Maternal Outcomes in Women with Bleeding Disorders According to Mode of Delivery: A Single-Center Retrospective Cohort Study
Authors: Niu Bonnie T. , Duffett Lisa D. , El-Chaâr Darine , Tinmouth Alan T. , Wang Tzu-Fei , Khalife Roy 
Published: November 2021

Abstract

Introduction:
Pregnant women with bleeding disorders (WBD) are at higher risk of postpartum hemorrhage (PPH) compared to women without bleeding disorders. Multidisciplinary care is essential to minimize bleeding and optimize maternal outcomes in pregnant WBD. The safest mode of delivery for pregnant WBD remains debated with variable clinical practices and guideline recommendations. Studies are needed to inform decision-making for pregnant WBD and their multidisciplinary team.
Objectives:
To describe the maternal and neonatal outcomes in pregnant WBD by mode of delivery, including spontaneous vaginal delivery (SVD), induction of labor (IOL), planned C-section (CS) and emergent CS.
Methods:
We performed a retrospective analysis of all pregnant WBD who delivered at our institution between 2010-2020. The comprehensive hemostasis program offered at our institution has been providing multi-disciplinary care for patients with bleeding disorders since 1985 and coordinates care for 5-10 pregnant WBD a year. Patient/disease characteristics, mode of delivery, peripartum hemostatic management, and maternal outcomes were collected. PPH was defined according to the American College of Obstetrics and Gynecology (ACOG) (doi:10.1097/AOG.0000000000002351). Primary PPH was defined as blood loss of ≥ 1000 mL or blood loss with signs and symptoms of hypovolemia within 24h delivery regardless of route of delivery, or blood loss of &gt; 500 mL in a vaginal delivery. Secondary PPH was defined as any abnormal or excessive vaginal bleeding beyond 24h of delivery to 12 weeks postpartum as documented by healthcare professionals' clinical notes. Data is presented using descriptive statistics. Fisher's Exact test was used to measure association between the mode of delivery and PPH.
Results:
A total of 73 pregnancies in 50 WBD were included. The incidence of primary PPH and secondary PPH were 6.8% (5/73, 95% CI [2.5, 14.5]) and 19.0% (12/63, 95% CI [10.8, 30.1]), respectively (Table 1). According to mode of delivery, primary PPH occurred in 1/34 for SVD, 3/21 for IOL, 0/11 for planned CS and 1/7 for emergent CS, and secondary PPH occurred in 6/31 for SVD, 5/19 for IOL, 0/6 for planned CS and 1/7 for emergent CS (Table 1). When comparing combined vaginal deliveries to CS, we found a numerically higher rate of both primary PPH (4/55, 7.2% vs. 1/18, 5.6%, p = 1.0) and secondary PPH (11/50, 22.0% vs. 1/13, 7.7%, p = 0.431), but both were not statistically significant (Table 1).
Discussion:
Our cohort of pregnant WBD showed rates of primary PPH (6.8%) comparable to those in a 2014 study of all Canadian deliveries (6.2%) (doi:10.1016/S1701-2163(15)30680-0). This likely reflected efforts for multidisciplinary and coordinated care for WBD within a hemophilia treatment centre with readily available clinical and laboratory monitoring as well as universal access to hemostatic therapies for Canadian WBD. In our cohort, planned CS did not result in any PPH which may reflect the ability to ensure clinical and laboratory expertise in hemostasis available (like recommendations for perioperative care in hemophilia) as opposed to spontaneous or unplanned deliveries that may occur outside of regular operating hours. Rates of secondary PPH remained high and problematic especially following vaginal deliveries. Several factors may explain these delayed bleeding events such as wound healing defects inherent to some bleeding disorders and decline in factor levels back to baseline in the early postpartum period.
Our study was limited by its retrospective and single-centred design, small sample size, missing secondary PPH data in 10 pregnancies, and potential confounding variables that were unaccounted for by the study. Nevertheless, we reported incidence rates of primary and secondary PPH according to the mode of delivery in women with bleeding disorders, which can be important to inform clinical practices.
Conclusion:
Women with bleeding disorders are at high risk of PPH. Although we did not find statistically significance correlation by mode of delivery, these findings are clinically relevant in supporting patient-centered care and shared decision-making between WBD, obstetricians and hematologists. Close monitoring and follow-up are of utmost importance and further larger prospective research focused on postpartum outcomes is much needed.
Figure 1 Figure 1.

Disclosures
Wang: Servier: Membership on an entity's Board of Directors or advisory committees; Leo Pharma: Research Funding. Khalife: Canadian Hemophilia Society: Research Funding; Pfizer Canada: Honoraria, Research Funding.