Obstetric Topic 58. Breastfeeding

I. Breast Changes and Lactation

Hormonal Regulation

• Mammogenesis: growth and development of mammary glands during pregnancy.

• Estrogen → ductal growth.
• Progesterone → alveolar/lobuloalveolar development.
• Other supporting hormones: prolactin, hPL, IGF-1, cortisol and insulin.

• Lactogenesis: initiation of milk secretion after delivery → mainly prolactin.

• Placenta delivery → ↓ progesterone/estrogen inhibition → prolactin effect becomes active.

• Galactokinesis / let-down reflex: milk ejection from alveoli to nipple → oxytocin.

• Suckling or crying baby → posterior pituitary oxytocin → myoepithelial contraction.
• Oxytocin also supports uterine involution and reduces postpartum bleeding.

• Galactopoiesis: maintenance of milk production → prolactin and regular breast emptying.

• Prolactin reflex: suckling → ↓ hypothalamic dopamine → ↑ prolactin → milk production.

II. Breast Milk

Types of Milk

• Colostrum: first milk, late pregnancy to day 3-5 postpartum; low volume, high protein, sodium, leukocytes and IgA; lower lactose/fat.
• Transitional milk: day 4-10/14; volume rises, lactose and fat increase.
• Mature milk: from about 2 weeks postpartum; high water content and stable nutrient composition.

Composition

• Water: about 87-90% → hydration; no extra water needed for healthy exclusively breastfed infants in normal conditions.
• Lactose and fat: main energy sources; PUFA/omega-3 fatty acids support brain and retina development.
• Protein: whey-predominant, especially alpha-lactalbumin.
• Immune and bioactive factors: IgA, lactoferrin, leukocytes, enzymes, hormones, growth factors and oligosaccharides.
• Low in vitamin D and vitamin K; vitamin D supplementation is needed, vitamin K is given after birth.
• Iron content is low but bioavailable.

III. Breastfeeding Practice

Initiation and Frequency

• Start: skin-to-skin and breastfeeding within the first hour if mother and infant are stable.
• Feed on demand, usually 8-12 times/day in early newborn life.
• Adequacy: weight trend, swallowing, satiety, wet diapers and stooling pattern.

Duration and Weaning

• Exclusive breastfeeding: recommended for about 6 months if possible.
• Continue with complementary foods after 6 months; wean gradually to avoid engorgement/mastitis.

IV. Benefits

Infant Benefits

• Ideal nutrition: correct balance of water, calories, protein, fat, lactose and micronutrients for early infancy.
• Antibodies and immune factors → fewer infections.
• Lower risks: SIDS, diarrhea, some allergies/atopy, obesity and diabetes.
• PUFA/omega-3 fatty acids support brain and retina development.
• Bonding: close skin/contact and feeding interaction → emotional security.

Maternal Benefits

• Oxytocin release → uterine involution and reduced postpartum bleeding.
• Lactational amenorrhea: prolactin suppresses GnRH → delayed ovulation; contraception only if strict criteria met.
• Lower long-term risks: breast cancer, ovarian cancer and type 2 diabetes.

V. Problems and Contraindications

Common Problems

• Poor latch / nipple pain / rhagades: correct positioning and latch; treat fissures or infection if present.
• Engorgement: painful fullness due to incomplete emptying → frequent effective feeding, expression, cold packs/analgesia.
• Low supply / agalactia: assess latch, feeding frequency, maternal illness, breast surgery and medications.
• Mastitis: fever + painful erythematous breast, usually milk stasis ± Staphylococcus aureus → continue breastfeeding/emptying + antibiotics if bacterial.
• Breast abscess: persistent focal mass/fluctuance or no response to antibiotics → ultrasound + drainage/aspiration + antibiotics.

Infant Causes of Difficulty

• Cleft lip/palate, prematurity, severe rhinitis, neurologic impairment or absent/weak sucking reflex.
• Metabolic contraindication: classic galactosemia → no breast milk because infant cannot metabolize galactose.

Maternal Contraindications and Temporary Stops

• Infections: untreated/non-suppressed HIV where safe alternatives exist, HTLV, Ebola; active HSV lesions on the breast; untreated active TB until noninfectious.
• Substances: cocaine/PCP and unsafe opioid use; avoid regular/heavy alcohol.
• Unsafe drugs/radiopharmaceuticals: check medication compatibility; classic examples include cytotoxic drugs, retinoids and some iodine/radioactive agents.
• Usually not contraindications: mastitis, hepatitis B with newborn immunoprophylaxis, hepatitis C if nipples are not bleeding, most common antibiotics/analgesics after protocol check.