Non-invasive prenatal DNA technique is a safe, accurate, simple detecting technique used to screen fetal chromosome disorders. Risk rate of fetal chromosome aneuploidy disease (Down’s syndrome, 18 Trisomy Syndrome and 13 Trisomy Syndrome ) can be calculated by using new generation high-throughput sequencing technology combined with bioinformatic analysis method to analyze the extracted free DNA from maternal peripheral blood. This technology has improved the detection accuracy of these three chromosome euploidy diseases to 99.7%.

When can we do Non-invasive prenatal DNA test?
 

The best period for doing this test is between 12 to 24 weeks.
 

People recommended to do this test
 

1. Maternal wishes to exclude fetal chromosome euploidy diseases
 

2. Maternal who has high risk in serological screening in the early-middle term pregnancy
 

3. One spouse has chromosome disease, or maternal has the pregnancy history of or gave birth to a baby having chromosome disease.
 

4. Maternal has the history of unknown spontenous miscarriage, stillbirth etc.
 

5. Fetal ultrasound showed abnormalities.
 

6. One spouse has the history of being exposed to teratogens.
 

Advantages
 

1. Non-invasiveness: compared with amniocentesis, it only needs to draw some blood from maternal, no body intervention.
 

2. Safety: no risk of intratuerine infection or miscarriage which might happen in the traditional way of screening Down’s Syndrome, amniocentesis.
 

3. Early intervention: amniocentesis can only be performed between 16 weeks to 20 weeks, while non-invasive Prenatal DNA test can be done after 12 weeks.
 

4. High accuracy: it is more accurate than amniocentesis. The accuracy of amniocentesis is 95%, while non-invasive Prenatal DNA test is 99.7%.