Enhanced Peripartum Hemostatic Management Does Not Decrease Postpartum Hemorrhage Incidence in Hemophilia Carriers: the Pregnancy and Inherited Bleeding Disorders study

Background Pregnant hemophilia carriers receive prophylactic factor [F]VIII or FIX concentrate based on third trimester FVIII/FIX activity to reduce the risk of severe postpartum hemorrhage (PPH, ≥ 1000 mL). Due to persistently high severe PPH rates, Dutch guidelines were revised in 2018. Consensus was reached to increase the third trimester threshold for prophylaxis from < 50 to < 80 IU/dL and peak target levels during childbirth from ≥ 100 to ≥ 150 IU/dL. Objectives To assess the severe PPH incidence after guideline revision. Methods Pregnant hemophilia carriers were prospectively enrolled (2018-2024) in Dutch hemophilia treatment centers to assess the severe PPH incidence after implementation of the revised guideline. FVIII/FIX activity and hematologic and obstetric outcomes were recorded and compared with a historical cohort (2012-2017). Statistics included descriptives and logistic regression to correct for confounders. Results Severe PPH occurred in 12.4% of 170 deliveries. No thrombosis was recorded. Prophylaxis in the subgroup with third trimester levels of < 80 IU/dL led to similar PPH rates to those with spontaneous rises of > 80 IU/dL. Compared with the historic cohort with the third trimester cutoff of < 50 IU/dL, the severe PPH incidence did not decrease ( n = 170 vs n = 197; odds ratio, 1.16; 95% CI, 0.46-2.93), neither in the third trimester of the 50- to 80-IU/dL subgroup ( n = 28/170 vs n = 21/197; odds ratio, 1.0; 95% CI, 0.20-2.90). Conclusion Increasing the third trimester cutoff to < 80 IU/dL and aiming for ≥ 150 IU/dL at delivery did not decrease the risk for severe PPH in hemophilia carriers. More research is needed on optimal clotting factor levels during delivery to prevent severe PPH.