Pregnancy & Parturition

Question 1

which hormones stimulate breast development and where do they come from

Answer 1

Prolactin (PRL) - ant. pituitary

Human placental lactogen (HPL), progesterone, oestrogen - placenta

Question 2

which hormone is responsible for milk production in the alveolar cells of the breast

Answer 2

prolactin

inhibition of prolactin secretion from the ant. pituitary by the hypothalamus is lifted during pregnancy

Question 3

which hormones inhibit milk secretion during pregnancy

Answer 3

progesterone, oestrogen and human placental lactogen (HPL) stop progesterone from stimulating milk let down.
– they are lost with the placenta at birth so breast feeding can begin.

Question 4

HPL =

Answer 4

human placental lactogen

Question 5

Describe the milk let-down reflex

Answer 5

Prolactin causes milk synthesis
Nipple stimulation causes oxytocin release
Oxytocin causes SM contraction and milk ejection
(“milk let-down”) and continued prolactin release

Question 6

How does prolactin release cause lactational amenorrea

Answer 6

Prolactin inhibits GnRH release from the hypothalamus
which inhibits FSH and LH release from the pituitary
so oestrogen and progesterone aren’t produced in the reproductive organs
so there’s no menstrual cycle

Question 7

how do you stop breast milk production - eg. in women who have had a still born

Answer 7

dopamine agonists - inhibit prolactin secretion

Question 8

where is human chorionic gonadotropin (hCG) secreted from

Answer 8

trophoblast cells - later form the placenta

Question 9

hCG hormone =

Answer 9

(beta subunit of the) human chorionic gonadotropin

the alpha subunit is also found in other hormones so is of no use

Question 10

What do blood tests early on in pregnancy screen for?

Answer 10

inherited conditions - sickle cell anemia and thalassaemia (done asap, within 10 weeks)
infectious diseases - HIV, syphilis, HBV (done asap)

Question 11

How and when are Edwards, Pataus, and Down’s syndrome screened for in pregnancy?

Answer 11

at the 12 week scan (11-14 weeks) via ultrasound to look at the amount of fluid at the back of the babies neck (and blood tests)
- these do not tell us for certain whether the baby has the condition

Question 12

What’s the only way to know for certain whether a baby will have Edwards, Pataus, and Down’s syndrome?

Answer 12

amniocentesis - sample of cells from amniotic fluid

this carries a chance of miscarriage

Question 13

What stimulates prolactin secretion during pregnancy

Answer 13

oestrogen both directly stimulates it and in-directly through suppressing dompamine

Question 14

Whereabouts in the body would the beta-hCG that is shown on a pregnancy test have been secreted from?

Answer 14

the placenta (syncytriotrophoblast)