PB0474 - Should anticoagulation be administered in all pregnant women with hereditary antithrombin deficiency?

Background: Hereditary antithrombin deficiency (HAD) is a rare thrombophilia with a prevalence between 0.02% to 0.2% in the general population. Pregnant women with HAD experience a high risk for developing venous thromboembolism (VTE) and adverse pregnancy outcomes. Heparin is recommended for thromboprophylaxis during pregnancy and the puerperium in asymptomatic carriers of HAD with family history of thrombosis and in those with prior history of thrombosis.

Aims: We sought to evaluate if the administration of heparin had an effect on pregnancy outcomes maternal and infant complications.

Methods: Retrospective evaluation of electronic medical records of pregnant women with HAD referred to the hematology clinic at an academic medical center between January 2006 and December 2022. Age, race, personal and family history of thrombosis was recorded. Participants were divided into two groups based on the use or not of heparin during pregnancy and/or puerperium. Pregnancy, maternal and infant complications were recorded for both groups.

Results: Demographics are shown in table 1. Most women had type 1 HAD. A total of 45 pregnancies among 17 women with HAD were analyzed. 36 pregnancies (80%) resulted in live births, and 8 pregnancies (18%) in miscarriages, one pregnancy had missing data and was excluded from the analysis. Of the 36 successful pregnancies, 20 and 16 were managed with or without heparin, respectively. There was no significant association between anticoagulant usage and maternal complications (p=0.48). Likewise, there was no significant association between anticoagulant usage and infant complications (p=0.40)

Conclusion(s): Women with HAD require careful monitoring during pregnancy and puerperium. Despite anticoagulation complications occurred. Larger studies are required to determine the optimal treatment for pregnant patients with HAD.