Puberty and Menstrual Cycle Flashcards
What age does menarche occur?
13
What hormonal changes occur prior to puberty?
Gonadotrophin releasing hormone (GnRH) produced by hypothalamus
Stimulates FSH + LH (from pituitary)
Stimulates oestrogen from ovary
Where is GnRH produced?
Hypothalamus
Where are LH and FSH produced?
Anterior pituitary gland
What does the anterior pituitary gland produce?
GH Prolactin LH and FSH (gonadotropes) ACTH TSH
What does the posterior pituitary produce?
Oxytocin
Vasopressin (ADH)
What are the three types of oestogen?
Estrone - menopause (ovary and adipose)
Estradiol - reproductive years (ovary/fat/liver/adrenal/breast/neural)
Estriol - pregnancy (placenta)
What occurs during days 1-4 of the menstrual cycle?
Menstruation
Endometrium is shed
Hormonal support withdrawn
What occurs during days 5-13 of the menstrual cycle?
Proliferation
Pulses of GnRH stimulate LH + FSH which induce follicular growth
Follicles produce oestradiol and inhibin
These suppress FSH secretion so only one follicle and oocyte mature
Oestrogen also causes endometrium to reform
When does ovulation occur?
Day 13
After sharp rise in LH
What occurs during ovulation?
Oestradiol rises, positive feedback on hypothalamus and pituitary -> increased LH -> ovulation
What occurs during days 14-28 of the menstrual cycle?
Luteal/secretory phase
Follicle from which egg was released becomes the corpus luteum
Produces low levels of oestradiol and more progesterone (peak at day 21)
Progestone causes secretory changes in endometrium
Corpus luteum fails if egg isn’t fertilised -> progesterone and oestrogen levels fall
What is normal menarche? Menarche? Menopause? Menstruation days? Blood loss? Cycle length?
Menarche 45 years
Menstruation
What is menorrhagia?
Heavy menstrual bleeding in otherwise normal menstrual cycle
What is dysmenorrhoea?
Painful periods
What is premenstrual syndrome?
Psychological and physical symptoms which are worse in the luteal phase
What pathologies cause menorrhagia?
Uterine fibroids
Polyps
Pelvic inflammatory disease
Ovarian, endometrial and cervical malignancies
Thyroid disease
Haemostatic disorders
Anticoagulant therapy
What investigations are done for menorrhagia?
Bloods - Hb, TSH, coagulation
Imaging
- transvaginal USS (polyp, fibroid, mass)
Other
- endometrial biopsy
- hysteroscopy
How is menorrhagia medically managed?
IUS - progesterone only
Antifibrinolytics (tranexamic acid) - taken during menstruation
NSAIDs - inhibit prostaglandin synthesis
COCP - less effective if pelvic pathology present
Progestogens - high dose oral or IM
GnRH analogues
How is menorrhagia surgically managed?
Hysteroscopic
- resection of polyps
- endometrial ablation (reduces fertility)
More radical
- myomectomy - removal of fibroids from endometrium
- hysterectomy
- uterine artery embolism
What are indications for an endometrial biopsy?
Endometrial thickness >10mm premenopausal, >4mm postmenopausal Age >40yrs Menorrhagia with IMB Polyp on USS Before IUS if irregular cycle Prior to endometrial ablation
What causes irregular bleeding?
Anovulatory cycles are common just after menarche and pre-menopause
Fibroids Uterine and cervical polyps Adenomyosis (endometriosis in uterine muscle wall) Ovarian cysts PID
What investigations are done for irregular bleeding?
Exclude STI (chlamydia) and pregnancy
Bloods - Hb
Other
- ?cervical smear
- endometrial ablation (thickened endometrium, polyp, >40yrs)
Imaging
- USS for >35yrs
How is irregular bleeding medically managed?
IUS or COCP
Cyclical progestogens
HRT in perimenopause
How is irregular bleeding surgically managed?
Ablative techniques less likely to work well
What are the types of amenorrhoea?
Primary - menstruation hasn’t occurred by age 16
Secondary - ceases for 6 months
Oligomenorrhoea - occurs every 35 days to 6 months
What are causes of amenorrhoea?
Physiological
- during pregnancy
- after menopause
- during lactation
Pathological
- hypothalamus
- pituitary
- thyroid/adrenals
- ovary, uterus, outflow tract
- drugs (antipsychotics raise prolactin)
What are hypothalamic causes of amenorrhoea?
Hypothylamic hypogonadism due to psychological factors, low weight or excessive energy
Reduces GnRH, FSH, LH and oestradiol
Reduced bone density Oestrogen replacement (plus progesterone for endometrial protection)
What are pituitary causes of amenorrhoea?
Hyperprolactinaemia caused by hyperplasia or benign adenomas
Tx: bromocriptine, cabergoline
Pituitary tumours
Sheehan’s sydrome (severe PPH -> pituitary necrosis, hypopituitary)
What are adrenal/thyroid causes of amenorrhoea?
Hypothyroidism - raised prolactin
Hyperthyroidism
CAH
What are ovarian causes of amenorrhoea?
Polycystic ovarian syndrome ( commonly causes oligomenorrhoea)
Premature menopause
Turner’s syndrome
Gonadal dysgenesis
What are outflow tract causes of amenorrhoea?
Imperforate hymen or transverse vaginal septum obstruct menstrual flow (builds up in vagina or uterus and may be palpatable)
Rokitansky’s syndrome - absence of vagina
Cervical stenosis -> haematometra
What are causes of post-coital bleeding?
Ectropions Benign polups Invasive cervical cancer Cervicitis Vaginitis
How is PCB managed?
Inspection of cervix and smear
Cryotherapy
Colposcopy to exclude malignant cause
What causes dysmenorrhoea?
High prostaglandins in endometrium
Contraction and uterine ischaemia
Primary - coincides with start of menstruation
Secondary - pain precedes and is relieved by menstruation Deep dyspareunia common Fibroids Adenomyosis Endometriosis PID Ovarian tumous
How is primary dysmenorrhoea managed?
NSAIDS or COCP
What is precocious puberty?
Menstruation
What causes precocious puberty and how is it managed?
No known cause - GnRH agonists inhibit sex hormone secretion
Increased GnRH secretion (meningitis, encephalitis, CNS tumours, hydrocephaly, hypothyroidism) may prevent normal pre-pubertal inhibition of hypothalamic GnRH release
Ovarian/adrenal causes - hormone producing tumours
What causes increased androgens in females?
CAH
- defective cortisol production
- excess ACTH causes increased androgens
- ambiguous genitalia
- glucocorticoid deficiency
- Addisonian crisis
Tx: cortisol and mineralocorticoid
What causes reduced androgens in males?
Androgen insensitivity syndrome
- androgens then converted to oestrogens so appear to be female
- absent uterus, rudimentary testes
How is PMS managed?
SSRIs given in second half of cycle
Continuous oral contraceptives
Evening primrose oil
