Lactation, galactorrhoea, prolactinoma

Question 1

Prolactin levels during pregnancy and breastfeeding

Answer 1

Rises during pregnancy

• Stimulates duct and lobule development in breast
• Develops acini [secretory units]

Question 2

Lactational amenorrhoea

Answer 2

Lack of menstrual periods during breastfeeding

• High prolactin levels dampens the gonadal axis.
• Inhibits GnRH, LH, FSH, oestrogen/progesterone

Question 3

Oxytocin and lactation

Answer 3

Stimulates milk let down
- Contraction of smooth muscle in the breast [myoepitheium]

Positive feedback
- Stimulation of the nipples/ pavlovian reflex

Question 4

Benefits of mammals lactating

Answer 4

Production of nutritious secretion
- Helps development both in brain and body

Hormones released helps to develop the ‘maternal’ aspect of the mother’s brain.
- Metabolic and psycho-social behavioural

Question 5

Hyperprolacteraemia

- Presentation in women

Answer 5

Amenorrhoea/ oligomenorrhoea

Galactorrhea

Sub-fertility
- Increases osteoporosis risk

Can present after contraceptive pill but is coincidental

Question 6

Hyperprolacteraemia

- Presentation in men

Answer 6

Presents later due to the non-specific symptoms

Erectile dysfunction [prolactin dampening gonadal axis]
Decrease in libido

Larger adenomas

• Visual defects
• Hypopituitary
• Headaches

Rarer

• Gynecomastia
• Galactorrhea

Question 7

Causes of hyperprolacteraemia

Answer 7

Physiological

• Pregnancy
• Lactation

Hypothalamico-pituitary

• Prolactinomas
• Non-functioning adenoma

Drugs

Stress [increases when stressed, like cortisol]

Poly cystic ovarian syndrome

Renal failure

Cirrhosis

Question 8

Drugs that increase prolactinoma

Answer 8

Antidepressants

Antipsychotics

Drugs for nausea and vertigo

• Phenothiazine
• Domperidone
• Metoclopramide

Question 9

Investigations into prolactinoma

Answer 9

Pregnancy tests

Renal function

Liver function tests

Repeating prolactin test [incase it was stress]

LH. FSH

Testosterone in males

MRI pituitary

Visual tests and anterior pituitary function [macroadenoma]

Question 10

Aims of treating prolactinoma

Answer 10

Restore fertility

Stop galactorrhoea
- Stocking nipple stimulation/ checking oxytocin

Restore menstrual periods/ libido [and bone strength]
- Hormone treatment [oestrogen/ testosterone]

Shrinking macroadenoma

Question 11

Drugs to treat macroprolactinoma

- Include side effect

Answer 11

Dopaminergic drugs
- Cabergoline

Shrinks macroadenoma and preserves pituitary function

Rare

• Fibrotic reaction [pulmonary, pericardial, retoperitoneal]
• Psychiatric disturbance.

Question 12

Drugs to treat microprolactinoma

Answer 12

Hormonal therapy if fertility is not required

- Then discontinue during pregnancy and give cabergoline

Question 13

Non functioning pituitary adenoma treatment

Answer 13

If compressing pituitary stalk
- Surgery and radiotherapy

Pituitary still monitored with MRI and visual field assessment
- Dopaminergic drugs will decrease prolactin

Question 14

Breast development

• Puberty
• Pregnancy
• Breastfeeding

Answer 14

Puberty

• Increase in oestrogen, progesterone, GH
• Alveolar buds and lobules increased

Pregnancy

• Oestrogen, progesterone increases
• As well as hCG and prolactin
• Increases alveolar development–> colostrum accumulate

Breastfeeding
- Copious milk production

Question 15

Milk composition

Answer 15

Sugar

Milk fats

Proteins

Minerals

Growth factors

Cellular components

• Immune cells
• Phospholipids

Question 16

Prolactin secretion regulation

Answer 16

Stimulation

• Serotonin
• TRH
• Oxytocin

Inhibition
- Dopamine

Question 17

Effects of prolactin of the gonadal axis

Answer 17

Depresses GnRH

• Decreases its pulsatility
• Depresses LH, FSH
• Depresses oestrogen and testosterone levels

Question 18

How to treat idiopathic hyperprolactinaemia

Answer 18

Assumed to be microprolactinoma

• Too small to be detected
• Treated with dopaminergic drugs