MAUI, HAWAII – The consensus among gastroenterologists with expertise in inflammatory bowel disease is that continuation of biologics or immunomodulators in affected women throughout pregnancy and breastfeeding poses no increased risks to the fetus – and therein lies a message for rheumatologists and obstetricians, Dr. Uma Mahadevan said at the 2016 Rheumatology Winter Clinical Symposium.
“The risk of uncontrolled disease must be weighed against the risk of medical therapy. And this is something that is often missed,” according to Dr. Mahadevan, professor of medicine and co–medical director of the Center for Colitis and Crohn’s Disease at the University of California, San Francisco.
Gastroenterologists – at least, those whose practices focus on inflammatory bowel disease (IBD) – have led the way within medicine in terms of establishing the safety of biologics and immunomodulators such as azathioprine in pregnant women with chronic inflammatory diseases and their babies. And having accomplished that, they have been ahead of the curve in terms of continuing such therapy throughout pregnancy and breastfeeding. That’s because active Crohn’s disease and ulcerative colitis are particularly common in women during their childbearing years. And a disease flare during pregnancy is associated with a markedly increased risk of preterm birth and other adverse outcomes.
Gastroenterologists’ longstanding interest in the safety to mother and fetus of continued use of effective, potent medications throughout pregnancy was the impetus for the ongoing prospective U.S. Pregnancy in Inflammatory Bowel Disease and Neonatal Outcomes (PIANO) study, now in its ninth year, with an enrollment of roughly 1,500 women with IBD. The study has included comparisons of outcomes of women on different medications during pregnancy versus unmedicated women.
In multiple publications, Dr. Mahadevan and other PIANO investigators have established that increased IBD activity adversely affects pregnancy outcomes, and that stabilization of disease and effective maintenance therapy throughout pregnancy is important. The PIANO group has demonstrated that IBD medication exposure well into the third trimester in patients in sustained remission was not associated with an increase in congenital anomalies, spontaneous abortions, intrauterine growth restriction, or low birth weight.
To the surprise of many gastroenterologists, the PIANO study has shown that women with Crohn’s disease generally have smoother pregnancies than do those with ulcerative colitis, who tend to get sicker and have more complications.
Since PIANO data show an increased rate of preterm birth and low birth weight in IBD patients on combination therapy with azathioprine plus a biologic throughout pregnancy, Dr. Mahadevan and others try to discontinue the azathioprine, even though the need for combination therapy is a marker for patients with more severe disease.
Anti-TNF-alpha use during third trimester
Of particular interest to rheumatologists, who rely heavily on many of the same biologic agents gastroenterologists use to treat IBD, the use of anti–tumor necrosis factor–alpha biologics in the third trimester was not associated with an increase in preterm birth or maternal disease activity in the third trimester or the first 4 months post partum. When women on certolizumab pegol (Cimzia) during the third trimester were excluded from the analysis, since this biologic uniquely does not cross the placenta at all, the most recent PIANO data show a modest yet statistically significant 35% increase in infections in infants at age 12 months whose mothers were on other biologics in the third trimester. But Dr. Mahadevan said she doesn’t yet consider this finding definitive.
“It’s still a small group of patients, and every year when we update the results the infant infection risk goes back and forth from statistically significant to nonsignificant. I think there’s a signal here; we just need to keep collecting more data,” she said.
Particularly reassuring is the finding that the offspring of PIANO participants who had in utero exposure to biologics and immunomodulators didn’t have any developmental delay, compared with unexposed babies, according to the validated Ages and Stages Questionnaire at ages 1, 2, 3, and 4 years and Denver Childhood Developmental Score at months 4, 9, and 12.
“These kids do great later in life. Actually, they have better scores than unexposed kids. Not to say that biologics make your kid smarter. It probably has to do with better IBD control,” Dr. Mahadevan said.
Effects while breastfeeding
Breastfeeding while on biologics or azathioprine didn’t adversely affect infant growth, infection rate, or developmental milestones. More specifically, levels of biologics in the mothers, babies, or cord serum were not associated with the likelihood of a neonatal intensive care unit stay, an increase in infant infections, or achievement of developmental milestones.
“Almost all the agents are detectable in breast milk, but only at the nanogram level. We tell all our patients on biologics they can breastfeed. It doesn’t matter when their last dose was, don’t worry about it,” the gastroenterologist said.