The nutrient composition of breast milk alters during lactation, and maternal BMI adds more intricacy into its complexity. We aimed to compare leptin, ghrelin, adiponectin, and IGF-1 levels of pre-feed and post-feed breast milk in mothers with obesity and normal weight, and tried to determine their effects on infants’ growth over weight for length z-score. 20 obese and 20 normal weight mothers with 2 month old infants were enrolled in this case-control study. 5 mL pre-feed breast milk and 5 mL post-feed breast milk were collected. Breast milk leptin, ghrelin, adiponectin, and insulin like growth factor-1 were measured by commercial kits. The pre-feed breast milk of mothers with obesity had significantly higher levels of ghrelin than mothers with normal weight (p= 0.025), whereas the post-feed breast milk of mothers with normal weight had higher levels of adiponectin than the mothers with obesity (p= 0.010). No significant differences were observed in leptin and IGF-1 levels between the two groups. Post-feed breast milk IGF-1 levels of mothers with obesity were correlated with infant’s weight for length z-score at 2 months (r= -0.476; p= 0.034). In linear regression models, parity affected the ghrelin in pre-feed breast milk (p= 0.025). Our results revealed that maternal pre-pregnancy BMI was associated with breast milk components.

Aim:The aim of this study is to determine the effect of maternal body mass index on leptin, ghrelin, adiponectin and IGF-1 levels in breast milk and to evaluate the relationship of these hormones with infant growth. Material and Methods: The study was conducted on 20 normal-weight and 20 obese mothers, who had a 2-month-old exclusively breastfed infants, who admitted to Child Health and Diseases, Hematology, Oncology Training and Research Hospital in Ankara from May 2018 to July 2018. Body weights and heights of infants at birth and at the 2-month-follow-up were recorded. Hormone concentrations in breast milk were measured by Elisa kits.Results: There was no significant difference leptin, ghrelin, adiponectin and IGF-1 concentrations in breast milk between normal-weight and obese mothers (p>0.05).Leptin hormone in breast milk was positively correlated with pre-pregnancy maternal body mass index and postpartum 2nd month maternal body mass index (r=0.829; p=0.021, r=0.857; p=0.014, respectively). While there was a positive correlation between infants' weight gain and ghrelin hormone in breast milk (r=0.406; p=0.011), there was a negative correlation between infants' weight gain and adiponectin hormone (r=-0.336; p=0.034). Infant weight for length z score at 2 months was negatively correlated with leptin in the breast milk of normal-weight mothers (r=-0.857; p=0.014), but not ghrelin in the breast milk of obese mothers (r=0.446; p=0.049). Conclusion:Maternal body mass index may affect the hormone levels in breast milk and leptin, adiponectin and ghrelin levels in breast milk may affect the growth of infants during early postnatal life.