['To evaluate whether methotrexate (MTX) compromises ovarian reserve and future reproductive outcome in women undergoing assisted reproductive technology (ART), when it is used as first-line treatment for ectopic pregnancy (EP).', 'Prospective, observational study.', 'University-affiliated private IVF unit.', 'Twenty-five women undergoing IVF-ICSI who were treated with MTX (1 mg/kg IM) for an EP after ART.', 'Evaluation of reproductive outcome and serum anti-Müllerian hormone (AMH) levels. Serum AMH was evaluated before administering MTX and >or=1 week after the resolution of the EP. Reproductive outcome was evaluated by comparing subsequent IVF-ICSI cycles after EP resolution.', 'Serum AMH levels, cycle length, gonadotropin dose required, peak serum E(2) level, oocytes collected, and embryos obtained.', 'Serum AMH levels before MTX were not statistically significantly different from those after treatment (3.7 +/- 0.3 ng/mL vs. 3.9 +/- 0.3 ng/mL). Patients undergoing a subsequent cycle after systemic treatment for EP had similar cycle durations (10.3 vs. 10.8 d), gonadotropin requirements (2,775 vs. 2,630.3 IU), peak E(2) levels (1,884.3 vs. 1,523.6 pg/mL), number of oocytes retrieved (12.1 vs. 10.5), and total number of embryos obtained (7.1 vs. 6.5).'] Does systemic methotrexate to treat ectopic pregnancy affect ovarian reserve?