1 Centre for Health Studies and Research of the University of Coimbra (CEISUC), Faculty of Economics, University of Coimbra, Coimbra, Portugal. vmo.goncalves@hotmail.com.
2 Department of Obstetrics and Gynecology, Grossman School of Medicine, New York University, New York, NY, USA.
3 Department of Population Health, Grossman School of Medicine, New York University, New York, NY, USA.