Gynecology - USMLE

• Menarche


  Onset of menstruation
• Normal male development


  • Testicular enlargement (onset 9-14 years of age)
  • Penile growth
  • Pubarche
  • Growth acceleration
  • Facial hair
• Normal female development


  • Thelarche (breast development, onset 8-13 years of age)
  • Pubarche (pubic hair growth)
  • Growth acceleration
  • Menarche (onset 10-16 years of age)
• Ages for stages of development vary by race/ethnicity
• Phases of normal menstrual cycle

  1. Menstruation and follicular phase (days 1-13)

  2. Ovulation (day 14)

  3. Luteal phase (days 15-28)
• Follicular phase


  Starts with menstruation and ends at LH surge/ovulation
• Luteal phase


  Length of time (10-14 days) that the corpus luteum can survive without further LH or hCG stimulation
• Menstruation/follicular phase restarts when there is no longer negative feedback to FSH
• Precocious puberty


  Onset of secondary sexual characteristics in a child <8 years of age
• Subtypes of precocious puberty

  • Central precocious puberty
  • Peripheral precocious puberty
• Central precocious puberty


  Early activation of hypothalamic GnRH production
• Peripheral precocious puberty


  Results from GnRH-independent mechanisms
• If onset of secondary sexual characteristics is seen before 8 years of age, work up for precocious puberty
• McCune-Albright syndrome


  Presents with precocious puberty, café au lait spots, and bony abnormalities (polyostotic fibrous dysplasia)
• Central precocious puberty


  ↑ estradiol, ↑ LH, ↑ FSH
• Peripheral precocious puberty


  ↑ estradiol, LH, FSH
• Workup for precocious puberty

  1. Bone age

  2. GnRH agonist (leuprolide) stimulation test
• Primary amenorrhea


  Absence of menses by 15 years of age with secondary sexual development present
• Delayed puberty


  Absence of secondary sexual characteristics by 13 years of age
• Etiologies of primary amenorrhea

  • Primary ovarian insufficiency
  • Central hypogonadism
  • Müllerian agenesis
  • Imperforate hymen
  • Complete androgen insensitivity
  • Congenital adrenal hyperplasia
• Workup of primary amenorrhea

  1. Pregnancy test

  2. Anatomic evaluation

  3. Karyotype analysis

  4. Measure FSH/LH
• Secondary amenorrhea


  Absence of menses for 6 consecutive months in females who have passed menarche
• Etiologies of secondary amenorrhea

  • Pregnancy
  • Ovary (PCOS, premature ovarian insufficiency, chemotherapy, radiation)
  • Hypothalamus (neoplasm, functional hypothalamic amenorrhea, systemic illness)
  • Pituitary gland (adenoma, sellar masses, Sheehan syndrome)
  • Thyroid gland (hypothyroidism, hyperthyroidism)
• Workup of secondary amenorrhea

  Cyclic estrogen/progesterone test
• Bleed


  Absence of menses for 6 consecutive months in females who have passed menarche
• Progestin challenge


  10 days of progestin administration
• No withdrawal bleed


  Indicates uterine abnormality or estrogen deficiency
• ↑ FSH


  Indicates primary ovarian insufficiency
• ↓ or normal FSH


  Indicates hypogonadotropic hypogonadism
• PCOS (suggested by LH:FSH ratio > 2)


  Polycystic ovarian syndrome
• Idiopathic anovulation


  Anovulation of unknown cause
• Hypergonadotropic hypogonadism


  Ovarian failure with high FSH and low estrogen
• Premature menopause


  Menopause before age 40
• Primary ovarian insufficiency


  Ovarian failure before age 40
• Cyclic estrogen/progesterone test


  Withdrawal bleed indicates anovulation, no withdrawal bleed indicates uterine abnormality or estrogen deficiency
• Withdrawal bleed


  Indicates anovulation that is probably caused by noncyclic gonadotropin secretion, pointing to PCOS or idiopathic anovulation
• Hypogonadotropic hypogonadism


  Indicates an endometrial or anatomic problem
• Secondary amenorrhea


  • The absence of menses for 6 consecutive months in females who have passed menarche
  • Etiologies include pregnancy, ovary, hypothalamus, pituitary gland, thyroid gland, uterus
• Diagnosis of secondary amenorrhea


  1. History and physical examination

  2. Exclusion of pregnancy with a pregnancy test

  3. If needed, measurement of FSH, TSH, and prolactin

  4. Initiation of a progestin challenge
• ↑ FSH indicates primary ovarian insufficiency