Women with rheumatic diseases are at greater risk of complications during pregnancy and childbirth, but for women with arthritis of the spine, so called axial spondyloarthritis, the risks have decreased over the last ten years, according to a register study from Karolinska Institutet. This decrease coincided with an increased use of biologic drugs during the same period. The study was published in The Lancet Rheumatology.

Research has previously shown that women with rheumatic diseases are at increased risk of complications during pregnancy and childbirth, but for women with the rheumatic disease axial spondyloarthritis there has been little and conflicting information. The aim of this study was therefore to assess the risks of adverse pregnancy outcomes in a large cohort of women with axial spondyloarthritis and to examine how these outcomes varied over time, as well as in relation to the anti-rheumatic treatment the women received for their disease.

The study showed that women with axial spondyloarthritis are generally at greater risk of complications such as preterm birth, delivery with cesarean section and for the baby having serious infections in the first year of life. The researchers also discovered that the risk of complications decreased over the study period of 14 years, ending up at similar levels as in the general population. This reduction coincided with the increasing use of effective biological drugs to treat axial spondyloarthritis.

The question of whether or not continue your anti-rheumatic treatment during pregnancy can be perceived as difficult for the pregnant woman, weighting risks of active rheumatic disease against potential risks of exposing the fetus to anti-rheumatic drugs. The study shows that, despite immunosuppressive treatment with biologic drugs, women who gave birth in recent years had fewer complications than those who gave birth early in the study period when these drugs were not available. This result reinforces current guidelines to continue treatment at least well into pregnancy and may be reassuring for women with axial spondyloarthritis who are considering pregnancy.

In this observational study, including the years 2007–2020, the researchers compared the incidence of complications during pregnancy and childbirth in 1580 births in women with axial spondyloarthritis to approximately 16,000 births from the general population, with the same distribution of year of delivery and maternal age. Other factors such as maternal BMI, smoking status and country of birth were also considered. Additionally, the researchers explored how the number of women who had collected prescriptions for biologic drugs and other anti-rheumatic drugs before and during pregnancy had changed over the study period.