Pregnancy can lead to remission of rheumatoid arthritis (RA), although less frequently than previously described, a prospective study has shown.
It is well recognized that pregnancy leads to RA remission, but the studies supporting this association have generally been retrospective and reliant on patient self-reporting or doctors' observations.
The one prospective study that has been conducted showed that RA symptoms improved in 63% of pregnant patients.
However, this study did not use objective information on disease activity from before conception or during early pregnancy, and it did not use validated systems for scoring disease activity and remission.
In addition, at the time of this study, treatments to reduce disease activity before pregnancy were not available.
Noting this, Yaël de Man (University Medical Center, Rotterdam, The Netherlands) and co-workers conducted a prospective cohort study of 84 women with RA who were assessed from before conception, where possible, until 26 weeks postpartum.
As published in the journal Arthritis Care and Research, approximately 30% of women experienced complete disease remission during the third trimester despite the fact that most women stopped taking anti-rheumatic medications shortly before becoming pregnant.
Improvement in disease symptoms was followed by a rebound effect after birth in 39% of women.
"Moderate" disease improvement, as defined by the 28-item disease activity score (DAS-28), was seen in 48% of the 52 women who had moderate disease before conception.
In contrast, women with low levels of disease activity during the first trimester showed no significant changes in disease severity during pregnancy.
Since only one third of patients in this study experienced disease remission during pregnancy, the investigators remark: "The assumption of rheumatologists, based on previous studies, that almost all patients with RA will experience a remission of disease activity during pregnancy does not seem to be valid today."
However, noting that this is the first study to use the validated DAS-28 to measure disease activity during pregnancy, they caution: "Any comparison with previous studies can only be made indirectly."