Effect of methotrexate treatment of ectopic pregnancy on subsequent pregnancy.

QUESTION: My last pregnancy was diagnosed as ectopic, and I was treated successfully with intramuscular methotrexate (MTX) 8 weeks ago. I am currently planning for another pregnancy; however, I have read that MTX causes birth defects and that it stays in my body for a very long time, ranging from 1 to 12 months after treatment. When is it safe to conceive?

ANSWER: We suggest that the outcomes of pregnancies conceived shortly after MTX therapy for extrauterine pregnancy are most likely to be favourable and similar to those pregnancies conceived 6 months after MTX treatment. However, as data are not sufficient to draw a definitive conclusion or to confirm the exact safe timing after MTX treatment, at least a 3-month waiting period is recommended for women who are planning pregnancy. Nevertheless, conception within 3 months of MTX treatment of extrauterine pregnancy should not be considered a definite indication of termination, and further targeted fetal anatomy assessment is recommended. Further retrospective and prospective studies are needed to define the safety period before 3 months and to solidify this recommendation.