Gynaecology Flashcards
Menstruation
Hormones (5)
Cycle controlled by hypothalamic-pituitary-ovarian axis
Gonadotrophin-releasing hormones are produced by the hypothalamus
Stimulates pituitary to produce gonadotrophins: FSH + LH
They stimulate the ovary to produce oestrogen and progesterone
They modulate production of gonadotrophins by negative feedback on the hypothalamus and pituitary
Menstruation
Cycle (8)
At start, FSH levels high, stimulating development of a primary follicle
The follicle produces oestrogen, which stimulates the development of a glandular ‘proliferative’ endometrium and of cervical mucus receptive to sperm
14 days before menstruation the oestrogen level becomes high enough to stimulate surge of LH, stimulating ovulation
Primary follicle forms corpus + produces progesterone
Endometrial lining prepared for implantation, ‘secretory phase’
Cervical mucus becomes hostile to sperm
If ovum not fertilised, corpus luteum breaks down and hormone levels fall
Reduced hormones causes arteries in uterine endothelium to constrict and slough
Hypothalamo-Pituitary Ovarian Axis Feedback
+ve feedback: oestrogen on hypothalamus and anterior pituitary days 12-14
-ve feedback: oestrogen and progesterone on hypothalamus and anterior pituitary for most of cycle, this prevent more than one egg being released
Hormones in the Ovarian Cycle
Oestrogen is present in the follicular phase
Progesterone is released in the luteal phase to prepare the uterus for pregnancy, if no implantation the corpus luteum degenerates
Corpus luteum secretes progesterone
Roles of Main Female Reproductive Hormones
GnRH (from hypothalamus): stimulates LH and FSH secretion from anterior pituitary
LH (from anterior pituitary): maintains dominant follicle and stimulates corpus luteum function
FSH (from anterior pituitary): stimulates follicular recruitment and development
Oestradiol (from granulosa cells): supports secondary sex characteristics, -ve feedback of LH + GnRH
Progesterone (from corpus luteum): maintains secondary endometrium
Primary Amenorrhoea
Definition (1)
Failure to start menstruating before age 16, or 14 if no secondary sexual characteristics
Primary Amenorrhoea
Aetiology (6)
Familial late puberty Heavy exercise/stress/weight loss Pituitary and hypothalamus disease Gonadal dysgenesis (ovaries prematurely depleted of follicles and oocytes) Turner syndrome PCOS
Primary Amenorrhoea
Treatment (4)
Weight gain/less exercise/less stress
If amenorrhoea persists for >12 months, consider osteoporosis prophylaxis
Treat hypothalamic/hypoprolactinaemic causes
HRT or COCP if amenorrhoea >12 months
Secondary Amenorrhoea
Definition (1)
Periods stop for >6 months in the absence of pregnancy
Secondary Amenorrhoea
Aetiology (7)
Hypothalamic-pituitary-ovarian causes are common: stress, weight loss, exercise
Hyperprolactinaemia: may have galactorrhoea
Hypo- and hyper-thyroidism
PCOS
Ovarian insufficiency/failure (premature menopause, secondary to chemo/radio, genetic- Turner’s)
Post-pill amenorrhoea
Asherman’s syndrome (adhesions after D+C)
Secondary Amenorrhoea
Investigations (6)
BhCG to exclude pregnancy
Serum free androgen index (increased in PCOS)
FSH/LH (low if hypothalamic-pituitary cause but may be normal if weight loss/exercise)
Prolactin (increased by stress, hypothyroidism, prolactinomas)
TFTs
Testosterone level (may indicate androgen secreting tumour)
Secondary Amenorrhoea
Treatment (2)
Premature ovarian failure can’t be reversed but hormone replacement is necessary to control symptoms of oestrogen deficiency and protect against osteoporosis
For hypothalamic-pituitary-ovarian malfunction: weight loss + lifestyle measures, clomifene/gonadotrophin releasing hormone for fertility
Polycystic Ovarian Syndrome
Signs + symptoms (5)
Oligomenorrhoea/amenorrhoea Hirsutism (excess hair) Acne Subfertility Acanthosis nigrans (reflects hyperinsulinaemia)
Polycystic Ovarian Syndrome Rotterdam Criteria (4)
2 out of 3 must be present
Polycystic ovaries (12 or more follicles or ovarian volume >10cm3 on ultrasound)
Oligo-ovulation or anovulation
Hyperandrogenism (clinical or biochemical signs)
Polycystic Ovarian Syndrome
Investigations (6)
TFTs (rule out dysfunction) Prolactin (rule out hyperprolactinaemia) Rule out androgen secreting tumours Rule out Cushing's Testosterone high LH high
Polycystic Ovarian Syndrome
Treatment (6)
Weight loss (high insulin sensitivity)
Metformin (improve insulin sensitivity and improve menstrual disturbance)
Clomifene (induces ovulation)
Ovarian drilling when don’t respond to clomifene (intent is to reduce steroid production)
COCP (control bleeding and reduce risk of unopposed oestrogen)
Anti-androgen (reduce hirsutism)
Polycystic Ovarian Syndrome
Complications (4)
Gestational diabetes
Type 2 diabetes
CV disease
Endometrial cancer
Menorrhagia
Definition (1)
Heavy periods, blood loss >80ml/cycle
Menorrhagia
Aetiology (8)
Dysfunctional uterine bleeding (most common)- heavy and/or irregular bleeding in absence of pelvic pathology Fibroids Endometriosis Adenomyosis Early pregnancy loss Hypothyroidism Coagulation disorders (vWB, platelet abnormalities, warfarin) Endometrial cancer
Menorrhagia
Signs + symptoms (7)
Heavy, prolonged vaginal bleeding, often worse at extremities of reproductive life
Dysmenorrhoea
Symptoms of anaemia
Pallor
If intermenstrual or post coital bleeding check smear history
Enlarged uterus suggests fibroids or adenomyosis
Speculum examination may reveal a cervical polyp
Menorrhagia
Investigations (6)
Exclude pregnancy FBC TSH Cervical smear if due STI screen If <45 no further investigation and start treatment, if >45 with risk factors/failed medical therapy then do transvaginal US and biopsy to look for fibroids, polyps, endometrial thickness
Menorrhagia
Treatment (7)
Mirena IUS 1st line
Antifibrinolytics eg.tranexamic acid during bleeding
NSAIDs eg. mefanamic acid during bleeding, especially if also dysmenorrhoea
COCP
3rd line progestogens IM eg. norethisterone stops heavy bleeding short term
Endometrial ablation
If have fibroids but wish to retain fertility: uterine artery embolisation or myomectomy, otherwise hysterectomy
Menopause Average age (1)
52
Menopause
Pathology (2)
Perimenopause: high number of anovulatory cycles leads to less progesterone and less endometrial secretory changes and irregular menses
Menopause: oestradiol falls due to lack of developing follicles and their granulosa cells, lack of -ve feedback to pituitary causes and increased FSH and LH