Role of Daily Milk Volume and Period of Lactation in Nutrient Content of Human Milk: Results from a Prospective Study.

Virginie Rigourd,Guy Benoit,Isabel Lopera,Alexandre Lapillonne,Benedicte Jacquemet,Florina Cata

doi:10.3390/nu12020421

Abstract

Most studies assessing the macronutrient content of human milk are published retrospectively using analyzers that fail to determine sodium content and do not take into account the role of volume in milk composition. We aimed to describe macronutrient content and sodium content in human milk over time, observe any associations between them, and determine the factors associated with the evolution of milk composition. A prospective, longitudinal, monocentric study was undertaken. Contents of protein, fat, and lactose of 102 milk samples from 40 mothers were determined using a human milk analyzer and that of sodium with a flame spectrophotometer. Milk volumes along with clinical data were recorded. Protein content in the fourth quartile of volume was significantly lower than that in the first three, suggesting the existence of a volume threshold for protein content at approximately 445 mL. After multivariate analysis, it was found that maternal age, average volume, and lactation period remained significantly associated with protein content, maternal age remained significantly associated with fat content, and only average volume with sodium content. In consideration of previous findings along with our data, we suggest that extra care should be taken with fortification for feeding preterm infants when the mother’s milk volume is greater than 400–450 mL.

Highlights

Human milk is the gold standard for feeding preterm infants, but it needs to be fortified to promote adequate growth
Average volume, and lactation period remained significantly associated with protein content
The present study provides a comprehensive assessment of protein, fat, and sodium contents during a six-month collection period

Summary

Introduction

Human milk is the gold standard for feeding preterm infants, but it needs to be fortified to promote adequate growth. The composition of human milk varies throughout the lactation period as a result of internal and external factors, such as gestational age, maternal body mass index (BMI), smoking status, and even diet [1,2,3,4,5]. Past studies have demonstrated that the duration of lactation is a primary determinant of some nutrient contents, such as proteins and sodium [1,2,6,7,8,9,10]. Other studies have been published qualifying breast milk volume as another determinant of protein and sodium contents [8,11,12]. Unlike the clear associations for protein and sodium, fat content trends are more difficult to discern. Studies on the effect of the lactation period show contradictory findings, with one study stating no observed statistical difference in response to length of time, and another reporting changes in a diurnal pattern [2,7]

Objectives

Methods

Conclusion