Prenatal diagnosis of sex chromosome aneuploidies: experience at a mainland Chinese hospital.

The aim of this study is to assess the initial indications, frequency and termination rates of pregnancies with sex chromosome aneuploidies (SCAs), at a mainland Chinese hospital. A total of 56 cases (0.9%) with SCAs were identified in 6,515 pregnancies referred for fetal karyotyping. Turner syndrome was the most commonly diagnosed SCA in prenatal diagnosis (48.2%). The most common referral reason for pregnancies with Turner syndrome was cystic hygroma on ultrasonography. The main reasons for fetal karyotyping in other types of SCAs were a positive prenatal screening test and advanced maternal age. A total of 47 (84%) of the pregnancies with SCAs were terminated and nine (16%) continued. This study first reported the rate of SCAs detected at prenatal diagnosis and the outcomes of these pregnancies in mainland China, and showed a very high termination rate for pregnancies with SCAs.