Amenorrhoea Flashcards
Definition of amenorrhea
- Absence of menstrual period in a women of reproductive age
- A symptom, NOT a diagnosis
- Primary vs Secondary
- Definition of primary amenorrhea
- What are its associations?
Failure to menstruate by the age of:
- 16 years, in the presence of normal secondary sexual development
- 14 years, in the absence of normal secondary sexual characteristics
– Congenital or genetic abnormalities
– Disturbance of normal endocrinological events of puberty
– All causes of secondary amenorrhea can also present as primary amenorrhea
What is secondary amenorrhea?
- Cessation of menstruation for 6 months
- Oligomenorrhoea: cycle length > 35 days
Must hae had
- Ovaries that had responded to pituitary gonadotrophins
- Endometrium that was responsive to ovarian hormone stimulation
- A patent lower genital tract
Outline the menstrual cycle
Follicular phase: FSH rises to encourage follicle development in ovary
- In the end, only one follicle develops (dominant follicle)
- Dominant follicle secretes estrogen, inhibiting FSH
- Estrogen rises together with the growth of the follicle = thickening of endometrium
Luteal phase: Estrogen rise stimulates surge in LH, triggering ovulation
- Follicle will turn into corpus luteum, which secretes progesterone
- Progesterone turns endometrium into secretory phase, preparing endometrium for implantation of embryo
If woman is not pregnant in this cycle, corpus luteum will regress and progesterone level will drop = shedding of endometrium
What are the hormones regulating the menstrual cycle?
What is the HPO axis?
Disturbance to any of the organs could give rise to disturbance in menstrual cycle
Causes of amenorrhea
Physiological:
- Pre-pubertal / constitutional delay of puberty
- Pregnancy & lactation
- Certain contraceptives
- Postmenopausal
Disorders of hypothalamus / CNS
Disorders of pituitary
Disorders of ovary
Disorders of outflow tract and / or uterus
Disorders of thyroid
Disorders of adrenal gland
What disorders of the hypothalamus / CNS could give rise to amenorrhea?
- Functional hypothalamic amenorrhoea (poor nutrition [including anorexia nervosa], systemic illness, excess exercise
- Isolated GnRH deficiency, including Kallmann’s syndrome (congenital GnRH deficiency = primary amenorrhea)
- Tumours - craniopharyngioma
- Cranial irradiation
What disorders of the pituitary can gives rise to amenorrhea?
Hyperprolactinaemia
- Prolactinomas / non-functioning adenomas
- Other causes
Hypopituitarism
- Pituitary surgery, cranial radiotherapy, Sheehan’s syndrome
What are causes of hyperprolactinaemia?
- Pregnancy, lactation
- Stress (transient)
- Prolactinoma
- Other pituitary tumours, non-functioning “disconnection” tumour (stalk effect)
** Disrupts the inhibitory influence of dopamine on prolactin - Drugs that inhibit dopamine secretion
** Dopaminergic antagonist, phenothiazines, domperidone, metoclopramide, cimetidine, methyldopa - Primary hypothyroidism = hypothalamus increase TRH = TRH stimulates pituitary = increase prolactin (must screen for this cause)
What are disorders of the ovary which may give rise to amenorrhea?
Premature ovarian insufficiency
- Genetic/chromosomal (Turner syndrome or variants, fragile X premutation [not the full-blown fragile X patients, only premutation])
- Iatrogenic (surgery, radiotherapy, chemotherapy)
- Autoimmune
- Idiopathic
Polycystic ovary syndrome
Androgen-secreting ovarian tumour
What are disorders of outflow tract and/or uterus which may give rise to amenorrhoea?
Congenital abnormality in Müllerian development
- Isolated defect (absence of hypoplasia of uterus)
- Androgen insensitivity syndrome
- 5-alpha-reductase deficiency
Congenital defect of urogenital sinus development
- Agenesis of lower vagina
- Imperforate hymen (cyclical abd pain)
Damage to endometrium
- Asherman syndrome
- Tuberculosis endometritis
What endocrinological (thyroid / adrenal) problems may cause amenorrhea?
Disorders of thyroid:
- Hypothyroidism
- Hyperthyroidism
Disorders of the adrenal gland:
- Adrenal tumours
- Cushing syndrome
- Congenital adrenal hyperplasia
Hx taking for amenorrhoea
- Anosmia: Kallmann’s
- Cyclical abdominal pain, ureinary retention: Outflow tract obstruction
- Nutrition, stress, excessive exercise: Functional hypothalamic amenorrhoea
- Weight gain: PCOS, Cushing’s syndrome
P/E for amenorrhoae
Clitoromegaly: Non-classical CAH
