Gene is the basic unit to control genetic traits, and gene detection is a technology to detect DNA by using patients' blood, body fluids or other tissues, cells and other biological samples. It can be used for diagnosis of hereditary diseases, genetic consultation, analysis of the probability of hereditary diseases among members of genetic family, determination of genetic carriers and prenatal diagnosis, and can also be used for predicting certain diseases, such as tumor diseases.

All women can choose genetic testing before or during pregnancy. In some cases, pregnant women's partners also need to be examined. If family history puts children at higher risk of genetic diseases, doctors will recommend genetic testing.

The tests that women need depend on genetic factors. Some ethnic groups are at higher risk of certain diseases. For example, people with Eastern European or Ashkenazi Jewish backgrounds have a higher risk of familial amaurotic dementia and spongiform degeneration of white matter (canavan's disease). African Americans are at higher risk of sickle cell disease. White people have a higher risk of cystic fibrosis.

The role of examination: Doctors will choose different types of genetic examination according to the description of women. Standard screening can check the risk of birth defects (such as Down syndrome, 18 trisomy syndrome, 13 trisomy syndrome, neural tube defects, etc.). ). Carrier test can show whether a woman or a partner carries a genetic disease-causing gene. These diseases include cystic fibrosis, fragile X syndrome, sickle cell disease and familial amaurosis.

Examination process: Nurses or technicians will collect blood or saliva samples from the subjects. This test will not bring any risks to pregnant women and fetuses.

Information about the test results: genetic testing can't diagnose what kind of disease the fetus is suffering from. Can only tell whether the female fetus has a higher risk of illness. Doctors will advise pregnant women to undergo further tests, such as amniocentesis or chorionic villus biopsy, to get more information.

Checking pregnant women's partners is also helpful. Some diseases can only be passed on to children if both parents carry this gene. Even if the pregnant woman's test result is positive, as long as the partner's test result is negative, the doctor can rule out some problems, such as familial amaurosis, cystic fibrosis and sickle cell anemia.

Frequency of check-ups during pregnancy: Only one check-up is needed.

Similar examinations include: carrier screening, triple screening, quadruple screening and multi-marker screening.

Similar examinations: amniocentesis, villus biopsy.