Anomalies in a Fetus Exposed to Methotrexate in the First Trimester

The increasing use of methotrexate for multiple indications in reproductive age women will likely lead to more frequent incidence of fetal exposure. Methotrexate is sometimes used for medical termination of first trimester pregnancy in combination with misoprostol. Teratogenesis in women exposed to low-dose methotrexate used for treatment of rheumatic conditions has been reported, but it has also been suggested that there is no teratogenic risk associated with low-dose exposure. Because medical termination with methotrexate and misoprostol has high success rates, reports of anomalies in ongoing pregnancies are rare. A 19-year-old gravida 3, para 1 presented in the third trimester after failing an attempt at medical termination with methotrexate. Ultrasonography revealed an absent right kidney and concern for stenosis of the tricuspid valve. After delivery, the absence of the right kidney was confirmed as well as a ventricular septal defect. Low-dose methotrexate, even in a single dose, may be associated with fetal anomalies. Caution must be taken with the use of methotrexate for termination of pregnancy. Patient reliability, adequate follow-up and appropriate counseling for the risk of failure are essential.