Methotrexate in pregnancy

M. Lloyd1, P. McElhatton2, M. Carr3, G. Hall4 and R. Hughes3

1 Rheumatology, Frimley Park Hospital, Frimley, 2 National Teratology Information Service, Newcastle, 3 Rheumatology, St Peter's Hospital, Chertsey and 4 Rheumatology, Royal London Hospital, London, UK

Correspondence to: M. Lloyd. E-mail: mark.lloyd{at}fph-tr.nhs.uk

SIR, We read with interest the report by Kinder et al. [1] of a patient who conceived while on methotrexate. However, we were concerned that our conclusions may have been misinterpreted. Our review [2], which was the largest of its kind at the time, concluded that exposure to methotrexate in pregnancy is associated with a roughly 25% risk of fetal malformation. We were not able to conclude that there is a threshold dose at which methotrexate is safe in pregnancy, partly because the numbers of cases of fetal exposure below 10 mg weekly are so few. This conclusion came from other authors and remains speculative [3, 4]. The National Teratology Information Service (NTIS) has a report of a pregnant woman who received a single dose of methotrexate 7.5 mg between 4 and 7 weeks of gestation. An emergency Caesarean section was performed at 28 weeks for placenta praevia and the baby had a number of abnormalities, including positive sweat test, ileal perforation and respiratory distress syndrome.

We would advise contacting the NTIS in any case of methotrexate exposure during pregnancy.

The authors have declared no conflicts of interest.

References

  1. Kinder AJ, Edwards J, Samanta A, Nichol F. Pregnancy in a rheumatoid arthritis patient on infliximab and methotrexate. Rheumatology 2004;43:1196–7.[Free Full Text]
  2. Lloyd ME, Carr M, McElhatton P, Hall GM, Hughes RA. The effects of methotrexate on pregnancy, fertility and lactation. Q J Med 1999;92:551–63.[ISI]
  3. Feldkamp M, Carey JC. Clinical teratology counselling and consultation report: low dose methotrexate exposure in the early weeks of pregnancy. Teratology 1993;47:533–9.[ISI][Medline]
  4. Donnenfield AE. Methotrexate exposure prior and during pregnancy. Teratology 1994;49:79–81.[ISI][Medline]
Accepted 22 February 2005





This Article
Full Text (PDF)
All Versions of this Article:
44/5/697    most recent
keh612v1
Alert me when this article is cited
Alert me if a correction is posted
Services
Email this article to a friend
Similar articles in this journal
Similar articles in ISI Web of Science
Similar articles in PubMed
Alert me to new issues of the journal
Add to My Personal Archive
Download to citation manager
Disclaimer
Request Permissions
Google Scholar
Articles by Lloyd, M.
Articles by Hughes, R.
PubMed
PubMed Citation
Articles by Lloyd, M.
Articles by Hughes, R.
Related Collections
Rheumatoid Arthritis