Text and Data Mining valid from 2018-07-01
Received: 19 February 2018
Accepted: 23 June 2018
First Online: 6 July 2018
Compliance with ethical standards
: The authors have no conflicts of interest to declare concerning the materials or methods in this study or the findings specified in this paper.
: The ethics committee of Tokyo Women’s Medical University (Tokyo, Japan) approved the research protocol, which was, therefore, performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Each patient agreed to participate in the study and provided written informed consent.