Obesity and Diabetes in Pregnancy and Maternal and Child Health: The Gerar Cohort Profile, Brazil

Background: Pre-pregnancy obesity and GDM increase maternal–fetal oxidative stress, but their consequences for women’s health and child development are still unclear. Objectives: This paper describes the methodological design, recruitment strategy, data collection methods, and baseline characteristics of the Gerar Cohort, a prospective longitudinal study designed to investigate the relationship between pre-pregnancy obesity and gestational diabetes mellitus (GDM) with oxidative stress biomarkers and their effects on maternal and child health outcomes through 12 months postpartum. Methods: Women were recruited early in their prenatal care in a city in Southern Brazil. Sociodemographic and clinical data, as well as blood samples, were collected each trimester. At childbirth, umbilical cord blood and placental tissue were collected. Children were followed up until 12 months of age, with blood collection at 4 and 12 months. The study was approved by the Research Ethics Committee. Results: A total of 189 women were recruited in the first trimester; 136 were followed up until the third trimester; 23 pregnancy losses were recorded. Pre-gestational obesity was observed in 24.3% (95% CI 18.4–31.1), and 27% (95% CI 20.8–33.9) of women were diagnosed with gestational diabetes mellitus. Fifty-nine umbilical cord blood samples and 61 placental fragments were collected. In the children’s follow-up, 71 children were taken for ophthalmological examination at 1 month of age; 60 attended the pediatric consultation at 4 months; 56 children attended the neurological evaluation at 6 months and 50 at 12 months. Conclusions: The Gerar Cohort successfully implemented its recruitment and biospecimen collection procedures within public healthcare services.