Optimal Time For Evaluation of Labor Related Pelvic Floor Changes: A 3D Transperineal Ultrasound Study

Sixty four of 72 primiparous women who vaginally delivered singleton babies that eligible for trial were examined within 36 h of delivery and at 3rd months after delivery.Parameters such as age, episiotomy, mode of delivery, duration of labor, birthweight and antenatal biparietal diameter (BPD) measures were obtained from the clinical files. The length of the first stage of labor was calculated from the beginning of regular and at least three strong uterine contractions in 30 min according to the women's statements, tocography and palpations to full dilatation. All static ultrasound volume acquisitions were performed by the same experienced sonographer trained in pelvic floor ultrasound within 36 h of delivery. Same patients invited for second evaluation.Two 3-D volumes (one at rest, one on Valsalva maneuver) were recorded in the supine position after voiding.The effectiveness of valsalva was ascertained by observing 2-D ultrasounds before acquiring volumes.. LAM thickness is determined at the plane of minimal hiatal dimensions rather than 1-1.5 cm above the actual LAM hiatus where LAM thickness is maximal as described by Dietz et al.(15). The following parameters were assessed for this study: maximum diameters of the LAM hiatus (anteroposterior and transverse) at rest and on Valsalva maneuver; area of the LAM hiatus at rest and on Valsalva; and pubovisceral muscle thickness (left and right of the rectum), difference in anteroposterior and transverse diameter of hiatus and LAM hiatus area between rest and Valsalva