OG17.1 | Physiology of Lactation and BFHI — Summary & Reflection

KEY TAKEAWAYS

Lactation unfolds in a physiologically precise sequence:

• Mammogenesis — pregnancy hormones (oestrogen, progesterone, HPL) prepare the alveolar gland for secretion.
• Lactogenesis I (mid-pregnancy) — alveolar secretory differentiation occurs but copious milk is blocked by high progesterone.
• Lactogenesis II (30–72 h postpartum) — placental delivery removes progesterone; prolactin acts unopposed, initiating copious milk production.
• Galactopoiesis (maintenance) — prolactin surges with each feed on a supply-demand basis; frequent suckling is the key driver.
• Milk ejection — oxytocin released from the posterior pituitary in response to suckling causes myoepithelial contraction; reflex is conditioned and is inhibited by stress.
• Colostrum (days 1–3): small volume, protein-rich, high sIgA, laxative; meets neonatal need precisely.
• Mature milk: 88% water; lactose and fat dominant; foremilk (watery) → hindmilk (fat-rich) within each feed.
• BFHI 10 Steps operationalise the physiology into hospital practice — each step protects a key physiological mechanism (early contact → oxytocin; no supplementation → sustained prolactin; rooming-in → demand feeding).
• Galactagogues (domperidone preferred) work by blocking dopamine's inhibitory control of prolactin secretion.
• Contraindications: maternal HIV (where alternatives available), active TB (until treated ≥2 weeks), infant galactosaemia, certain cytotoxic drugs.

REFLECT

Think about the last postnatal ward round or antenatal consultation you observed. What breastfeeding support was offered, and when? Given what you now know about lactogenesis II and the oxytocin reflex, which aspects of the environment or communication could have been improved? Consider how the BFHI framework translates neuroendocrine physiology into specific, actionable institutional practices — and reflect on what would be needed to implement each step in the context of a district hospital in India. What barriers would you anticipate, and how might you address them?