Wang, Yanshuang
Xu, Mingjun http://orcid.org/0000-0003-0536-1086
Article History
Received: 6 December 2018
Accepted: 24 September 2019
First Online: 2 January 2020
Ethics approval and consent to participate
: This study was approved by the institutional ethics committees of the Beijing Obstetrics and Gynecology Hospital and written informed consent was obtained from parturients before labor analgesia.
: Not applicable.
: The authors declare that they have no competing interests.