anovulation

Question 1

what causes increases the release of follicle-stimulating hormone (FSH) and luteinising hormone (LH)

Answer 1

The early follicular phase requires an increase in gonadotropin-releasing hormone (GnRH) pulse frequency which increases the release of follicle-stimulating hormone (FSH) and luteinising hormone (LH), to allow for stimulation and development of multiple ovarian follicles, and usually only one of which will become the dominant ovulatory follicle in that menstrual cycle.

Question 2

what happens in the mid follicular phase

Answer 2

FSH gradually stimulates estradiol production, following which estradiol itself produces a negative feedback loop on the hypothalamus and pituitary gland to suppress FSH and LH concentrations.

Question 3

what happens in luteal phase

Answer 3

In the luteal phase, there is a unique switch from negative to positive feedback of estradiol, resulting in a surge of LH secretion and this leads to subsequent follicular rupture and ovulation.

Question 4

what is hypothalamic amenorrhoea

Answer 4

This condition occurs when the hypothalamus, a gland in the brain that regulates body processes, slows or stops releasing gonadotropin-releasing hormone (GnRH), the hormone that starts the menstrual cycle

Question 5

What is class 1 anovulation

Answer 5

Class 1 (hypogonadotropic hypogonadal anovulation) - notably hypothalamic amenorrhoea (5-10% of women)

Question 6

What is class 2 anovulation

Answer 6

Class 2 (normogonadotropic normoestrogenic anovulation) - polycystic ovary syndrome (80% of cases)