American Journal of Pharmacology and Toxicology

Anomalies in a Fetus Exposed to Methotrexate in the First Trimester

Landon B. Lorenz and Eric J. Knudtson

DOI : 10.3844/ajptsp.2007.146.147

American Journal of Pharmacology and Toxicology

Volume 2, Issue 4

Pages 146-147


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.


© 2007 Landon B. Lorenz and Eric J. Knudtson. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.