Endocrine Control Female Reproduction 7

Question 1

List the types of gonadotropin profiles in reproductive disorders.

Answer 1

• Hypogonadotropic hypogonadism
• Hypergonadostropic hypogonadism

Question 2

Describe the common features of hypogonadotropic hypogonadism.

Answer 2

• Findings:
  
  • anovulation
  • oligomenorrhea or amenorrhea
  • low or “inappropriately” normal circulating LH and FSH levels
• A single blood level does not reflect LH secretion
  
  • circulating levels must be asses because of pulsatile nature
  • done in context of reproductive function
  • ex. if LH levels are normal but there is anovulation, then LH secretion is inadequate
  • circulating E2 levels may be normal or low depending ont he diagnosis and duration of the condition
  • common organs affected:
    
    • hypothalamus
    • pituitary

Question 3

Describe the common features of hypergonadotropic hypogonadism.

Answer 3

• Findings:
  
  • anovulation
  • oligomenorrhea or amenorrhea
  • high circulating FSH and variably elevated LH levels
• Elevated FSH levels are a reliable indicator of ovarian follicular damage
• Circulating E2 levels are usually low
• Damage or loss of ovarian follicles results in this

Question 4

List the common hypothalamus disorders that affect reproduction.

Answer 4

• Absence/destruction of GnRH secretory neurons
• GnRH deficiency - Functional Hypothalamic Amenorrhea (FHA)

Question 5

What are the common causes of absence/destruction of GnRH secretory neurons?

Answer 5

• Idiopathic hypogonadotropic hypogonadism (IHH)
  
  • more common in men than women
  • usually presents with delayed puberty
  • can be caused by several genetic defects
  • can be acquired and result in secondary amenorrhea
• Structural lesions
  
  • ex. craniopharyngiomas
• Infiltrative disorders
  
  • ex. sarcoidosis

Question 6

What is functional hypothalamic amenorrhea (FHA) and what are the common causes? What is the treatment?

Answer 6

• GnRH deficiency
  
  • due to disruption of GnRH release in the absence of structural lesions (hence “functional”)
  • ovulation depends on the precisely coordinated pulsatile secretion of GnRH
    
    • disruption can result in failure of ovulation and irregular or absent menses
  • GnRH secretion is often present but disrupted
  • LH and FSH are usually within the normal range but inappropriately low due to anovulation
• Treatment
  
  • ​opiate antagonists or leptin
    
    • restores ovulator cycles
• Causes
  
  • weight loss
    
    • anorexia nervosa
    • simple weight loss
  • exercise
    
    • elite runners
    • gymnasts
    • ballet dancers
  • stress
    
    • change in environment
    • systemic disease

Question 7

What are the common disorders of the pituitary that lead to reproductive problems in females?

Answer 7

• Prolactinomas
  
  • hyperprolactinemia
  • results in alterations in dopaminergic thone
  • disrupts GnRH release
  • ovulatory cycles can be restored by lowering prolactin levels
  • macroadenomas can cause mass effect as well
• Other secretory pituitary tumors
  
  • elevated cortisol levels of Cushing’s syndrome can suppress GnRH release
• Gonadotrope destruction
  
  • non-functional tumors
  • postpartum necrosis (Sheehan’s)
  • primary and secondary hemachromatosis

Question 8

What happens in dysfunction of the ovary? How is this detected?

Answer 8

• Primary gonadal failure with loss of gonadal steroid and inhibin feedback
  
  • results in increased LH and FSH levels
• FSH most sensitive marker of gonadal failure
  
  • inhibin secretion can be diminished before steroid secretion
  • loss of inhibin results in a selective increase in circulating FSH levels

Question 9

What is premature ovarian insufficiency (POI)?

Answer 9

• Defined as the onset of menopause or evidence of follicular loss
  
  • ex. increased FSH levels before 40
• Common causes:
  
  • idiopathic
  • 45 XO mosaics
    
    • presenting as secondary amenorrhea
  • cytotoxic drugs
    
    • ex. cytoxan
  • radiation
  • autoimmune polyendocrine syndromes (APSs)
• Some causes can wax and wane so there may onl be intermittent elevations of FSH

Question 10

Aside from PCOS, what is the other cause of androgen excess?

Answer 10

• Hyperandrogenic chronic anovulation differential
  
  • ​PCOS
  • Classic congenital adrenal hyperplasia
    
    • presents in infancy
  • Non-classic congenital adrenal hyperplasia
    
    • 21-hydroxylase deficiency
    • presents after menarche with hyperandrogenism and chronic anovulation
  • Extreme insulin resistance syndromes
    
    • Type A syndrome
    • Familial partial lipodystrophy syndromes
  • Hyperprolactinemia
  • Androgen secreting tumors
  • Cushing’s
  • Iatrogenic - anabolic steroids