Compression stimuli increase the efficacy of breast pump function

Eur J Obstet Gynecol Reprod Biol. 1998 Apr;77(2):131-9. doi: 10.1016/s0301-2115(97)00269-8.


Objective: The dynamics of milk ejection and also prolactin concentration in the blood during milk expression by means of a breast pump were studied in 82 lactating women.

Study design: The design of the breast pump used in this study is new. It is based on the correlation with the amplitude, duration and frequency of vacuum and compression stimuli formed by the baby's mouth apparatus during the suckling process.

Results: It was found that during continuous co-action of the vacuum and compression stimuli at a frequency of 1 cycle per second, the rate of milk ejection from the breast changed periodically. The highest rates of milk ejection coincided with the greatest rises in intramammary pressure. When the compression stimulus was turned off, leaving only the vacuum, the period of the first rise in pressure increased 1.5-2 fold, with a 1.5-2 fold reduction in the milk ejection rate as compared with the normal function of the breast pump. The basal prolactin level on day 3 and 5 post delivery in women who used a breast pump was not significantly different from that of puerperal women who only breast-fed their babies. Prolactin concentration in the blood of puerperal women did not change within the 5-6 min of expression and stimulation with the breast pump. The prolactin level began to increase by the 10th minute, whereas by the 25th minute it exceeded the initial concentration 1.3-1.5-fold.

Conclusion: It is suggested that by introducing a tactile component to the mechanism of the breast pump, milk secretion is enhanced, as well as stimulating the breast milk flow. This directly improves the dynamics of breast milk expression.

MeSH terms

  • Adolescent
  • Adult
  • Female
  • Humans
  • Lactation
  • Milk Ejection*
  • Milk, Human*
  • Pressure*
  • Prolactin / blood*
  • Time Factors
  • Vacuum


  • Prolactin