Arthuis CJ, Perrotin F, Patat F, Brunereau L, Simon EG. Computed tomographic study of anatomical relationship between symphysis and ischial spines to improve interpretation of intrapartum translabial ultrasound. Ultrasound Obstet Gynecol 2016; 48: 779–785.
Henrich W, Dudenhausen J, Fuchs I, Kamena A, Tutschek B. Intrapartum translabial ultrasound (ITU): sonographic landmarks and correlation with successful vacuum extraction. Ultrasound Obstet Gynecol 2006; 28: 753–760.
Tutschek B, Braun T, Chantraine F, Henrich W. A study of progress of labour using intrapartum translabial ultrasound, assessing head station, direction, and angle of descent. BJOG 2011; 118: 62–69.
Armbrust R, Henrich W, Hinkson L, Grieser C, Siedentopf JP. Correlation of intrapartum translabial ultrasound parameters with computed tomographic 3D reconstruction of the female pelvis. J Perinat Med 2016; 44: 567–571.
Molina FS, Terra R, Carrillo MP, Puertas A, Nicolaides KH. What is the most reliable ultrasound parameter for assessment of fetal head descent? Ultrasound Obstet Gynecol 2010; 36: 493–499.
Duckelmann AM, Bamberg C, Michaelis SA, Lange J, Nonnenmacher A, Dudenhausen JW, Kalache KD. Measurement of fetal head descent using the 'angle of progression' on transperineal ultrasound imaging is reliable regardless of fetal head station or ultrasound expertise. Ultrasound Obstet Gynecol 2010; 35: 216–222.
Dupuis O, Silveira R, Zentner A, Dittmar A, Gaucherand P, Cucherat M, Redarce T, Rudigoz RC. Birth simulator: reliability of transvaginal assessment of fetal head station as defined by the American College of Obstetricians and Gynecologists classification. Am J Obstet Gynecol 2005; 192: 868–874.
Tutschek B, Braun T, Chantraine F, Henrich W. Quantification of fetal head direction and descent. Ultrasound Obstet Gynecol 2013; 41: 99–100.
Hagadorn-Freathy AS, Yeomans ER, Hankins GD. Validation of the 1988 ACOG forceps classification system. Obstet Gynecol 1991; 77: 356–360.
