The Menstrual Cycle and its Disorders Flashcards
Define menarche
- Onset of menstruation
- Avg. age 13yrs
Describe the physiology of puberty
- Controlled by the hypothalamic-pituitary axis
- Hypothalamic GnRH pulses increase in amplitude and frequency
- Leads to increase in pituitary FSH and LH which stimulate release of oestrogen from the ovary
- Oestrogen is responsible for development of secondary sexual characteristics
- Menarche is final stage
What happens on days 1-4 of the menstrual cycle?
- Menstruation
- Endometrium shed as hormonal support withdrawn
- Myometrial contraction occurs
What happens on days 5-13 of the menstrual cycle?
- Proliferative phase
- Pulses of GnRH stimulate FSH and LH release which induce follicular growth
- Follicles produce oestradiol and inhibin which suppress FSH secretion = only one follicle matures
- Oestradiol levels reach maximum which has positive feedback on LH causing a surge in LH
- Ovulation follows 36hrs after surge
- Oestradiol causes endometrium to reform and become proliferative
What happens on days 14-28 of the menstrual cycle?
- Luteal/secretory phase
- Follicle from which oocyte was released becomes corpus luteum
- Produces oestradiol, but mainly progesterone which peaks around 1wk later (day 21 of 28 day cycle)
- Induces secretory changes in endometrium
- Towards end corpus luteum starts to fail if egg not fertilised, causing progesterone and oestrogen levels to decrease
- Endometrium breaks down, menstruation follows and cycle restarts
What are the characteristics of normal menstruation?
- Menarche <16
- Menopause >45
- Menstruation 3-8 days in length
- Blood loss <80ml
- Cycle length 24-38days
- No intermenstrual bleeding
Define abnormal uterine bleeding (AUB)
Any variation from the normal menstrual cycle which includes:
- changes in regularity and frequency of menses
- changes in duration of flow
- changes in amount of blood loss
List the causes of AUB
- Structural causes:
- Polyps
- Adenomyosis
- Leiomyomas
- Malignancy and hyperplasia - Non-structural causes:
- Coagulopathy
- Ovulatory dysfunction
- Endometrial (primary disorder of mechanisms regulating local endometrial haemostasis)
- Iatrogenic
- Not yet specified
PALM COEIN
Define heavy menstrual bleeding (HMB)
- Excessive menstrual blood loss that interferes with a woman’s quality of life (clinical)
- Blood loss of >80ml in an otherwise normal menstrual cycle (objective)
Define irregular menstrual bleeding
Cycle-to-cycle variation >20days
Define amenorrhea
No bleeding in a 6mth interval (absent menstrual bleeding)
Define oligomenorrhea (infrequent menstrual bleeding)
Bleeding at intervals >38days apart
Define frequent menstrual bleeding
Bleeding at intervals <24days apart
Define prolonged menstrual bleeding
Bleeding >8days duration
Define shortened menstrual bleeding
Bleeding <3days duration
Define intermenstrual bleeding (IMB)
Irregular episodes of bleeding, often light and short, occurring between otherwise normal menstrual periods
Define postcoital bleeding (PCB)
Bleeding post intercourse
Define premenstrual and postmenstrual spotting
Bleeding for one or more days before or after the recognised menstrual period
Define postmenopausal bleeding (PMB)
Bleeding occurring more than 1yr after the acknowledged menopause
Define precocious menstruation
Bleeding before the age of 9yrs
List the causes of HMB
- Uterine fibroids and polyps
- Chronic pelvic infection
- Ovarian tumours
- Endometrial and cervical malignancy
- Thyroid disease
- Haemostatic disorders
- Anticoagulant therapy
*5-7 = rare
What factors should be assessed in a hx of HMB?
- Amount and timing of bleeding
- Flooding and passage of clots = excessive loss
- Any contraception?
What features are present on exam in HMB?
- Anaemia
- Pelvic signs often absent
- Irregular enlargement of uterus (fibroids)
- Tenderness (adenomyosis)
- Ovarian mass or fibroids may be felt
What investigations should be done for HMB?
- Check Hb
- Coagulation (only if hx suggestive)
- TFTs (only if hx suggestive)
- TVUS pelvis:
- endometrial thickness
- exclude fibroids or ovarian mass
- detect polyps - Endometrial biopsy done in:
- >40yrs
- bleeding not responsive to medical therapy
- younger women with risk factors for endometrial cancer
What is the medical management of HMB?
- Intrauterine system (firstline):
- Progestogen impregnated
- Decreases menstrual flow by >90%
- Fewer SEs than systemic
- Contraceptive - Antifibrinolytics (Tranexamic acid):
- Taken during menstruation only
- Decrease blood loss by ~50%
- Few SEs
- Second line - NSAIDs:
- Inhibit prostaglandin synthesis
- Decrease blood loss by ~30%
- Useful for dysmenorrhea
- SEs similar to aspirin
- Second line - COCP:
- Induces lighter menstruation
- Less effective if pelvic pathology
- Contraceptive
- Second line - Progestogens:
- High doses induce amenorrhea
- Bleeding will follow withdrawal
- Third line - GnRH agonists:
- Produce amenorrhea
- Duration limited to 6mths unless add-back HRT given (osteoporosis)
- Bleeding will follow withdrawal
- Third line
What is the surgical management of HMB?
- Hysteroscopic:
- Polyp removal
- Endometrial ablation (most appropriate in older women)
- Transcervical resection of fibroid (submucosal fibroids up to 3cm) - Radical:
- Myomectomy (removal of fibroids; open or laparoscopic; GnRH agonists or ulipristal acetate used preoperatively to shrink)
- Hysterectomy (last resort)
- Uterine artery embolization (treats menorrhagia due to fibroids; want to retain uterus and avoid surgery)
List the causes of irregular menstruation and intermenstrual bleeding
- Anovulatory cycles (common in early and late reproductive years)
- Pelvic pathology:
- Non-malignant
- Malignant
What investigations should be done in cases of IMB?
- Check Hb
- Exclude malignancy
- Cervical smear
- US women >35yrs + younger women with failed medical tx
- Endometrial biopsy:
- Focally or very thickened
- Polyp suspected
- Woman >40yrs
- Significant IMB
- Risk factors for endometrial cancer
- Endometrial ablation surgery or IUS to be used
What is the medical management of IMB?
- IUS or COCP = first line
- Progestogens - when given on a cyclical basis can mimic normal menstruation
- HRT - may regulate erratic uterine bleeding during perimenopause
- Other treatments that are second line tx for HMB
What is the surgical management of IMB?
- Same as for women with HMB
- Ablative techniques less helpful
Define primary amenorrhea
Menstruation not started by 16yrs
Define secondary amenorrhea
When previously normal menstruation ceases for 3mths or more
List the causes of amenorrhea
Physiologial:
- Pregnancy
- After menopause
- During lactation
- Constitutional delay
Pathological:
- Hypothalamus
- Pituitary
- Thyroid
- Adrenals
- Ovary
- Uterus and outflow tract
Drugs:
- Progestogens
- GnRH analogues
- Antipsychotics (increase prolactin levels)
What are the most common causes of amenorrhea?
- Premature menopause
- PCOS
- Hyperprolactinaemia
What are the causes of amenorrhea that originate from the hypothalamus?
- Hypothalamic hypogonadism:
- Usually due to physiological factors (low weight/ anorexia nervosa/excessive exercise)
- Tumours uncommon
- Treatment is supportive (oestrogen replacement)
What are the causes of amenorrhea that originate from the pituitary?
- Hyperprolactinaemia:
- Pituitary hyperplasia or benign adenomas
- Tx = bromocriptine, cabergoline or surgery
- Sheehan’s syndrome - severe PPH causes pituitary necrosis
What are the causes of amenorrhea that originate from the adrenal or thyroid glands?
- Hyper or hypothyroidism
2. Congenital adrenal hyperplasia or virilising tumours
What are the causes of amenorrhea that originate from the ovary?
- Acquired disorders:
- PCOS (most common)
- Premature menopause
- Virilising tumours (rare) - Congenital disorders:
- Turner’s syndrome (most common)
- Gonadal dysgenesis
What are the causes of amenorrhea that originate from outflow tract problems?
- Congenital problems:
- Imperforate hymen
- Transverse vaginal septum
(Tx of both above = surgical)
- Absence of vagina with or without a functioning uterus (Rokitansky’s syndrome) - Acquired problems:
- Cervical stenosis
- Asherman’s syndrome (uncommon consequence of excessive curettage at ERPC)
What is postcoital bleeding (PCB)?
- Vaginal bleeding following intercourse that is not menstrual loss
- Always abnormal except for first intercourse
- Must exclude cervical carcinoma
List the causes of PCB
- Cervical:
- Ectropions
- Polyps
- Invasive cervical cancer - Occasionally from vaginal wall
What is the management of PCB?
- Cervix carefully inspected and smear taken
- Polyp - removed and sent for histology
- Ectropion - frozen with cryotherapy
- Colposcopy to exclude malignant cause
Define dysmenorrhea
- Painful menstruation
- High prostaglandin levels in endometrium
- Due to contraction and uterine ischaemia
Discuss the causes and management of dysmenorrhea
- Primary dysmenorrhea:
- No organic cause
- Coincides with start of menstruation
- Usually responds to NSAIDs or ovulation suppression (COCP)
- Pelvic pathology more likely if medical tx fails - Secondary dysmenorrhea:
- Pain due to pelvic pathology
- Precedes and is relived by onset of menstruation
- Deep dyspareunia + menorrhagia or irregular menstruation common
- Pelvic US and laparoscopy useful
Most significant causes:
- Fibroids
- Adenomyosis
- Endometriosis
- PID
- Ovarian tumours
