The Sri Lanka Mother and Newborn Growth (S-MaNGro) Cohort: Protocol of a Nationwide Prospective Study.

Perinatal cohort studies with a prospective longitudinal design are critical for determining the effects of early-life exposures on offspring's health outcomes. The Sri Lanka Mother and Newborn Growth cohort study aims to investigate the impact of maternal nutritional and psychosocial factors on newborns' birth weight in the Sri Lankan context. This paper presents the methodology of participant recruitment, follow-ups, an overview of measurements, and planned data analyses. This study included a nationally representative sample of Sri Lankan pregnant women recruited in their first trimester of pregnancy. Follow-up assessments were conducted once during the second and third trimesters of pregnancy and after the baby's birth, prospectively tracking the women's dietary intake, mental health, hemoglobin concentrations, and gestational weight gain data. Once the participants delivered their babies, the data on gestational age, sex of the newborn, birth weight, length and occipitofrontal circumference at birth, and mode of delivery were collected. Between August 2022 and August 2023, we recruited 2000 first-trimester pregnant women to the cohort and continued to follow up with them until the baby's birth. The response rates were 90.4%, 81.4%, and 75.2% in the first, second, and third follow-ups. We plan to analyze the data in July 2024. We expect this study to provide valuable insights into various early-life exposures affecting neonatal birth weight. The study's findings will serve as a valuable information resource for a broader scientific community, enabling the development of effective policies to prevent low-birth-weight deliveries in low-resource settings.