**Core Concept**
Chorionic villus sampling (CVS) is a prenatal diagnostic procedure used to detect chromosomal abnormalities and genetic disorders in the fetus. This procedure involves obtaining a small sample of placental tissue, specifically chorionic villi, for genetic analysis.

**Why the Correct Answer is Right**
CVS is typically performed between 10-12 weeks of gestation. This timing allows for early detection of genetic abnormalities, while minimizing the risk of miscarriage associated with the procedure. The placental tissue obtained during CVS is rich in cells that will eventually form the fetus, making it an ideal target for genetic analysis. The results of CVS can be used to guide pregnancy decisions, such as termination of pregnancy or preparation for the birth of a child with a genetic disorder.

**Why Each Wrong Option is Incorrect**
**Option A:** CVS is not typically performed before 10 weeks of gestation, as the placenta is not fully developed at this stage. Performing CVS too early may lead to incorrect or inconclusive results.

**Option B:** CVS is not typically performed after 12 weeks of gestation, as the risk of miscarriage increases with gestational age. Additionally, the placental tissue may become less accessible and more difficult to sample after 12 weeks.

**Option C:** While CVS can be performed between 10-12 weeks of gestation, this option is incomplete and does not specify the correct range.

**Clinical Pearl / High-Yield Fact**
CVS is a valuable diagnostic tool for detecting genetic disorders, but it carries a small risk of miscarriage. It is essential to discuss the risks and benefits of CVS with patients before proceeding with the procedure.

**Correct Answer:** C. 10-12 weeks of gestation.