Miscarriages, terminations rise after RA onset.(OBSTETRICS)

SAN FRANCISCO -- Women who got pregnant after the onset of rheumatoid arthritis had a slightly higher risk of miscarriage, compared with pregnant women as a whole, according to a study of 1,461 pregnancies in 636 women with rheumatoid arthritis.

Many more pregnancies in the retrospective study occurred before rheumatoid arthritis symptoms appeared than occurred after disease onset.

The 2% rate of pregnancy termination in the 86% of women who got pregnant before the onset of rheumatoid arthritis symptoms was significantly lower than a 6% termination rate among the 14% of women who got pregnant after developing arthritis, Dr. Cecilia Friden and her associates reported at the annual meeting of the American College of Rheumatology.

The investigators compared data on pregnancy histories in women who were enrolled in a hospital-based rheumatoid arthritis registry in Boston with U.S. data on pregnant women of comparable ages (20-44 years), and compared outcomes between women who became pregnant before or after developing arthritis.

The cohort's history of 1,461 pregnancies included 1,146 live births, with birth defects in 2% of neonates.

There was no association between the risk of birth defects and the timing of the onset of rheumatoid arthritis, said Dr. Friden of the Karolinska Institute, Stockholm.

The study did not collect information on the use of disease-modifying antirheumatic drugs.