612 A resolved placenta previa is still associated with postpartum hemorrhage

Placenta previa and low-lying placentas are associated with pregnancy-related hemorrhage. However, most cases resolve prior to delivery. Our objective was determine whether resolution of a placenta or postpartum hemorrhage (PPH). This is retrospective matched-control cohort study women who underwent transvaginal sonography during fetal anatomic survey at the University Pennsylvania from 1/2017-5/2019. Exposure defined as (?1cm cervical os) followed by on third trimester ultrasound. For each exposure, we identified control >1cm internal os performed same day. Exclusion criteria were: multiple gestation, malpresentation delivery, bleeding disorder, anticoagulation therapy, accreta, persistent previa. The primary outcome PPH estimated blood loss >1000 mL. 447 were included (225/group). Of exposed, 85.0% had resolved placenta, while 15.0% previa; these grouped for analysis. rate significantly higher versus controls (9.8% vs. 4.4%, p=0.03; Table). Women 2.5 times more likely experience than (aOR 2.58, 95%CI 1.17-5.69), even when controlling parity, cesarean, delivery mode. also present triage (16.4% 8.0%, p=0.006), receive antenatal corticosteroids, (9.3% 3.1%, p=0.006) require intravenous iron (7.6% p=0.04). data demonstrate that remain increased risk bleeding-related complications in pregnancy compared those never Clinicians should consider this association counseling performing stratification.