Repro - puberty and abnormalities of menstruation Flashcards Preview

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When do changes in the male at puberty begin?

9-14 years


When do changes in the female at puberty begin?

8-13 years


What is adrenarche?

The onset of an increase in the secretion of androgens.


What is the first sign of puberty in males?

Genital development - testicular enlargement


What is the first sign of puberty in females

Breast bud (thelarche) development


What is the series of changes that occur in males at puberty?

1. Genital development begins
2. Pubic hair growth (puberarche)
3. Spermatogenesis begins
4. Growth spurt (~10cm/year)
5. Genitalia adult
6. Pubic hair adult


Describe the changes that occur to male pubic hair:

PH1: none
PH2: Sparse, pigmented, long, mainly along labia and base of penis
PH3: dark, coarse, curlier
PH4: filling out towards adult distribution
PH5: adult in quantity and type with spread to medial thighs


Describe the changes that occur to male genitalia:

G1: preadolescent
G2: lenghening of penis
G3: further growth in length and circumference
G4: Development of glans penis, darkening of scrotal skin
G5: adult genitalia


What is the series of changes that occur in females at puberty?

1. Breast bud (thelarche) development
2. Pubic hair growth (puberarche)
3. Growth spurt (9cm/year)
4. Onset of menstrual cycles (Menarche)
5. Pubic hair adult
6. Breasts adult


Describe the changes that occur to breasts during puberty:

B1: Prepubertal
B2: Breast bud
B3: juvenial smooth contour
B4: Areolar and papilla project above breast
B5: adult


What causes the onset of puberty?

A steady rise in FSH and LH secretion caused by pulsatile GnRH secretion. This could be due to a reduction in sensitivity to the negative feedback by steroids but is more likely due to 'maturation' of central mechanisms e.g. the brain initiates it.


What is the most important factor in the timing of pubert?

Body weight


What is the critical weight for menarche?



What may be the cause of secondary amenorrhoea with low body weight?

Reproductive cycle stops - this may be due to leptin signalling to the brain.


What is the rough growth spurt start weight in boys and girls?

Boys - 55kg
Girls - 30kg


What has happened to the average age of menarche in the last 200 years?

It has fallen - it used to be 17 and now it is 13 years. This is though to be because children are bigger now.


What cause puberarche?

Androgens in males and females. In females these androgens are from the adrenal glands.


Why are growth spurts shorter in females?

Oestrogen closes the epiphyses earlier in females. Oestrogen is needed to initiate the growth spurt, but once levels reach a certain point it causes epiphyses to fuse.


What is the difference between the growth spurts males experience versus females?

Males: longer and slightly faster
Females: earlier and shorter


What hormones does the growth spurt depend upon?

Growth hormone and steroids


What hormone is thelarche dependent upon?



What hormone is male genital development dependent upon?



What is precocious puberty?

The development of the signs of puberty before the age of 8 in girls and 9 in boys.


What is the cause of precocious puberty?

1. Unknown in the majority of cases
2. Neurological causes - early stimulation of central maturation giving early inappropriate GnRH secretion e.g. pineal tumours and meningitis
3. Uncontrolled gonadotrophin or steroid secretion e.g. hormone secreting tumours


What pre-menopause changes do woman experience?

1. Changes to their menstrual cycle: follicular phase shortens, with ovulation early or absent
2. Reduced fertility - though still possible to get pregnant


When do woman experience pre-menopause changes?



What hormonal changes occur in pre-menopause woman?

Less oestrogen and inhibin is secreted therefore reduced negative feedback occurs and FSH and LH levels rise.


What hormonal changes occur in the menopause?

Female has run out of follicles therefore:
1. Oestrogen and inhibin levels fall dramatically
2. Negative feedback lost and therefore GnRH, FSH and LH levels increase


What is the menopause?

Cessation of the menstrual cycle for 12 months.


When is the average age of the menopause?

49-50, but varies


What are the vascular effects of the menopause?

Transient rises in skin temperature and flushes (affects ~80% to some degree). Somehow caused by decrease in oestrogen.


What changes occur to oestrogen-sensitive tissues after the menopause?

1. Uterus: regression of endometrium, shrinkage of myometrium, shrinks to a small organ
2. Thinning of cervix
3. Vaginal rugae lost - thinner, less distensible
4. Involution of some breast tissue
5. Changes in skin
6. Reduction in bladder tone


What changes occur to bone after the menopause?

Bone mass reduced by 2.5% per year for several years due to an increased reabsorption relative to production. This can cause osteoporosis.


What are the advantages of hormone replacement in post-menopausal women?

1. Relieves symptoms of the menopause
2. Can limit osteoporosis (but is no longer recommended as first line protection (bisphoshonates are)


How is HRT administered?

Orally or topically by patch or gel.


What are the disadvantages of HRT?



What is amenorrhoea?

Absence of periods for at least 6 months


What is primary amenorrhoea?

Absence of menses by age 14 with absence of secondary sexual characteristics e.g. breast development or absence by age 16 with normal secondary sexual characteristics.


What is secondary amenorrhoea?

Established menstruation has ceased for three months in a woman with a history of regualr cyclic bleeding or nine months in a woman with a history of irregular periods.


What is the most common cause of amenorrhoea?

Pregnancy and menopause


What is oligomenorrhoea?

Infrequent periods occurring at intervals of 35 days - 6 months


What is dysmenorrhoea?

Painful periods


What is menorrhagia?

Heavy periods (>80ml), prolonged (>7 days) uterine bleeding.


What is cryptomenorrhoea?

Periods occur but not visible due to obstruction in outflow tract.


What is dysfunctional uterine bleeding?

Abnormal bleeding - no obvious organic cause


What are anovulatory cycles?

Menstrual cycles with no ovulation/luteal phase. This cause oligo-/amenorrhoea +/- menorrhagia.


What are the main categories of causes of amenorrhoea?

1. Hypothalamic/pituitary
2. Ovarian
3. Outflow tract (uterus, vagina, cervix)


Why can hypothalmic/ pituitary problems cause amenorrhoea?

Inadequate levels of FSH lead to inadequately stimulated ovaries, which then fail to produce enough oestrogen to stimulate the endometrium of the uterus.


What is a cause of primary hypothalamic amenorrhoea?

Kallmann syndrome - inability to produce GnRH


What are some causes of secondary hypothalamic amenorrhoea?

1. Exercise amenorrhoea
2. Stress amenorrhoea
3. Eating disorders and weight loss (below critical weight)


What are causes of secondary pituitary amenorrhoea?

1. Sheehan syndrome - hypopituitarism
2. Hyperprolactinaemia (inhibits GnRH secretion)
3. Haemachromatosis -> pituitary damage
4. Can be cause by hyp-/hyper-thyroidism


What is the general mechanism of gonadal amenorrhoea?

Ovary does not respond to pituitary stimulation, giving low oestrogen levels. The lack of negative feedback raises FSH levels to the menopausal range.


What are some primary causes of gonadal amenorrhoea?

1. Gonadal dysgenesis - e.g. Turner's syndrome
2. Androgen insensitivity syndrome
3. Receptor abnormalities for FSH and LH
4. Specific forms of adrenal hyperplasia


What are some secondary causes of gonadal amenorrhoea?

1. Pregnancy
2. Anovulation
3. Menopause (or premature menopause)
4. Polycystic ovarian syndrome
5. Drug-induced


What is outflow tract amenorrhoea?

Amenorrhoea where the HPG axis is functional, therefore FSH levels are normal but the outflow tract is obstructing the blood flow during menses.


What are primary causes of outflow tract amenorrhoea?

1. Uterine - Mullerian agenesis (15% of primary amenorrhoea)
2. Vaginal - vaginal atresia, cryptomenorrhoea, imperforate hymen


What are secondary causes of outflow tract amenorrhoea?

1. Intrauterine adhesions (Asherman's syndrome)


What is the major cause of dysfunctional uterine bleeding (DUB)?

90% occurs when ovulation is not occurring. The corpus luteum does not form to release progesterone and therefore oestrogen is produced continuously which cause overgrowth of uterus and subsequent bleeding.


How is dysfunctional uterine bleeding diagnosed?

It is a diagnosis of exclusion. The following is tested to rule out other causes:
1. hCG, TSH (exclude pregnancy and thyroid disease)
2. Coagulation work up
3. Smear if appropriate (exclude cancer)
4. Sample endometrium


What is the usual cause of menorrhagia?

It is usually secondary to distortion of the uterine cavity, leaving the uterus unable to contract down on open venous sinuses in the zona basilis.


What are other causes of menorrhagia?

Organic, endocrine, haemostatic and iatrogenic


Is menorrhagia normally ovulatory?



How is menorrhagia managed?

Progesterone - taken in days 15-26 of the menstrual cycle in order to help coordinate shedding.


What is the difference between menorrhagia and dysfunctional uterine bleeding?

DUB reflects a disruption in the normal cyclic pattern of ovulatory hormonal stimulation to the endometrial lining, whereas menorrhagia is heavy bleeding.


What is puberarche?

Development of axillary and pubic hair.


A pulse of what hormone may account for some of the early pubertal changes seen in males?

Sleep-dependent nocturnal rise in LH, causing a nocturnal rise in testosterone. (A similar pattern is seen in females with concomitant increase in oestrogen).


What is spermarche?

Mature spermatocytes in secretions.


Precise timing of LH surge and therefore ovulation are affected by what environmental triggers?

Altitude and lattitude, light and dark phases etc...


What is delayed puberty?

When the initial changes of puberty are not present by age 13 years in girls (or primary amenorrhoea at 15-16) and age 14 in boys. Or pubertal development is inappropriate - the interval between the first signs of puberty and menarche in girls/ completion genital growth in boys is >5 years.


What are the causes of delayed puberty?

1. Gonadal failure
2. Gonadal deficiency


What are causes of gonadal failure?

1. Turner's syndrome
2. Post-malignancy chemo/radiotherapy/surgery
3. Polyglandular autoimmune syndromes


What are causes of gonadal deficiency?

1. Congenital hyporgonadotrophic hypogonadism
2. Hypothalamic/ pituitary lesions (tumours, post-radiotherapy)
3. Rare gene mutations inactivating FSH/LH receptors