Low dose weekly methotrexate in early pregnancy. A case series and review of the literature

J Rheumatol. 2000 Aug;27(8):1872-5.


Objective: To assess the teratogenic risk of low dose weekly pulses of methotrexate (MTX) inadvertently taken during the first trimester of pregnancy.

Methods: We assessed pregnancy and neonatal outcome of 4 patients with rheumatic disease treated with weekly pulses of 5 to 15 mg of MTX for a mean duration of 4 years.

Results: The 4 patients had continued MTX treatment from one to 6 weeks of gestation. One patient miscarried at Week 6, the other pregnancies ended with the delivery of healthy children. Chromosome analysis of one child was normal.

Conclusion: In spite of the absence of congenital anomalies in our cases, safe contraception in fertile patients who start low dose weekly MTX is mandatory.

Publication types

  • Review

MeSH terms

  • Abnormalities, Drug-Induced / etiology
  • Abortion, Spontaneous / chemically induced
  • Adult
  • Antirheumatic Agents / administration & dosage*
  • Antirheumatic Agents / adverse effects
  • Arthritis, Rheumatoid / drug therapy*
  • Dose-Response Relationship, Drug
  • Female
  • Folic Acid Antagonists / adverse effects*
  • Gestational Age
  • Humans
  • Maternal-Fetal Exchange
  • Methotrexate / administration & dosage*
  • Methotrexate / adverse effects
  • Pregnancy
  • Pregnancy Outcome


  • Antirheumatic Agents
  • Folic Acid Antagonists
  • Methotrexate