A study published today in the journal Gut shows that women with inflammatory bowel disease (IBD) are at greater risk of developing a mental illness after giving birth compared to the overall population. Study authors found that more than one-fifth of pregnant women with IBD had a new-onset mental health diagnosis. For every 43 pregnancies, there is one extra case of mental illness in a woman with IBD, compared to other women. The study used healthcare data on women who gave birth between 2002 and 2014 in Ontario, Canada to analyze the frequency of a new mental illness diagnosis in these women during and up to one year after a pregnancy.

Inflammatory bowel disease, or IBD, are a group of chronic gastrointestinal disorders in which people have ulceration, inflammation, and bleeding of their gastrointestinal tract, and are at risk for complications in other parts of the body. The two main subtypes are Crohn's disease and ulcerative colitis. People with IBD have an elevated risk of mental illness, especially anxiety and depression, potentially related to the inflammation in the gut affecting their brain.

"There's increasing awareness about mental illness in women during pregnancy and postpartum," said Dr. Eric Benchimol, senior author on the paper, and Senior Scientist at the CHEO Research Institute, Core Scientist at ICES, Associate Professor of Pediatrics and Epidemiology at the University of Ottawa, and a Pediatric Gastroenterologist at the CHEO Inflammatory Bowel Disease Centre. "Because of the elevated risk of mental illness in people with IBD, we felt it was important to study if women with IBD were at greater risk of developing a new mental illness during pregnancy and after giving birth compared to the overall population. We found the risk to be elevated during the post-partum period for women with IBD, particularly in the first 90 days after birth. We did not find an elevated risk during pregnancy."

In the study population, pregnant women with IBD had an elevated risk of developing a new-onset mental illness postpartum when compared to women without IBD -- 22.7 per cent compared to 20.4 per cent. The women with IBD were at increased risk of two out of the four mental illness diagnostic categories: mood disorders (such as anxiety and depression) and substance use disorders (such as opioid dependency). These women were primarily treated by doctors in the outpatient setting, and did not need to be hospitalized. There was no evidence of increased risk for psychotic disorders (such as schizophrenia or hallucinations). The risk appeared elevated in women with Crohn's disease, but not ulcerative colitis.

"This is a small but significantly increased risk of new-onset mental illness in women with IBD," says Dr. Simone Vigod, lead author of the study, Scientist at the Women's College Hospital Research Institute, Chief, Department of Psychiatry, Women's College Hospital, and Adjunct Scientist at ICES. "Women with IBD face increased health challenges during pregnancy and after giving birth, and it's not just physical challenges. We need to look at both the physical and mental health needs of women and ensure they are getting the best treatment and support."

"These findings are very important for both patients and healthcare providers in the IBD community," says Mina Mawani, President and CEO of Crohn's and Colitis Canada. "If a pregnant woman with IBD knows that there's an elevated risk of mental illness during the post-partum period, she should discuss this potential risk with her healthcare provider. It's important that healthcare providers are aware of this increased risk in women with IBD. Together, women and their healthcare providers can look for opportunities to prevent mental illness during pregnancy and after birth as well as identify and treat it earlier."