The dimension of the levator hiatus is a possible predictor of pelvic organ prolapse (POP). This retrospective study investigated 360 women who went to urogynecological clinic for pelvic floor discomfort. Levator hiatus dimensions were obtained by three-dimensional transperineal ultrasound and results were compared between women with and without significantly objective prolapse (International Continence Society POP quantification, grade 2 or higher). Receiver operating characteristic (ROC) curve analyses were performed to determine valid screening index for detecting abnormal levator hiatus distensibility. Women with significantly objective prolapse had significantly higher levator hiatus dimensions than those without (all P < 0.001). ROC curve analyses confirmed that hiatal area (HA) of 19.5 cm2 during Valsalva maneuver can be used as single-screening index for abnormal levator hiatus distensibility with sensitivity of 0.80 and specificity of 0.70. In this study, we used a two-step method and achieved higher sensibility (0.80 vs. 0.87) without reducing specificity (0.70 vs. 0.71) compared with a single-screening index method. As a result, we suggest that HA ⩾ 19.5 cm2 during Valsalva maneuver is an indicator of abnormal levator hiatus distensibility in Chinese women and that the two-step method has higher sensitivity in detecting abnormal distensibility.
Keywords: levator ani muscle; levator hiatus; pelvic organ prolapse; three-dimensional transperineal ultrasound.