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Puberty

Puberty. Clinic of Reproduction and Gynecology Pomeranian Medical Academy Iwona Szydłowska. It is a physiological phase lasting 2 to 5 years , during which the genital organs mature. SEXUAL MATURATION. Physical, emotional and sexual transition from childhood to adulthood

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Puberty

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  1. Puberty Clinic of Reproduction and Gynecology Pomeranian Medical Academy Iwona Szydłowska

  2. It is a physiological phase lasting 2 to 5 years,during which the genital organs mature

  3. SEXUAL MATURATION Physical, emotional and sexual transition from childhood to adulthood Gradually. Sequence of physiological changes.

  4. The first sign of pubertal development is usually breast growth (thelarche), followed by appearance of pubic hair (pubarche), then axillary hair(adrenarche), then menarche. • The mean interval between breast budding and menarche is 2.5 years with a standard deviation of about one year.

  5. ADRENARCHE Somatic changes dependent on adrenal steroid hormones means increased activity of the suprarenal cortexat puberty with increased production of adrenal androgens which lead to appearance of pubic and axillary hair.

  6. GONADARCHE Somatic changes dependent on gonadal sex steroid hormones

  7. CAUSE OF PUBERTY: • During childhood, the hypothalamus is extremely sensitive to the negative feedback exerted by the small quantities of estradiol & testosterone produced by the child's ovaries. • As puberty approaches, the sensitivity of the hypothalamus is decreased and subsequently, it increase the pulsatile GnRH secretion .

  8. CNS-Hypothalamus-Pituitary Ovary-Uterus Interaction Neural control Chemical control Dopamine (-) Norepinephrine (+) Endorphines (-) Hypothalamus Gn-RH ? ± – Ant. pituitary FSH, LH Ovaries Estrogen Progesterone Uterus Menses

  9. HYPOTHALAMUS-PITUITARYOVARIAN AXIS • Necessary for the normal sexual maturation. • Pulsatile secretion of gonadotropins begins the maturation process. • Important is not the amplitude of Gn pulses, but the frequency. • In the late prepubertal period secretion of Gn is reinforced – subsequent pulses of GnRH reinforce the release of Gn. • Activation of positive and negative feedback loops at puberty.

  10. The anterior pituitary responds by progressive secretion of FSH and LH associated with increased secretion of growth hormone.

  11. The ovariesrespond to the increase Gonadotrophin secretion by follicular development & estrogen secretion.

  12. Estrogen causes development of the genital organs and the appearance of the secondary sexual characters. • With increased estrogen secretion, menarche and cyclic estrogen secretion occurs.

  13. SECONDARY SEX CHARACTERS INCLUDE: • development of the breast, • appearance of pubic and axillary hair.

  14. FACTORS AFFECTING THE INITIATION OF PUBERTAL DEVELOPMENT: 1 - Height and weight ratio- 48 kg (nutritional factors). 2 - Maturation of the hypothalamus. 3 - Increased neurotransmitter output in CNS. 4 - Onset of adrenal androgen activity.

  15. DEPOSITION OF SC FAT: 17% to menstruate & 22% to ovulate

  16. PUBERTY Five stages from childhood to full maturity (P1 to P5), described by Marshall and Tanner. In bothsexes, these stages reflect the progressivemodifications of the external genitalia and of sexual hair. Secondary sex characteristics appear at a mean age of10.5 y in girlsand 11.5 to 12 y in boys.

  17. SEQUENCE AND AGE OF SEXUAL MATURATION AND HORMONES RESPONSIBLE FOR THIS PROCESSES.

  18. FEMALE PUBERTAL STAGES (TANNER) P1 Prepubertal P2 Early development of subareolar breast bud +/-small amounts of pubic hair and axillairy hair P3Increase in size of palpable breast tissue and areolae, increased amount of dark pubic hair and/of axillary hair P4Further increase in breast size and areolae that protrude above breast leveladult pubic hair P5Adult stage, pubic hair with extension to upper thigh

  19. TANNER’S CLASSIFICATION OF SEXUAL MATURITY: BREASTS • Th 1- child (only papillae are elevated) • Th 2 – prepubertal (breast bud and papilla are elevated and a small mount is present; areola diameter is enlarged); age 11,2 yrs (9,0-13,3 yrs) • Th 3 - early pubescent, age 12,2 yrs (10,0-14,3) • Th 4 - late pubescent, age 13,1 yrs (10,8-15,3) • Th 5 - adult mature breast (recession of areola to the mound of breast tissue, rounding of the breast mound, and projection of only the papilla are evident); age 15,3 yrs (11,9-18,8)

  20. TANNER’S CLASSIFICATION OF SEXUAL MATURITY: PUBIC HAIR • P1- prepubertal/Pre-adolescent (vellus hair only, no pubic hair) • P2 - presexual hair (sparse growth of long, slightly pigmented, downy hair or only slightly curled hair, appearing along labia) - age 11,7 (9,3-14,1) • P3 - sexual hair (hair is darker, coarser, more curled, and spreads above the syphysis pubis) – age 12,4 (10,2-14,6) • P4 - mild-escutcheon (Adult-type hair; area covered is less than that in most adults; there is no spread to the medial surface of thigh) – age 13,0 (10,8-15,1) • P5 - female escutcheon (Adult-type hair with increased spread to medial surface of thighs; distribution is as an inverse triangle) – age 13,4 ( 12,2-16,7)

  21. GENITAL ORGANS CHANGES: • Mons pubes, labia majora & minora: increase in size. • Vagina: • length: increase, appearance of the rugae • epithelium: thick, stratified squamous, containing glycogen • pH: acidic.

  22. GENITAL ORGANS CHANGES: • Uterus: enlarge, Uterus / Cervix :2 / 1 • Ovaries: • Increase in size, almond shape • 300 thousands primary follicle at menarche (2 million at birth)

  23. In prepuberty, the ovarian size volume extends from 0.3 to 0.9cm3. More than 1.0cm3 indicates that puberty has begun. During puberty, the ovarian size increases rapidly to a mean postpubertal volume of 4.0 cm3 (1.8 to 5.3 cm3).

  24. MENARCHE During puberty, plasma E2 levels fluctuate widely, probably reflecting successive waves of follicular development that fail to reach the ovulatory stage. The uterine endometrium is affected by these changes and undergoes cycles of proliferation andregression, until a point is reached when substantial growth occurs so that withdrawal of estrogen results in the first menstruation (menarche).

  25. OVULATION Plasma progesterone remains at low levels evenif secondary sexual characteristics have appeared. A rise in progesterone after menarche is, in general, indicative that ovulation has occured. The first ovulation does not take place until 6-9 months after menarche because the positive feedback mechanism of estrogen is not developed.

  26. ADOLESCENCE : • Is the period of life during which the child becomes an adult person i.e. the physical , sexual and psychological development are complete . • Puberty represents the first part of adolescence .

  27. ABNORMALITIES OF PUBERTY 1 - Precocious puberty. 2 - Delayed puberty. 3 - Growth problems: during adolescence e.g. short stature or tall stature, marked obesity and menstrual disorders at puberty .

  28. FEMALE PRECOCIOUS PUBERTY

  29. DEFINITION: It means menarche or appearance of any of the secondary sexual characters before the age of 8 years.

  30. TYPES: 1 - Trueprecocious puberty. 2 - False(pseudo-precocious puberty). 3 - Incomplete precocious puberty.

  31. 1. TRUE (CENTRAL,CEREBRAL) PRECOCIOUS PUBERTY. It is due to increased production of pituitary gonadotrophins.

  32. 2. FALSE (PERIPHERAL) PRECOCIOUS PUBERTY • It is of peripheral origin. • It is due to secretion of sex hormones(estrogen or androgen) which is not dependent on pituitary gonadotrophins as in case of estrogenic or androgenic ovarian tumors.

  33. 2. FALSE (PERIPHERAL) PRECOCIOUS PUBERTY • False precocious puberty may be isosexual or heterosexual. • A girl who feminizes early is defined as having isosexual precocious puberty. • A girl who virilize early is defined as having heterosexual precocious puberty.(female pseudohermaphrodite)

  34. 3. INCOMPLETE PRECOCIOUS PUBERTY • In this case only one pubertal change as breast development is present before the age of 8 years without the presence of any other pubertal changes and in absence of increased estrogen production. • The other pubertal changes occur at the normal age.

  35. 3. INCOMPLETE PRECOCIOUS PUBERTY Incomplete forms of precocious puberty include premature thelarche (unilateral or bilateral), premature pubarche and premature adrenarche with appearance of pubic and axillary hair.

  36. PRECOCIOUS PUBERTY- TERMS • breast development - prematurethelarche, • pubicdevelopment - prematurepubarche • axillary hairdevelopment - prematureadrenarche • menses - premature menarche

  37. ETIOLOGY OF PRECOCIOUS PUBERTY 1.Constitutional or idiopathic: • In most cases of precocious puberty (90%) no cause is found. • For some unknown reason the hypothalamus stimulates the pituitary gland to secrete its gonadotrophic hormones. • There is normal menstruation and ovulation. • Pregnancy can occur at young age.

  38. ETIOLOGY OF PRECOCIOUS PUBERTY 2. Organic lesions of the brain: • The next common cause. • Organic lesions affecting the midbrain, hypothalamus, pineal body, or pituitary gland may lead to premature release of pituitary gonadotrophins. • Examples include traumatic brain injury, meningitis, encephalitis, brain abscess, brain tumor as glioma, craniopharyngioma, and hamartomas. 3. McCune-Albright syndrome.

  39. McCune-Albright Syndrome: • The disease is found more frequently in girls. • It consists of a triad of : • Precocious puberty, • Cystic changes in bones, and • Cafe-au lait patches of the skin. • The cause of precocious puberty is autonomous production of estrogen by the ovaries. • FSH and LH levels are low. • The treatment is testolactone oral tablets which inhibit ovarian steroidogenesis.

  40. ETIOLOGY OF PRECOCIOUS PUBERTY 4. Adrenal causes: (a) Hyperplasia, adenoma, or carcinoma of suprarenal cortex. Congenital adrenal hyperplasia and Cushing syndrome lead to precocious puberty in the male direction, i.e. heterosexual precocious puberty; (b) Estrogen secreting adrenal tumor which is very rare.

  41. ETIOLOGY OF PRECOCIOUS PUBERTY 5. Ovarian causes : (a) Estrogen producing tumors as granulosa and theca cell tumor; (b) Androgen producing tumors as androblastoma; (c) Choriocarcinoma because it secretes human chorionic gonadotrophin (HCG) which may stimulate the ovaries to secrete estrogen; (d) Dysgerminoma if it secretes HCG.

  42. ETIOLOGY OF PRECOCIOUS PUBERTY 6. Juvenile hypothyroidism: Lack of thyroxine leads to increased production of TSH and the secretion of pituitary gonadotrophins may also be increased. 7. Drugs: • Iatrogenic may follow oral or local administration of estrogen. • A long course of estrogen cream used for treatment of vulvovaginitis of children may lead to breast development or withdrawal bleeding.

  43. DIAGNOSIS OF PRECOCIOUS PUBERTY 1. History: • It excludes iatrogenic source of estrogen or androgen. • It differentiates between isosexual and heterosexual precocious puberty.

  44. DIAGNOSIS OF PRECOCIOUS PUBERTY 2. Physical examination: • It diagnoses McCune-Albright syndrome. • Neurologic and ophthalmologic examinations exclude organic lesions of the brain.

  45. DIAGNOSIS OF PRECOCIOUS PUBERTY 3. Special investigations: These are done according to the history and clinical findings and include:

  46. 3. SPECIAL INVESTIGATIONS: a. X-ray examination of the hand and wrist to determine bone age. Estrogen stimulates growth of bone but causes early fusion of the epiphysis. So the child is taller than her peers during childhood, but she is short during adult life.

  47. 3. SPECIAL INVESTIGATIONS: b. Hormonal assay: including serum FSH, LH, prolactin, estradiol, testosterone, 17α-hydroxy progesterone, TSH, and human chorionic gonadotrophin to diagnose Choriocarcinoma.

  48. 3. SPECIAL INVESTIGATIONS: c. Ultrasonography to diagnose ovarian or adrenal tumor. d. CT or MRI : to diagnose an organic lesion of the brain, or adrenal tumor.

  49. Hypothyroidism retards bone ageand is the only condition of precocious puberty in which bone age is retarded

  50. IDIOPATHIC PRECOCIOUS PUBERTY: is diagnosed after excluding all other causes.

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