We hypothesized that poor sleep quality exacerbates glucose intolerance manifested as elevated glycosylated hemoglobin (HbA1c), which increases the risk for gestational diabetes. To test this, 38 pregnant and 22 non-pregnant (age, 18–35 years; body-mass index, 20–35 kg/m2) otherwise healthy women were enrolled in the study. Sleep quality was assessed during gestational week 24 (pregnant), or outside of the menstrual period (non-pregnant), using qualitative (Pittsburgh Sleep Quality Index) and objective (actigraphic wrist-watch) measures. Blood glucose, total cortisol, and depression status were evaluated. Eight pregnant and one non-pregnant women were lost to follow-up, or withdrew from the study. There was a higher incidence of poor sleep quality in pregnant (73%) relative to non-pregnant women (43%). Although actigraphic data revealed no differences in actual sleep hours between pregnant and non-pregnant women, the number of wake episodes and sleep fragmentation were higher in pregnant women. Poor sleep quality was positively correlated with higher HbA1c in both pregnant (r = 0.46, n = 26, p = 0.0151) and non-pregnant women (r = 0.50, n = 19, p = 0.0217), reflecting higher average blood glucose concentrations. In contrast, poor sleep was negatively correlated with cortisol responses in pregnant women (r = −0.46, n = 25, p = 0.0167). Three pregnant women had elevated one-hour oral glucose tolerance test results (>153 mg/dL glucose). These same pregnant women exhibited poor sleep quality. These results support the suggestion that poor sleep quality is an important risk factor that is associated with glucose intolerance and attendant health complications in pregnancy.

INTRODUCTION: There is a paucity of studies that have evaluated the attendant health risk of sleep disturbances during pregnancy. We tested the hypothesis that poor sleep quality is a major risk factor for gestational diabetes mellitus. METHODS:We recruited 29 pregnant women (13 nulliparous, 16 multiparous) and 13 nonpregnant women as controls who met the criteria for inclusion (ie, healthy, ages 18-35 years, body mass index 20-35 kg/m 2 ). Sleep quality and duration were measured using Actigraphic sleep watches. Oral glucose tolerance test, hemoglobin A1C, and cortisol levels were also measured. RESULTS:One-way analysis of variance yielded no significant differences among the three groups in bedtime sleep duration (F [2, 38] 1.240, P,.301, or daily sleep content, F [2, 37] 1.538, P#.229). Significant differences were in the high number of wake episodes (F [2, 37] 9.855, P,.001) and higher sleep fragmentation index in pregnant women (F [2, 37] 5.023, P,.012). We found a significant correlation between increased sleep disturbances and elevated hemoglobin A1C in pregnant women (r50.4649, n525, P,.017). By contrast, cortisol levels did not correlate significantly with elevated HbA1C (r520.2398, n525, P,.229). Three pregnant women had elevated 1-hour oral glucose tolerance test scores (greater than 153 mg/dL glucose). These same pregnant women also had poor sleep quality. CONCLUSIONS:The results were consistent with our proposition that poor sleep quality may be a risk factor for gestational diabetes mellitus.