How is a chromosome test performed?

Chromosome testing is mainly performed through the following methods: 1. **Peripheral blood testing**: Venous blood is drawn and the cells are cultured and analyzed for a period of time to screen for chromosomal abnormalities. This method is commonly used to determine whether either partner carries chromosomal abnormalities. 2. **Chorionic villus sampling (CVS)**: Performed during early pregnancy (usually around 11–12 weeks of gestation), this test involves taking a sample of chorionic villus tissue via needle aspiration to check for fetal chromosomal disorders or hidden genetic diseases. 3. **Amniocentesis**: Conducted between 18 and 22 weeks of pregnancy, this procedure involves extracting fetal cells shed into the amniotic fluid for chromosomal analysis. It is commonly used for prenatal diagnosis, especially for detecting chromosomal abnormalities such as Down syndrome.