Abnormal bleeding associated with preeclampsia: a population study of 315,085 pregnancies

To study the association of preeclampsia with abnormal bleeding in the first trimester and after delivery.

Register-based population study. Setting. The Medical Birth Registry of Norway. Population. A total of 315,085 women in Norway with singleton deliveries after 21 weeks of gestation (1999-2004).

We compared frequencies of vaginal bleeding in the first trimester between women who subsequently developed preeclampsia and women without preeclampsia development, and made similar comparisons for postpartum bleeding.

Proportion of women with bleeding.

In the first trimester, vaginal bleeding occurred in 1.6% (215/13,166) of subsequent preeclampsia cases, compared to 2.0% (6,112/301,919) of normotensives (p<0.01). After delivery, excess postpartum bleeding (>1,500 mL) occurred in 3.0% (399/13,166) of preeclampsia cases and in 1.4% (4,223/301,919) of normotensives (p<0.01). Moderate bleeding postpartum (>500 mL) was also more common in preeclampsia cases (22.9% versus 13.9%, p<0.01). Similar patterns were present in first time mothers and in women with more than one birth, and the patterns did not vary according to type of delivery (cesarean section or not).

These results suggest that factors associated with preeclampsia are inversely related to vaginal bleeding early in pregnancy, but positively associated with excess bleeding after delivery.