First trimester naproxen exposure and outcome of pregnancy - A German case series

In contrast to other non-steroidal anti-inflammatory drugs (NSAIDs), naproxen use during pregnancy is not well studied. The objective of this analysis was to assess negative effects on pregnancy outcomes following naproxen exposure in the first trimester of pregnancy. Out of 121 exposed pregnancies prospectively recorded by two German teratology information services (TIS) 15 ended as spontaneous abortion and ten were electively terminated; in one case for prenatal diagnosis of anencephaly. Four pregnancies were stillborn, in these cases naproxen was discontinued more than two months before the event. Of 95 live-born infants, including three pairs of twins, two were born with major birth defects: one with dysmelia of the left hand and foot and another with a complex congenital heart defect, esophageal atresia with tracheoesophageal fistula, and choanal stenosis. The results of this case series do not suggest that naproxen has a significant teratogenic effect. However, due to the limited cohort size and lack of comparable reference group results should be interpreted with caution and better studied NSAIDs such as ibuprofen should be preferred in the first and second trimester of pregnancy. This work was supported by the German Federal Institute for Drugs and Medical Devices (BfArM).