USE OF DIRECT ORAL ANTICOAGULANTS (DOACs) IN PREGNANCY

Direct oral anticoagulants (DOACs) include Factor Xa inhibitors (apixaban, rivaroxaban, edoxaban) and the direct thrombin inhibitor (dabigatran). These drugs act on specific components of the coagulation cascade, resulting in reduced thrombin generation and inhibition of fibrin clot formation. They are widely used for stroke prevention in atrial fibrillation, and the treatment and prevention of venous thromboembolism.

Published data relating to DOAC exposure in pregnancy are highly limited (~400 exposed pregnancies) and derive primarily from a large case series, a disproportionality analysis of adverse event reporting, and two additional case reports. The majority of data relate to short -term exposure to rivaroxaban in early pregnancy (>300 exposures). 

The limited available information does not raise concern that rivaroxaban is a major structural teratogen, but data are too limited to exclude an increased risk. Data relating to miscarriage, preterm birth and small for gestational age are highly limited but do not provide compelling evidence of increased risks. There are no data relating to risks of stillbirth or adverse neurodevelopmental outcomes. Data for apixaban, dabigatran and edoxaban are extremely limited, and it is not currently possible to characterise pregnancy risks for these agents individually. 

The European Society of Cardiology guidelines recommend that women taking DOACs receive pre‑pregnancy counselling. Where possible, DOACs should be discontinued and replaced with low-molecular-weight heparin (LMWH) either prior to conception or as soon as pregnancy is recognised. 

DOACs cross the placenta, presenting a theoretical risk of fetal and neonatal anticoagulation and bleeding complications. Women receiving anticoagulant therapy in late pregnancy are at increased risk of bleeding complications during labour and delivery. 

Exposure to DOACs at any stage of pregnancy would not usually be regarded as medical grounds for termination of pregnancy. No additional fetal monitoring is required solely due to DOAC exposure. However, given the paucity of pregnancy safety data, women should be strongly encouraged to attend their routine anomaly scan (at 18-22 weeks of pregnancy). As maternal cardiovascular pathology independently increases adverse pregnancy outcome risks, individualised risk assessment is essential when counselling and managing pregnant women requiring anticoagulant therapy.