NEW YORK (Reuters Health) – Among couples wanting to conceive, the routine practice of having men with inflammatory bowel disease discontinue thiopurine medications is not necessary, a Spanish group has shown.
The concern has been that thiopurines interfere with purine metabolism and can therefore cause DNA mutations.
“The general perception is that thiopurines can be safely administered to female patients during pregnancy,” Dr. Carlos Teruel at Hospital Ramon y Cajal, Madrid and colleagues write in an online issue of the American Journal of Gastroenterology. “However, information about thiopurine safety in pregnancies fathered by exposed males is both scarce and contradictory.”
To see if male IBD patients taking thiopurines have reduced fertility or if their offspring are adversely affected, the researchers looked at outcomes of 130 pregnancies fathered by men with IBD; in 46 pregnancies the men had been taking 6-mercaptopurine or azathioprine, while in 84 pregnancies the fathers were not on thiopurines.
Time to conception was slightly but not significantly longer in the thiopurine-exposed group than the control group, and the number of unsuccessful pregnancies was similar at 10.9% and 13.1%, respectively.
“The difference in the proportion of premature births was not statistically significant (4.3% in the exposed group vs. 2.4% in the control group; OR: 1.3), and neither was the difference in the mean duration of the successful pregnancies (38.9 vs. 39.4 weeks),” the investigators report.
There was one congenital malformation in the exposed group and two in the control group, and no cases of congenital or infant neoplasia were seen during a median of 108 months’ follow-up after birth.
The team concludes there is no reason to recommend that male patients interrupt thiopurine therapy when looking to conceive. “Nevertheless,” they add, “when facing a patient in such a circumstance, it is essential to provide all the available evidence, empowering them to make a decision.”
Am J Gastroenterol 2010.