Received: 23 October 2019
Accepted: 22 May 2020
First Online: 26 June 2020
Ethics approval and consent to participate
: The study was conducted with strict adherence to the Declaration of Helsinki. The study protocol was reviewed and approved by the Ethics Review Committee of Tokyo Women’s Medical University (4101). Informed consent to participate this study was obtained from all patients in writing or orally. The procedure for oral consent was approved by the ethics committee.
: Not applicable.
: The authors declare no competing interests to this study.