## **Core Concept**
Ovarian reserve refers to the quantity and quality of eggs remaining in the ovaries, reflecting a woman's reproductive potential. It is an important consideration in assessing fertility. Various markers and tests can evaluate ovarian reserve.

## **Why the Correct Answer is Right**
The correct answer, **Anti-Müllerian Hormone (AMH)**, is considered the best indicator of ovarian reserve. AMH is produced by the granulosa cells of small antral follicles in the ovaries and reflects the number of remaining follicles. Unlike other hormones, AMH levels are relatively stable throughout the menstrual cycle and are not influenced by exogenous hormones, making it a reliable marker.

## **Why Each Wrong Option is Incorrect**
- **Option A:** FSH (Follicle-Stimulating Hormone) is used to assess ovarian reserve but is less specific than AMH. FSH levels can fluctuate and are influenced by the menstrual cycle phase and exogenous hormones.
- **Option B:** Estradiol levels can provide information on ovarian function but are not a direct measure of ovarian reserve. Estradiol levels vary significantly during the menstrual cycle.
- **Option D:** Inhibin B is another marker of ovarian function, but it is less sensitive and specific than AMH for assessing ovarian reserve.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **AMH levels decrease with age** and are used to predict response to ovarian stimulation in fertility treatments. Low AMH levels indicate a reduced ovarian reserve, suggesting a poorer response to fertility medications.

## **Correct Answer:** . **Anti-Müllerian Hormone (AMH)**