Rheumatoid arthritis in pregnancy linked to adverse fetal outcomes

Rheumatoid arthritis is a chronic inflammatory disease that affects a person's joints, causing pain and disability. It can also affect internal organs. RA is more common in older people, but there is also a high prevalence in young adults, adolescents, and even children, and it affects women more frequently than men.

During pregnancy many women with RA experience improvement in their symptoms. This is thought to be due to adaptation in the body which suppress the immune system to stop the mother from rejecting the fetus. However, lesser is known about the effect of RA on fetuses.

For the study, the investigators identified 845 women with single pregnancies who also had RA from over two million pregnancies within the Taiwan National Health Insurance database and birth registry between 2001 and 2012. Statistical analysis was conducted using an adjusted generalized estimating equation model to estimate the association between RA and pregnancy outcomes.

• Babies born to women with RA were associated with an increased chance of low birthweight (OR 1.65, 95% CI 1.37-1.98), prematurity (OR 1.41, 95% CI 1.13-1.68), and being small for their gestational age (OR 1.62, 95% CI 1.36-1.92).


• There were no potential risks to the mother, apart from preterm labor.


• Investigated outcomes included birth-related death, cardiovascular complications, surgical complications and other systemic organ dysfunction.

"Our results add to a growing body of evidence from different populations suggesting small but significant increases in prematurity and a decrease in birth weight in pregnancies in mothers with rheumatoid arthritis," said Dr. Tsai. "While these findings are important, they should not discourage women with RA from trying to conceive."

"Pregnancies in women with RA were at a higher risk for multiple adverse fetal-neonatal outcomes, especially low birthweight (<2500 g), prematurity (<37 weeks), and small for gestational age. Maternal outcomes showed that just preterm labor was more common in women with RA. Women with RA should not be discouraged to seek pregnancy based on the disease alone," concluded the authors.