Background: Spontaneous vaginal delivery without intervention is the ideal route for most pregnancies. Failure of progression in some women may need interventions including Caesarian section or instrumental delivery. Objective: To assess the accuracy of the fetal occiput-spine angle measured through transabdominal ultrasound during the first stage of labor on the prediction of progress and outcome of labor. Patients and Methods: The study included (65) cases recruited from the prelabour unit in Ain Shams University hospital who was in labor. The fetal OSA is measured by abdominal ultrasound during the first stage of labor to assess its effect on the progress of labor, mode of delivery, and postnatal events. Results: It was found that there is a significant relationship between occiput-spinal angle with both mode of delivery and duration of the first and second stage of labor, Cut off was more than (118) degrees. Which had a high negative predictive value in predicting caesarian section at the present age of 97.7% while less than or equal to (118) degrees had a positive predictive value for caesarian section and instrumental delivery of 52.6% only, at the same time it was found that there was a positive correlation between the fetal occiput-spinal angle with advanced gestational age, the angle increased with advanced gestational age we did not have any obvious explanation for it. Conclusion: OSA equal to or less than (118) degrees correlates with a significant increase in the rate of cesarean delivery and prolongation of the active and second stage of labor. There is no correlation between the angle and maternal or fetal complications.