Pre-eclampsia in the first pregnancy and subsequent risk of stillbirth in black and white gravidas.

OBJECTIVE

To examine the association between prior pre-eclampsia and subsequent stillbirth in black women and white women.

STUDY DESIGN

This is a population-based retrospective study of Missouri maternally linked birth cohort files from 1989 to 2005. We analyzed singleton first and second births to mothers in the state of Missouri. The study population comprised women who experienced pre-eclampsia in their first pregnancy and a comparison group consisting of women who did not. The two groups were followed to their second pregnancy to document stillbirth occurrence. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between prior pre-eclampsia and subsequent stillbirth were obtained from logistic regression models.

RESULTS

Women who experienced prior pre-eclampsia had a 43% increased risk of subsequent stillbirth [OR=1.43; 95% CI=1.08-1.89]. Whereas women with a history of late-onset pre-eclampsia had no elevated risk for subsequent stillbirth, those whose first pregnancy resulted in early-onset pre-eclampsia had a more than 4-fold increased risk of stillbirth in their second pregnancy [OR=4.07; 95% CI=2.32-7.14]. When sub-analysis was performed on the two main racial groups in the State, we found that elevated risk for subsequent stillbirth in a second pregnancy was observed among black women with prior early-onset pre-eclampsia (OR=8.21; 95% CI=4.03-16.70) but not in whites (OR=1.95; 95% CI=0.72-5.26).

CONCLUSION

Initiation of pregnancy with pre-eclampsia elevates the risk for subsequent stillbirth. The risk elevation is most pronounced in black women with early-onset pre-eclampsia in their first pregnancy. This information is valuable for inter-pregnancy counseling of affected women.