TOPLINE:

Patients with rheumatoid arthritis (RA) experienced more disease flares in the first 6 months postpartum than during pregnancy, whereas those with spondyloarthritis (SpA) had similar flare rates. Only a small proportion of patients with RA and SpA continued biologic disease-modifying antirheumatic drug (bDMARD) therapy throughout the pregnancy and the postpartum period, although approximately half resumed treatment after delivery.

METHODOLOGY:

• Researchers conducted an ancillary analysis of a French prospective cohort study to evaluate postpartum disease activity, treatments, and effects of breastfeeding on disease outcomes in patients with RA and SpA.
• The study included 218 pregnant women ­— 94 with RA and 124 with SpA — who were enrolled at or before 12 weeks of gestation, had a live birth, and had at least one postpartum visit; the mean age at pregnancy was approximately 32 years in both groups.
• Participants were followed up every trimester during pregnancy and at 6 and 12 months postpartum. Data on treatments (the use, discontinuation, and resumption of bDMARDs during pregnancy and the postpartum period), flares, and breastfeeding status were collected.
• Disease activity was assessed using the disease activity score 28 joints C-reactive protein (DAS28-CRP) for RA and the Bath Ankylosing Spondylitis Disease Activity Index and axial SpA DAS CRP for SpA, along with physician-confirmed flares at each visit.

TAKEAWAY:

• Among patients with RA with available data, 62.0% experienced at least one flare within the first 6 months postpartum and 43.5% experienced it during pregnancy (P = .02). For those with SpA, flare rates were identical at 40.7% during pregnancy and at 6 months postpartum.
• No significant differences in disease activity were observed between pregnancy and 6 months postpartum among patients with RA and those with SpA; however, CRP levels were higher during pregnancy than at 6 months postpartum in those with SpA (7.0 vs 3.2 mg/L; P = .014).
• The continuation of bDMARDs throughout pregnancy and postpartum was low, with only 13 of 91 (14.3%) patients with RA and 29 of 123 (23.6%) patients with SpA continuing treatment across both periods. More than half of those who were untreated at delivery restarted bDMARDs postpartum.
• In patients with RA, the mean DAS28-CRP during pregnancy (adjusted hazard ratio [aHR], 1.4; P = .016) and resuming or initiating bDMARDs during the postpartum period (aHR, 2.4; P = .005) were independently associated with an increased likelihood of flares during the postpartum period. In those with SpA, no such factors were identified.

IN PRACTICE:

"The use of bDMARDs during pregnancy may be appropriate for some patients with active disease, with the potential benefit of lowering postpartum flare risk, while carefully weighing risks and benefits," the authors wrote.

SOURCE:

This study was led by Marie Hornez, Université de Lille, CHU Lille, Lille, France. It was published online on April 28, 2026, in RMD Open.

LIMITATIONS:

Data on disease activity measures such as CRP levels and DASs were lacking. Flares were reported by patients, which may have overestimated flare rates. The frequency of visits during pregnancy varied across patients, and only a limited number of patients were enrolled during the preconception period.

DISCLOSURES:

The GR2 (Groupe de recherche sur la Grossesse et les Maladies Rares) study received support from Lupus France, association des Sclérodermiques de France, Association Gougerot Sjögren, UCB, and other sources. Several authors reported receiving research grants, consulting fees, honoraria, and travel grants and having advisory roles in various pharmaceutical or biopharmaceutical companies such as AbbVie, Amgen, Biogen, and others.

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