Managing Arthritis

Research on biologics use before and during pregnancy

Research on biologics use before and during pregnancy

This article is the third in our special series on Women and Arthritis.  To read the first article in the series, visit Women and Arthritis.

Biologics and Pregnancy: What You Need to Know

It can be daunting trying to weigh the risks and benefits of using medications during pregnancy, particularly if the medication or the way it’s used is fairly new. The class of pharmaceuticals known as “biologics” are made from living cells, and block specific types of immune cells that attack healthy tissue. They’ve had a tremendous impact on treating autoimmune conditions including inflammatory arthritis like rheumatoid arthritis (RA), psoriatic arthritis and ankylosing spondylitis. The challenge is getting a complete picture of how medication can affect a mom and baby, says Dr. Mary De Vera, a Canada Research Chair in Medication Adherence, Utilization, and Outcomes and an assistant professor in the faculty of pharmaceutical sciences at the University of British Columbia. “It’s not as simple getting pregnant and deciding not to take medication. Having arthritis itself is harmful for the mom and the baby. When there is active arthritis in pregnancy, that can lead to complications like premature birth or spontaneous abortion,” she says. “Arthritis has to be well-controlled in order to have a successful pregnancy.”

So, Dr. De Vera and her team analyzed data to see whether women with autoimmune diseases who use biologics before conceiving or during pregnancy are at risk of certain birth complications. The results are encouraging.

Preterm deliveries and birth weight

The researchers looked at more than 6,000 women in British Columbia who had an autoimmune disease diagnosis, including 109 women who had used biologics in the three months before or during their pregnancy, between 2002 and 2012. Their analysis, published in the medical journal Annals of Rheumatic Disease in 2018
found that the use of biologics was not associated with an increased risk of preterm delivery or smaller-than-gestational age birth weight. “Having active arthritis can lead to those outcomes, so it was important to see whether the medication would affect outcomes, says Dr. De Vera.

Infection in baby and mother

“Biologics suppress the immune system so we wanted to look at increased risk of infection [in the mother,]” says Dr. De Vera. “As well, some studies have measured levels of biologics in the placenta and there is an elevation particularly near the end of pregnancy, so we thought if there is potential transfer of that drug to baby’s blood then they may also be at risk for infection, so we wanted to look at the babies as well.” That analysis, published in the British Medical Journal in 2019, looked at data about 8607 pregnancies in BC women, again over the 10-year period, where there were 100 pregnancies where women were exposed to biologics. The results: the use of biologics during pregnancy was not associated with an increased risk of serious infections for mom during the post-partum period or in infants in the first year of life.

Birth defects

“When you’re talking about medications and pregnancies, one of the things women ask, ‘is my baby going to have congenital malformation?’” says Dr. De Vera. A third study, published in 2019 in the medical journal Clinical and Experimental Rheumatology, also looked at women in British Columbia who were pregnant between 2002 and 2012: 117 pregnancies where the women had a prescription for biologics three months before conceiving or in the first trimester, and 585 pregnancies where women were not exposed to biologics. In both groups, 6% of babies had congenital anomalies at birth, suggesting no increased risk for the biologics group.

“It’s important to do the research to determine the risks of medication use during pregnancy, but it’s not enough. The next step is to see how this information is actually helping women make decisions,” notes Dr. De Vera, who adds that for women living with RA it’s not uncommon to experience anxiety about making decisions about medication. “They have a lot of information needs about the safety of medications, and we want to close that gap and be able to get this information to women and their rheumatologists so they can make an informed decision. We can help support healthy pregnancies.”