- Address correspondence and reprint requests to Qin-ping Liao, PhD, Department of Obstetrics and Gynecology, Peking, University First Hospital, No.8 Xishiku St, West District, Beijing 100034. E-mail: .
- Received February 8, 2012
- Accepted March 5, 2012
- First published July 1, 2012.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.