Medication use during pregnancy and pregnancy outcomes in women with immune mediated inflammatory diseases: a...

Immune mediated inflammatory diseases (IMID) affect women of childbearing age, yet there is a lack of evidence about the risk of adverse pregnancy outcomes and the interaction with medication. This study aims to characterize prescribing patterns and pregnancy outcomes in women with an IMID diagnosis.

Pregnancies to women with rheumatoid arthritis (RA), psoriatic arthritis (PsA), psoriasis (PsO), spondyloarthritis (SpA) and inflammatory bowel disease (IBD) were identified within the Clinical Practice Research Datalink, between 1 January 2000 and 31 June 2020, and matched to pregnancies in women with no such diagnosis. Drug prescribing patterns were described during and surrounding pregnancy. The risk of spontaneous pregnancy loss and major congenital malformations (MCMs) were evaluated compared with women without an IMID. Exposure to commonly prescribed disease-modifying anti-rheumatic drugs was evaluated.

The risk of a spontaneous pregnancy loss ranged from adjusted hazard ratio (HRadj) 1.01 (95% CI: 0.79, 1.28) for PsA to HRadj 1.18 (95% CI: 1.07, 1.30) for IBD when compared with women without these conditions. No significant increases in the overall risk of MCMs were observed, with the exception of IBD where it reached borderline significance based on sensitivity analyses [adjusted odds ratio 1.31 (95% CI: 1.00, 1.71)]. No evidence of an increased risk of spontaneous loss was observed in women taking azathioprine, mesalazine and sulfasalazine.

We found no increased risk of spontaneous loss in women with RA, PsA or SpA but a small increase in women with psoriasis or IBD. There was a borderline increased risk of all MCMs in offspring of women with IBD, which should be interpreted cautiously because of potential residual confounding.