0310 Low light exposure during wake is associated with antepartum depressive symptoms

Abstract

Abstract Introduction Antepartum depression affects 7-16% of pregnant women and occurs most frequently in the 3rd trimester. Previous studies have demonstrated a relationship between the level and timing of daytime light exposure and depression in non-pregnant populations. However, much less is known about the relationships between light exposure and depression during pregnancy. Thus, in this study, we tested the hypothesis that exposure to less daytime light will be associated with more antepartum depressive symptoms. Methods Data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b) and the nuMoM2b Sleep Duration and Continuity Substudy were used (N=708). Women enrolled in the substudy wore wrist actigraphy (Spectrum, Phillips Respironics) and completed a sleep log for seven days between 160-230 weeks of gestation. Daytime light exposure was defined as minutes spent at or above the threshold of 50 lux (TAT50) during the wake period, averaged over valid actigraphy recording days. Participants were divided into two groups by TAT50: >25th percentile and ≤25th percentile. The Edinburgh Postnatal Depression Scale (EPDS) was administered during the 1st and 3rd trimesters. A positive screening was defined as an EPDS composite score ≥10 or any endorsement of self-injurious thoughts. Wilcoxon rank sum tests were used to test differences between TAT50 groups. Results Low light exposure during the day was associated with antepartum depressive symptoms during the 1st and 3rd trimesters, after adjusting for age, season, race, poverty, sleep midpoint, and sleep duration (OR 1.7, p=0.047). Additionally, later sleep timing, greater day-to-day sleep variability, and increased time spent awake after sleep onset was seen in those exposed to less light (all p< 0.001). Conclusion Lower daytime light exposure is associated with poorer sleep quality and may increase risk for antepartum depressive symptoms. These data suggest that in addition to improving sleep quality, promoting daytime light exposure may be a modifiable risk factor for depression during pregnancy. Support (if any) Work supported by NHLBI grant R01 HL105549 and NICHD grant U10 HD063036. C.D.W. was funded, in part, by T32HL007909. K.J.R., and P.C.Z. are supported, in part, by R01 HL140580 and P01 AG011412. M.K. is supported, in part, by NIA P30AG059988.