Will Using Your Arthritis Medications During Pregnancy Cause You or Your Baby to Have More Infections?

Scientific Study Title

Perinatal Use of Immunosuppressant Therapies and Risk of Infections in Mothers and Babies

 Why Did We Do This Research? 

Research shows that certain arthritis treatments namely, biologics, can weaken the immune system, putting people at risk of having infections that can be mild (for example, catching a cold) or serious (for example, pneumonia). Some of these treatments are used by women during their pregnancies; however, it is not clear what impact these treatments have on mothers’ or their baby’s immune system. The goal of this research project was to find out whether using biologics during pregnancy causes moms and babies to have more infections, so that prevention and monitoring can take place to ensure that both moms and babies can be healthy. We specifically wanted to explore what happens in mothers during the postpartum period, and what happens in babies during the first year of their life.

What Was Done?

Using administrative health data with approved access from the Ministry of Health and the University of British Columbia Research Ethics Board, we investigated… 

1. How often infections occur in moms around the time of delivery, and in babies during the first year after they are born. 
2. Whether the use of biologics is associated with infections and/or whether there are other factors that play a role. 

Who Was Involved? 

This study included women with autoimmune diseases who were either taking biologics during pregnancy or not taking them, and it looked at the impact of these treatments on both the mothers and their infants.  

More specifically:  

• The participants were women who had at least one autoimmune disease.  
• The study focused on women who had pregnancies between 2002 and 2012. 
• The women were divided into two groups: 

1. Those who took biologics during their pregnancy. 
2. Those who did not take biologics during their pregnancy. 

• The infants born to these women were also part of the study. Infants born to women taking biologics during pregnancy were considered to be exposed to biologics, while infants born to women who did not take biologics during pregnancy were considered unexposed. 

What Did We Find?

The results of this study found that using biologics during pregnancy was not associated with an increased risk of serious infections in mothers after delivery or in babies during their first year of life.  

 Specifically for mothers: for women who took biologics during pregnancy, the rate of serious infections after giving birth was low, ranging from 0% to 5%, depending on whether they also took other immunosuppressant drugs, suggesting that biologics alone did not significantly increase the risk of serious infections for mothers. 

Specifically for babies: babies born to mothers who took biologics during pregnancy also had a low rate of serious infections in their first year of life, ranging from 0% to 7%, depending on whether they were exposed to other immunosuppressant drugs in the womb. This suggests that the use of biologics during pregnancy did not seem to raise the risk of serious infections in infants. 

 Next Steps

Dr. Mary De Vera is currently working on the Following Maternal, Neonatal, and Childhood Outcomes Associated with Use of Arthritis Medications Perinatally (FAMILY) study, which will build upon this body of research. We expect that the FAMILY study will have more participants and longer follow-up periods, thus providing us with more data on this subject. 

The main takeaway from this research is that using biologics during pregnancy is safe and doesn’t appear to significantly increase the risk of serious infections for mothers and their babies.  

The Research Team

Principal Investigator:

Mary De Vera, MSc, PhD, Senior Scientist, Pharmacoepidemiology, Associate Director of Training, Arthritis Research Canada (University of British Columbia)

Co-Investigators

Gillian Hanley, PhD, Assistant Professor, Department of Obstetrics and Gynaecology, (University of British Columbia), Vancouver, Canada

Larry Lynd, PhD, BSP, Professor Faculty of Pharmaceutical Sciences, (University of British Columbia), Vancouver, Canada

Eric Sayre, PhD, Statistician, Arthritis Research Canada, Richmond, British Columbia, Canada

Nicole Tsao, BSc, MP, PhD candidate, Research Trainee, Arthritis Research Canada; PhD Student, Faculty of Pharmaceutical Sciences, (University of British Columbia), Vancouver, Canada

Mohsen Sadatsafavi, MD, PhD, Associate Professor, Faculty of Pharmaceutical Sciences, (University of British Columbia), Vancouver, British Columbia, Canada

Who Funded This Research?

Canadian Institutes of Health Research