Session 13 - Lecture 1 - Review Flashcards
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3 - Case 1
A 17 year old girl sees the GP because she has not had a period for 3 months.
The history reveals that the patient has previously had regular periods, with an average cycle length of 28 days. She is sexually active and uses barrier contraception. She is revising for A Levels.
On examination her BMI is 21, and secondary sexual characteristics are present. Observations are normal.
The GP suspects secondary amenorrhoea.
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4 - Case 1: Amenorrhoea
Definition of secondary amenorrhoea?
Causes of secondary amenorrhoea?
Definition of secondary amenorrhoea?
- Cessation of menstrual periods, usually for 6 consecutive months
Causes of secondary amenorrhoea?
“Amenorrhoea after having normal cycles – cessation of a menstrual period – important thing is that they have had periods but now stopped. Had periods before but stopped – definition on period of time will vary but average of about 6 months – so periods are regular, then 6 months, it can be longer if it’s irregular period but helpful ballpark definition.
Primary amenorrhoea – never had one.
What causes secondary amenorrhoea? Pregnancy, weight loss, prolactin, menopause, polycystic ovaries, stress.”
5 - HPG Axis: Amenorrhoea
Female HPG Axis Hypothalamus --+--> GnRH - Anterior pituitary --> + LH FSH --> + - Ovaries --> + Estrogen Progesterone --> - / + Hypothalamus, Anterior pituitary
Hypothalamus ->
- Stress / weight loss / excessive exercise
- Prolactin
- Hypo-/ hyperthyroidism
Ovaries ->
- PCOS
- Premature ovarian failure
Progesterone ->
- Pregnancy
- Hormone-containing contraception
“Just go through this on our HPG Axis – most of our factors can influence this in some way so ovulation doesn’t occur so menstruation doesn’t occur.
Some of these external factors can come in and influence the HPG axis, can inhibit so nothing else down below those events can happen.
Premature ovarian failure – menopause is valid – if <40 years we say premature ovarian failure. If problem occurs here then what kind of test result might we actually see? If I was to do a blood test in either of those situations – might see raised FSH certainly for menopause or premature ovarian failure – trying to stimulate something happening but nothing responding to ovaries in it.
Then we have these, can be exogenous or endogenous hormones causing negative feedback. Pregnancy – progesterone oestrogen rise – progesterone released once ovulation occurs, going to have in conjunction with oestrogen, negative inhibition on cycle. Mimic this state in progesterone/oestrogen to mimic -ve feedback on HPG axis for contraception. “
6 - Case 1: Amenorrhoea
If it were primary amenorrhoea, how would the differentials change?
If it were primary amenorrhoea, how would the differentials change?
Secondary sexual characteristics present?
- YES
Consider similar causes to secondary amenorrhoea
Also consider: - Outflow obstruction/ anatomical abnormality
(e.g. androgen resistance) - Constitutional delay
- NO
“Secondary sexual characteristics present (examination)? i.e. breast bud development, pubic hair development etc., - if yes then there can be some overlap with 2o amenorrhoea causes - e.g. if someone before starting period experienced extreme stress or weight loss she might not start her period.
Bear in mind might be anatomical problem – outflow obstruction – imperforate hymen. Or genetic abnormality such as androgen resistance – phenotypically female but genetically male – rare. Constitutional delay – might just be later developer if 14/15 (not so much if 17) – so overlap. If they are not present however we do need to think of some other differentials.”
{An imperforate hymen is a congenital disorder where a hymen without an opening completely obstructs the vagina}
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