Pregnant women with Sjögren's syndrome have pregnancy outcomes similar to those of the general population, according to the first study to prospectively track pregnancy outcomes among people with the autoimmune condition.
"Most early studies of pregnancy in rheumatic disease patients were retrospective and included only small numbers, making it difficult to know how generalizable the reported results were," said Lisa Sammaritano, MD, a rheumatologist at Hospital for Special Surgery in New York City, in an email interview with Medscape Medical News. She was not involved with the research.
Most of these previous studies suggested an increased risk of adverse outcomes, such as miscarriages, preterm deliveries, and small-for-gestational-age birthweight. But in addition to small patient numbers, retrospective studies "are subject to greater reporting bias, which may predispose patients with negative outcomes being more likely to be included because they were followed more closely," Sammaritano said.
"This prospective study has several advantages over the earlier retrospective reports: The same data were collected in the same way for all the patients, the patients were recruited at similar time points, and ― due to the multicenter nature of the cohort ― numbers are larger than in prior studies. All these factors make the results stronger and more generalizable to the Sjögren's patients we see in our practices," she added.
In the study, published May 8 in The Lancet Rheumatology, first author Grégoire Martin de Frémont, MD, of the rheumatology service at Bicêtre Hospital, Paris-Saclay University, Paris, France, and colleagues used the GR2 registry, an observational database of pregnancies of women with systemic autoimmune diseases managed at 76 participating centers in France, to identify pregnant women with primary Sjögren's syndrome. To avoid bias, only women who entered the database before 18 weeks' gestation were included. The final cohort included 106 pregnancies in 96 women with primary Sjögren's syndrome and 420 control pregnancies that were matched from the general population.
Adverse pregnancy outcomes, including preterm delivery (<37 weeks of gestation), intrauterine growth retardation, and low birth weight occurred in nine pregnancies (9%) in the Sjögren's syndrome group and in 28 pregnancies in the control group (7%). Adverse pregnancy outcomes were not significantly associated with Sjögren's syndrome (P = .52). Researchers found that there were more adverse pregnancy outcomes among women with Sjögren's syndrome with antiphospholipid (aPL) antibodies. Negative outcomes also increased among those with anti-RNP antibodies, but this association was not statistically significant.
"The main message ― based on strong data from a well-designed study ― is that patients with Sjögren's overall do as well as the general population in terms of standard adverse pregnancy outcomes. The rate of flare of Sjögren's disease was relatively low during the second and third trimesters, also reassuring," Sammaritano said. She noted that the association between adverse pregnancy outcomes and aPL antibodies was not unexpected, given that they are a known risk factor.
The study authors recommend that patients with Sjögren's syndrome be screened for aPL and anti-RNP antibodies prior to conception because of the potential increased risk for complications and that patients with positive screens be closely monitored during their pregnancy.
Sammaritano noted that there are other health problems to keep in mind. "It is important to remember that Sjögren's patients ― more than any other rheumatic disease patients ― have the additional risk for neonatal lupus and complete heart block in their infant, since about two thirds of Sjögren's patients are positive for anti-Ro/SSA antibody," she said. "This is a distinct issue related to the presence of this antibody alone and not specifically related to the underlying diagnosis. In clinical practice, positive anti-Ro/SSA antibody is often the main reason for counseling, monitoring, and even recommending therapy (hydroxychloroquine) in these patients."
The study received funding from Lupus France, the France Association of Scleroderma , and the Association Gougerot Sjögren, among others. Sammaritano reports no relevant financial relationships.
Lancet Rheumatol. Published online May 8, 2023. Abstract
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Image 1: Hospital for Special Surgery
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Cite this: First Prospective Study Finds Pregnancies With Sjögren's to Be Largely Safe - Medscape - May 25, 2023.