Pregnancy, fertility, and disease course in patients with Crohn's disease and ulcerative colitis.

Pattern recognition of the long-term disease course before, during, and after pregnancy can provide us with data about the influence of pregnancy on IBD, and vice versa. Determinants that predict an indolent versus an aggressive disease course are currently being sought. Our intention is to analyze the disease course during pregnancy in an EU-IBD inception cohort of 1200 patients diagnosed from 1991 to 1993 and followed up for 10 years. We also attempt to evaluate such factors as smoking and medication and to predict pregnancy course and fertility in IBD as well as in a cross-sectional study of members of the patient organization EFCCA. One of the questions that arose was: what factor is responsible for the observation that pregnancy decreases the incidence of relapses and the development of fibrostenotic lesions? Relaxin and the glycoprotein YKL-40 are validated in the cohort. The protein relaxin, produced by the corpus luteum during pregnancy, increases the laxity of fibrous tissue. Collagen fibers are dissolved and disorganized. As maternal rejection of the fetus does not occur, a protein from the fetal lymphocytes most likely decreases the maternal lymphocyte response. Multiparity may lead to subtle, acquired immune deficits. Glycoprotein YKL-40, which causes fibrosis in RA and cirrhosis, is speculated to be lower in multiparous women than in nonpregnant women due to the fetal lymphocytes that secrete a protein that is a potential immune modulator. Knowledge gained from future EC-IBD studies may result in new legislation (e.g. regarding adoption) that can benefit IBD patients throughout Europe.