Is light before bed linked to diabetes during pregnancy?

Researchers have found an association between greater light exposure before sleep during the second trimester of pregnancy and an increased risk of gestational diabetes.

The study, which was published in American Journal of Obstetrics and Gynecology Maternal Fetal Medicine, involved 741 pregnant women across eight clinical US sites who completed a sleep diary for seven consecutive days and wore a light sensor on their wrist.

The researchers compared this data with how many women developed gestational diabetes during routine screening between 24 and 28 weeks gestation.

The scientists found that greater pre-sleep light exposure was linked to an increased risk of gestational diabetes.

Women who developed gestational diabetes had greater light exposure in the three hours before sleep, but did not differ in light exposure during the daytime or during sleep.

Activity levels did not vary between participants who developed gestational diabetes and those who did not.