Lactation

COMPOSITION OF THE COLOSTRUM:

• Deep yellow serous fluid, alkaline
• High specific gravity
• Components:
• IgA
• Complements
• Macrophages
• Lymphocytes
• Lactoferrin 
• Lactoperoxidase

REQUIREMENTS DURING PREGNANCY:

• Additional protein:25 gm
• Additional Calcium600 mg
• Folic acid:150 microgram/day
• Required more during lactation as compared to pregnancy : Energy, Vitamin A, thiamin, riboflavin, Vitamin C, niacin, and Vitamin B12.
• Same requirment in pregnancy and lactation : Fat, calcium, zinc, magnesium, and vitamin B6.

PHYSIOLOGY OF LACTATION:

Mammogenesis:

• Pregnancy is associated with remarkable growth of both ductal and lobuloalveolar systems.

Lactogenesis:

• Milk secretion actually starts on 3rd or 4th postpartum day
• Steroids — estrogen and progesterone circulating during pregnancy make the breast tissues unresponsive to prolactin
• Prolactin begins its milk secretory activity when estrogen and progesterone withdrawn following delivery
• Prolactin, insulin, growth hormone and glucocorticoids
• Prolactin is Highest during pregnancy and fall during lactation 

Galactokinesis: 

• Oxytocin is the major galactokinetic hormone

FATORS:

• Suckling
• Contractile mechanism

DURING SUCKLING, A CONDITIONED REFLEX IS SET:

Nipple and areola

↓

Thoracic sensory (4, 5 and 6) afferent neural arc

↓

Ascending tackle impulses

↓

Paraventricular and supraoptic nuclei of hypothalamus

↓

Synthesize and transport oxytocin

↓

Posterior pituitary

↓

Released (efferent arc via blood)

↓

Myoepithelial cells of alveoli & ducts contraction

↓

Milk ejection

↓

Forced down into ampulla of lactiferous ducts

MILK EJECTION REFLEX INHIBITORS:

• Pain
• Anxiety
• Breast engorgement or adverse psychic condition (depression).
• Galactopoiesis:
• Prolactin:galactopoietic hormone.
• Frequency of suckling (>8/24 hours) is essential 

MILK PRODUCTION:

• 500–800 mL of milk/ day using 700 Kcal/day

STIMULATION OF LACTATION:

• Put the baby to the breast at 2–3 hours interval from the 1st day
• Plenty of fluids to drink
• Avoid breast engorgement
• Early (½ – 1 hour) and exclusive breastfeeding in correct position

INADEQUATE MILK PRODUCTION:

• Endogenous suppression of prolactin:
• Ergot preparation
• Pyridoxin
• Diuretics or retained placental
• Infrequent suckling

Galactogogues:

• Sulpiride (dopamine antagonist)
• Domperidone
• Intranasal oxytocin

Lactation suppression:

Methods:

• Stop breastfeeding  
• Avoid pumping or milk expression
• Wear breast support
• Ice packs to prevent engorgement 
• Analgesics (aspirin) to relieve pain
• Tight compression bandage is applied for 2–3 days

Exam Question

• The hormone responsible for lactation is Prolactin
• Initiation of lactation is affected by Progesterone, Prolactin & HPL
• Strongest stimulus of lactation is by Suckling
• Galactokinesis means Ejection of milk
• Prolactin is Highest during pregnancy and fall during lactation 
• Most common immunoglobulin secreted by mother in milk and colostrum is IgA
• Colostrum is rich in   Proteins as compared to breast milk
• Daily additional requirement of protein in lactation is 25 gm 
• Folic acid requirement during lactation is 150 microgram/day
• Calcium requirement above the normal during the first six month of lactation is 600mg/day
• Daily additional requirement of protein in lactation is 25 gm