Maternal IL-10 and IL-6 levels are associated with fetal growth in RA. In the first trimester, high IL-10 levels are associated with higher birth weight SDS, and high IL-6 levels are associated with lower birth weight SDS, even after correction for disease activity.

Objective Pregnant women suffering from autoimmune disease use glucocorticoids. Glucocorticoids can partly diffuse to the foetus and may influence the development of the foetal hypothalamic-pituitary-adrenal axis, especially in early stage of pregnancy. The objective was to investigate whether prednisone exposure in utero influences the cortisol levels of the prepubertal children. Design Mothers participated in a prospective cohort study on rheumatoid arthritis (RA) and pregnancy. Children were exposed (n = 44) or nonexposed (n = 65) to prednisone in utero. Salivary cortisol levels were taken from all children during 1 day: at awakening, 30 min after awakening, 1 p.m. and bedtime. Cortisol levels between groups were also analysed using area under the curve (AUC), cortisol awakening response (CAR) and slope. Results The mean age (SD) of the children was 6Á98 (1Á23). The difference in mean (SD) cortisol level at '1 p.m.' was 5Á42 nM (4Á08) in the prednisone-exposed and 3Á97 nM (4Á00) in the nonexposed (P = 0Á03). Prednisone-exposed children had a higher AUC (b = 13Á28; P = 0Á02), even after correction for RA disease activity. No differences were found on CAR, slope or blood pressure. The cortisol levels of the nonexposed were more similar to the age-specific references than the prednisoneexposed. Conclusion Prednisone use during pregnancy is associated with a higher daytime cortisol level, in the prepubertal offspring, not yet accompanied with clinical outcomes. This conclusion will have no consequences at this moment, but it does raise questions concerning prednisone exposure in utero and the long-term consequences for the offspring.

Objective. Active rheumatoid arthritis (RA) during pregnancy and the presence of rheumatoid factor (RF) or anti-citrullinated protein antibodies (ACPAs) are associated with lower birth weight of the child. Moreover, treatment of the mothers with prednisone may shorten the gestational age at birth. Rapid catch-up in weight for length during the first year of life has been related to a worse cardiovascular and metabolic profile in early adulthood. This study was therefore undertaken to assess the influence of RA disease activity, medication use, and presence of RF or ACPAs during pregnancy on the growth of the child in the first year of life.Methods. Among 180 children born to mothers with RA, the tempo of catch-up in weight during the first year of life was studied. Independent variables were the extent of RA disease activity (according to the Disease Activity Score in 28 joints [DAS28]), medication use, and presence of RF or ACPAs during pregnancy.Results. Of 167 children with available data, 52 (31%) showed catch-up in weight in the first year of life, of whom 90% (47 of 52) showed rapid catch-up. An elevated DAS28 score in the mother was associated with rapid catch-up in weight of the offspring, independent of maternal medication use or the presence of RF or ACPAs during pregnancy (odds ratio 1.44 [95% confidence interval 1.07-1.95] per 1-point increase in the DAS28). Use of medications during pregnancy had no influence on postnatal growth.Conclusion. Elevated RA disease activity during pregnancy should be avoided because it is associated with rapid postnatal catch-up in weight, a risk factor for a worse cardiovascular and metabolic profile in adults. Medication for RA during pregnancy, including prednisone, had no effect on growth. Continuation or extension of medication will not only improve maternal health during pregnancy, but could be beneficial for the future health of the unborn child.