endocrine regulation of female fertility

Question 1

primary amenorrhoea

Answer 1

• never had a period
• genitourinary abnormalities
• chromosomal abnormalities
• secondary hypogonadism

Question 2

secondary amenorrhoea

Answer 2

• no periods for 6 months
• uterine, ovarian, pituitary, hypothalamic

Question 3

amenorrhoea, other causes

Answer 3

Physiological
Pregnancy
Lactation

Iatrogenic
OCP or other hormonal contraceptives

Thyroid dysfunction

Hyperandrogenism
Cushing’s syndrome
CAH
Adrenal or ovarian tumour

Question 4

hirsutism

Answer 4

“Excess hair growth in a male pattern due to increased androgens and increased skin sensitivity to androgens”

Question 5

presentation of PCOS

Answer 5

Classic presentation is with symptoms of
anovulation (amenorrhoea, oligomenorrhoea, irregular cycles)

Associated with symptoms of
hyperandrogenism (hirsutism, acne, alopecia)

Question 6

gonadotrophins

Answer 6

Increased LH concentration
Increased LH receptors in PCOS ovaries
Support ovarian theca cells
Increased ovarian androgen production

Decreased FSH
Low constant levels result in continuous stimulation of follicles without ovulation
Decreased conversion of androgens to oestrogens in granulosa cells

Question 7

androgen biosynthesis and action

Answer 7

Increased androgen production from theca cells under influence of LH

Disordered enzyme action
- Ovarian enzyme expression
- Peripheral conversion

Decreased SHBG
- Produced in liver, binds testosterone
- Only free testosterone is biologically active
.Hyperandrogenism
. Hyperinsulinaemia

Question 8

insulin secretion and action

Answer 8

Increased insulin in response to glucose load
Increased insulin resistance

Cause Vs Association?

Insulin stimulates theca cells of ovaries
Insulin reduces hepatic production of SHBG
Increased circulating androgens

Question 9

investigations

Answer 9

Confirm profile of PCOS
Testosterone
Andrestenedione
DHEAS
SHBG
FSH/LH
Assess for other features
Type 2 diabetes
Abnormal lipids
Exclude other pathologies