Seoul, Researchers have found that inflammatory bowel disease (IBD) - including Crohn's disease and ulcerative colitis - often affects women of childbearing age.

Inflammatory bowel disease (IBD) is an umbrella term used to describe disorders that involve chronic inflammation of your digestive tract.

"Previous studies could be easily biased since considerable numbers of pregnant women with IBD with quiescent or mild activity were likely to be excluded. We overcame this limitation by using a nationwide database covering 98 per cent of the 52 million citizens of an entire nation," said study corresponding author Bo-In Lee from The Catholic University in South Korea.

According to the researchers, several studies regarding these issues have been conducted and findings on whether IBD is associated with adverse pregnancy and birth outcomes are still conflicting.

Recent studies that have focused on IBD disease activity have revealed that active disease is associated with a significant increase in adverse pregnancy and birth outcomes.

For the findings, published in the journal Alimentary Pharmacology & Therapeutics, they compared the health of pregnant and non-pregnant women with IBD.

They included 2,058 Korean women with IBD who became pregnant between 2007 and 2016 and 20,580 women of similar age who did not have IBD.

Overall, women with IBD did well during pregnancy; however, they had higher rates of Caesarean section and intrauterine growth retardation (low birth weight babies) than women without IBD.

Of the patients who had Crohn's disease, those with the quiescent-to-mild disease did as well as women without IBD; however, women with Crohn's disease that was not mild-to-moderate had a higher rate of miscarriage and almost a 3-fold higher rate of intrauterine growth retardation than women without IBD, the researchers said.

In conclusion, women with IBD have a lower pregnancy rate compared to non-IBD women.

'With the exception of moderate to severe disease, the incidences of adverse pregnancy outcomes in women with IBD are similar to that of the general population," the researchers noted.