## **Core Concept**
A partial mole, also known as a partial hydatidiform mole, is a type of gestational trophoblastic disease (GTD) characterized by an abnormal proliferation of the trophoblastic tissue and the presence of fetal tissue. It is usually associated with triploidy, where the embryo has 69 chromosomes instead of the usual 46. This condition results from the fertilization of an egg by two sperm or a sperm that fails to undergo the usual halving of its chromosomes.

## **Why the Correct Answer is Right**
The correct statement about partial mole that is false needs to be identified. Let's evaluate each option:
- a. Caused by triploidy: This is true. Partial moles are commonly caused by triploidy.
- b. Can be diagnosed very early by USG: This statement can be misleading. While ultrasound (USG) can suggest a molar pregnancy, early diagnosis of a partial mole specifically can be challenging due to its similarities with a normal pregnancy or other types of GTD.
- c. Can present as missed abortion: This is true. Partial moles often present with nonspecific symptoms, and some cases may be diagnosed after a missed abortion.
- d. Rarely causes persistent GTD: This is true. Compared to complete moles, partial moles have a lower risk of progressing to persistent gestational trophoblastic neoplasia (GTN).

## **Why Each Wrong Option is Incorrect**
- **Option B:** This option is potentially the false statement regarding partial mole because while ultrasound can raise suspicion for molar pregnancy, specific early diagnosis of partial mole can be difficult. It often requires histopathological examination for confirmation.
- **Option A:** Incorrect because triploidy is indeed a cause of partial mole.
- **Option C:** Incorrect because partial mole can indeed present as a missed abortion.
- **Option D:** Incorrect because it is true that partial moles rarely cause persistent GTD.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that while partial moles are less likely to cause persistent GTD compared to complete moles, they still pose a risk. Therefore, follow-up with serum beta-hCG levels is crucial for all patients with a history of molar pregnancy.

## **Correct Answer:** B. Can be diagnosed very early by USG