Biologics for autoimmunity not tied to risk for preterm birth, SGA infants

Last Updated: 2018-04-30

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Pregnant women with autoimmune disease who use biologics before and during pregnancy are not at increased risk of preterm delivery or having small-for-gestational-age (SGA) babies, according to a population-based study from Canada.

"Knowing that biologics could be a compatible treatment option is important for women with inflammatory disease and physicians caring for these women. This information could become part of their discussion on balancing the risks and benefits of treatments during pregnancy," said senior author Dr. Mary A. De Vera of the University of British Columbia in Vancouver.

"Planning for pregnancy is an important consideration for many women with arthritis because having inflammatory disease can lead to difficulty getting pregnant or having poor pregnancy outcomes," she told Reuters Health by email. "So part of the planning includes deciding whether they will continue their treatments throughout their pregnancy and what impact the treatments may have on the pregnancy."

As reported online April 11 in Annals of the Rheumatic Diseases, Dr. De Vera's team used British Columbia population-based administrative data to identify women with one or more autoimmune diseases and pregnancies between 2002 and 2012. They found 6,218 women with more than 8,600 pregnancies - including 109 women with 120 pregnancies who used biologics three months before or during pregnancy.

In unadjusted analyses, biologics use before and during pregnancy was associated with a significantly higher risk of preterm delivery (odds ratio, 1.64; 95% confidence interval, 1.02 to 2.63), but not SGA birth (OR, 1.34; 95% CI, 0.72 to 2.51).

After using high-dimensional propensity scores (HDPS) to match each exposed pregnancy with five unexposed pregnancies, biologics use was not linked with preterm delivery (OR, 1.13; 95% CI, 0.67 to 1.90) or SGA birth (OR, 0.91; 95% CI, 0.46 to 1.78).

"Our previous research showed that more and more women with arthritis are using biologic treatments to manage their disease and are even continuing these medications throughout pregnancy," Dr. De Vera said. "There is limited research about the safety of using biologics during pregnancy, especially since pregnant women are not studied in clinical trials. So our research aimed to find out what impact biologics may have on pregnancy outcomes including delivering preterm or having babies that are small for gestational age."

Dr. Vikram Garg, a rheumatologist at Scripps Clinic in Encinitas, California, told Reuters Health by email, "This study is significant because of the numerous conditions for which biologics have been indicated. For several autoimmune conditions - rheumatoid arthritis, inflammatory bowel disease, psoriatic arthritis, ankylosing spondylitis - biologics are indicated to treat afflicted women of child-bearing age."

Dr. Garg, who was not involved in the work, added, "Although the main limitation of the study is the relatively small sample size, it is worthy to note that this is an important contribution to our understanding of the risks of exposure and the pregnancy outcomes in mothers who may potentially need to use biologics during pregnancy. It is reassuring to know that no association was seen with increased risk of preterm delivery or small for gestational age births."

Dr. Dale Mitchell, chair of Obstetrics and Gynecology at Scripps Clinic in San Diego, California, who was also not involved in the study, told Reuters Health by email that its findings mean there is "another 'tool' to treat inflammatory disease in pregnancy."

However, Dr. Mitchell cautioned, "The study does not provide any long-term data outcome for these infants."

The study had no commercial funding. One coauthor reported ties to companies making biologics.

SOURCE: https://bit.ly/2DrBEXv

Ann Rheum Dis 2018.