Women with arthritis at increased risk for preterm delivery

Women with juvenile idiopathic arthritis (JIA) and rheumatoid arthritis (RA) are at increased risk for preterm delivery (PTD) as compared to healthy women, finds a prospective cohort study published in the journal Arthritis Care & Research.

Pregnant women with inflammatory arthritis may be at increased risk for preterm delivery (PTD), yet it is unclear what drives this risk. Chelsey J. F. Smith, Division of Rheumatology, Allergy, and Immunology, University of California San Diego, CA, and colleagues conducted the study to analyze independent effects of maternal disease activity, medication use, and comorbid pregnancy conditions on PTD risk in women with rheumatoid arthritis and juvenile idiopathic arthritis versus normal healthy women.

The research team analyzed a total of 657 women with RA, 170 with JIA, and 564 comparison women without the autoimmune disease who delivered live‐born infants. Data on pregnancy events, medications, disease activity, and outcomes were obtained by maternal report and validated by medical records.

Disease activity was evaluated with the Health Assessment Questionnaire, pain scores, and patient global assessment of disease activity, with those three scores used to calculate a Patient Activity Scale (PAS), which ranged from zero to 10. High disease activity was a PAS above 3.70. Preterm delivery was defined as birth before 37 weeks' gestation.

Also Read: Rheumatoid arthritis in pregnancy linked to adverse fetal outcomes

Key Results:

• Both RA and JIA groups had an increased risk of PTD versus the comparison group (RR 2.09, 95% CI 1.50‐2.91; and RR 1.81, 95% CI 1.14‐2.89, respectively).


• Active RA at enrollment (aRR 1.58, 95% CI 1.10‐2.27) and anytime during pregnancy (aRR 1.52, 95% CI 1.06‐2.18) was associated with PTD.


• Corticosteroid use in every trimester was associated with an approximate 2 to 5‐fold increased risk for PTD for both arthritis groups, independent of disease activity.


• More women with RA or JIA had a history of three or more spontaneous abortions and reported more tobacco use and pre-gestational hypertension.

Most participants were white and were in higher socioeconomic strata. Maternal age at the estimated due date was significantly higher in the RA group than in the comparison group (33.14 versus 32.09 years, P<0.001) and lower in the JIA group (30.55, P<0.001).

Among the RA group, medication exposure during pregnancy included the use of biologics in 71.5% of the participants, disease-modifying anti-rheumatic drugs (DMARDs) in 40%, nonsteroidal anti-inflammatory drugs (NSAIDs) in 27.9%, and corticosteroids in 53.4%. In the JIA group, exposures to those classes of drugs were reported in 76.5%, 26.5%, 31.8%, and 54.7%, respectively.

In univariate analyses, women with RA and JIA were at increased risk for preterm labor, early term and moderate preterm delivery, and cesarean section. Women with RA also had a higher risk of very preterm delivery and gestational diabetes, while those with JIA had an increased risk of preeclampsia.

On a multivariate analysis that adjusted for age, race, socioeconomic status, body mass index, tobacco use, parity, previous adverse pregnancy outcomes, and steroid use during the first trimester, active disease in women with RA was associated with preterm delivery at the time of enrollment (RR 1.58, 95% CI 1.10-2.27) as well as at any time during pregnancy (RR 1.52, 95% CI 1.06-2.18).

Also on the multivariate analysis, use of corticosteroids during any trimester was significantly associated with preterm delivery for women with both RA and JIA. During the first trimester, the adjusted risk ratios for preterm delivery with corticosteroid exposure were 1.96 (95% CI 1.36-2.83) for women with RA and 3.37 (95% CI 1.53-7.43) for those with JIA. In the second trimester, the adjusted risk ratios were 1.86 (95% CI 1.27-2.73) and 4.64 (95% CI 1.98-10.84), respectively, while in the third trimester, the risk ratios were 2.13 (95% CI 1.46-3.11) and 4.90 (95% CI 2.02-11.89).

Further work will be needed to differentiate the influence of disease activity and steroid exposure, as these drugs may have been given for disease flares, the authors explained.

The risk for preterm delivery also was increased among women with JIA who were exposed to NSAIDs during the first trimester (RR 2.31, 95% CI 1.04-5.14). No increased risk was observed with exposure to biologics or DMARDs.

Adjusted risks for preterm delivery also were elevated for women with RA with these pregnancy complications:

• Preeclampsia, RR 2.05 (95% CI 1.18-3.55)


• Pregnancy-induced hypertension without preeclampsia, RR 1.88 (95% CI 1.13-3.13)


• Placenta previa or abruption, RR 4.39 (95% CI 2.26-8.53)


• Gestational diabetes, RR 1.87 (95% CI 1.10-3.20)

For women with JIA, the only pregnancy complication associated with preterm delivery was fever during pregnancy (RR 3.06, 95% CI 1.42-6.56). That may signify active disease, the authors noted.

Study limitations, the authors noted, included the small JIA sample and a lack of information about the timing of onset of preeclampsia.

"Women with RA and JIA are at increased risk for PTD. Maternal disease activity and corticosteroid use may contribute to some of this excess risk. Further studies will be needed to examine other types of arthritis and the effects on pregnancy outcomes," concluded the authors.

For more information log on to https://doi.org/10.1002/acr.23730