(811) Does risk of postpartum hemorrhage increase in twin pregnancies with birthweights greater than 4000g?

Twin pregnancy carries a unique increased risk of postpartum hemorrhage (PPH) when compared to singleton gestations. Increased fetal weight in twin pregnancy may exacerbate uterine distension and result in increased risk of PPH secondary to uterine atony. In singletons, macrosomia is defined as a birthweight of 4000 grams (g) and is associated with risk of PPH. While prior studies have concluded PPH increases linearly with increasing birthweight in twins, our aim was to examine whether patients with a sum birthweight >4000g were at increased odds of PPH when compared to those with a sum birthweight < 4000g.

Study Design:

Retrospective review of patients who delivered dichorionic-diamniotic twins at a single academic institution from 2013-2021. The primary outcome was PPH, defined as quantitative blood loss ≥ 1000mL in either vaginal or cesarean delivery. Secondary outcomes included PPH due to atony and use of uterotonic medications. Outcomes were assessed using univariable and multivariable logistic regression.

Results:

Among 431 twin gestations, 94 (21.8%) had a sum of birthweights  ≤ 4000g and 337 (78.2%) had a sum of birthweights > 4000g. PPH occurred in 24.8% of individuals overall. There was no significant difference in odds of PPH in the ≤4000g group compared to the >4000g group (20.2% vs. 26.1%, p=0.24). There also was no significant difference in PPH due to atony or use of uterotonics between the two groups. After adjusting for age, insurance type, BMI, IVF, multiparity, history of cesarean delivery or uterine surgery, fibroids, and placenta accreta spectrum, there was insufficient evidence to conclude an association between PPH and the allotted birthweight categories (p=0.11).  

Conclusion:

In this retrospective study, risk of PPH does not appear to increase in patients with combined birthweights of greater than 4000g when compared to those ≤ 4000g.