Is a Decreased Rate of Postpartum Oxytocin Associated with Increased Postpartum Bleeding Episodes After the Initial Recovery Period?

Purpose: Patients on magnesium for seizure prophylaxis receive lower rate of postpartum oxytocin infusion to maintain a maximum IV fluid rate of 125cc/hr. We explore if this reduced rate is linked to increased incidence of postpartum bleeding within 24 hours after delivery. Methods: This IRB-approved retrospective study examines 2020 deliveries at a single institution, focusing on singletons with severe pre-eclampsia requiring 24 hours postpartum magnesium. We identified 71 eligible patients and matched 1:2 with controls based on delivery year, age, parity, and delivery method. Data analysis involved relative risk and Chi-Square calculations with p less than 0.05 considered significant. The primary outcome was episodes of post-partum bleeding defined as any episode of bleeding secondary to atony regardless of quantitative blood loss. Secondary outcomes included postpartum hemorrhage and uterine atony at time of delivery. Results: Gestational age, birth weight, age, parity, delivery method, gestational hypertension, and gestational diabetes between the two groups were similar. Chronic hypertension (21% vs 1% P<0.01) and BMI (38 vs 32 P<0.05) were higher in the magnesium cohort. The primary outcome suggested a trend toward increased incidence of postpartum bleeding, not statistically significant (RR=3, (CI:-0.94 to 2.97) p=0.3). Secondary outcomes revealed significantly higher atony rates at delivery (RR 14, (CI:1.5 to 5.5) p<0.05) and an increase in postpartum hemorrhage, not statistically significant (RR 1.6, (CI:-1.24 to 2.68) p=0.09). Conclusion: This study does not show a significant increase in episodes of post-partum bleeding in the first 24 hours with decreased rate of post-partum oxytocin in patients receiving magnesium. Further research is warranted to confirm these findings with better matched cohorts and larger sample size so that a standardized protocol may be instituted across all hospitals to appropriately target bleeding secondary to atony in high risk populations.