The Impact of Maternal Fiber Intake on Infant Birth Outcomes

Abstract

Maternal metabolic status plays a critical role in infant birth outcomes, yet the specific role of dietary fiber during pregnancy remains underexplored, particularly in the context of maternal obesity. This research aims to assess how maternal dietary fiber intake impacts gestational age and infant birthweight. Data was obtained from the Breastfeeding and Early Child Health study. Three-day diet records were collected at 4 time periods, and fiber was computed using ESHA Food Processor Nutrition Analysis Software. Multivariable linear regression models were performed using R programming to analyze data. Results were stratified by maternal BMI, which has been previously shown to modify associations. Birthweight results showed a BMI-dependent effect with opposite directions for normal weight vs obese mothers. Average daily fiber intake during the third trimester was found to have a significant positive impact on birthweight when looking at mothers in the normal BMI range (p=0.037). When adjusted for caloric intake, this association strengthened (p=0.013), and a significant negative association was found in the obese BMI category (p<0.01). However, only 24% of participants in the third trimester and 16.9% of participants in all time periods met the recommended average fiber intake of 28 g/day. No significant associations were found between fiber intake and gestational age. These findings suggest fiber’s main role is effect modification, with particular importance on its potential to reduce risk of LGA. Future research should contain a larger population with a greater proportion reaching adequate intake levels to strengthen evidence of fiber’s impact in infant health outcomes.