3) Puberty & Abnormalities of Menstruation Flashcards
At what age does puberty take place in girls?
8-13 years
At what age does puberty take place in boys?
9-14 years
What changes take place in a boy at puberty?
Genital development begins
Adrenarche (pubic hair growth)
Spermatogenesis begins
Growth spurt (10cm/year)
What changes take place in a girl during puberty?
Thelarche - breast bud development, 1st sign of puberty
Adrenarche - pubic hair growth
Growth spurt (9cm/year)
Menarche - onset of menstrual cycles
Puberty is under hormonal control. Which hormones are involved?
Onset of puberty:
Rise in FSH & LH (brain initiates)
due to Pulsatile GnRH secretion
What is the significance of body weight and puberty?
Body weight most important factor in timing of puberty
47kg critical weight for menarche
What happens to the reproductive cycle if body weight falls significantly below 47kg?
Reproductive cycle ceases
May be signalled to brain by leptins
At what weight does the growth spurt start in boys & girls?
30kg girls
55kg boys
What is adrenarche and how does it occur?
Pubic and axillary hair growth
Depends on androgens in both sexes
From adrenal glands in girls
What causes the growth spurt in girls & boys during puberty?
Growth hormone & Steroids
Ended by epiphyseal fusion
Oestrogen closes epiphyses earlier in girls
Growth spurt earlier & shorter in girls
What is thelarche?
Breast development
dependant on oestrogen
What is male genital development dependant on?
Testosterone
What is precocious puberty?
Development of signs of puberty before 8yrs in girls or 9yrs in boys
What causes precocious puberty?
Unknown
Can be due to:
Neurological causes, inappropriate GnRH secretion
- Pineal tumours, meningitis
Uncontrolled gonadotrophin or steroid secretion
- Hormone secreting tumours
What happens during pre-menopause and what age does it occur?
>40 years Changes in menstrual cycle Follicular phase shortens, ovulation early or absent Less oestrogen secreted Less -ve feedback - FSH & LH rise FSH rises more - loss of inhibin too Reduced fertility
What changes occur during menopause?
Cessation of menstrual cycles Average age 49-50 Female has run out of follicles Oestrogen falls dramatically Less -ve feedback - FSH & LH rise FSH rise dramatically - loss of inhibin
What are the vascular effects of menopause?
Hot flushes (80%)
Transient rises in skin temp
Relieved by oestrogen treatment
What are the effects of menopause on oestrogen sensitive tissues?
Uterus: regression of endometrium, shrinkage of myometrium
Thinning of cervix
Vaginal rugae lost (thinner, less distensible)
Involution of some breast tissue
Changes in skin
Reduction in bladder tone
What are the effects of menopause on bone?
Bone mass reduces by 2.5% per year for several years
Increased reabsorption relative to production
Osteoporosis (limited by oestrogen therapy)
What are positives and negatives about Hormone Replacement Therapy (HRT)?
Relieves symptoms of menopause
Orally/topically by patch/gel
Can limit osteoporosis
Not advised for cardio-protection
What is amenorrhoea?
Absence of periods for at least 6 months
What is primary amenorrhoea?
Never had a period
Absence of menses by 14 with abscence of secondary sexual characteristics e.g. thelarche
or Absence by age 16 with normal SSC
What is secondary amenorrhoea?
Established menstruation has ceased for 3 months in woman with history of regular cyclical bleeding
9 months in a woman with a history of irregular periods
Normally aged 40-55
What is oligomenorrhoea?
Infrequent periods occurring at intervals of 35days - 6months
What is dysmenorrhoea?
Painful periods
What is menorrhagia?
Heavy vaginal bleeding that is not DUB Heavy periods Excessive >80ml Prolonged >7 day uterine bleeding Usually ovulatory
What is cryptomenorrhoea?
Periods occur but not visible due to obstruction in outflow tract
What is dysfunctional uterine bleeding(dub)?
Abnormal bleeding, no obvious organic cause
What are anovulatory cycles?
No ovulation/luteal phase
Oligo/Amenorrhoea +/- Mennorhagia
What are ovulatory cycles?
Normal menstrual cycles + dysmenorrhoea/mastalgia (sore breasts)
What causes amenorrhoea?
Origin is Hypothalamic/Pituitary, Ovarian or Outflow tract (uterus, vagina, cervix)
How do problems with the hypothalamus/pituitary cause amenorrhoea?
Inadequate levels of FSH
Inadequately stimulated ovaries
Ovaries fail to produce enough oestrogen to stimulate the endometrium of uterus
Hypo/hyperthyroidism may cause secondary
Name a cause of primary hypothalamic amenorrhoea
Kallmann syndrome - Inability to produce GnRH (& FSH subsequently)
Name some causes of secondary hypothalamic amenorrhoea
Exercise amenorrhoea
Stress amenorrhoea
Eating disorders & weight loss (obesity, anorexia, bulimia)
Fall below critical weight 47kg & menses ceases
Name some causes of secondary pituitary amenorrhoea
Sheehan syndrome - hypopituitarism
Hyperprolactinaemia
Haemochromatosis - ‘Iron overload’
What is hypergonadotrophic amenorrhoea?
Ovarian amenorrhoea, ovary doesn’t respond to pituitary stimulation - low oestrogen levels
Lack of -ve feedback - elevated FSH levels in the menopausal range
Name some causes of primary gonadal/end-organ amenorrhoea
Gonadal dysgenesis - e.g. Turner’s syndrome (45,X)
Androgen Insensitivity Syndrome
Receptor abnormalities for FSH & LH
Specific forms of congenital adrenal hyperplasia
Name some causes of secondary gonadal/end-organ amenorrhoea
Pregnancy Anovulation Menopause (or premature menopause) Polycystic Ovarian Syndrome Drug-induced
What is outflow tract amenorrhoea?
Hypothalamic-Pituitary-Ovarian Axis is functional
FSH level normal
Problem with uterus/vagina/cervix
Name some causes of primary outflow tract obstruction (amenorrhoea)
Uterine - Mullerian agenesis (15% primary)
Vaginal - Vaginal atresia, cryptomenorrhoea, imperforate hymen
Name a cause of secondary outflow tract obstruction (amenorrhoea)
Intrauterine Adhesions (Asherman’s syndrome)
How is amenorrhoea managed?
Depends on cause:
Hormone replacement
Modification of lifestyle factors (exercise, weight loss)
Explain what happens when dysfunctional uterine bleeding (DUB) occurs when ovulation is not occurring
90%
CL does not form to release progesterone
Oestrogen is produce continuously - overgrowth of uterine endometrium & subsequent bleeding
Explain what happens when dysfunctional uterine bleeding (DUB) occurs when ovulation is occurring
10%?
Progesterone secretion prolonged as oestrogen levels are low
Irregular shedding of uterine lining & erratic bleeding
How is dysfunctional uterine bleeding (DUB) diagnosed?
Exclusion of other causes: hCG, TSH - Exclude pregnancy, thyroid Coagulation workup Smear if appropriate - Exclude cancer Sample endometrium
Name some causes of menorrhagia
Usually secondary to distortion of uterine cavity
Uterus unable to contract down on open venous sinuses in zona basalis
Or organic, endocrine, haemostatic, iatrogenic (fibroids, hypothyroidism)
How is menorrhagia managed?
Progesterone
