Maternal breast volume in pregnancy and lactation capacity

Successful breastfeeding, crucial for a child's development, depends on a woman's ability to initiate lactation, milk yield, and composition. Those traits differ among women, but the cause and physiological mechanisms responsible for this variation are not fully understood yet. Growing evidence shows that lactation and milk composition vary among women and depend on maternal traits. The aim of this study was to test whether breast volume and its changes during pregnancy are related to the nutritional quality of breastmilk and to breastfeeding dynamics.

Almost 93 pregnant women (mean age: 29.67 ± 3.65), participated in the longitudinal study. Breast measurement was performed at each pregnancy trimester using 3D scanning. Milk samples were collected in the beginning of the second month of lactation from 69 women. Milk macronutrient and calorie content were measured. Women were also interviewed on breastfeeding time and frequency.

Breast volume changes during pregnancy were not related to the probability of establishing successful lactation, milk calorie, fat and protein content. We found a negative correlation between milk lactose content and breast volume in the second and third trimester but not with breast volume change. Maternal breast volume in pregnancy was also positively related to the total breastfeeding time (per 24 hr).

The results are in line with the notion that milk macronutrient content tends to be weakly associated with various maternal factors and adverse conditions. However, maternal breast volume and its changes during pregnancy are related with time spent breastfeeding per day, what suggests a positive correlation between breast volume in pregnancy and milk yield.