Chronic inflammatory bowel disease and pregnancy

Effects of 6-mercaptopurine treatment on sperm production and reproductive performance: a study in male mice

OBJECTIVE

Azathioprine and 6-mercaptopurine interact in purine metabolism and DNA synthesis, thus their potential mutagenic effects have been of concern in the management of inflammatory bowel disease (IBD), especially in patients of childbearing age. Although several clinical studies have indicated their safety in both reproduction and pregnancy, in a recent large epidemiological study concerns were raised about their adverse effects in pregnant patients with IBD, and experimental or basic data on this subject are limited. The aim of this study was to investigate sperm production, sperm quality, and reproductive outcome following prolonged 6-MP administration to male mice.

MATERIAL AND METHODS

Highly inbred Balb/c adult male mice were used. 6-MP at doses of 2, 5, and 8 mg/kg (n = 9 for each group) was given daily for 51 days and the treatment group was compared with controls. After 45 days of treatment, the mice were mated with females. Following 13 days of pregnancy, the products of conception were evaluated and live fetuses were examined for gross malformations. Sperm production and morphology were examined after 51 days of 6-MP administration.

RESULTS

Treatment with 6-MP at all doses did not affect sperm morphology and sperm production in the testicular tubules, as compared with controls (70% normal sperm). However, pregnancy rates were inversely related to escalating doses of 6-MP: 55%, 41%, 28%, and 16% for control, 2, 5, and 8 mg/kg groups, respectively. Resorption rates (abortions) were 21% in the control group as compared with 45-50% in all the treatment groups, but the incidence of major congenital malformations was not increased.

CONCLUSIONS

Long-term 6-MP treatment in male mice did not impair sperm production and sperm morphology. However, a significantly high rate of embryonic resorption indicated occult sperm damage. Thus, normal sperm analysis does not necessarily imply that sperm damage at genetic level did not occur. It is difficult to extrapolate from these results to the clinical use of 6-MP/azathioprine in IBD patients; however, further basic genetic testing for DNA damage and clinical follow-up are warranted.

Irritable bowel syndrome and inflammatory bowel disease in pregnancy

Irritable bowel syndrome and inflammatory bowel disease are gastrointestinal disorders affecting young adults. The peak incidence of irritable bowel syndrome and inflammatory bowel disease is in the late adolescence and early adult years, the time during which many women are planning and beginning their families. Since the potential for life-altering changes and pregnancy complications exist with these diseases, affected pregnant women present a challenge for the gastroenterologist, pregnancy provider, and nurses caring for them. This article outlines what is known about these diseases and their effect on fertility and pregnancy as well as their clinical management during pregnancy.