Intrapartum sonographic evaluation of fetal head descent in relation to maternal position: comparison between dorsal lithotomy and kneeling squat positions. - Melito C; Rizzo L; Yurhel L; Corno E; Renzetti S; Malvezzi MC; Frati F; Neri S; Ghi T; Dall'Asta A (Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2026)