Association between maternal serum alpha-fetoprotein and adverse outcomes in pregnancies with placenta previa

Objective: To determine whether increased maternal serum alpha-fetoprotein (MSAFP) level at 15-20 weeks' gestation is a marker of adverse outcomes in women with placenta previa at delivery. Methods: We conducted a retrospective cohort study of singleton pregnancies complicated by placenta previa, diagnosed sonographically, and confirmed a t delivery. All women had MSAFP screening at 15-20 weeks' gestation and del ivered nonanomalous live-born infants at or after 24 weeks' gestation. Results: One hundred seven women with placenta previa delivered during the study. Fourteen (13%, 95% CI 7%, 21%) had MSAFP at least 2.0 multiples of t he median (MoM). They were significantly more likely than those with lower MSAFP levels to have one or more of the following outcomes: hospitalization for antepartum bleeding before 30 weeks' gestation (50% versus 15%), deliv ery before 30 weeks' gestation (29% versus 5%), or preterm delivery for pre gnancy-associated hypertension before 34 weeks' gestation (14% versus none) . The MSAFP cutoff of 2.0 MoM provided the best combination of sensitivity and specificity for those outcomes, using receiver operating characteristic curves. Conclusion: Women with placenta previa who also have high MSAFP levels are at increased risk of bleeding in the early third trimester and preterm birt h. We did not find women who required cesarean hysterectomy, including thos e with placenta accreta, to consistently have elevated MSAFP. (Obstet Gynec ol 2001;97:35-8. (C) 2001 by The American College of Obstetricians and Gyne cologists.)