Clinical Research Directory

Inclusion Criteria: * Studies needed to be population-based observational designs and report nutrient composition data for both preterm and term human milk. They must clearly define gestational age (preterm: 25-36 weeks; term: 37-42 weeks) and examine at least one comparable nutrient in both groups, such as energy, macronutrients (such as protein, fat, lactose), and/or micronutrients (including minerals like calcium and phosphorus, and vitamins such as vitamin D). We included articles published in Chinese or English only. Exclusion Criteria: * Studies were excluded if they focused solely on mothers with specific medical conditions (such as malnutrition, mastitis, or diabetes), if they involved nutrient supplementation as an intervention, or if they were published in languages other than Chinese or English.