Text and Data Mining valid from 2018-09-27
Received: 1 December 2017
Accepted: 19 September 2018
First Online: 27 September 2018
Ethics approval and consent to participate
: This research project was approved by the research committee at the Department of Gynecology and Obstetrics CAISM/UNICAMP and by the University of Campinas School of Medical Sciences ethics review board (Project number 351/2006) and since it is a retrospective study, it was exempt from an informed consent form.
: Not applicable.
: The authors declare that they have no competing interests.
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