[1] Univ Complutense Madrid, Hosp Gen Gregorio Maranon, Dept Obstet & Gynecol, Madrid, Spain
[2] Univ Complutense Madrid, Hosp Gen Gregorio Maranon, Dept Pediat Cardiol, Madrid, Spain
[3] Univ Complutense Madrid, Hosp Gen Gregorio Maranon, Dept Pediat Cardiac Surg, Madrid, Spain
[4] Univ Alcala de Henares, Hosp Cent Def Gomez Ulla, Dept Obstet & Gynecol, Madrid, Spain
[5] Hosp Marques de Valdecillas, Dept Pediat Cardiol, Santander, Spain