For a woman with history of prior two molar pregnancies, the risk of having a third molar pregnancy is
**Core Concept**
The underlying principle being tested is the risk of recurrent molar pregnancies, which is related to **gestational trophoblastic disease (GTD)**. This condition is characterized by abnormal proliferation of trophoblastic cells. Women with a history of prior molar pregnancies are at increased risk of developing another molar pregnancy.
**Why the Correct Answer is Right**
A woman with a history of two prior molar pregnancies has a significantly increased risk of having a third molar pregnancy. This is because the risk of recurrence in **gestational trophoblastic disease** increases with each subsequent molar pregnancy, due to potential genetic predisposition and other factors influencing **trophoblastic cell behavior**.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the risk is higher than this for a woman with two prior molar pregnancies.
**Option B:** This option underestimates the risk associated with two prior molar pregnancies.
**Option D:** This option is too high and not accurate for the given scenario.
**Clinical Pearl / High-Yield Fact**
It's crucial to remember that a history of molar pregnancy significantly increases the risk of **gestational trophoblastic neoplasia (GTN)**, emphasizing the need for close follow-up and monitoring of **beta-hCG levels** after evacuation of a molar pregnancy.
**Correct Answer:** C. 15-20%