Premium
Mediation of Adverse Pregnancy Outcomes in Autoimmune Conditions by Pregnancy Complications: A Mediation Analysis of Autoimmune Conditions and Adverse Pregnancy Outcomes
Author(s) -
Bandoli Gretchen,
Singh Namrata,
Strouse Jennifer,
Baer Rebecca J.,
Donovan Brittney M.,
Feuer Sky K.,
Nidey Nichole,
Ryckman Kelli K.,
JelliffePawlowski Laura L.,
Chambers Christina D.
Publication year - 2020
Publication title -
arthritis care and research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.032
H-Index - 163
eISSN - 2151-4658
pISSN - 2151-464X
DOI - 10.1002/acr.24037
Subject(s) - medicine , pregnancy , preeclampsia , gestational diabetes , obstetrics , adverse effect , premature birth , gestational hypertension , gestation , genetics , biology
Objective Autoimmune conditions are associated with an increased risk of adverse pregnancy complications and outcomes, suggesting that pregnancy complications may mediate the excess risk. We performed a causal mediation analysis to quantify the mediated effects of autoimmune conditions on adverse pregnancy outcomes. Methods We queried a California birth cohort created from linked birth certificates and hospital discharge summaries. From 2,963,888 births, we identified women with rheumatoid arthritis ( RA ), systemic lupus erythematosus ( SLE ), psoriasis, and inflammatory bowel disease ( IBD ). Pregnancy complications included preeclampsia/hypertension, gestational diabetes mellitus, and infection in pregnancy. Adverse pregnancy outcomes were preterm birth, cesarean delivery, and small for gestational age. We performed a mediation analysis to estimate the total effects of each autoimmune condition and adverse pregnancy outcome and the indirect effects through pregnancy complications. Results All 4 autoimmune conditions were associated with preterm birth and cesarean delivery, and RA , SLE , and IBD were associated with offspring that were small for gestational age. The strongest mediator of RA , SLE , and psoriasis was preeclampsia/hypertension, accounting for 20–33% of the excess risk of preterm births and 10–19% of excess cesarean deliveries. Gestational diabetes mellitus and infections generally mediated <10% of excess adverse pregnancy outcomes. Of the 4 autoimmune conditions, selected pregnancy complications mediated the least number of adverse pregnancy outcomes among women with IBD . Conclusion We found evidence that some excess risk of adverse pregnancy outcomes is mediated through pregnancy complications, particularly preeclampsia/hypertension. Quantifying excess risk and associated pathways provides insight into the underlying etiologies of adverse pregnancy outcomes and can inform intervention strategies.