Researchers from the Beth Israel Deaconess Medical Center in Boston, MA conducted a study on the link between postpartum hemorrhage (PPH) and women with mild factor XI (FXI) deficiency. The results were included in a research poster abstract presented on December 9, 2019 during the 61st American Society of Hematology Annual Meeting in Orlando, Florida.

Since direct-to-consumer genetic testing companies now often screen for FXI mutations, more people are learning that they have a mild from of the disease. While many of these individuals have never exhibited symptoms, they may still be vulnerable for excessive bleeding related to surgery. The investigators from Beth Israel looked at a particularly at-risk group, postpartum women with mild FXI deficiency, including those who have undergone a cesarean delivery.

Investigators initiated a retrospective analysis that included two groups, a control group that included 200 women who had undergone deliveries between 2016 and 2018, and a second group which included 40 women with mild FXI deficiency.

The FXI deficiency group included 71 deliveries, of which 45 were vaginal and 26 were cesarean. The control group encompassed 200 deliveries, of which 125 were vaginal and 75 were cesarean. PPH was defined as estimated blood loss of at least 1000 milliliters (mL) or reported symptoms of hypovolemia (a decreased volume of circulating blood in the body) related to blood loss within 24 hours post-delivery.

In both groups, median estimated blood loss for vaginal deliveries was 300 mL and median estimated blood loss for cesarean deliveries was 800 mL. Among patients undergoing vaginal delivery, PPH occurred after no deliveries in the FXI deficiency group and after one delivery in the control group. In contrast, women with mild FXI deficiency undergoing cesarean delivery were approximately 2-fold more likely to develop PPH when compared to the control group. The overall rates of PPH among those FXI women who underwent cesarean delivery was 38.4% (10 of 26 deliveries) compared with 18.7% (14 of 75 deliveries).

Investigators ultimately found that a prior history of hemorrhage was the best predictor of PPH following cesarean delivery. In fact, most of the women (7 out of 10) who developed PPH following caesarean had a prior history of bleeding. Notably, only two of the women with PPH received some type of prophylactic care prior to delivery. Among the women 16 caesarean deliveries in the FXI group without PPH, significantly fewer had a history of bleeding.

“In this case control study, we did not observe any cases of PPH among women with FXI deficiency who underwent a vaginal delivery but noted a greater than 2-fold increase in PPH among those women who underwent a cesarean delivery,” concluded the study authors. “In those women with a bleeding history, the risk of PPH following cesarean section was nearly 10-fold higher compared to women without a history of hemorrhage supporting the role for prophylactic measures in this high-risk group.”

Source: Hematology Advisor, December 10, 2019