Longitudinal Changes in the Macronutrient Contents of Breast Milk in the Mothers with Preterm Delivery

Background: Contents of breast milk may change during the first weeks after childbirth, especially in preterm deliveries. The present study aimed to determine the macronutrient contents of breast milk in the mothers with preterm delivery. Methods: This prospective-descriptive study was conducted in Mahdieh Hospital in Tehran, Iran in 2015. Participants included the mothers with preterm delivery, whose infants had a gestational age of Results: In total, 51 mothers were enrolled in the study. Mean gestational age and birth weight of the neonates were 28.44±2.20 weeks and 1064±260 grams, respectively. Mean age and body mass index (BMI) of the mothers were 27.5±5.6 years and 26.44±17.54-40 kg/m², respectively. In terms of socioeconomic status, 28 participants (60.8%) were categorized as class II (simple workers), and 20 mothers (45.4%) received basic prenatal care. During weeks 2-3 of delivery, the fat and calorie contents of breast milk increased significantly. However, protein content of breast milk was variable, and the carbohydrate level was observed to decrease. No significant associations were observed between the maternal age, socioeconomic status, BMI, and number of twins with the contents of breast milk, while the mode of delivery and level of prenatal care had significant effects on the protein level of breast milk. Conclusion: According to the results, the levels of macronutrients in the breast milk of the mothers with preterm delivery were variable and within the normal range during the first four weeks of delivery.