Offspring exposed to maternal obesity in utero are at increased risk for the development of metabolic disorders. Recent evidence also links exposure to maternal obesity with impaired cognition during childhood. While the underlying mechanisms are unclear, studies in animals have shown that fetal exposure to maternal obesity causes decreased neurogenesis in the dentate gyrus and impaired hippocampal learning. The hippocampus is important for memory, and its development is sensitive to the in utero metabolic environment. We tested the hypothesis that in utero exposure to maternal obesity would be associated with reduced hippocampal volume in children. Sixty-seven children (41 girls, 26 boys) ages 7 to 11 years participated in the study. Children were born at Kaiser Permanente Southern California. Maternal pre-pregnancy BMI was obtained from electronic medical records. Children’s height and weight were measured, and a high-resolution anatomical scan was performed using a 3 Tesla MRI. Total hippocampus volume and hippocampus subfield volumes were analyzed using FreeSurfer 6.0. Linear regression was used to investigate relationships between maternal pre-pregnancy BMI and child hippocampus volume. Maternal pre-pregnancy BMIs ranged from 19.0 to 50.4 kg/m2. Children’s BMI z-scores ranged from -1.8 to 2.6. Maternal pre-pregnancy BMI was negatively correlated with total hippocampus volume, adjusting for child age, sex, BMI-z score, intracranial volume (P=0.05). Results remained after further adjusting for maternal diabetes exposure (P=0.04). A 5-unit increase in maternal pre-pregnancy BMI was associated with 78 mm3 (95% CI:3.3-152.8 mm3) reductions in total hippocampus volume. The inverse correlation was also observed in CA3 (P=.04), CA4 (P=.03), dentate gyrus (P=.03) and subiculum (P=.01) subfields, adjusting for the same covariates. Our results suggest that exposure to maternal obesity adversely impacts hippocampus volume in children, and this impact is uniform across subfields.
K.A. Page: None. S. Luo: None. X. Wang: None. J. Alves: None. M.P. Martinez: None. A. Xiang: None.