ILA- amenorrhoea Flashcards
What are the hormones involved in the Hypothalamicpituitary-gonadal-target organ axis?
GnRH from the hypothalamus –> LH and FSH from anterior pituitary –> oestrogen and progesterone from ovaries
briefly describe the embryology of the genital tract?
Genital tract develops in the same way for both sexes, SRY gene differentiates it into male
Since no testosterone is produced the mesenteric ducts regress
Since there is no MIS the paramesonephric ducts produce oviducts, uterus and the upper third of the vag
The urogenital sinus forms the bublourethral glands and the lower 2/3rd of the vagina
What is primary amenorrhoea?
no periods ever. Primary amenorrhoea can be diagnosed in female children by age 13 if no secondary sex characteristics, such as enlarged breasts and body hair, are present. If secondary sex characteristics are present, but menstruation is not, primary amenorrhoea can be diagnosed by age 16.
What is secondary amenorrhoea?
where menstruation begins as normal but then stops for 6 plus months not due to natural causes eg lactation, pregnancy or the menopause
What is oligomenorrhoea?
32 day plus between periods
What are some causes of primary amenorrhoea in the absence of secondary sex characteristics?
Constitutional delay: short with pre-pubertal levels of GnRH and low steroids
Hypogonadotropic hypogonadism – (will have GnRH and low steroids)
Premature ovarian insufficiency
Low FSH and LH levels
What are some causes of hypogonadotrophic hypogonadism?
Hypothalamic failure due to anorexia, stress, chronic illness, obesity
Tumour of hypopituitary glands
Kallmann’s
What are some causes of premature ovarian insufficiency?
autoimmune eg thyroid, adrenal disease chromosomal causes eg Turner’s, fragile X chemo or radiotherapy oophorectomy infection
What are some causes of primary amenorrhoea in the presence of secondary sex characteristics?
Malformation of the uterine duct
Androgen insensitivity syndrome- are phenotypically female but have male chromosomes- intersex
hyperprolactinaemia
Constitutional delay- may just reach a little later, ask about Fhx
What are some physiological causes of secondary amenorrhoea?
pregnancy/ lactation/ menopause/ contraception
What are some causes of secondary amenorrhoea?
Premature ovarian insufficiency (early menopause) Hypogonadotropic hypogonadism Thyroid problems Hyperprolactinemia PCOS- excess androgens Sarcoidosis Sheehan’s syndrome Ovarian carcinoma- can produce androgens Asherman's syndrome Cushing's - excess androgens
What are some hypothalamic causes of amenorrhoea?
-stress, anorexia, weight loss or exercise
What is Sheehan’s syndrome?
Caused by ischemic necrosis of pituitary gland due to severe PPH
What is Asherman’s syndrome?
Cervical stenosis due to adhesions in uterine cavity that obstruct menstrual flow usually due to surgery
What is Kallman’s syndrome?
A genetic disorder characterised by failure of secretion of gonadotropin-releasing hormone (GnRH)
Is caused by neurones failing to migrate from the nose region to the hypothalamus during fetal development . So GnRH, LH and FSH is low and therefore oestrogen is low.
What investigations can be carried out for amenorrhoea?
History- Duration of amenorrhoea. Contraception, recent and current. Vasomotor symptoms. Galactorrhoea. Exercise habits. Stresses. Medication history. Past medical history.
O/E- BMI, Cushing’s and thyroid signs
Pregnancy test!!
FSH and LH (raised in ovarian failure, if short with high levels indicates Turner’s, normal height with low levels indicates constitutional delay or hypothalamic causes eg weight loss, stress, exercise)
Oestrogen levels
Prolactin
Serum free androgen index – raise in PCOS
Testosterone (slight raise indicates PCOS, big raise indicates androgen secreting tumour),
TFTs (low TSH can indicate pituitary failure, look for hypo/hyper thyroid)
Pelvic U/S (PCOS or congenital abnormalities)
Karyotype for Turner’s and androgen insensitivity syndrome
Look for illness if indicated
CT/MRI for tumour
Hysteroscopy for Asherman’s
What is the management for amenorrhoea?
Hormone replacements eg HRT or OCP
fertility advice
Structural abnormalities may have surgery
Tumour do surgery/ RT
Management of patients with Turner syndrome includes growth hormone for short stature and also identifying and monitoring any associated cardiac, renal and thyroid abnormalities. Oral contraceptives should also be given. Fertility preservation through the cryopreservation of oocytes or ovarian tissue may be an option for some girls with Turner syndrome.
Bone protection due to associated low oestrogen levels
What are the characteristics of Turner’s syndrome? (think CLOWNS)
Cardiac abnormaly - coarctation of the aorta Lymphoedema Ovaries not developed Webbed neck Nipples wide spaced Short stature
also: don’t completely develop sex characteristics, infertile, kidney problems, low hairlines, koilonychia, eyes slant downwards, ptosis, strabismus (squint), amblyopia (lazy eye), ear infections
Belinda Cochrane has been referred by her GP with the following letter: Dear Doctor Please see this lady who is having very infrequent periods. She is 32 years old and has had no previous pregnancies but would like to become pregnant. Her periods started at the age of 13 and have never been very regular. She started the combined pill at the age of 17 to regulate her cycle. She stopped the pill two years ago and has only had 2 or 3 periods each year with a very irregular pattern. Belinda is an accountant. She is generally healthy but has had problems with anorexia in the past and finds it difficult to maintain weight. She also has problems with facial hirsutism. Periods occur every three to four months.
2 Baseline investigations are: Random sample LH 7.1 IU/L FSH 4.5 IU/l Prolactin 425 pmol/L Progesterone 2 nmol/L TSH normal
What are the differentials?
May be due to stress/ weight loss – affecting the hypothalamic-pituitary axis
PCOS- oligomenorrhoea, hirsutism, acne, subfertility
Cushing’s
Congenital adrenal hyperplasia
hyperprolactinaemia
What is the management for PCOS?
advise weight loss if needed, monitor for DM and high cholesterol, clomifene citrate or letrozole (induces ovulation for fertility), ovarian drilling (reduced steroid production), COCP (help with period regulation and unopposed oestrogen), cyproterone spironolactone, flutamide, finasteride (for hirsutism- anti-androgen)
What is the most common cause of primary amenorrhoea? how does the mechanism work?
Turners syndrome
missing X chromsome means follicles are depeleted at an accelerated rate - menopause occurs before menarche
no rise in oest or prog from corpus luteum –> high LH and FSH
What is the second most common cause of primary amenorrhoea? how does the mechanism work?
Mullerian agenesis
- -> mullerian duct doesn’t develop properly (uterus, vag and cervix may be absent or malformed/obstructed)
- > ovaries are normal so normal level of hormones
Explain androgen insensitivity syndrome
biologically male (46XY) - but receptors don't respond to testosterone Have internal testes and absent female sex organs have female ext genitalia and seconday sex characteristics
