Funding for this research was provided by:
National Basic Research Program of China (973 Program) (2016YFC1000104)
Beijing Municipal Science and Technology Commission (Z161100000116089)
Capital Health Research and Development of Special (2014-2-2113)
Beijing Municipal Administration Hospital Ascent Plan (DFL20151302)
Received: 9 April 2019
Accepted: 3 July 2019
First Online: 13 July 2019
Ethics approval and consent to participate
: The present study was approved by the ethics committee of our hospital, and all parents of the fetuses provided a signed informed consent prior to prenatal diagnosis and sample collection.
: We have obtained consent to publish from the parents of the fetuses to report individual patient data.
: The authors declare that they have no competing interests.