- 2025-06-29
- Journal of human lactation : official journal of International Lactation Consultant Association 41(3)
Study Design
- Type
- Observational
- Population
- 252 participants who delivered term infants classified as small for gestational age, appropriate for gestational age, and large for gestational age
- Methods
- Exploratory cross-sectional observational study; colostrum (on postpartum Day 2) collected and categorized by gestational weight group; protein, fat, carbohydrate, and energy levels measured using a mid-infrared human milk analyzer; values dichotomized at the median and compared using logistic regression
Background
Human milk and colostrum have been well studied; however, limited data are available on the variations in macronutrient content when compared across different infant weight categories for infants with similar gestational ages.Research aims
To compare the colostrum macronutrient content of participants who delivered term infants classified as small for gestational age, appropriate for gestational age, and large for gestational age.Methods
In this exploratory cross-sectional observational study (N = 252), colostrum (on postpartum Day 2) was collected and categorized by gestational weight group. The protein, fat, carbohydrate, and energy levels of colostrum were measured using a mid-infrared human milk analyzer. Values were dichotomized at the median and compared using logistic regression.Results
Median colostrum protein content was significantly higher in the small for gestational age (4.8 [IQR = 3-6.4] gr/dl) and large for gestational age (4.4 [IQR = 3.5-5.3] g/dl) groups compared to the appropriate for gestational age group (2.8 [IQR = 2.1-3.7] g/dl; p < 0.001). Median carbohydrate content was significantly higher in the large for gestational age group (5.3 [IQR = 4.2-6] g/dl) than appropriate for gestational age group (4.5 [IQR = 3.5-5.3] g/dl; p = 0.002). In multivariate analysis, being SGA or LGA was independently associated with higher milk protein content (OR 4.68; 95% CI [2.25, 9.77; p < 0.001; and OR 6.76; 95% CI [3.30, 13.87]; p < 0.001, respectively). Only being LGA was associated with higher carbohydrate content (OR 2.74; 95% CI [1.46, 5.16]; p = 0.002).Conclusion
Colostrum macronutrient content varies depending on whether the birthweight is small or large for gestational age. Studies are needed to investigate these potential associations and the clinical consequences of this relationship.