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Use of biologics during pregnancy and risk of serious infections in the mother and baby: a Canadian population-based cohort study
  1. Nicole W Tsao1,
  2. Larry D Lynd1,2,
  3. Eric C Sayre3,
  4. Mohsen Sadatsafavi1,
  5. Gillian Hanley4,
  6. Mary A De Vera1
  1. 1 Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
  2. 2 Centre for Health Evaluation and Outcomes Sciences, Vancouver, British Columbia, Canada
  3. 3 Arthritis Research Canada, Richmond, British Columbia, Canada
  4. 4 Department of Obstetrics & Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada
  1. Correspondence to Dr Mary A De Vera; mdevera{at}


Objectives To investigate the association between exposure to biologics during pregnancy and serious infections in mothers and infants.

Design Retrospective cohort study.

Setting Population-based.

Participants Women with one or more autoimmune diseases identified by International Classification of Diseases 9th/10th revision codes in healthcare administrative databases in British Columbia, Canada, who had pregnancies ending in a live or stillbirth between 1 January 2002 and 31 December 2012. Women were defined as exposed if they had at least one biologic prescription during pregnancy, and infants born to these women were considered exposed in utero. Disease-matched women with no biologics prescriptions during pregnancy, and their infants, comprised the unexposed groups.

Primary outcome measures Serious infections requiring hospitalisation.

Results Over the 10-year study period, there were 6218 women (8607 pregnancies) who had an autoimmune disease diagnosis, of which 90 women were exposed to biologics during pregnancy, with 100 babies born to these women. Among women exposed to biologics during pregnancy, occurrence of serious postpartum infections were low, ranging from 0% to 5%, depending on concomitant exposures to immunosuppressants. In multivariable models using logistic regression, the OR for the association of biologics exposure with serious maternal postpartum infections was 0.79 (95% CI 0.24 to 2.54). In infants exposed to biologics in utero, occurrence of serious infections during the first year of life ranged from 0% to 7%, depending on concomitant exposures to immunosuppressants in utero. Multivariable models showed no association between biologics exposure in utero and serious infant infections (OR 0.56, 95% CI 0.17 to 1.81).

Conclusions These population-based data suggest that the use of biologics by women with autoimmune diseases during pregnancy is not associated with an increased risk of serious infections in mothers, during post partum or in infants during the first year of life.

  • adverse events
  • rheumatology
  • inflammatory bowel disease
  • epidemiology

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  • Patient consent for publication Not required.

  • Contributors Concept and design: MADV, NWT; acquisition, analysis and interpretation of data: MADV, NWT, ECS; drafting of manuscript: NWT, MADV; critical revision of manuscript for important intellectual content: NWT, MADV, MS, GH, LDL; statistical analysis: NWT, ECS; obtained funding: MADV.

  • Funding This research was funded by Arthritis Society Operating Grant (YIO-13-07) and Canadian Institutes of Health Research Operating Grant: Analyses of Existing Canadian Cohorts and Databases (AO1-151540).

  • Disclaimer The funders had no part in the design, conduct or reporting of this study.

  • Competing interests LDL has received honoraria from Boehringer Ingelheim and Pfizer Canada for consulting services unrelated to this study. NWT is a Canadian Institutes of Health Research Fellowship holder. LDL is a Professor, and Director of Collaboration for Outcomes Research and Evaluation. ECS is a Research Associate and Statistician at Arthritis Research Canada. MS is an Assistant Professor, Canadian Institutes of Health Research New Investigator, and Michael Smith Foundation for Health Research Scholar. GH is an Assistant Professor, Canadian Institutes of Health Research New Investigator, and a recipient of Canadian Cancer Society Research Institute Capacity Development Award. MADV is an Assistant Professor, Canada Research Chair in Medication Adherence, Utilization, and Outcomes, The Arthritis Society Network Scholar, and Michael Smith Foundation for Health Research Scholar.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Due to privacy agreements, data used in this study cannot be shared.