Women with active psoriatic arthritis during pregnancy were found to have a higher risk of pre-eclampsia compared with population controls, according to a Norwegian population-based cohort study.
Specifically, the researchers reported that pre-eclampsia occurred in 8.8% of women with active psoriatic arthritis compared with 2.6% in controls. Gestational hypertension was also more common among women with active psoriatic arthritis (PsA; 5.9% vs 1.7%). In contrast, women with inactive PsA had rates of pre-eclampsia (1.3%) and gestational hypertension (2.7%) that were comparable with those of controls. No differences were observed in rates of preterm birth, small for gestational age births, or large for gestational age births across groups.
No preterm cases of pre-eclampsia or gestational hypertension were identified, except for one preterm pre-eclampsia case in a woman without recorded disease activity. Although the numbers were small, the higher proportion of severe pre-eclampsia among women with active PsA indicates a possible association between disease activity during pregnancy and hypertensive disorders.
A subgroup analysis of women with obesity (body mass index of at least 30) demonstrated a higher frequency of pre-eclampsia among those with active PsA (20%) compared with controls (5.4%), though this finding did not reach statistical significance. Women with PsA were also more likely than controls to be obese and to have conceived through assisted reproductive technology, but parity, smoking, diabetes, and chronic hypertension did not differ significantly.
This prospective cohort study, published in RMD Open, analyzed 109 singleton pregnancies among women with PsA who were enrolled in the RevNatus registry between 2010 and 2019, and linked to 575,798 population controls from the Medical Birth Registry of Norway. Disease activity was assessed using the Disease Activity Score in 28 joints with C-reactive protein (CRP). Active disease was defined as Disease Activity Score in 28 joints with CRP scores of 2.6 or greater, while inactive disease was defined as less than 2.6 during the second or third trimester. Of the 109 pregnancies, 34 women had active PsA and 75 had inactive PsA.
More than half of the women with PsA in the study reported methotrexate use before pregnancy, which was consistent with its role in disease management prior to conception. Approximately 45% had used a tumor necrosis factor inhibitor before pregnancy, and about one quarter continued tumor necrosis factor inhibitor treatment during pregnancy. Corticosteroid use was reported by roughly 13% of participants in the first trimester and about 10% in the second and third trimesters. Dosage information was not available, but frequencies were similar between women who had active and inactive disease.
The primary limitation of the study was the method used to assess disease activity. DAS28-CRP, although validated for use in pregnancy for inflammatory arthritis, does not account for manifestations such as enthesitis, dactylitis, or axial disease which are common in PsA and may have resulted in underestimation of activity. PsA-specific activity measures were not available in the RevNatus registry for most of the study period, which limited evaluation of phenotype-related differences, and CRP values may have been influenced by obesity in some participants. Comparisons with previous research are also challenging because studies have used different activity indices. Missing data further affected analysis: maternal body mass index was unavailable for 31% of pregnancies due to phased implementation of electronic reporting, and exploratory models adjusting for obesity showed reduced and nonsignificant estimates. Smoking status was missing for 18% of controls, and although underreporting cannot be excluded, the higher smoking proportion in the active PsA group was not statistically significant.
“These results are relevant for clinicians and patients, especially women with active disease, as disease activity may be modified before and better controlled during pregnancy, thereby possibly improving pregnancy outcomes,” noted lead author Carina Gotestam Skorpen, of Rheumatology, Helse More og Romsdal HF in Alesund, Norway, with colleagues.
The researchers reported no conflicts of interest or external funding related to the study.
Source: RMD Open