Bloody amniotic fluid during labor – Prevalence, and association with placental abruption, neonatal morbidity, and adverse pregnancy outcomes

Objective: To study the association between bloody amniotic fluid (BAF) during labor and adverse pregnancy outcomes. Study design: In the last 10 years we have implemented an institutional protocol that mandates obstetricians/midwives to report their subjective impression of the color of amniotic fluid (clear, meconium stained, bloody) during labor. The medical records, and neonatal charts of all singleton deliveries ≥ 37 ^0/7 weeks between 2008–2018 were reviewed. The cohort was divided into two groups: clear AF (Clear group) and BAF (BAF group). Cases with meconium stained AF were excluded. The primary outcome was a composite of the following complications: umbilical Ph ≤ 7.1, seizures, hypoxic-ischemic encephalopathy, intra-ventricular hemorrhage, periventricular leukomalacia, hypoglycemia, hypothermia, mechanical ventilation, meconium aspiration syndrome, RDS, NEC, phototherapy, sepsis, or transfusion. Results: Overall, 21,300 deliveries were reviewed, 20,983 (98.5%) in the Clear group and 317 (1.5%) in the BAF group. The rate of the primary outcome did not differ between the BAF (2.2%) and the Clear (2.1%) groups. The rate of placental abruption (both clinically and hystopathologically) did not differ between the groups (3.2% vs. 1.9% and 1.6% vs. 0.6%, respectively). BAF was associated with higher rates of labor induction (p = 0.002), assisted vaginal deliveries (p = 0.04), cesarean deliveries (p = 0.03), and lower birth weights (p = 0.03). Conclusion: BAF observed in labor was not associated with composite adverse neonatal outcome, nor with placental abruption. BAF was associated with higher rates of labor induction, assisted vaginal deliveries, cesarean deliveries, and lower birth weights. These findings may assist obstetricians and neonatologists in the interpretation of BAF observed in labor.