[1] Univ Chile, Fac Med, Escuela Obstet, Dept Promoc Salud Mujer & Recien Nacido, Santiago, Chile
[2] Pontificia Univ Catolica Chile, Fac Med, Dept Salud Publ, Santiago, Chile
[3] Univ Chile, Inst Nutr & Tecnol Alimentos, Dept Epidemiol Nutr, Santiago, Chile
[4] Univ Chile, Fac Med, Santiago, Chile
[5] Pontificia Univ Catolica Chile, Fac Med, Dept Pediat, Santiago, Chile