Non-invasive DNA testing is best performed between the 12th and 24th weeks of pregnancy. During this period, the results of non-invasive DNA testing for pregnant women are most accurate. Since non-invasive DNA testing does not require surgery, neither the pregnant woman nor the fetus will be significantly harmed. If, around the 12th week of pregnancy, the pregnant woman undergoes an NT examination and discovers that the thickness of the fetal nuchal translucency is greater than 3 mm, a non-invasive DNA test and Down's syndrome screening are generally required to exclude Down's syndrome.
1. The best time for non-invasive DNA testing is between the 12th and 24th weeks of pregnancy. This is because during the 15th to 20th weeks, the fetus's bones gradually harden, and nerve cells in the brain stem and spinal cord also gradually form. During this time, the accuracy of non-invasive DNA testing for chromosome detection is relatively higher. Therefore, it is recommended that pregnant women choose this stage for non-invasive DNA testing.
2. Although non-invasive DNA testing has a high screening accuracy for chromosomal diseases such as Down's syndrome, for pregnant women with special conditions such as multiple pregnancies, pregnancies achieved through in vitro fertilization, and older mothers, the accuracy of the test results is relatively low. Therefore, it is recommended that such pregnant women exercise caution in choosing or opt for other screening methods such as Down's syndrome screening.
3. Before undergoing non-invasive DNA testing, pregnant women should ensure adequate sleep to ensure the accuracy of the test results. Unlike other blood sampling tests, non-invasive DNA testing does not require fasting, so pregnant women can eat normally but should maintain a light diet.
