Maternal night-eating pattern and glucose tolerance during pregnancy: study protocol for a longitudinal study.

introductionCoordinating eating schedules with day-night cycles has been shown to improve glucose regulation in adults, but its association with gestational glycaemia is less clear. A better understanding on how eating time can influence glucose levels in pregnancy may improve strategies for gestational glycaemic control. This study aims to examine the association of maternal night-eating pattern with glucose tolerance in the second trimester of pregnancy, and to investigate how lifestyle factors may be related to night-eating pattern. METHODS AND ANALYSIS: This is an observational longitudinal study that targets to recruit 200 pregnant women at 18-24 weeks' gestation from the KK Women's and Children's Hospital in Singapore. Data collection includes sociodemographics, lifestyle habits and obstetric information. Maternal dietary intake is collected using the 4-day food diary and food frequency questionnaire; while 24-hour physical activity, sedentary behaviour, sleep and light exposure are captured using the accelerometer at 18-24 weeks' gestation. Continuous glucose monitoring at 18-24 weeks' gestation, oral glucose tolerance test and insulin test at 24-28 weeks' gestation are performed to assess glycaemic outcomes. Multivariable generalised linear models will be used to analyse the association of maternal night-eating pattern (consumption of meal and snack during 1900-0659 hours) with glycaemic measures, and the associated factors of night-eating pattern, controlling for potential confounders. Recruitment began in March 2019 and is estimated to end in November 2020. ETHICS AND DISSEMINATION: Ethical approval has been granted by the Centralised Institutional Review Board of SingHealth, Singapore (reference 2018/2529). The results will be presented at conferences and disseminated in journal articles. TRIAL REGISTRATION NUMBER: NCT03803345.