertension plus proteinuria greater than or equal to 2+on dipstick or > 0.3 g/24 h). Maternal and fetal complications in gestational hypertension or pre-eclampsia were compared with a control group of 223 randomly selected normotensive women. The main outcome measures were severe maternal disease, preterm birth and small for gestational age infant. Results A stepwise increase in adverse maternal and fetal outcomes occurred in gestational hypertension (n = 117, 7.8%) and pre-eclampsia (n = 71, 4.8%). Severe maternal disease developed in 26.5% (21.4% severe hypertension alone, 5.1% multisystem disease) of women with gestational hypertension and 63.4% (21.1% severe hypertension alone, 42.3% multisystem disease) of women with preeclampsia (OR 4.8; 95% CI 2.4-9.5). Preterm birth and small for gestational age infants were more frequent in gestational hypertension (OR 1.7; 95% CI 0.5-5.4, and OR 2.0; 95% CI 1.0-3.7, respectively) and pre-eclampsia (OR 14.6; 95% CI 5.8-37.8, and OR 2.6; 95% CI 1.2-5.3) than in the normotensive group. Among women with gestational hypertension severe maternal disease was more common in women with '+' proteinuria (41.7%) than in those with no proteinuria (15.9%): OR 3.8; 95% CI 1.5-9.8. Pregnancies were uncomplicated in the 27% of normotensive women who had a rise of 2 30 mmHg systolic blood pressure and/or 2 15 mmHg rise in diastolic blood pressure. Conclusions In the nulliparous population studied our definition of gestational hypertension and preeclampsia identified women at increasing risk of maternal and fetal complications. In gestational hypertension, the presence of proteinuria '+' was associated with a 3.8-fold increase in severe maternal disease. Normotensive women who have a rise in blood pressure greater than or equal to 30/15 mmHg had uncomplicated pregnancies.