1. Department of Obstetrics and Gynecology, School of Medicine, University of Campinas, Campinas, SP, Brazil
2. CISAM Maternity Hospital, University of Pernambuco, Recife, PE, Brazil
3. Department of Obstetrics, Screening and Prevention of Preterm Birth Sector, Discipline of Fetal Medicine, Escola Paulista de Medicina, Federal University of Sao Paulo, São Paulo, SP, Brazil
4. Department of Obstetrics and Gynaecologic, Monash University, Clayton, Victoria, Australia
5. Aberdeen Centre for Women's Health Research, University of Aberdeen, Aberdeen, United Kingdom