Background: Breastfeeding is the optimal infant feeding practice. However, bottle-feeding with expressed breast milk is increasingly prevalent, with the reasons for this practice being diverse and closely related to maternal educational level.

Objective: To explore the association between maternal educational level and expressed breast milk feeding among infants in China, and examine the underlying mediating pathway.

Methods: This study is a secondary analysis of data from a nationwide feeding survey in China. Child healthcare physicians enrolled infants aged 0–23 months and administered a standardized questionnaire to their mothers or caregivers. Data collected included demographic characteristics, perinatal information, breastfeeding practices, and the introduction of liquids other than breast milk. Logistic regression was used to identify factors associated with expressed breast milk feeding, and mediation analysis was performed to examine the pathways through which maternal education influences expressed breast milk feeding.

Results: A total of 2208 infants aged 0-23 months were included in the analysis. 18.4% of mothers regularly used expressed breast milk for feeding. Exclusive expressed breast milk feeding was practiced by 7.5% of mothers, comprising 7.15% who used bottle-feeding and 0.35% who relied solely on spoon-feeding. Higher maternal educational level was the strongest predictor of regular expressed breast milk feeding (OR = 3.211), followed by parity, maternal employment status, formula as the first non-breastmilk liquid, and early initiation of breastfeeding. Mediation analysis indicated that maternal employment, parity, early Initiation of breastfeeding, and formula as the first non-breastmilk liquid mediated the relationship between maternal education and regularly expressed breast milk feeding of infants aged 0-23 months, accounting for 24.73%, 17.45%, 6.18%, and 5.31% of the total effect, respectively. The stratified mediation analysis revealed distinct patterns across infant age groups and breastfeeding status. Among infants within the first six months of life, only parity (15.25%) and formula as the first non-breastmilk liquid (8.11%) mediated the relationship between maternal education and expressed breast milk feeding. For mothers who continued breastfeeding, maternal employment (56.21%) served as the sole mediator.

Conclusion: The prevalence of expressed breast milk feeding among Chinese infants warrants attention, which is closely associated with maternal educational level. Higher educated mothers may be more likely to use expressed breast milk feeding due to primipara, employment demands, lack of early initiation of breastfeeding, and formula as the first non-breastmilk liquid.

Optimal breastfeeding is critical for infant health. However, data on current breastfeeding status in China and associations between breastfeeding practices and gastrointestinal outcomes remain limited. This cross-sectional study enrolled 2,405 infants and children aged 0–23 months and their mothers from 10 provinces and cities across five regions of China (Southwest, East, Northeast, Northwest, and Central). A standardized questionnaire was used to collect data on breastfeeding practices, non-breast milk feeding status, complementary feeding practice, as well as sociodemographic and perinatal characteristics. Gastrointestinal symptom profiles, including numbers and severity, were assessed using the Infant Gastrointestinal Symptom Questionnaire. The WHO-recommended Infant and Young Child Feeding indicators were used as core indexes to assess breastfeeding practices. Multivariate logistic regression analysis was performed to assess the relationship between each breastfeeding indicator and gastrointestinal symptoms. Among 2,405 infants and children, 29.6%, 32.5%, and 37.9% were aged (0–5) months, (6–11) months, and (12–23) months, respectively. Ninety-five-point two percent (95.2%) had been breastfed, while 49.2% initiated breastfeeding within 1 hour of delivery. 44.5% of children received their first intake of non-breast milk fluids within the first 24 hours of life. For infants under six months, 53.9% were exclusively breastfed, 22.6% were fed mixed milk, and 10.7% were provided additional water while breastfeeding. Breastfeeding continuation rates were 44.7% of children at 1 year of age and 16.8% of those at 2 years of age. Multivariate logistic regression analysis revealed that early initiation of breastfeeding (within 1 hour), exclusive breastfeeding, delayed introduction of non-breast milk fluids (no less than 1 month), and continued breastfeeding (CBF) 6-11 months were significantly associated with fewer gastrointestinal (GI) symptoms and lower GI symptom scores (P < 0.05), after adjusting for all covariates, including complementary feeding indicators. No significant associations were observed between number of GI symptoms and GI symptom scores and CBF 12-23 months, age 1 year, or age 2 years (P > 0.05). China's breastfeeding status are improving, and the appropriate breastfeeding practices benefit infants’ gastrointestinal health. Efforts on supporting and guiding mothers to achieve optimal breastfeeding and research on the benefit of CBF in complex feeding conditions should be conducted in the future to better support child health.