Evening blue‐light exposure, maternal glucose, and infant birthweight

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/m 2 ; 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 ( β = 3.82, p = 0.03). In the final model of multiple linear regression for fasting glucose, evening blue‐light exposure ( β = 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 ( β = 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.