SAN DIEGO – Researchers found no evidence of increased risk of serious or opportunistic infections in infants born to pregnant women who were treated with biologic medication for their rheumatoid arthritis, according to a cohort study.
“These data add to what we’re beginning to learn about these medications that are so commonly used in women of reproductive age, and who have concerns about whether they can use them safely or not during pregnancy,” lead study author Christina D. Chambers, PhD, MPH, said during a press briefing at the annual meeting of the American College of Rheumatology. To date, theoretical concern exists that the use of biologics could interfere with postnatal immune function in the infant, said Dr. Chambers, a perinatal epidemiologist and teratologist at the University of California, San Diego. “The theory has been that because of the size of the molecule, little placental transfer is thought to take place early in pregnancy, but later in pregnancy, more placental transfer may be possible,” she said.
In an effort to investigate the risk of serious or opportunistic infections for infants whose mothers used biologics during pregnancy, the researchers conducted an observational cohort study from pregnant women participating in the Organization of Teratology Information Specialists (OTIS) Autoimmune Diseases in Pregnancy Project from 2004 through 2016. Mothers fell into one of three groups: 502 pregnancies where the mother with RA was treated with a biologic with or without other disease modifying anti-rheumatic medications during her pregnancy (group A); 231 pregnancies where the mother had RA but did not use any biologics during pregnancy (group B), and 423 pregnancies where the mother had no chronic diseases at all (group C). The investigators defined the serious or opportunistic infections as a list of 16 infections that included X-ray proven pneumonia, septic arthritis, osteomyelitis, tuberculosis, herpes, listeria, legionella, mycobacteria, systemic cytomegalovirus and abscess. The one-year follow-up data was collected from medical records and corroborated with maternal reports.
Among the pregnant mothers in group A, 43% took their last dose in the first or second trimester, and 57% percent took their last dose in the third trimester. Dr. Chambers reported that 20 of the 502 infants in group A developed at least one serious or opportunistic infection, for a rate of 4%, while the rates among infants in groups B and C were 2.6% and 2.1%, respectively. The most common infections seen were X-ray proven pneumonia, sepsis, bacteremia, meningitis, and abscess. Between 11% and 19% of infants had more than one infection over the one-year period.
In a subset analysis of 285 women in group A who had third trimester exposure to one of the biologics, 10 infants had at least one serious or opportunistic infection, for a rate of 3.5%, which was statistically similar to that of groups B and C (2.6% and 2.1%, respectively).
“These data provide some reassurance for clinicians who are concerned that their patients need to be treated with a biologic late in pregnancy rather than take them off the drug during that period of time,” Dr. Chambers said. She acknowledged certain limitations of the study, including the fact that the researchers did not examine risk of less serious infections, such as more frequent colds or ear infections in the infants, and they did not have any direct measure of their immune function.
Dr. Chambers disclosed having received research support from AbbVie, Amgen, Bristol Myers Squibb, Celgene, Janssen Pharmaceutica Products, L.P., Pfizer Inc, Roche Pharmaceuticals, Seqirus, GSK, UCB, and Sanofi-Aventis.