Amenorrhoea and dysmenorrhoea in adolescence

Question 1

What is primary amenorrhoea

Answer 1

Absence of menstruation
By age 16
Or by age 14 if there are no secondary sexual characteristics

Question 2

What is the incidence of primary amenorrhoea?

Answer 2

3-4%

Question 3

What is the incidence of imperforate hymen?

Answer 3

1:4000

Question 4

How does imperforate hymen present?

Answer 4

Primary amenorrhoea and cyclical pelvic pain

Urinary retention secondary to urethral compression from the distended vagina (haematocolpos)

Question 5

What % of cycles are anovulatory in the first year after menarche?

Answer 5

85%

Question 6

What % of adolescent women have ovulatory cycles by:

• Two years post menarche
• Two to four years post menarche
• Four to five years post menarche

Answer 6

• Two years post menarche 18-45%
• Two to four years post menarche 45-70%
• Four to five years post menarche 80%

Question 7

Describe your approach to prescribing NSAID for primary dysmenorrhoea including mechanism of action

Answer 7

NSAID is first-line therapy if contraception is not desired.

Mechanism of action: COX-2 inhibitor; COX-2 produces PGs causing inflammation and pain.

How to take: start at onset of menses and continue for duration of pain; if severe commence a few days before expected menses.

Side-effects: GI upset and bleeding; advise to take with food.

If one class if NSAID is not effective, try another class.
Classes:
- Propionic: ibuprofen, naproxen
- Fenamate: mefenamic acid