The relationship between maternal and fetal fatness in healthy women and women with gestational diabetes mellitus: a prospective, population-based cohort study in Araraquara, SP

Abstract

Obesity elevates the risk of non-communicable chronic disease among adolescents and adults and is increasing in its prevalence, particularly in low and middle-income countries. Prevalence is likewise increasing among pregnant women. Obesity is now recognized as a disease with a complex, life course etiology, wherein fetal exposure to maternal obesity and/or gestational diabetes mellitus (GDM) shapes lifetime risk. It is important to develop a better understanding of associations between maternal phenotype and the phenotype of the developing fetus in utero. However, studies to date have been limited, and no study in Brazil has addressed fetal body composition. As part of a population-based prospective cohort study on maternal/offspring nutrition and metabolism, we propose to explore the relationship between maternal and fetal fatness (degree and distribution) and investigate whether these relationships differ between healthy women and women with GDM. Two-thousand pregnant women with gestational age d15 weeks attending antenatal care at 33 Health Care Units in Araraquara, SP will be measured in each trimester of pregnancy until birth. Maternal body composition will be assessed by segmented bioelectrical impedance analysis, validated by the reference deuterium isotope method, with diabetes status assessed in collected blood samples by glucose, insulin, HOMA-IR and glycated hemoglobin. Fetal body composition will be measured by ultrasound. Multivariable regression analysis and structural equation modeling will be used to test relationships between maternal and fetal fat mass, both within healthy mothers and between healthy and GDM mothers, controlling for relevant confounding variables.