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Hormonal support withdrawn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