[1] Hosp Perinatal Mon Pretelini, Toluca, Mexico State, Mexico
[2] Hosp Gen Queretaro, Queretaro, Mexico
[3] Hosp Gen Alta Especialidad Dr Juan Graham Casasus, Villahermosa, Tabasco, Mexico
[4] Hosp Dr Santiago Raman y Cajal, ISSSTE, Durango, Mexico
[5] Hosp Cent Estado Chihuahua, Chihuahua, Mexico
[6] Hosp Miguel Hidalgo, Aguascalientes, Aguascalientes, Mexico
[7] Hosp Gen ISSSTE Zacatecas, Zacatecas, Mexico
[8] Inst Nacl Perinatol Ciudad Mexico, Mexico City, DF, Mexico
[9] Hosp Gen Puebla Dr Eduardo Vazquez Navarro, Puebla, Mexico
[10] Hosp Gen Dr Manuel Gea Gonzalez, Mexico City, DF, Mexico
[11] Inst Nacl Neurol & Neurocirugia Manuel Velasco, Mexico City, DF, Mexico