Menstrual cycle Flashcards
What are the hormonal changes during puberty?
• Puberty is centrally controlled (HPG axis)- >8y/o GnRH pulses increase in amplitude and frequency- FSH & LH release increases- stimulates oestrogen release from the ovary
• Oestrogen is responsible for development of 2o sexual characteristics
o Thelarche- breast development, starts 9-11y/o
o Adrenarche- growth of pubic hair, starts 11-12y/o, dependent on adrenal activity
o Menarche- irregular at first, but becomes regular as oestrogen secretion rises
• These changes are accompanied by a growth spurt, due to increased GH release, by 16y/o most growth has finished and epiphyses fuse
What occurs in menstruation day1-4?
start of the menstrual cycle endometrium is shed as hormonal support is withdrawn
myometrial contraction may cause pain
What is the proliferative phase of the menstrual cycle day5-13?
GnRH pulses stimulate LH & FSH release inducing follicular growth
follicles produce oestradiol & causing –ve feedback to suppress FSH allowing only one follicle and oocyte to mature
oestradiol levels continue to rise causing a +ve feedback on HPG axis cause LH to rise sharply
ovulation follows 36hrs after LH surge
oestradiol causes the endometrium to re-form and become proliferative
What occurs in the luteal/secretory phase day14-28?
he egg is released from the follicle, which becomes the corpus luteum (CL) and produces progesterone (& a little oestradiol)
this induces secretory changes in the endometrium (stromal cells enlarge, glands swell & blood supply increases)
towards the end of the luteal phase, the CL starts to fail if the egg is not fertilised causing progesterone & oestrogen levels to fall withdrawing hormonal support
endometrium breaks down, menstruation follows and the cycle restarts
continuous administration of exogenous progestogens maintains a secretory endometrium- this can be used to delay menstruation
What are abnormal menstruation definitions?
Menarch: >16 Menopause: <40 Cycle length: 23-25 days Menorrhagia Primary amenorrhoea: period never starts Secondary amenorrhoea: periods stop >6 months Oligomenorrhoea: infrequent periods Dysmenorrhoea: painful periods Menstruation: >8days Blood loss: >80ml
What is the aetiology of menorrhagia?
majority of menorrhagia shows no histological abnormality
subtle abnormalities of the endometrial fibrinolytic system or utergine prostgladin levels
• Uterine fibroids (30%) and polyps (10%) are the most common pathology found- chronic pelvic infection, ovarian tumours, endometrial/cervical malignancy are rare and more likely to cause irregular bleeding
Rarer causes:
Thyroid disease
o Haemostatis disorders- eg. von Willebrand’s disease
o Anti-coagulant therapy
What are the clinical features of menorrhagia?
Anaemia
Fibroids
o Adenomyosis: tenderness +/- uterine enlargement
o Ovarian mass
o Infection: tenderness and immobile pelvic organs
o Endometriosis: tenderness and immobile pelvic organs- co-exists not cause
What are the investigations for menorrhagia?
Hb
Exclude systemic cause: coagulation & thyroid function is only checked if it is indicated
o Transvaginal US: assesses endometrial thickness and excludes uterine fibroids, ovarian mass and larger intrauterine polyps
o Endometrial biopsy: used to exclude malignancy or premalignancy
Endometrial thickness >10mm
Polyps suspected
>40yrs with recent onset
Not responded to treatment
o Hysteroscopy- allows an inspection of the uterine cavity, detects polyps and submucous fibroids that could be resected
What is the management for menorrhagia?
1st line: progestogen- impregnated IUD is a coil that reduces menstrual flow by >90% with considerably fewer side effects than systemic progestogens
2nd line:
o Anti-fibrinolytics (tranexamic acid)-taken during menstruation only, acts by reducing fibrinolytic activity
o NSAIDs (mefanamic acid)-inhibits prostaglandin synthesis reducing blood loss by 30%, useful in dysmenorrhoea, but side effects similar to aspirin
o Combined oral contraceptive-induces lighter menstruation, but is less effective if there is pathology
3rd line:
o Progestogens- taken in high doses orally or by IM injection will cause amenorrhoea, but bleeding will follow withdrawal
o Gonadotrophin-releasing hormone agonists- produce amenorrhoea, but bleeding will follow withdrawal
What are the hysteroscopic management for menorrhagia?
o Polyp removal- GA or local anaesthesia
o Endometrial ablation techniques- more effective in older women
o Transcervical resection of fibroid (TCRF)
o Myomectomy- removal of fibroids from the myometrium
o Hysterectomy- last resort
o Uterine artery embolization (UAE)- treats menorrhagia due to fibroids and suitable for women who want to retain their uterus and avoid surgery
What are the causes of irregular menstruation?
• Anovulatory cycles- common in the early and late reproductive years o Fibroids o Uterine/cervical polyps o Adenomyosis o Ovarian cysts o Chronic pelvic infection
What are the investigations for irregular menstruation?
o Intrauterine system (IUS) or COC are considered 1st line
o Progestogens in high doses will cause amenorrhoea, but bleeding will follow withdrawal, induce secretory changes in the endometrium mimicking a normal menstruation
o Other treatments that are 2nd line for menorrhagia may also be used
• Cerivcal polyps can be avulsed and sent for histological examination
• Surgery is the same as menorrhagia, but some endometrium often remains and so irregular and light bleeding may continue
What are the most common causes of secondary amenorrhoea or oligomenorrhoea?
o Premature menopause
o Polycystic ovarian syndrome (PCOS)
o Hyperprolactinaemia
• Hypothalamus hypogonadism- common and usually due to psychological factors, low weight/anorexia nervosa or excessive exercise, tumours are uncommon and excluded by MRI- GnRH and therefore LH, FSH & Oestradiol are reduced, treatment is supportive, but oestrogen & progesterone replacement is required via COC or HRT
• Hyperprolactinaemia- usually caused by pituitary hyperplasia or benign adenomas, treatment is with dopamine agonists (bromocriptine or cabergoline) or surgery
Rarer: Sheehan’s syndrome- severe post-partum haemorrhage causes pituitary necrosis and varying degrees of hypopituitarism
What are the other causes of secondary amenorrhoea or oligomenorrhoea?
• Adrenal & thyroid gland- over or under active thyroid can cause amenorrhoea
o Hypothyroidism: leads to raised prolactin levels
o Congenital adrenal hyperplasia
• Acquried ovarian disorders: sub fertility, premature menopause in 1 in 100 women
Congenital:
Turner’s
Gonadal dysgenesis: ovary is imperfectly formed due to mosaic abnormalities of the X chromosome
Androgen insensitivity
What are the causes of obstructed menstrual flow or for it to be absent?
• Congenital problems: cause 1O amenorrhoea with normal secondary sexual characteristics-imperforate hymen and transverse vaginal septum obstruct the menstrual flow, so blood collect in the vagina or uterus over month- treatment is surgical
• Acquired problems: cause 2O amenorrhoea
o Cervical stenosis: prevents release of blood causing haematometra
o Asherman’s syndrome: consequence of excessive curettage at ERPC
What is post-coital bleeding?
• The cervix is more likely to bleed after mild trauma if it is not covered in healthy squamous epithelium- cervical ectropions, benign polyps and invasive cervical cancer account for most cases
Bleeding can occasionally come from the vaginal wall if it’s atrophic
it a polyp is evident, then it is avulsed and histology sent off
• If the smear is normal, an ectropion can be frozen with cryotherapy- if not, colposcopy is undertaken to exclude a malignant causes
What are the causes of primary dysmenorrhoea?
when no organic cause is found, it usually coincides with the start of menstruation and responds to NSAIDs or ovulation suppression
pelvic pathology is more likely if medical treatment fails
What are the causes of secondary dysmenorrhoea?
when pain is due to pelvic pathology and often precedes/relieved by the onset of menstruation- deep dyspareunia and menorrhagia/oligomenorrhagia are common- pelvic US and laproscopy are useful, most significant causes are o Fibroids o Adenomyosis o Endometriosis o Pelvic inflammatory disease o Ovarian tumours
What causes premature sexual maturation?
hormone-producing tumours of the ovary or adrenal glands can cause premature sexual maturation – regression will occur after removal- McCune- Albright syndrome consists of bone and ovarian cysts, café au lait spots and precocious puberty – treatment is with cyproterone acetate (anti-androgenic progestogen)
What is congenital adrenal hyperplasia?
autosomal recessive
cortisol production is defective, 21-hydroxylase deficiency- ACTH excess causes increased androgen production
Ambiguous genitalia- glucocorticoid deficiency may cause Addisonian crisis
• Occasionally, it presents at puberty with an enlarged clitoris and amenorrhoea
• Treatment involves cortisol and mineralocorticoid replacement
What is androgen insensitivity syndrome?
occurs when a male has cell receptor insensitivity to androgens, which are converted peripherally to oestrogens
• The individual will appear to be female- the diagnosis is only discovered when ‘she’ presents with amenorrhoea, the uterus is absent and rudimentary tests are present, these are removed because of possible malignant change and oestrogen replacement therapy is started
What is the management for PMS?
o SSRIs are effective- can be given continuously or intermittently in the 2nd half of the cycle
o Endometrial ablation- reduces hormones
o Continuous oral contraceptive
o HRT oestrogen patche
o GnRH agonist & add-back oestrogen therapy (pseudomenopause)- severe cases
