[1] Univ Siena, Dept Prevent Pediat & Neonatol, I-53100 Siena, Italy
[2] Univ Siena, Inst Pathol, I-53100 Siena, Italy
[3] Univ Siena, Dept Obstet & Gynecol, I-53100 Siena, Italy
[4] Univ Turin, Div Fetomaternal Med, Turin, Italy
[5] Univ Lausanne, Div Dev Pathol, Lausanne, Switzerland