**Question:** In a woman on subdermal progesterone implant, the menstrual abnormality seen is -

A. Amenorrhea
B. Irregular periods
C. Oligomenorrhea
D. Hypomenorrhea

**Core Concept:**
Progesterone is a hormone produced by the corpus luteum during the luteal phase of the menstrual cycle. It plays a crucial role in maintaining the corpus luteum, preventing the luteinizing hormone (LH) from stimulating the corpus luteum to degenerate. Progesterone also prepares the uterine lining for implantation and supports the growth and differentiation of the uterine lining.

**Why the Correct Answer is Right:**
Subdermal progesterone implants are a form of contraception that releases progesterone directly into the bloodstream. This high level of progesterone suppresses the pituitary gland's secretion of follicle-stimulating hormone (FSH) and LH, leading to the following:

1. Amenorrhea: Complete absence of menstruation, which can occur due to excessive suppression of LH.
2. Hypomenorrhea: Reduced frequency or amount of menstrual bleeding, often caused by suppressed LH secretion and reduced uterine lining growth.
3. Oligomenorrhea: Less frequent or scanty bleeding, resulting from suppressed LH secretion and reduced uterine lining growth.

**Why Each Wrong Option is Incorrect:**
A. Amenorrhea is not the correct answer because the woman might still menstruate occasionally due to fluctuations in progesterone levels or due to other factors affecting the pituitary gland.
B. Irregular periods are not the correct answer because the correct term is oligomenorrhea, which refers to less frequent or scanty bleeding.

**Core Concept:**
Progesterone is a hormone produced by the corpus luteum during the luteal phase of the menstrual cycle. It plays a crucial role in maintaining the corpus luteum, preventing the luteinizing hormone (LH) from stimulating the corpus luteum to degenerate.

**Why the Correct Answer is Right:**
Subdermal progesterone implants release high levels of progesterone into the bloodstream, suppressing the pituitary gland's secretion of follicle-stimulating hormone (FSH) and LH. This suppression leads to the following:

1. Amenorrhea: Complete absence of menstruation, which can occur due to excessive suppression of LH.
2. Hypomenorrhea: Reduced frequency or amount of menstrual bleeding, resulting from excessive suppression of LH secretion and reduced uterine lining growth.
3. Oligomenorrhea: Less frequent or scanty bleeding, caused by excessive suppression of LH secretion and reduced uterine lining growth.

**Why Each Wrong Option is Incorrect:**
A. Amenorrhea is not the correct answer because menstruation might still occur sporadically due to fluctuations in progesterone levels