Is race a determinant of stillbirth recurrence?

BACKGROUND

A history of stillbirth may result in an increased risk for recurrence, although information regarding this remains scanty. It is also uncertain whether race is a determinant of stillbirth recurrence given that the risk of stillbirth varies across racial and ethnic populations.

METHODS

The Missouri maternally linked cohort data set containing births from 1978 through 1997 was used. We identified the study group (women who experienced a stillbirth in the first pregnancy) and a comparison group (women who delivered a live birth in their first pregnancy) and compared the outcome (stillbirth) in the second pregnancy between the 2 groups.

RESULTS

We analyzed 404,180 women with information on first and second pregnancies (1,979 [0.5%] in the study arm, and 402,201 [99.5%] in the comparison arm). Of the 1,929 cases of stillbirths in the second pregnancy, 45 cases occurred in mothers with a history of stillbirth (stillbirth rate = 22.7/1000) and 1,884 in the comparison group (stillbirth rate 4.7/1,000, P < .001). The adjusted risk of stillbirth was almost 5-fold as high in women with a prior stillbirth (odds ratio 4.7, 95% confidence interval 3.3-6.6). Analysis across racial groups revealed that whites had lower absolute risk for stillbirth recurrence than African Americans (19.1/1,000 compared with 35.9/1,000, P < .05). The elevated stillbirth recurrence risk was confirmed after adjusting for potential confounders (odds ratio 2.6, 95% confidence interval 1.2-5.7).

CONCLUSION

History of stillbirth is associated with a 5-fold increase for subsequent stillbirth. The recurrence of stillbirth is almost tripled in African Americans as compared with whites.

LEVEL OF EVIDENCE

II-2.