Outcome of DOAC Exposure During Pregnancy (…and the Problem of Event Reporting…)

On Monday, Jan Beyer-Westendorf of Dresden University Hospital in Dresden, Germany, presented results evaluating pregnancy outcomes after direct oral anticoagulant (DOAC) exposure using data from various sources. Exposure of pregnant women to vitamin K antagonists (VKAs) carries a high risk for embryopathy, but for DOACs, the embryopathy risk is still unknown. By looking into cases of DOAC pregnancy exposure via literature search, from questionnaires sent to German gynecologists, obstetricians, and hematologists and from pharmacovigilance databases with the DOAC manufacturers, the German drug authority (BfArM), and the European Medicines Agencies (EMA), Beyer-Westendorf was able to provide some analysis and direction.

A total of 588 cases of DOAC exposure in pregnancy could be identified, with the limitation being the lack of details and insufficient follow-up data in the datasets provided by DOAC manufacturers and authorities. Information on pregnancy outcome was available in a little more than half of those cases and consisted of 172 live births (55.0%), 69 miscarriages (22.0%), and 72 elective pregnancy interruptions (23.0%). In one case, the pregnancy was still ongoing. In 273 cases, no outcome data were available. Nineteen abnormalities were reported (6.1%), of which 12 could potentially be related to DOAC exposure, which would translate into an overall embryopathy risk of 3.8%. Within the 172 live births, abnormalities occurred in 12 cases, and 9 were rated as potential embryotoxicity (5.2%).

Beyer-Westendorf said the data suggest that the risk for DOAC embryopathy is lower than that reported for VKA exposure. Despite increasing case numbers, however, pregnancy outcomes are insufficiently reported and significant data gaps remain. Pregnancy has to be consequently avoided in DOAC patients, but available data do not justify pregnancy termination based on DOAC exposure alone. Instead, nondirective counselling, close pregnancy surveillance, and outcome reporting to pharmacovigilance is recommended.