Prevalence of Autoimmune Diseases Rose in UK Pregnancies

TOPLINE:

Over the past two decades, the prevalence of autoimmune diseases among pregnant women in the UK has significantly increased, with psoriasis being the most common condition. The likelihood of diagnosis varied across sociodemographic factors, including age, ethnicity, and socioeconomic status.

METHODOLOGY:

• Researchers conducted a UK population-based retrospective cohort study using routinely collected primary care data from Clinical Practice Research Datalink Gold and Aurum pregnancy registers.
• This study included 5,165,960 pregnancies in 2,831,472 women aged 15-49 years from 2000 to 2021, including 185,208 pregnancies in 100,655 women with a coded diagnosis of autoimmune disease.
• Researchers evaluated the prevalence trend, calculated annually for both overall and each of 17 autoimmune diseases, during pregnancy via diagnostic codes and analysed their associations with sociodemographic factors.

TAKEAWAY:

• The overall prevalence of autoimmune diseases during pregnancy increased from 3.5% in 2000 to 4.7% in 2021; psoriasis was the most prevalent condition, followed by inflammatory bowel disease and rheumatoid arthritis between 2000 and 2010 and type 1 diabetes and inflammatory bowel disease in 2010-2021.
• The prevalence of most of the autoimmune diseases significantly increased between 2000 and 2021, with the steepest rise observed in Hashimoto’s thyroiditis (+6.22%), coeliac disease (+6.20%), and alopecia areata (+4.75%).
• Women living in less deprived areas had higher odds of autoimmune diseases during pregnancy than those living in more deprived areas (adjusted odds ratio [aOR], 1.10; 95% CI, 1.07-1.14), and Black women had significantly lower odds than White women (aOR, 0.48; 95% CI, 0.45-0.51).
• Compared with women aged 15-20 years, those aged 21-30 years (aOR, 1.17; 95% CI, 1.14-1.20), 31-40 years (aOR, 1.50; 95% CI, 1.45-1.55), and 41-50 years (aOR, 1.75; 95% CI, 1.68-1.82) had increased odds of being diagnosed with autoimmune disease before pregnancy.

IN PRACTICE:

“This study gives a clear estimate of the burden of autoimmune diseases in pregnancy in the UK and the possible association with various demographic factors, and will help the process of improving maternity care for women with these health conditions,” the authors wrote.

SOURCE:

This study was led by Megha Singh, PhD, Department of Applied Health Sciences, College of Medicine and Health, University of Birmingham, Birmingham, England. It was published online on June 02, 2025, in The Lancet Rheumatology.

LIMITATIONS:

This study did not include some rare autoimmune diseases like dermatomyositis. Although the use of primary care data reduced entry-level coding biases, improvements in recording practices over time might affect data quality and completeness, potentially affecting observed trends. Additionally, this study may have underestimated the prevalence of autoimmune diseases since most cases are diagnosed and managed in secondary care.

DISCLOSURES:

This study was supported by the Strategic Priority Fund “Tackling multimorbidity at scale” programme. One author initially worked at the University of Birmingham and later joined AstraZeneca and currently holds an honorary contract with the University of Birmingham.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.