Breastfeeding COPY Flashcards
Describe the embryological origins of the breast
Arises from single ectodermal bud.
Milk streak develops as an ectodermal thickening extending rom axilla to pelvis (galactic band).
Most of the band atrophies leaving a mammary ride in the pectoral region.
Squamous cells migrate into nipple bud to form mammary ducts whilst mesenchymeal cells differentiate into smooth muscle of nipple and areola.
What hormone is responsible for pubertal breast development?
What are the main changes in breast development at puberty?
Oestrogen.
Increase in fat deposition and glandular development.
Areola and nipple enlargement.
What changes occur to the breast during pregnancy?
Weight increases from 200g pre-pregnancy to 500 mg in pregnancy.
Lactating breast weights 600-800g.
Outline the flow of milk from production to ejection and associated structures
- Milk made in alveolI (up to 100 in a lobule/tubosaccular unit).
- Flow from alveoli to lactiferous duct and stored in reservoir at tip of duct called lactiferous sinus.
- Flow from lactiferous sinus to milk duct (15-20 ducts at tip of each nipple).
- Flow from milk duct out nipple
What is the innervation of the breast?
- Anterior and lateral cutaneous branches of the 4th - 6th intercostal nerves
What is the lymphatic drainage of the breast?
- Lateral (>75%): axillary –> clavicular –> subclavian lymphatic trunk.
- Medial: parasternal lymph nodes or opposite breast.
Inferior: to abdominal lymph nodes
What is the vasculature of the breast?
- Internal thoracic artery –> medial mammary branches
- Axillary artery –> lateral thoracic and thoraco-acromial arteries
- Venous drainage: axillary vein
What is lactogenesis stage I?
Hormones: oestrogen, progesterone, prolactin, human placental lactogen.
Development of:
- Mammary lobules under progesterone.
- Lactiferous ducts under oestrogen.
Full lactation function suppressed in pregnancy by high levels of progesterone.
What is lactogenesis stage II?
Hormones: prolactin, glucocorticoids.
Loss of inhibition of progesterone due to loss of placenta.
Increase in prolactin stimulating milk production.
Increase in mammary blood flow, oxygen and glucose uptake.
Colostrum production (up to 400 mL/day) increases to 500-700 mL/day by day 2-5.
What is the main differences between colostrum and mature milk?
Colostrum has:
- More protein including IgA
- More lactose
- Less fat
What is lactogenesis stage III?
Indefinite period of milk production:
Hormones: prolactin, oxytocin.
Stimulation of nipple/areola and infant behavioural cues cause oxytocin release and contraction of myoepithelial cells surrounding the alveoli triggering milk ejection.
What is lactogenesis stage IV?
Involution and cessation of breastfeeding.
Hormones: lactation inhibitory factor.
Decrease breastfeeding (<6x/day or <400 mL/day) leads to fall in prolactin levels.
After 24-48 hrs of no milk transfer, increased intraductal pressures and release of lactation inhibitory factor causes alveolar secretory epithelium apoptosis.
How much of total birthweight does a breastfeeding infant lose in the first week of life?
What is the upper limit of tolerance of weight loss in the first week?
7%.
Upper limit 10% of birthweight.
How often does a neonate need to be fed?
Every 2-3 hours 8-12 times a day.
Duration usually 20 mins per feed
List the maternal benefits of breastfeeding:
- Reduced risk of premenopausal breast cancer: dose-dependent effect with duration of BFing.
- Reduced risk of cardiovascular disease.
- Reduced risk of T2DM.
- Cost-effective for family and society
- Enhances postpartum weight loss
- Contraceptive (LAM)
- Improves maternal-infant bonding:
- Reduces risk of ovarian cancer
