Longitudinal study of breastfeeding and growth in 0-6 month infants.

Objective: To explore advantages and challenges for exclusive breastfeeding (EBF), compared to non-exclusive breastfeeding (nEBF).

Methods: Mothers from 7 cities in China were visited at 3, 10, 60, 120, and 180 days postpartum. Data about feeding practices, infant growth, and the macronutrient contents of human milk (HM) were collected.

Results: 130 lactating mothers attended 5 visits. 59 mothers (45.4%) exclusively breastfed infants for 0-4 month. Frequencies of breastfeeding per day were higher in the EBF group than the nEBF group at day 3, 10, 120 and 180, and were less than 8 times per day in the nEBF group. For Weight-for-age z scores, there were no differences between the two groups. Length-for-age z score was greater in the nEBF group at day 180 (0.74±1.05 vs 0.33±1.28). Weight-for-length z scores were greater in the EBF group at day 120 and 180 (day 120: 0.88±1.08 vs 0.36±1.1, day 180: 1.1±0.94 vs 0.54±1.07). The average protein and lactose contents of HM in the nEBF group were higher than in the EBF group at day 10.

Conclusions: For nEBF infants, intake of formula replaced intake of breastmilk, due to lack of breastfeeding frequency, which did not bring weight gain for nEBF infants. During the introduction of complementary foods, EBF infants needed complementary nutrients to support growth. Therefore, lactating mothers may need to provide appropriate complementary feeding and maternal leave extension to attend to their infant's nutritional requirements. The criteria for linear growth may also need to be more commensurate with breastfeeding and relevant to later health outcomes.