Objective: To investigate the effect of pre-pregnancy obesity on maternal and newborn microbiomes and fetal growth.
Methods: Individuals who gained body weight in accordance with the recommendations during pregnancy and normal gestastional age are included in the study and were separated into two groups, normal (n = 20) and obese (n = 20), based on their body mass index (BMI) value of pre-pregnancy. Maternal stool samples collected during the first trimester of pregnancy and meconium samples collected at birth were evaluated using 16S rRNA gene-based microbiome analysis.
Results: The stool samples of mothers who were obese before pregnancy harbored a higher (59.9 versus 52.3%) relative abundance of Firmicutes and a lower (7.1 versus 4.1%) relative abundance of Proteobacteria than the stool samples of mothers with normal body weight pre-pregnancy. In contrast, in the meconium samples of mothers who were obese pre-pregnancy, compared to those of mothers who had a normal body weight pre-pregnancy, the phylum Firmicutes was less (56.0 versus 69.0%) abundant and Proteobacteria (9.0 versus 8.5%) was more abundant. There was a negative correlation between pre-pregnancy BMI, birth weight, weight/height ratio and alpha diversity indices (Shannon and Chao1).
Conclusions: Pre-pregnancy obesity can affect pregnant and newborn gut microbiota, which might related to fetal growth of the newborn.
Keywords: Pregnancy; birthweight; gut microbiome; meconium; obesity.