Validity of a 3-Hour Breast Milk Expression Protocol in Estimating Current Maternal Milk Production Capacity and Infant Breast Milk Intake in Exclusively Breastfeeding Dyads

Breastfeed Med. 2020 Oct;15(10):630-638. doi: 10.1089/bfm.2019.0182. Epub 2020 Jul 16.


Objective: An efficient method for measuring maternal milk production is needed. Our objectives were to: (1) validate a milk production rate (MPR) protocol in exclusively breastfeeding mothers; (2) determine MPR change following 48 hours of increased breast emptying; (3) assess agreement between MPR and infant test-weighing; and (4) characterize MPR in early postpartum exclusively breastfeeding mothers. Materials and Methods:N = 23 mothers emptied both breasts hourly over 3 hours (h0, h1, h2, and h3). We estimated steady-state MPR as mean (h2 and h3). Subset A mothers (n = 5) also completed MPR measurements after 48 hours of increased breast emptying. Subset B mothers (n = 16) also test-weighed for 48 hours. We used paired t-test to examine within-participant change in hourly milk yield and MPR; and we used Bland-Altman analysis to compare 24-hour milk production (g/24 hours) measured using test-weight versus MPR. Results are reported as mean ± standard deviation or (±95% limits of agreement). Results: Mothers were 54 ± 14 days postpartum. Paired difference in h3-h2 hourly milk yield was not significantly different (p > 0.05, 3 ± 10 g/hour). In Subset A (n = 5), MPR declined from 50 ± 13 to 43 ± 16 g/hour (p = 0.003) following 48 hours of increased breast emptying. In Study B (n = 16), mean infant test-weighed intake (TW) was 717 ± 119 g/24 hours, and mean MPR was 1,085 ± 300 g/24 hours. Mean difference (MPR-test-weigh) and mean ratio (MPR/test-weigh) significantly increased as MPR increased (p < 0.05). For infants with adequate weight gain (>20 g/24 hours, n = 12), mean MPR = 48 ± 12 g/hour (range, 35-78 g/hour). Conclusion: MPR is a valid measure of current maternal milk production capacity, but is not accurate for evaluating infant intake in exclusively breastfeeding dyads.

Keywords: breastfeeding; human lactation; insufficient milk production; low milk supply; measurement of breast milk output; milk production rate; test-weighing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Breast
  • Breast Feeding*
  • Breast Milk Expression*
  • Female
  • Humans
  • Infant
  • Lactation*
  • Male
  • Milk, Human
  • Mothers / psychology*
  • Mothers / statistics & numerical data
  • Postpartum Period
  • Reproducibility of Results
  • Time Factors