Placenta accreta and vaginal bleeding according to gestational age at delivery

To evaluate the incidence of vaginal bleeding in women with placenta accreta according to gestational age at delivery.

This is a retrospective cohort study of women with prior cesarean delivery and persistent placenta previa delivered at our institution between December 1997 and December 2011. Diagnosis of invasion was based on hysterectomy performed for an abnormally adherent placenta with histologic confirmation. Suspicion for invasion was based on the impression of the attending physician at the time of ultrasonography. Records were reviewed to identify indication for delivery and estimated blood loss. Statistical analyses were performed using Student's t test, χ2 test, and Mantel-Haenszel and Jonckheere-Terpstra tests for trend.

Of 216 women with prior cesarean delivery and persistent previa, 65 (30%) required cesarean hysterectomy and had histologic confirmation of invasion. Urgent delivery for bleeding was performed in 20% of these pregnancies (13/65). Delivery for bleeding decreased significantly with advancing gestation (P=.001). In our series, 71% with accreta were delivered at 36 weeks of gestation or greater with delivery for bleeding in five (11%), and estimated blood loss was not increased in these pregnancies. Of 79 women with ultrasonographic suspicion for accreta, the incidence of vaginal bleeding prompting urgent delivery also decreased with advancing gestation (P<.001).

Likelihood of vaginal bleeding necessitating delivery declined with advancing gestation in pregnancies with placenta accreta as did blood loss. Most were delivered at 36 weeks of gestation or greater, nearly 90% in the absence of bleeding complications. Thus, although preterm delivery is an important consideration when placenta accreta is suspected, our findings support individualizing delivery planning.