From time to time there are requests for the Ectopic Pregnancy Trust to explain why in their literature it’s suggested that women treated with more than one injection of Methotrexate should avoid pregnancy for a period of 6 months, when there is little research based evidence of support this. And finding clinically based evidence is hard for waiting even 3 months after one injection.
It is very hard to find information to substantiate the advice, deemed mainly because of the ethics of designing a study on humans to support the theory that ‘Methotrexate may damage a future pregnancy if conception occurs too soon’. Taking a large group of women and encouraging them to become pregnant soon after treatment with Methotrexate and then seeing how many of their babies were born with Spina Biffida or other Neural Tube defects is a difficult one to justify!
The following article is an example that describes tests mainly based on animal study but does include some human research:
http://qjmed.oupjournals.org/cgi/content/full/92/10/551
This particular study discusses such areas as the importance of folic acid in embryonic development and goes on to suggest “risk of foetal exposure†in babies of mothers who have taken the drug up to 4 months prior to conception”.
To add further complication, this advice and information are given to patients who have been treated throughout the UK, across which there are widely varying protocols and follow up arrangements in each individual authority.
But we cannot know the ‘lifestyle’ of the person our literature is being provided to or who’s reading the website and, for example, the use of ‘leisure’ drugs is now widespread; many of these drugs, compromising liver function while they are being metabolised.
Each individuals metabolism is different and folate levels are restored at differing rates. It is not usual to test for folate levels at 3 or 6 months after treatment.
It takes varying amounts of time for hCG levels to drop after treatment with Methotrexate, during which time, best practice advises the patient does not supplement her diet with oral folic acid. However, it’s widely accepted that a woman planning pregnancy should take folic acid for 12 weeks prior to conception and for 6 weeks afterwards. By suggesting 6 months after a second dose of Methotrexate this allows the hCG levels to drop and the patient to recommence folic acid supplementation in preparation for a new pregnancy.
Our advice at the Ectopic Pregnancy Trust, has to be ‘all encompassing’ to preserve the best interests of the patient, her future fertility and the health of her ensuing pregnancies. Without access to individual medical records and insight into the patients’ background and lifestyle it was agreed that the 6-month wait after 2 injections was the safest way for the EPT to generalise.
At the Ectopic Pregnancy Trust, we work with a group of medical advisers who have extensive experience in the field of ectopic pregnancy and they establish ‘best practice protocols’ with ourselves. These reviews are as evidence based as possible and are, of course, peer reviewed. Our information is then be updated again accordingly. As such we are currently considering if we should amend our own advice to 4 months and not 3 after one injection of Methotrexate.
For the reasons stated above, our advisors do suggest 6 months after a multiple dose protocol - however, arranging with your doctor for serum folate levels to be done, confirming good supplies of folacin after 3 to 4 months might be a way forward for you to feel you can try again a little sooner, with confidence