Phenprocoumon therapy during pregnancy: case report and comparison of the teratogenic risk of different coumarin derivatives.

The case report is about an infant suffering from coumarin embryopathy and coumarin syndrome after its mother underwent phenprocoumon treatment (Marcumar, Falithrom) during pregnancy (until 26th week of gestation). Interestingly, a hearing disorder was diagnosed, which had never been described in context with this substance. The coumarin derivatives warfarin, acenocoumarol and phenoprocoumon were compared with regards to spontaneous abortion rate, perinatal mortality and teratogenic risk. Eye anomalies or malformations seem to appear only under warfarin treatment, whereas CNS-malformations are more frequent under phenprocoumon. As a consequence, phenprocoumon treatment of fertile women seems rather doubtful. Upon discovery of a pregnancy under coumarin treatment, vitamin K should immediately be substituted in order to minimize the risk of anomalies and malformation.