Outcome following high-dose methotrexate in pregnancies misdiagnosed as ectopic

OBJECTIVE: The objective of this study was to report the outcomes of intrauterine pregnancies misdiagnosed as ectopic and exposed to methotrexate, a major teratogen. STUDY DESIGN: We report the outcomes of all subjects who sought consultation after exposure to high-dose methotrexate to induce abortion in presumed ectopic pregnancies, which were later identified as viable intrauterine pregnancies by 3 North American Teratology Information Services between 2002 and 2010. RESULTS: Eight women with normal, desired pregnancies were administered high-dose methotrexate in the first trimester because of presumed, misdiagnosed ectopic pregnancies. All pregnancies resulted in catastrophic outcomes. Two pregnancies resulted in severely malformed newborns with methotrexate embryopathy; 3 women miscarried shortly after exposure, and in 3 the erroneous diagnosis led the physicians to advise and perform surgical termination. CONCLUSION: Erroneous diagnosis of intrauterine pregnancies as ectopic with subsequent first-trimester exposure to methotrexate may result in the birth of severely malformed babies or fetal demise.