Multiple congenital anomalies associated with weekly low-dose methotrexate treatment of the mother

This report describes an infant with multiple congenital anomalies born to a 20-year-old mother with juvenile rheumatoid arthritis who had been taking weekly low-dose methotrexate (MTX) during the first trimester of pregnancy. The abnormalities found were consistent with those associated with maternal ingestion of MTX at dosage levels used to induce abortions, i.e., the group of abnormalities referred to as the "aminopterin syndrome." Although weekly low-dose MTX has been associated with spontaneous abortions, this is, to our knowledge, the first case report describing multiple congenital abnormalities consistent with MTX embryopathy secondary to weekly low-dose MTX treatment.