Physiological changes during pregnancy do not appear to effect faecal calprotectin levels – making it more suitable than other biomarkers such as C-reactive protein to assess IBD disease activity.
The novel finding is important to help optimise treatment during pregnancy and minimise the risk of adverse outcomes in both mother and baby, when other more invasive investigations of muscosal inflammation are ruled out.
Co-author Associate Professor Sally Bell, from St Vincent’s Hospital Melbourne, told the limbic active IBD in pregnancy was associated with the risk of intrauterine growth retardation and premature birth.
“Women worry about the effects of IBD drugs on the baby as do their GPs, obstetricans and midwives, but we know they should be more worried about the potential effects of active disease on their baby.”
The multi-centre study found the median faecal calprotectin levels in 46 pregnant women with IBD was 131ug/g compared to 0ug/g in 21 pregnant but healthy controls.
The research found faecal calprotectin levels correlated with active disease as measured by the Physician Global Assessment (PGA) before, during and after pregnancy.
Fecal calprotectin only correlated with the Harvey–Bradshaw Index (HBI) and Simple Clinical Colitis Activity Index (SCCAI) before and after but not during pregnancy.
The study concluded the combined use of fecal calprotectin and PGA was optimal to assess disease activity in IBD during pregnancy.
Associate Professor Bell said while ‘poo testing’ was never popular, women were likely to agree to the test when the benefits were carefully explained.
“You can change their perception when it’s framed carefully as an alternative to bowel prep and colonoscopy, and as a non-invasive predictor of relapse in non-pregnant women. If we see the calpro rising, we can intervene early before their IBD has an impact on the baby.”
Associate Professor Bell said the main barrier to the test was the $80-100 price tag as it was not on the PBS.
Yet monitoring was important as constipation, non-specific abdominal discomfit, reflux and nausea associated with pregnancy can mimic IBD symptoms and lead to unnecessary escalation of treatment.
In addition, it may be possible to use the marker to identify pregnant women whose disease was in remission and in whom immunomodulator and biologic therapy could be tailored to minimise foetal exposure.
“We now know it is not necessary to stop biologic therapy but some women, who are well controlled, are still keen to stop or reduce their treatment and using calpro to monitor them may make this strategy safer.”