Poster Topical Area: Maternal, Perinatal and Pediatric Nutrition
Location: Hall D
Poster Board Number: 370
Objective: A protocol for estimating Milk Production Rate (MPR, g/h) in lactating women from hourly breast emptying was proposed by Lai, et al. (J Breastfeed Med, 2010). Our pilot study objectives were to determine: 1) validity in estimating MPR from hour 2 (h2) and hour 3 (h3) milk output and 2) if increased breast emptying for 48 hours will increase MPR.
Method: We enrolled mothers 6-8 weeks postpartum who were exclusively breastfeeding their healthy infant. At Baseline mothers emptied their breasts at a morning session (h0) and then hourly for 3 hours (h1, h2, h3). All milk output was weighed and infant fed only expressed milk after h0. Mothers increased breast emptying over the next 48 hours and we conducted Follow-up MPR measurements. For objective 2, left and right breast output at h2 and h3 were summed and divided by exact time to determine average MPR (g/h). Change was examined with paired t-test.
Result: We intended to enroll 12 mothers, but stopped after 6 due to significant unexpected results. One mother did not complete the study because her infant refused to take a bottle; thus, n=5 for paired results. At Baseline, MPR at h2 and h3 were similar (mean ± SD, 51 ± 11 vs. 49 ± 17 g/h; change = -2 ± 11 g/h, P=0.67). In the 24 hours prior to Baseline, breast emptying was 15 ± 2 /day (each side counted separately); and over the next 48 hours breast emptying increased to 21 ± 2 /day (+6 ± 1 /day, P=0.0004). Average MPR (h2+h3) at Baseline was 50 ± 13 g/h and significantly declined at Follow-up (43 ± 16 g/h; change = -7 ± 5 g/h, P=0.02). In the 2-3 weeks prior to Baseline, the rate of infant weight gain was 43 ± 14 g/d, and this rate declined significantly at Follow-up (17 ± 15 g/d; change = -27 ± 9, P=0.003). All mothers reported resumption of normal feeding patterns following the study.
Conclusion: Similar to Lai, et al., we did not observe a significant difference in MPR between h2 and h3, indicating steady state was reached. After 48 hours of increased breast emptying, MPR declined, and this aligned with a decrease in the rate of infant weight gain, suggesting a decline in milk availability to the infant. Further study is needed to determine why MPR declined Baseline to Follow-up, and how much time is needed to detect an increase in MPR with increased breast emptying.
University of Cincinnati