Evaluation of selected ultrasonography parameters in the second stage of labor in prediction mode of delivery.

OBJECTIVES: The aim of the study is to determine the usefulness of ultrasound parameters in the second stage of labor in prediction of the method of delivery and to evaluate the benefits to be derived from this study.

MATERIAL AND METHODS: Ultrasound scan was performed with Convex transabdominal probe on 68 pregnant women in labor at term with fetuses in cephalic presentation at the beginning of the second stage of labor and parameters such as angle of progression, head progression distance, head-symphysis distance and head-perineum distance were measured. The parameters were observed in two scans: a midline scan visualizing the pubic symphysis with the head of the fetus and a transverse scan approximately 1-2 cm below the pubic symphysis visualizing the head of the fetus.

RESULTS: The ultrasound parameters measured at the beginning of the second stage of labor, differed in the group in which women have delivered vaginally and in the group, in which caesarean section was performed: angle of progression and head progression distance were greater in group of women who delivered naturally and head-perineum distance and head-symphysis distance were smaller in this group. Some relations between each measured parameter and time left to delivery were observed as well as strong relations among parameters were also observed.

CONCLUSIONS: Intrapartum sonography is a useful and objective tool to assess the progress of labor. Transperineal ultra-sound scans performed in the second stage of labor may play a role in making the decision about the mode of delivery.