A 34-year-old healthy pregnant woman was referred to the reproductive center in Southeast China. Serological screening results at 18 gestational weeks indicated a low risk (risk value: 1:3900). Doctors recommend non-invasive prenatal testing (NIPT) in view of the woman’s advanced maternal age. NIPT results showed that the fetus has a high risk of trisomy 21 which following confirmed by amniocentesis diagnosis of 47, XN, +21. Finally, this woman chose to terminate pregnancy to avoid giving birth to a sick baby. Two years later, with a normal NIPT result, the woman finally gives birth to a healthy baby