Human Milk Intake of Thai Breastfed Infants During the First 6 Months Using the Dose-to-Mother Deuterium Dilution Method.

Background: Data on infant human milk intakes in low- and middle-income countries are limited, although the deuterium oxide dose-to-mother method (DTM) is an accurate tool for its estimation.

Objective: We assessed human milk intakes of Thai infants during the first 6 months comparing exclusive breastfeeding (EBF), predominant breastfeeding (PBF), and partial breastfeeding (PartBF).

Methods: One hundred and ten healthy Thai lactating mother-infant pairs were followed from birth. Human milk intakes were determined at 6 weeks, 3 months, and 6 months using the DTM method. Daily energy and protein intakes were assessed using 3-day nonconsecutive 24-hour recalls. Sociodemographic characteristics were collected using a questionnaire. To compare breastfeeding practices, one-way analysis of variance with Tukey post hoc test assessed normally distributed data, while the Kruskal-Wallis test with Mann-Whitney test was used for not normally distributed data.

Results: No difference existed in human milk intakes during the first 6 months between EBF (743-776 g/d) and PBF (748-862 g/d). Human milk intakes of PartBF infants were significantly lower compared to other infants. Human milk intake was sufficient to meet infant energy and protein requirements during the first 3 months for EBF and PBF groups. Infant formula largely replaced human milk during the first 3 months; other solid foods were also introduced among the PartBF infants.

Conclusions: Human milk intakes were comparable between EBF and PBF infants during the first 6 months and provided adequate energy and protein to meet requirements. Infant formula largely replaced breast milk among PartBF infants, although other foods were also given early. This study was registered at clinicaltrials.gov as NCT04020640.