Sleep disruption during pregnancy: how does it influence serum cytokines?

Women report their sleep to be disrupted during pregnancy. Sleep deprivation has been linked to elevations in pro-inflammatory cytokine levels. No information currently addresses the sleep-immune relationship during pregnancy. This study explores the relationship between subjectively reported sleep variables and circulating serum cytokine levels. Pregnant women (n=35; mean age=31.0+/-3.7 years) seen once a trimester completed sleep questionnaires, gave blood and recorded their sleep on a sleep diary at home for 2 weeks. Nonpregnant women (n=43; mean age=28.2+/-5.2 years) underwent the same protocol once. Subjective sleep variables were compared to serum cytokine levels for IL-4, -6, -10 and TNF-alpha as well as C-reactive protein (CRP) determined by ELISA. Nonparametric analyses and linear regression were performed to explore relationships between the sleep and immune variables. Pregnant women subjectively reported their sleep to be worse than in the nonpregnant group. Serum cytokine levels differed between the two groups and varied by trimester. As anticipated, IL-10 was significantly higher in all trimesters; however CRP, an indicator of systemic inflammation, was higher in all trimesters compared to the nonpregnant sample. Subjectively reported sleep disruption was associated with increases in TNF-alpha in the pregnant sample and CRP in the nonpregnant sample. These data confirm that disrupted sleep experienced during pregnancy, as well as during the nonpregnant state, is related to increases in inflammatory markers. Future exploration of these relationships should include functional assessments of immunity as well as polysomnographically recorded sleep.