Lactation Physiology

    This article explains the physiology of lactation – hormonal changes preparing breasts during pregnancy and promoting milk production after delivery, and regulation of milk production according to baby’s demands.


    Important Points

    hormones prepare breasts to produce milk
    • Lactogenesis I is the stage of maturation of breasts under hormonal control during pregnancy.
      • Progesterone, prolactin, and placental lactogen increases the number of alveoli
      • Estrogen and growth hormone increases the number of milk ducts
    • Lactogenesis II is the stage of copious milk secretion 36-48 hours after birth because of:
      • Fall in progesterone levels
      • Prolactin hormone
      • Early and frequent breastfeeding
      • Cortisol and insulin hormone
    • Lactogenesis II is called delayed if happens after 72 hours. Delay in lactogenesis II can be prevented by:
      • Direct breastfeeding
      • Frequent and exclusive breastfeeding
      • Initiation of breastfeeding within one hour of birth
    • Prolactin is the main hormone for milk production and its levels increase when the baby breastfeeds.
    • Metoclopramide and domperidone increase breast milk production by increasing prolactin levels.
    • Oxytocin hormone causes ‘let down’ of breast milk.
    • Lactogenesis III is the stage of maintenance of milk production.
    • Feedback inhibitor of lactation is secreted in alveoli when they are full of milk. It inhibits further milk production.
      • Frequent emptying of breasts –> more milk production
      • Full breasts –> decreases milk production

    Posttest Quiz

    Lactation Physiology

    1 / 11

    All of the following helps mother boost her breast milk production except:

    2 / 11

    Drugs used to suppress lactation act on which hormone:

    3 / 11

    A newborn placed on mother's chest soon after birth has an ability to find the breast and start breastfeeding. This is called as:

    Question Image

    4 / 11

    All of the following hormones maintain lactation (lactogenesis III), except:

    5 / 11

    All of these hormones are required for milk production after delivery, except:

    6 / 11

    A primigravida mother delivers a full-term healthy newborn 12 hours back via cesarean section. Grandparents ask you what they can feed their baby as mother's milk is not coming in (अभी तो माँ के दूध ही नहीं आ रहा). Upon asking, they reveal they were feeding toned dairy milk to the baby (सरस की नीली थैली वाला दूध) because someone from the medical field told them to. What is your advice?

    7 / 11

    All of the following can delay lactogenesis II, except:

    8 / 11

    All of the following is true about prolactin, except:

    9 / 11

    All of the following are true about oxytocin hormone, except:

    10 / 11

    All of these may suppress lactation, except:

    11 / 11

    All of these mothers need intensive lactation support, except:

    Your score is

    Related articles: Breast Anatomy


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    4. Anderson GC, Moore E, Hepworth J, Bergman N. Early skin-to-skin contact for mothers and their healthy newborn infants. Cochrane Database Syst Rev. 2003;(2):CD003519. doi: 10.1002/14651858.CD003519. Update in: Cochrane Database Syst Rev. 2007;(3):CD003519. PMID: 12804473.
    5. Neubauer, Suzanne & Ferris, Ann & Chase, C & Fanelli, J & Thompson, C.A. & Lammi-Keefe, Carol & Clark, R & Jensen, R & Bendel, R & Green, K. (1993). Delayed lactogenesis in women with insulin-dependent diabetes mellitus. The American journal of clinical nutrition. 58. 54-60. 10.1093/ajcn/58.1.54.
    6. Boss M, Gardner H, Hartmann P. Normal Human Lactation: closing the gap. F1000Res. 2018 Jun 20;7:F1000 Faculty Rev-801. doi: 10.12688/f1000research.14452.1. PMID: 29983914; PMCID: PMC6013763.

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