(P07-040-23) Associations of Maternal Body Mass Index With Infant Feeding Characteristics and Eating Behaviors

Objectives: To determine associations of maternal early pregnancy body mass index (BMI) with infant feeding characteristics and eating behaviors.

Methods: This analysis included 59 mother-infant dyads enrolled in the Maternal & Infant Metabolome & Microbiome Study, a longitudinal cohort study in Boston, MA. We obtained early pregnancy weight and height from the first pregnancy visit’s medical records, calculated, and categorized BMI per WHO criteria. During a 24-hour period at 6-weeks postpartum, mothers recorded infant feeding data for each feeding event, including pre- and post- breastfeeding (BF) weights, BF session duration, and volumes of any formula or expressed breast milk (BM) intake. At 6 months, mothers completed the Baby Eating Behavior Questionnaire, which measured food responsiveness, satiety responsiveness, food enjoyment, and slowness in eating. We determined associations of maternal BMI category with infant feeding volumes (overall and among exclusive BF infants), BF duration, feeding type (exclusive BM vs. any formula), feeding mode (BF vs. any bottle), and eating behaviors using multivariate linear and logistic regression adjusted for maternal age and household income.

Results: Mean ± SD maternal age was 35 ± 4.9 years. Eighteen mothers (30%) had BMI in the overweight range and 11 (19%) had obesity. Forty-two infants (71%) received exclusive BM and 17 (29%) received formula. Twenty-one infants (36%) breastfed exclusively and 38 (64%) were bottle fed. Infants of mothers with obesity (vs. normal BMI) had higher average overall feeding volume (β 27.6 mL/feed; 95% CI 1.2, 53.9). Exclusively breastfed infants of mothers with obesity (vs. normal BMI) had higher average BF volume (77.9 mL/feed; 41.2, 114.6) though BF duration did not differ. However, exclusively breastfed infants of mothers with BMI in the overweight (vs. normal) range had lower average BF volume (-42.1 mL/feed; -77.7, -6.6) and shorter average BF duration (-8.0 min/feed; -14.9, -1.10). Maternal BMI category was not associated with odds of exclusive BM feeding, BF, or with any infant eating behaviors.

Conclusions: Early pregnancy BMI was associated with infant feeding volume and BF session duration. Future studies should examine the maternal and child factors underlying these associations and implications for future child growth.

Funding Sources: Mass Life Sciences Center