OC30.03: the Impact of First Delivery on the Levator Hiatus and the Urogenital Hiatuxs

The aim of this study was to measure the levator hiatus and the urogenital hiatus before and after delivery at rest. Between June 2007 and July 2008 one person examined 84 nulliparous women using Endo-vaginal ultrasound examination, at Hvidovre Hospital, Copenhagen, Denmark. We used a 3D B-K Medical pro focus machine with a 9 MHz 2050 endo-probe, resolution 0,2 mm to measure the levator hiatus (LH) and the urogenital hiatus (UH) before and after delivery. The LH was defined as the minimal area between the symphysis pubis and the proximal part of the levator ani in the axial plane. The UH was defined as the area between the symphysis pubis and the proximal part of the perineal body in the axial plane. Eighty-two women (82) were scanned from gestation of 18–20 weeks. The examination was repeated three months post partum. Seventeen had Cesarean section 17/84 (21%) and four declined from follow-up examination, leaving sixty-one women to be examined. Retrospectively one of the authors (AS) examined the scans to measure the area (cm sq) of the levator hiatus and the area (cm sq) of the urogenital hiatus. The mean size of the LH before and after delivery was 15.9 cm sq (11.3–22.3) respectively 18.4 cm sq (11.2–27.6), p = 0.0001 (ci − 4.2; − 1.54). The mean size of the UH before and after delivery was 16.7 cm sq (11.8–25) respectively 18 cm sq (10.7–27.8), p = 0.39 (ci − 2.12; 0.85). A significant increase in the LH following delivery was demonstrated. No significant increase in the UH was demonstrated. Supporting information can be found in the online version of this abstract. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.