Indirect Test Weighing: A New Method for Measuring Overnight Breast Milk Intakes in the Field

• Published in: Journal of pediatric gastroenterology and nutrition Vol. 7; no. 5; pp. 699 - 706
• Main Authors: Imong, Stella M, Jackson, Dorothy A, Woolridge, M W, Wongsawasdii, Lumduan, Ruckphaophunt, Somsri, Amatayakul, Kosin, Baum, J D
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott-Raven Publishers 01.09.1988; Lippincott
• Subjects: Biological and medical sciences; Body Weight; Breast Feeding; Female; Gynecology. Andrology. Obstetrics; Humans; Infant; Infant, Newborn; Medical sciences; Methods; Mothers; Population; Thailand; Water Loss, Insensible; Thailand; Measurement; Laboratory Examinations And Diagnoses; Lactation; Human Milk; Biology; Data Collection; Research Methodology; Thailand; Examinations And Diagnoses; Maternal Physiology; Body Weight > changes; Asia; Rural Population; Southeastern Asia; Population Characteristics; Data Analysis; Population; Developing Countries; Physiology; Demographic Factors
• ISSN: 0277-2116; 1536-4801
• DOI: 10.1002/j.1536-4801.1988.tb09621.x

SummaryIndirect test weighing (ITW), a new method for measuring nighttime breast milk intake, is based on separate weighings of the mother and infant at the start and end of the nighttime sleep period. All other incidental weight changes overnight are measured, so that the corrected infantʼs overnight weight gain and the motherʼs overnight weight loss are then accounted for by breast milk transfer and evaporative water loss (EWL) alone. The combined EWL is partitioned between mother and infant on the basis of metabolic body size (body weight raised to the power of 0.73). The infantʼs EWL is added onto the corrected overnight weight gain to give nighttime milk intake. A field validation study on 24 northern Thai infants, conducted in the subjectʼs homes, in which ITW was compared with nighttime direct test weighing (DTW) on the same night, gives 95% confidence intervals for the method of × 39 g for a range of milk intakes of 77–344 g. Confidence intervals for estimates using feeding patterns alone, or multiplying 12 h intakes by a constant, range from × 104 to 180 g, indicating that these methods are insufficiently accurate for individual estimates.