Which procedure analyzes fetal chromosomes by aspirating fetal blood through the umbilical cord?

Which procedure analyzes fetal chromosomes by aspirating fetal blood through the umbilical cord?

• A. Cordocentesis
• B. Amniocentesis
• C. Chorionic villus sampling
• D. Embryoscopy

Answer: (A)

Cordocentesis, also called percutaneous umbilical blood sampling, directly aspirates fetal blood from the umbilical cord to obtain cells for chromosomal analysis. Because you’re sampling fetal blood, you get fetal blastomeres directly, which allows rapid and direct karyotyping (and sometimes rapid tests like FISH) when timely genetic information is needed. This approach is distinct from amniocentesis, which analyzes fetal cells shed into the amniotic fluid, and chorionic villus sampling, which analyzes placental tissue. Embryoscopy, on the other hand, is a visualization procedure rather than a method to obtain chromosomal material. Cordocentesis is typically performed under ultrasound guidance after about 18–20 weeks of gestation and carries procedure-related risks, including fetal loss, which is why it’s used when direct fetal blood analysis is specifically required.

Cordocentesis, also called percutaneous umbilical blood sampling, directly aspirates fetal blood from the umbilical cord to obtain cells for chromosomal analysis. Because you’re sampling fetal blood, you get fetal blastomeres directly, which allows rapid and direct karyotyping (and sometimes rapid tests like FISH) when timely genetic information is needed. This approach is distinct from amniocentesis, which analyzes fetal cells shed into the amniotic fluid, and chorionic villus sampling, which analyzes placental tissue. Embryoscopy, on the other hand, is a visualization procedure rather than a method to obtain chromosomal material. Cordocentesis is typically performed under ultrasound guidance after about 18–20 weeks of gestation and carries procedure-related risks, including fetal loss, which is why it’s used when direct fetal blood analysis is specifically required.