1. World Health Organization; Department of Reproductive Health and Research; Office X031 Geneva Switzerland 1211
2. Centro Rosarino de Estudios Perinatales (CREP); Rosario Argentina
3. World Health Organization; UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research; 20 Avenue Appia Geneva Switzerland 1211
4. Hospital Regional de Ushuaia; Servicio de Ginecología; 12 de Octubre y Maipu Ushuaia Tierra del Fuego Argentina CP 9410