Effects of recombinant human prolactin on breast milk composition

Abstract

Objective: The objective of this study was to determine the impact of recombinant human prolactin (r-hPRL) on the nutritional and immunologic composition of breast milk.

Methods: We conducted 2 trials of r-hPRL treatment. In the first study, mothers with documented prolactin deficiency were given r-hPRL every 12 hours in a 28-day, open-label trial. In the second study, mothers with lactation insufficiency that developed while they were pumping breast milk for their preterm infants were given r-hPRL daily in a 7-day, double-blind, placebo-controlled trial. Breast milk characteristics were compared before and during 7 days of treatment.

Results: Among subjects treated with r-hPRL (N = 11), milk volumes (73 ± 36 to 146 ± 54 mL/day; P < .001) and milk lactose levels (155 ± 15 to 184 ± 8 mmol/L; P = .01) increased, whereas milk sodium levels decreased (12.1 ± 2.0 to 8.3 ± 0.5 mmol/L; P = .02). Milk calcium levels increased in subjects treated with r-hPRL twice daily (2.8 ± 0.6 to 5.0 ± 0.9 mmol/L; P = .03). Total neutral (1.5 ± 0.3 to 2.5 ± 0.4 g/L; P = .04) and acidic (33 ± 4 to 60 ± 6 mg/L; P = .02) oligosaccharide levels increased in r-hPRL-treated subjects, whereas total daily milk immunoglobulin A secretion was unchanged.

Conclusions: r-hPRL treatment increased milk volume and induced changes in milk composition similar to those that occur during normal lactogenesis. r-hPRL also increased antimicrobially active oligosaccharide concentrations. These effects were achieved for women with both prolactin deficiency and lactation insufficiency.

Trial registration: ClinicalTrials.gov NCT00181610 NCT00181623.

Figures

FIGURE 1

Correlation between milk lactose levels and milk volume before (n = 11) (closed circles and solid line) and after (n = 11) (open circles and dashed line) treatment with r-hPRL.

FIGURE 2

Mean ± SE milk prolactin concentrations for prolactin-deficient mothers treated with r-hPRL (n = 5) (closed circles) and mothers of preterm infants treated with r-hPRL (n = 6) (closed triangles) and individual prolactin concentrations for mothers of preterm infants treated with placebo (n = 2) (open squares). Prolactin concentrations were higher on days 5 to 7, compared with baseline, for mothers treated with r-hPRL (*P < .01). Prolactin concentrations returned to baseline on day 14 for prolactin-deficient mothers treated with r-hPRL for 28 days (n = 5; **P < .001).