Intrapartum ultrasound assessment of fetal head position, tip the scale: natural or instrumental delivery?

Abstract

Objectives: The main objective of this study was to observe the behavior of the fetal head position during labor, when starting from occiput anterior or posterior position and also to determine their importance in labor management (if the starting fetal head position can be a strong argument in favour of vaginal or cesarean delivery). Methods:187 patients in labor were included in this study, with gestational age over 37 weeks and estimated fetal weight over 2500 g, singleton pregnancy, cephalic presentation, empty urinary bladder. For these patients the ultrasound assessed parameters were: fetal head position at the beginning of labour and fetal head rotation during labour. Results: 89,18 percent of the patients starting from OTP (occiput transverse or posterior position) had a vaginal birth after an anterior rotation of the fetal head, and only 10,82 % presented persitent occiput posterior requiring cesarean section for delivery. Furthermore, considering only initial occiput posterior position, we observed an increased rate for cesarean section delivery (22,72%) by persistence of this position during labour. None of the patients starting with an anterior fetal head position rotated posteriorly. Conclusions: vaginal delivery in occiput anterior position was the most common result in both OTP and OP fetal head initial position. The main reason for cesarean delivery was persistent OP position. Patients with occiput posterior position were subsequent only to an initial posterior/transverse position.