Allostatic load in early pregnancy is associated with poor sleep quality.

Background: Allostatic load (AL) measures the cumulative impact of chronic stress and is associated with adverse health outcomes. A novel scoring system has previously been developed for AL in early pregnancy that is associated with pre-eclampsia. It was hypothesized that AL, as identified by the present model, is associated with psychosocial stressors and, specifically, poor sleep quality.

Methods: Women were selected from a low-risk, community-dwelling study population who enrolled at <15 weeks gestation. Nine physiologic components were divided among the domains of cardiovascular, metabolic, and inflammatory function. Spearman's rank correlations were used to examine the association of AL with age, income, the Revised Prenatal Distress Questionnaire (NuPDQ), Inventory of Depressive Symptoms (IDS), and Pittsburgh Sleep Quality Index (PSQI). The Wilcoxon rank-sum test was used to compare AL by race and educational attainment.

Results: A total of 103 women were identified, with: a mean age of 29.8 ± 5.0 years, 17.5% black, and mean gestational age 12.2 ± 1.1 weeks. Allostatic load was positively correlated with the PSQI (ρ = 0.23, p = 0.018). There were no associations with age, income, prenatal distress, race, or depression scores. College-educated women had lower AL compared with those with less education (0.57 ± 0.43 vs 0.81 ± 0.55, p = 0.045).

Conclusion: Higher AL, measured by the pregnancy-specific model, was associated with poorer sleep quality and lower educational attainment, both of which were considered to be chronic stressors. These relationships were consistent with previous findings in non-pregnant populations, and suggest that AL may be useful for capturing the physiologic impact of chronic stress in early pregnancy.