Birth and lactation

Question 1

Define parturition:

Answer 1

Birth

Question 2

Define labour:

Answer 2

Events associated with parturition

Question 3

Define lactation:

Answer 3

Secretion and formation of breast milk

Question 4

Describe Parturition Onset/ Maintenance

Answer 4

• Uterine contractions during pregnancy are normal
• Stretching of cervix signals oxytocin release from posterior pituitary
• Oxytocin stimulates uterine muscles to contract (directly and through prostoglandins)
• Uterine contractions push the head against the cervix, stretch it more, more oxytocin relased
• Positive feedback cycle

Question 5

What are the three stages of parturition?

Answer 5

• Dilation
  -Contractions and stretching cause cervix to open (dilate)
  -Lasts 2 to 20 hours
• Expulsion
  
  • Baby moves through the birth canal
  • Pushed by forceful contractions
  • Lasts 0.5 to 2 hrs
• Placental
  
  • Placenta and umbilical cord (afterbirth) are expelled
    -10-15 minutes after baby born

Question 6

Describe prolactin

Answer 6

• Hormone needed for milk production
• Secreted from anterior pituitary
• Suppressed by high levels of estrogen and progesterone during pregnancy
• Secretion begins after birth

Question 7

Describe milk secretion:

Answer 7

• Suckling stimulates nerve endings in nipples and areola (area around nipple)
• Hypothalamus is stimulated
• Posterior pituitary is signalled to release oxytocin
• Lobules in breast are stimulated to contract
• Alveoli in lobules contain milk – are squeezed and milk flows into ducts

Question 8

Describe suckling and milk production:

Answer 8

• The more suckling, the more milk produced
• If suckling stops, milk production stops
• If suckling continues, milk production continues (sometimes for several years)

Question 9

Describe colostrum:

Answer 9

• First secretions from nipples right after birth
• Yellowish fluid
• Important source of antibodies for baby (important to get baby colostrum right after birth)