The chances of an amniocentesis reversing a chromosomal problem vary greatly depending on how high the risk is. For example, some pregnant women have only a one in a few thousand chance of having a chromosomal problem, and some have a very small chance of being able to flip. 1. If the pregnant woman just because 35 weeks old to do amniocentesis test, Down’s syndrome, NT test is normal, and non-invasive DNA belongs to the results close to ± 3, amniocentesis normal results are extremely high. 2. If the pregnant woman is over 40 years old and the ultrasound suggests multiple structural abnormalities in the fetus, the probability of a normal amniocentesis result is relatively low. Different ultrasound structural anomalies have corresponding incidence of fetal defects, and therefore there will be great individual differences. It is recommended to have regular checkups during pregnancy, complete the amniocentesis at the required time, and have the results evaluated by a medical professional to determine whether the pregnancy should continue.