Fetal descent in nulliparous women assessed by ultrasound: a longitudinal study
Ultrasound measurements offer objective and reproducible methods to measure the fetal head station. This study aimed to use ultrasound measurements to describe the fetal head descent as labor progressed through the active phase in nulliparous women with spontaneous onset of labor. Nulliparous women with a single fetus in cephalic presentation and spontaneous labor onset at a gestational age of 37 weeks were eligible. The ultrasound-measured fetal head station was associated with the delivery mod
