Short-term prolactin administration causes expressible galactorrhea but does not affect bone turnover: pilot data for a new lactation agent

Effects of recombinant human prolactin on breast milk composition

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.

Recombinant human prolactin for the treatment of lactation insufficiency

CONTEXT

Lactation insufficiency has many aetiologies including complete or relative prolactin deficiency. Exogenous prolactin may increase breast milk volume in this subset. We hypothesized that recombinant human prolactin (r-hPRL) would increase milk volume in mothers with prolactin deficiency and mothers of preterm infants with lactation insufficiency.

DESIGN

Study 1: R-hPRL was administered in an open-label trial to mothers with prolactin deficiency. Study 2: R-hPRL was administered in a randomized, double-blind, placebo-controlled trial to mothers with lactation insufficiency that developed while pumping breast milk for their preterm infants.

PATIENTS

Study 1: Mothers with prolactin deficiency (n = 5). Study 2: Mothers of premature infants exclusively pumping breast milk (n = 11).

DESIGN

Study 1: R-hPRL (60 μg/kg) was administered subcutaneously every 12 h for 28 days. Study 2: Mothers of preterm infants were randomized to receive r-hPRL (60 μg/kg), placebo or r-hPRL alternating with placebo every 12 h for 7 days.

MEASUREMENTS

Change in milk volume.

RESULTS

Study 1: Peak prolactin (27·9 ± 17·3 to 194·6 ± 19·5 μg/l; P < 0·003) and milk volume (3·4 ± 1·6 to 66·1 ± 8·3 ml/day; P < 0·001) increased with r-hPRL administration. Study 2: Peak prolactin increased in mothers treated with r-hPRL every 12 h (n = 3; 79·3 ± 55·4 to 271·3 ± 36·7 μg/l; P < 0·05) and daily (101·4 ± 61·5 vs 178·9 ± 45·9 μg/l; P < 0·04), but milk volume increased only in the group treated with r-hPRL every 12 h (53·5 ± 48·5 to 235·0 ± 135·7 ml/day; P < 0·02).

CONCLUSION

Twice daily r-hPRL increases milk volume in mothers with prolactin deficiency and in preterm mothers with lactation insufficiency.