The subject of pregnancy and inflammatory bowel disease has been written about extensively. Treatments are changing, and one worries about the effect on the unborn child. One reader wrote the following:
Thanks for an informative web page. I also subscribe to the IBD list and appreciate your comments. I have looked through some old IBD posts and saw where you said taking Imuran when conceiving a child gave you the willies. I was diagnosed with Crohn's in 1993. I am now 27 years old and my husband and I want a child. I have been taking Imuran (50 mg a day) since November 1994. My GI has reluctantly agreed to let me try to taper off Imuran. He feels Imuran is the reason that I was finally able to taper off prednisone after 3 years. I have been on Pentasa since March 1994. My GI feels that I will have a flare up when I discontinue the Imuran and that would be a greater risk to the baby than the risk of birth defects caused by continuing to take Imuran. My OB says the Imuran is unsafe during pregnancy. I also would like to breast feed and Imuran would make that impossible. I've been told by my GI and OB that Pentasa is safe during pregnancy.
The above situation is a real example of the problems that face one who is contemplating pregnancy with Crohn's. The physicians seem to be giving contradictory advice. Actually, each is concerned about the outcome for the patient, and different factors come into play.
While no one advocates the use of Azathioprine in pregnancy, the reports of the outcomes for patients on azathioprine who get pregnant seem to be no worse than the results of patients with untreated Crohn's. That is to say, fetal loss is common in active Crohn's and also when on azathioprine. The incidence of birth defects is not higher when on azathioprine. My interpretation of this is that if azathioprine causes birth defects in a given pregnancy, they are so severe that the fetus will not survive. There was some controversy a while back on what the effect of pregnancy on Crohn's is. I think the literature pretty much now shows that people respond variably, but that if Crohn's is active at the time of conception that things will probably not go well.
All that said, most drugs used in treatment of IBD have been found to be safe during pregnancy. Steroids are known to be safe, as is sulfasalazine. Mesalamine is probably safe during pregnancy. Flagyl is not to be used (though the data I recall are just scattered case reports, and the warning to not use it may not stand up in the future).
Remember that many people were successfully treated with medications before azathioprine came into common use for Crohn's disease. While azathioprine may be used to get a patient off steroids, the situation generally is not that steroids were ineffective, but that steroids were needed chronically and side effects were a concern.
My feeling about this is that since pregnancy is self limited in duration, getting off azathioprine at worst will mean 12 to 16 months of steroids. If the Crohn's can be controlled with other medications, then all the better. In general, I would advise patients on azathioprine to get off the azathioprine and start steroids, a form of mesalamine, or both depending on circumstances. Also, I generally advise Crohn's patients to avoid anything with sucrose in it, since some studies in the past showed a 50% reduction in complications of Crohn's when that was done.
The above notwithstanding, there is the possibility that a particular case of Crohn's was so bad that even the thought of recurrence is painful. I could imagine someone who had multiple fistulas, obstructions, operations and wound failure, was starting to get cataracts, and who only got out of a cycle of repeated hospitalizations when put on azathioprine. A case such as that might warrant the risk of azathioprine.
I cannot tell what is the right choice, however. This will depend on how the risks sound to you and many aspects of your views on life, death, having children, and dealing with birth defects. It is not your responsibility to make the medical decisions, but the input to your physicians on how you value the various outcomes will let your doctors, who have a sense for the relative rates of occurrence of the above outcomes, give better advice on how to proceed.
Best of luck in your efforts.
Stephen Holland, M.D.
Section of Clinical Pharmacology
University of Illinois College of Medicine at Peoria
Gastroenterology Ltd, Peoria, IL