P01.09: The occiput spine angle: a new sonographic index of fetal head deflexion during the 1st stage of labour. (1st October 2015) - Ghi, T.; Krsmanovic, J.; Azzarone, C.; Bellussi, F.; Azzerboni, A.; Franchi, L.; Mazzone, E.; Youssef, A.; Rizzo, N.; Pilu, G.; Frusca, T.