Effect of methotrexate treatment of ectopic pregnancy on subsequent pregnancy

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?

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.