1. Department of Obstetrics and Gynaecology , School of Medical Sciences, , Campinas, 13083-881 , Brazil
2. University of Campinas , School of Medical Sciences, , Campinas, 13083-881 , Brazil
3. Department of Metabolism , Digestion and Reproduction, , London, SW7 2AZ , United Kingdom
4. Imperial College London , Digestion and Reproduction, , London, SW7 2AZ , United Kingdom
5. Chelsea and Westminster Hospital , London, SW10 9NH , United Kingdom
6. Department of Epidemiology and Biostatistics , , London, SW7 2AZ , UK
7. Imperial College London , , London, SW7 2AZ , UK