Pre-eclampsia in the second pregnancy: does previous outcome matter?

To assess the effect of initial pregnancy outcome and gestational age on the risk of pre-eclampsia in the second pregnancy.

We conducted an observational study using routinely collected data from the Aberdeen Maternity and Neonatal Databank between 1986 and 2006. Cases were women who developed pre-eclampsia in their second pregnancy and controls were normotensive in their second pregnancy. Crude and adjusted odds ratios were produced for each of the risk factors using logistic regression.

Inter-pregnancy intervals of 6 years or more were associated with increased incidence of pre-eclampsia (19.4% vs. 14.7%). A change of partner had a protective effect while an increase in BMI increased the risk of pre-eclampsia. A history of pre-eclampsia was associated with 5 times higher risk {adjusted O.R. 5.12 (95% C.I. 4.42-6.48)} of pre-eclampsia in the second pregnancy. Compared to a term delivery, a previous second trimester pregnancy loss was associated with a 4 times higher risk {adjusted O.R. 4.22 (95% C.I. 2.54-7.03)} of pre-eclampsia in the next pregnancy. Previous very preterm and preterm births were associated with adjusted odds ratios of 2.32 (95% C.I. 1.62-3.32) and 1.62 (95% C.I. 1.46-1.72) respectively. The risk of pre-eclampsia was no higher in women with a previous history of fetal death after 20 weeks than those with a previous live birth, after adjusting for pre-eclampsia in the first pregnancy.

Only initial deliveries beyond 37 weeks, irrespective of outcome, were protective against pre-eclampsia in the second pregnancy.