European survey of fertility and pregnancy in women with Crohn's disease: a case control study by European collaborative group.

Two hundred and seventy five patients with Crohn's disease from five countries were interviewed. Each patient was matched with a control of the same age. Of the 275 women with Crohn's disease 224 had been married at some time compared with 208 controls. The mean age at marriage was 23 years. Diagnosis of Crohn's disease was made five years later and the survey was conducted on average 16 years after marriage. Cases and controls had a similar obstetric study before diagnosis. After diagnosis there was a significant reduction in the number of children born to patients (0.4) compared with controls (0.7). Crohn's disease did not increase the rate of miscarriage or Caesarean section but prematurity was more common in patients (16%) than controls (7%). The site of disease at diagnosis did not affect these findings. Medical advice against pregnancy may be partly responsible for this reduction in fertility, but patients practised contraception less than controls and a significantly greater proportion of these (42%) failed to become pregnant compared with controls (28%). Crohn's disease results in subfertility.