This population-based, case-control study examined whether use of NSAIDs in early pregnancy was associated with a range of structural birth defects. Data were obtained from the National Birth Defects Prevention Study (NBDPS), an ongoing case-control surveillance study designed to identify infants with major birth defects and evaluate genetic and environmental risk factors. Case infants for the study were identified from the state birth defect surveillance system of ten US states. Cases include live births, stillbirths of 20 weeks or longer gestation or greater than 500 grams, or elective terminations with any of more than 30 eligible birth defects groups diagnosed in the first year of life.

The following findings were reported:

• 22.6% reported use of NSAIDs in the first trimester of pregnancy, most commonly ibuprofen, aspirin, and naproxen.

• Of the 29 defect groups examined, most were not associated with NSAID use.

• Small to moderate increased risks of some oral cleft groups, some neural tube defect groups, anophthalmia/microphthalmia, pulmonary valve stenosis, amniotic bands/limb body wall defects, and transverse limb deficiencies, were associated with ibuprofen, aspirin, and naproxen exposure.

The researchers conclude from these data that “use of NSAIDs in early pregnancy does not appear to be a major risk factor for birth defects although there were a few moderate associations between NSAIDs and anophthalmia/microphthalmia, amniotic bands/limb body wall defects, pulmonary valve stenosis, oral clefts and neural tube defects. Because these associations have not previously been reported from other datasets, with the exception of naproxen and cleft lip with or without cleft palate, further studies with detailed data on timing, frequency, dose, and indication are necessary.”