How to test for chromosomes during pregnancy

In early pregnancy, chorionic villus sampling can be performed for testing; in the second trimester, amniocentesis is an option; and in late pregnancy, fetal chromosomes can be examined through cordocentesis (umbilical cord blood sampling). If chromosomal abnormalities are detected in the fetus, a prenatal diagnosis specialist must further evaluate whether the fetus can be carried to term and assess the prognosis. After comprehensive analysis by the physician, a decision should be made regarding whether to continue the pregnancy.