Association of Maternal Diet with Infant Birthweight in Women with Gestational Diabetes Mellitus

Objective: This study aimed to explore the potential impact of pre-pregnancy and early pregnancy maternal nutrition on the incidence of small-for-gestational-age neonates (SGA) in women with gestational diabetes mellitus (GDM). Methods: A prospective cohort study was conducted between 2020 and 2022 at the 3rd Department of Obstetrics and Gynaecology (School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece). Pregnant women from routine care were surveyed about their dietary habits during two distinct periods: six months prior to pregnancy (period A) and from the onset of pregnancy until the oral glucose tolerance test at 24-28 gestational weeks (period B). The intake of various micronutrients and macronutrients was quantified from the questionnaire responses. Logistic regression models, adjusted for potential confounders including age, pre-pregnancy body mass index (BMI), smoking status, physical activity and parity, were used to evaluate the association between nutrient intake and small-for-gestational-age neonate incidence. Results: In total, 850 women were screened and of these, 90 (11%) were diagnosed with gestational diabetes mellitus and were included in the study. There were significant associations between the intake of specific nutrients and the occurrence of small-for-gestational-age neonates; higher fat intake compared to non-small for gestationa age during period B (aOR: 1.1, p = 0.005) was associated with an increased risk for small-for-gestational-age neonates, while lower intake of carbohydrates (g) (aOR: 0.95, p = 0.005), fiber intake (aOR: 0.79, p = 0.045), magnesium (aOR: 0.96, p = 0.019), and copper (aOR:0.01, p = 0.018) intake during period B were significantly associated with a decreased risk for small-for-gestational-age neonates. Conclusions: The findings of this study highlight the potential role of maternal nutrition in modulating the risk of small for gestational age neonatesamong women with gestational diabetes mellitus. The results advocate for further research on the assessment and modification of both pre-pregnancy and early pregnancy nutrition for women, especially those at higher risk of gestational diabetes mellitus, to reduce the risk of gestational diabetes mellitus.