What does a positive progestin challenge test suggest in women experiencing infertility?

A positive progestin challenge test indicates that the endometrium has responded to progesterone, suggesting that there is normal ovarian function related to the corpus luteum activity. During the test, progestin (usually medroxyprogesterone acetate) is administered, and if there is a withdrawal bleed after stopping the progestin, it confirms that the endometrium is capable of responding to hormonal cues, which typically indicates that the ovaries are producing estrogen and are functioning adequately.

This response indicates that the hypothalamic-pituitary-gonadal axis is intact, and therefore, it helps to rule out certain conditions, such as anovulation due to severe ovarian insufficiency. While the test does not directly confirm ovulation, the positive result suggests that the hormonal pathways involved in the menstrual cycle are operational.