Abnormal menstruation Flashcards
Outline the basic causes of abnormal menstruation
What is primary amenorrhoea?
This is failure to start menstruating. It needs investigation in a 15-year-old, or in a 14-year-old who has no breast development. For normal menstruation to occur she must be structurally normal with a functioning control mechanism (hypothalamic-pituitary-ovarian axis).
Describe your approach to determining the aetiology of primary amenorrhoea.
This may cause great anxiety. In most patients puberty is just late (often familial), and reassurance is all that is needed. In some, the cause is structural or genetic, so check:
- Has she got normal external secondary sexual characteristics? If so, are the internal genitalia normal?
- If she is not developing normally, examination and karyotyping may reveal Turner’s syndrome or testicular feminization. The aim of treatment is to help the patient to look normal, to function sexually, and, if possible, to enable her to reproduce if she wishes.
What is secondary amenorrhoea?
This is when periods stop for >6 months, other than due to pregnancy. Hypothalamic-pituitary-ovarian axis disorders are common, ovarian and endometrial causes are rare.
Describe the aetiology of secondary amenorrhoea.
Hypothalamic-pituitary-ovarian causes are very common as control of the menstrual cycle is easily upset, eg by emotions, exams, weight loss, excess prolactin (30% have galactorrhoea), other hormonal imbalances, and severe systemic disease, eg renal failure. Pituitary tumours and necrosis (Sheehan’s syndrome) are rare.
Ovarian causes: polycystic ovary syndrome (p 252) is common; tumours, ovarian failure (premature menopause: the cause in ˜1%) are uncommon.
Uterine causes: pregnancy-related, Asherman’s syndrome (uterine adhesions after a D&C: consider also TB, p 274). ‘Post-Pill amenorrhoea’ is generally oligomenorrhoea masked by regular withdrawal bleeds.
How would you investigate amenorrhoea?
Serum LH and testosterone (↑in polycystic ovary syndrome), FSH (very high in premature menopause), prolactin (↑by stress, prolactinomas and drugs, eg phenothiazines) and TFT are the most useful blood tests. 40% of those with hyperprolactinaemia have a tumour so do MRI scan (p 294).
Describe oligomenorrhoea.
This is infrequent periods. It is common at the extremes of reproductive life when regular ovulation often does not occur. A common cause throughout the reproductive years is polycystic ovary syndrome (p 252).
What is menorrhagia?
This is excessive blood loss
Describe dysmenorrhoea.
This is painful periods (± nausea or vomiting). 50% of British women complain of moderate pain, 12% of severe disabling pain.
Primary dysmenorrhoea is pain without organ pathology—often starting with anovulatory cycles after the menarche. It is crampy with ache in the back or groin, worse during the first day or two. Excess prostaglandins cause painful uterine contractions, producing ischaemic pain.
How is primary dysmenorrhoea treated?
NSAIDs inhibit prostaglandins, eg mefenamic acid 500mg/8h PO during menstruation so reduce contractions and hence pain. No particular preparation seems superior. Paracetamol is a good alternative to NSAIDs. In pain with ovulatory cycles, ovulation suppression with the combined Pill can help (thus dysmenorrhoea may be used as a covert request for contraception). Smooth muscle antispasmodics (eg alverine 60-120mg/8h PO) or hyoscine butylbromide (20mg/6h PO) give unreliable results. Cervical dilatation in childbirth may relieve it but surgical dilatation may render the cervix incompetent and is no longer used as therapy.
Describe secondary dysmenorrhoea.
adenomyosis, endometriosis, chronic sepsis (eg chlamydial infection), fibroids—and so it appears later in life. It is more constant through the period, and may be associated with deep dyspareunia. Treatment of the cause is the best plan. IUCDs increase dysmenorrhoea, except the Mirena® which usually reduces it.
What are the causes of intermenstrual bleeding?
This may follow a midcycle fall in oestrogen production. Other causes include Cervical trauma; polyps; cervical, endometrial and vaginal carcinoma; cervicitis and vaginitis of any cause. Screen for chlamydia and treat if positive. Refer all with persistent bleeding. Risk of cervical carcinoma in those with post-coital bleeding is 1:2400 aged 45-54; 1:44000 aged 20-24.
Describe post-menopausal bleeding.
This is bleeding occurring >1yr after the last period. It must be considered due to endometrial carcinoma until proved otherwise (p 278). Other causes: vaginitis (often atrophic); foreign bodies, eg pessaries; carcinoma of cervix or vulva; endometrial or cervical polyps; oestrogen withdrawal (hormone replacement therapy or ovarian tumour). She may confuse urethral, vaginal, and rectal bleeding.
