Glucocorticosteroids in pregnant patients with rheumatoid arthritis.

The ameliorating effect of pregnancy on rheumatoid arthritis (RA) has been well known since 1938 and repeatedly confirmed for 75% of RA pregnancies. Improvement of symptoms usually occurs already in the first trimester and increases as pregnancy progresses. A flare of RA is observed within 6 months after delivery in most patients. Originally believed to be due to the increase of cortisol during pregnancy, three studies of the 1950-60s did not find a correlation between cortisol levels and disease activity in pregnant patients. Also the timing of gestational improvement and the postpartum flare does not coincide with the rise and fall of cortisol levels. New research has disclosed neuroendocrine disturbances in RA including a relative glucocorticoid deficiency. The complex hormonal and immunological alterations of pregnancy may temporarily correct the neuroendocrine defects. The precise role of glucocorticoids in pregnancy-induced remission of RA still needs to be clarified.