Ge, Juan
Li, Tang
Article History
Received: 25 December 2018
Accepted: 4 February 2019
First Online: 20 March 2019
Compliance with ethical standards
:
: This study was approved by the Ethical Committee of Qingdao Women and Children’s Hospital.
: No financial or nonfinancial benefits have been received or will be received from any party related directly or indirectly to the subject of this article.