This is a 2 day-old term baby with history of methotrexate exposure during first trimester as an abortion attempt. No other relevant clinical history. The MRI study shows large bilateral choroid plexus cysts, partial sacral agenesis and a filar lipoma.  If anyone has had experience with this situation, please let us know.

Methotrexate is a folic acid antagonist, which is known to have teratogenic effects in the first trimester of gestation. It interrupts the synthesis of thymidylate, purine nucleotides, and some amino acids, thereby interfering with the formation of DNA, RNA, and proteins. Methotrexate has multiple therapeutic uses in women of reproductive age such as treatment of neoplastic disease, psoriasis, rheumatoid arthritis, lupus, ulcerative colitis, ectopic pregnancy and as well as an agent for induce abortion. Failure rate of abortion is 2-10% and there are reports of normal pregnancy outcomes.

There are well described congenital anomalies resulting from methotrexate exposure in first trimester of pregnancy; dose dependence is unclear. Cranial dysostosis, hypertelorism, external ear anomalies, micrognathia and posterior cleft palate have been described. Multiple skeletal and axial anomalies are also noted.

We have found two case reports in the literature of choroid plexus cysts after methotrexate exposure during the first trimester of pregnancy. The caudal vertebral anomalies have been reported mostly in rats.