BLNST cheat sheet

Breast is a modified apocrine/sweat gland; functional unit is the alveolus, clustered into lobules drained by lactiferous ducts that widen into the ampulla (lactiferous sinus) beneath the areola.

Lactogenesis I begins mid-pregnancy (secretory differentiation); Lactogenesis II (copious milk secretion) follows delivery of the placenta and the fall in progesterone, typically 30-72 hours postpartum.

Milk ejection reflex: nipple mechanoreceptors -> afferent spinal pathways -> hypothalamic paraventricular/supraoptic nuclei -> posterior pituitary oxytocin -> myoepithelial cell contraction. Prolactin release is suppressed by hypothalamic dopamine.

Infant suckling mechanics: latch takes ~1-2 cm of breast tissue, not just nipple; peristaltic tongue wave strips milk, with vacuum generated by mandibular depression; fat content rises during a feed as alveoli empty.

Infant anatomy relevant to feeding: short soft palate, relatively large tongue, buccal fat pads, and a larynx positioned high in the neonate support simultaneous breathing and suckling.

Colostrum is low volume (roughly 2-20 mL/day in the first 24-48 h), high in secretory IgA, lactoferrin, and protein, lower in lactose and fat than mature milk; transitional milk follows over ~2 weeks.

Milk synthesis is receptor-mediated: frequent effective removal lowers intraluminal pressure and prolactin-receptor downregulation; FIL (feedback inhibitor of lactation) accumulates when milk is not removed and locally suppresses secretion.

Breast storage capacity varies widely (roughly 70-400 mL between feeds); smaller capacity requires more frequent feeds, not supplementation, to maintain supply.

WHO/UNICEF Ten Steps include immediate skin-to-skin, rooming-in, feeding on demand, no pacifiers or artificial teats for breastfed infants, and no promotion of breast-milk substitutes.

Early initiation within the first hour is associated with reduced neonatal mortality; skin-to-skin contact supports thermoregulation, blood glucose stability, and oxytocin release.

Responsive (baby-led) feeding: at least 8-12 feeds per 24 h in the early weeks, with cues such as rooting, hand-to-mouth, and sucking motions; crying is a late cue.

Effective latch signs: wide gape, chin to breast, lips flanged outward, more areola visible above than below, audible swallowing, no maternal pain after the first seconds.

Positions (cradle, cross-cradle, football, side-lying) alter nipple angle and maternal hand support; cross-cradle improves head control in the early learning period.

Hand expression and colostrum harvesting in the antenatal or early postnatal period support preterm or at-risk dyads and provide oral immune factors.

Paced bottle feeding with a slow-flow nipple and upright position reduces flow preference when expressed milk or formula is medically indicated.

Rooming-in and unrestricted access to the breast support prolactin pulsatility and reduce early supplementation rates.

Weight: expect up to ~7-10% loss in the first week; regain birth weight by 10-14 days; then ~20-30 g/day in the first months.

Output markers: day 1-2 one wet diaper, day 3 three, day 4 four, day 5+ six or more per 24 h; stools transition from meconium to yellow seedy by day 4-5.

LATCH and IBFAT are validated tools scoring latch, audible swallowing, nipple type/comfort, and positioning; document a score to track change.

Oral assessment: check for tongue-tie (ankyloglossia) using a structured tool such as the Hazelbaker Assessment Tool for Lingual Frenulum Function, plus palate and suck evaluation.

Breast assessment: look for erythema, fissures, engorgement, plugged ducts, and nipple shape (flat, inverted, retracted); document with a diagram or structured note.

Jaundice in a breastfed infant requires bilirubin measurement, feeding frequency review, and stool output check; breastfeeding jaundice and breast-milk jaundice are distinct entities.

Dehydration signs: sunken fontanelle, dry mucosa, decreased tears, lethargy, and concentrated urine; these warrant urgent evaluation.

Documentation should include feeding frequency, duration, position, latch quality, output, weight trend, and any referral made.

Mastitis: localized tenderness, erythema, fever ≥38.5°C, and flu-like symptoms; continue breastfeeding, use cold packs between feeds, and consider antibiotics (dicloxacillin or cephalexin) if no improvement in 24 h.

Plugged duct: tender lump without systemic symptoms; treat with frequent feeding, gentle massage toward the nipple, and moist heat before feeds.

Low supply: assess with a pre/post feed weight or test weighing; causes include poor latch, infrequent removal, hypoplasia, retained placenta, and thyroid disease.

Overactive letdown and foremilk/hindmilk imbalance present with explosive stools, gas, and rapid feeds; management includes block feeding and reclined positioning.

Tongue-tie management: frenotomy is considered when function is impaired; evidence supports improvement in latch and maternal pain in selected cases.

Preterm and late-preterm infants need fortification or donor milk when intake is insufficient; feeding cues and stamina are limited.

Twins: tandem feeding is feasible; supply is driven by demand from both infants; monitor each infant's weight and output separately.

Nipple pain beyond the first seconds of latch indicates a problem (poor latch, tongue-tie, infection, vasospasm); persistent pain warrants reassessment, not just nipple cream.

Relative infant dose (RID) = (infant dose in mg/kg/day) / (maternal dose in mg/kg/day) × 100; RID <10% is generally considered compatible.

Milk-to-plasma (M/P) ratio estimates transfer; a value near 1 suggests substantial transfer; low protein binding and high lipid solubility increase transfer.

Drugs generally considered compatible: acetaminophen, ibuprofen, most penicillins and cephalosporins, insulin, heparin, and most vaccines.

Drugs requiring caution or avoidance: codeine (CYP2D6 ultrarapid metabolizers), tramadol, and other opioids with neonatal respiratory depression risk; check current guidance.

Radioactive iodine (I-131) requires temporary cessation; contrast media and most radiopharmaceuticals have defined washout periods.

Alcohol: no safe threshold is established; if consumed, wait ~2 h per standard drink before feeding; pumping does not accelerate clearance.

Cannabis and nicotine transfer into milk; both are discouraged, and nicotine replacement is preferred over smoking if needed.

Galactagogues (domperidone, metoclopramide) are not first-line; evidence is limited and adverse effects (QT prolongation, extrapyramidal effects) must be weighed.

Exclusive breastfeeding for ~6 months, then complementary foods with continued breastfeeding to 2 years or beyond (WHO).

Human milk provides ~70 kcal/100 mL; energy needs are met by volume, and intake is ~150-200 mL/kg/day in early infancy.

Growth references: WHO Child Growth Standards are the appropriate standard for breastfed infants; breastfed infants may grow more slowly after 3-6 months than formula-fed peers.

Iron: breast milk iron is low but highly bioavailable; iron stores deplete by ~4-6 months, so iron-rich complementary foods should start then.

Vitamin D: 400 IU/day supplementation is recommended for exclusively breastfed infants from birth.

Vitamin K: 1 mg IM at birth prevents hemorrhagic disease of the newborn.

Docosahexaenoic acid (DHA) and arachidonic acid are present in human milk and support retinal and neural development; maternal diet influences DHA content.

Complementary feeding: introduce iron-rich foods and allergens early (around 4-6 months) with repeated exposure; avoid honey before 12 months (botulism risk).

Scope of practice: IBCLCs provide clinical lactation care within their training; medical diagnosis and prescribing remain with licensed clinicians.

Informed consent requires disclosure of benefits, risks, and alternatives for any recommendation, including supplementation or device use.

Conflict of interest: the WHO Code restricts promotion of breast-milk substitutes; IBCLCs should not accept gifts or samples from manufacturers.

Documentation standards: objective, time-stamped, and retrievable; include assessment, plan, education, and referral in every note.

Research appraisal: distinguish randomized controlled trials from observational studies; check for confounders, blinding, and intention-to-treat analysis.

Evidence hierarchy: systematic reviews and RCTs rank above cohort and case reports for questions of effect; GRADE rates certainty of evidence.

Cultural humility and shared decision-making: align recommendations with the family's values, language, and access to care.

Referral pathways: know when to refer to a physician, speech-language pathologist, dentist, or dietitian, and document the referral.