SBA — Single Best Answer · Review
Question 509
Endocrinology → General
Classification
Question
SSBAQuestion Header
A woman has amenorrhoea and hyperprolactinaemia secondary to a prolactinoma. Which alteration most directly links the raised prolactin concentration with her reproductive dysfunction?
Question Stem
Select the single best answer.
Options
A
Increased GnRH pulse frequency
B
Direct stimulation of ovarian androgen synthesis
C
Increased pituitary sensitivity to GnRH
D
Reduced GnRH pulsatility
E
Increased oxytocin secretion
Explanation
Hyperprolactinaemia reduces GnRH pulsatility. This provides the endocrine link between raised prolactin and reproductive manifestations such as oligomenorrhoea, amenorrhoea, hypogonadism and subfertility.
Option Validity
A) Hyperprolactinaemia reduces rather than increases GnRH pulsatility.
B) The reproductive disturbance described is linked to suppression of GnRH pulsatility rather than direct stimulation of ovarian androgen synthesis.
C) Increased pituitary sensitivity to GnRH is not the mechanism given for prolactin-associated reproductive dysfunction.
E) Oxytocin secretion does not mediate the suppression of reproductive function described in hyperprolactinaemia.
Further Reading
Saxena, MRCOG-1 Basic Sciences, Endocrinology: Prolactin and Hyperprolactinaemia.