RESUMO
Maternal-fetal consequences of exposure to blue-wavelength light are poorly understood. This study tested the hypothesis that evening blue-light exposure is associated with maternal fasting glucose and infant birthweight. Forty-one pregnant women (body mass index = 32.90 ± 6.35 kg/m2 ; 24-39 years old; 16 with gestational diabetes mellitus [GDM]) wore actigraphs for 7 days, underwent polysomnography, and completed study questionnaires during gestational week 30 ± 3.76. Infant birthweight (n = 41) and maternal fasting glucose (n = 30; range = 16-36 weeks) were recorded from the mothers' medical charts. Blue-light exposure was obtained from Actiwatch-Spectrum recordings. Adjusted and unadjusted linear regression analyses were performed to determine sleep characteristics associated with maternal fasting glucose and infant-birthweight. The mean fasting mid- to late-gestation glucose was 95.73 ± 24.68 mg/dl and infant birthweight was 3271 ± 436 g. In unadjusted analysis, maternal fasting glucose was associated with blue-light exposure (ß = 3.82, p = 0.03). In the final model of multiple linear regression for fasting glucose, evening blue-light exposure (ß = 4.00, p = 0.01) remained significant after controlling for gestational weight gain, parity, sleep duration, and GDM. Similarly, blue-light exposure was associated with infant birthweight (69.79, p = 0.006) in the unadjusted model, and remained significant (ß = 70.38, p = 0.01) after adjusting for weight gain, wakefulness after sleep onset, gestational age at delivery, and GDM. Higher blue-light exposure in pregnancy is associated with higher fasting glucose and infant birthweight. Reduced use of electronic devices before bedtime is a modifiable behavior.
