Delivery Outcomes in Pregnant Women With Third-Trimester Vaginal Bleeding [ID: 1376165

Abstract

INTRODUCTION: We sought to determine delivery-related morbidity outcomes in patients presenting with third-trimester vaginal bleeding in the absence of placenta previa or placenta accreta spectrum (PAS). METHODS: A retrospective cohort study was conducted among women presenting with third-trimester vaginal bleeding at our tertiary center from July 2020 to June 2022 with exclusion of placenta previa or PAS. Bleeding was categorized by amount documented on provider examination as follows: “light,” less than 50 mL; “heavy,” 50 mL or more. The primary outcome was postpartum hemorrhage (PPH; ≥1,000 mL). Secondary outcomes included relevant maternal and neonatal morbidity measures. RESULTS: Among 6,584 singleton pregnancies, 76 (1.2%) presented with third-trimester vaginal bleeding without evidence of placenta previa or PAS; 68 of patients had light and 8 had heavy bleeding. Bleeding was frequently accompanied by contractions (62%) and cervical change (74%). Bleeding on admission was not associated with increased risk of PPH (light: relative risk [RR] 0.7, 95% CI [0.3, 1.4], P=.14; heavy: RR 1.7, 95% CI [0.5, 5.5], P=.2) or need for blood transfusion. Cesarean delivery (CD), general anesthesia, preterm birth (PTB), and neonatal intensive care unit admissions were more common in patients with heavy bleeding (all P<.05). Light bleeding did not increase the risk of PTB or CD and was associated with a higher rate of spontaneous vaginal delivery (RR 1.24, 95% CI [1.1, 1.4], P=.0003). No patients with bleeding required intensive care unit admission, hysterectomy, or had neonatal demise. Seventy-five percent of patients with heavy bleeding (n=8) and 16% of patients with light bleeding (n=11) had clinical or pathological evidence of abruption. CONCLUSION: Third-trimester vaginal bleeding, without placenta previa or PAS, is not associated with increased risk for PPH. Heavy bleeding, however, is associated with increased risk of preterm delivery and cesarean section, with abruption evident in 75% of these patients. Light bleeding on admission is usually not associated with an abruption or an increase in adverse maternal or neonatal outcomes.