Amenorrhoea Flashcards
Normal age of Menache
Should have secondary sexual characteristics by 14 and menstruating by 16
Primary amenorrhoea -
Never starting most likely due to imperforate hymen, hormonal or chromosomal problems
Secondary amenorrhoea
Cessation of normal menstruation for six months in someone with a previously established cycle
Menstrual cycle
Usually 28 days with days 1-3/5 of bleeding (menses)
1-14 days is follicular/proliferative phase
ovulation at ~14 days
14-28 is luteal/secretory phase
Follicular phase
Increasing estrogens (estradiol) from the ovaries drives growth of 1 follicle Estrogen from the ovaries drive LH and FSH from the hypothalamus and pituitary by positive feedback.
Luteal phase
The ruptured follicle becomes the corpus luteum which continues to produce progesterone to suppress LH/FSH by negative feedback, convert endometrium to secretory phase and thickens cervical mucus
When the corpus regresses progesterone withdrawal bleeding occurs.
HPO axis
The axis of the ovaries, the hypothalamus and the pituitary which controls the menstrual cycle.
Puberty
The development of secondary sexual characteristics of which menarche is the last
Over 8yo GnRH pulses increase causing LH & FSH to stimulate oestrogen release from the ovary
Oestrogen drives secondary sexual characteristics
Thelarche
9-11yrs,
breast development in girls at the beginning of puberty
Adrenarche
Development of androgen production in the adrenal gland leading to pubic hair development
Physiological Amenorrhoea
Occurs when normal hormonal states prevent menstruation
Pre-menarche or post-menopausal
During pregnancy or while lactating
Drug causes of Amenorrhoea
Contraceptive Progestogens
GnRH analogues
Tranquilizers
Outflow obstruction amenorrhoea (6)
Most often congenital - imperforate hymen, transverse vaginal septum, Mullerian agenesis (46XX) or androgen insensitivity (46XY)
Acquired can also occur - cervical stenosis or asherman’s syndrome (traumatic uterine atrophy)
Pituitary amenorrhoea
Pituitary adenomas
Sheehans syndrome - hypopituitism due to hypovolemia and ischemia post partum
Thyroid/adrenal causes of amenorrhoea
Both hypo and hyperthyroidism can cause amenorrhoea
Congenital adrenal hyperplasia
Virilising tumors
Hypothalmaic amenorrhoea
The Majority cause of secondary amenorrhoea
hypogonadism due to weight loss or excessive exercise (AN), stress, craniophayngioma or Kallmans syndrome (failure of puberty)
Ovulation
A spike in LH and FSH from the pituitary causes rupture of the follicle and release of the egg.
There is a change from positive to negative feedback from estrogen/progesterone on the hypothalamus and pituitary
Causes of secondary amenorrhoea (4)
PCOS
Weight related/AN
Hyperprolactinaemia
Primary ovarian failure
Causes of primary amenorrhoea (4)
Turners syndrome
Androgen insensitivity syndrome
Congential abnormality
Acquired
Ovarian Disorders
Will cause secondary amenorrhoea etc turners
Include PCOS, primary ovarian failure, resistant ovary syndrome, virilising tumors
Investigating Amenorrhoea
If prolactin high –> pituitary tumor
If thyroid disease –> treat accordingly
If testosterone high –> T. secreting tumor
If hormones normal give progestin –> if withdrawal bleed anovulation, if not check FSH –> if high gonadal failure, if FSH normal oestrogen challenge,
If no bleeding then outflow obstruction, if bleeding then pituitary or ovarian abnormality
Body temperature changes during the menstral cycle
Low through the follicular phase, dips slightly just before ovulation and then high during the luteal phase.
Levels of Progesterone during the menstral cycle
Absent during the follicular phase and rises after ovulation to peak at 21 days and drop by 28.
Levels of Oestrogen during the menstral cycle
Increases from day 7 until ovulation and drops but peaks again at a lower level at day 20.
FSH and LH levels during the menstral cycle
FSH slightly higher until day ten when it drops. both LH and FSH spike to cause ovulation but LH is much higher. They remain low for the rest of the cycle.
Symptoms of hyperprolactinaemia
Anovulation and amenorrhoea
Sexual impairment & loss of libido. women may get hairy
Galactorrhoea (milk secretion). Children may present with growth failure and delayed puberty.
