- Address correspondence and reprint requests to Hextan Yuen Sheung Ngan, MD, or Vincent Wing Sun Liu, PhD, Department of Obstetrics and Gynecology, The University of Hong Kong, 6th Floor, Professorial Block, Queen Mary Hospital, Pokfulam, Hong Kong SAR, People’s Republic of China. E-mail: or .
- Received May 24, 2011
- Accepted August 10, 2011
- First published January 1, 2012.
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