Persistence of levator ani sonographic defect detected by three-dimensional transperineal sonography in primiparous women.

Abstract

Correlation of the sonographic appearance of levator ani muscle (LAM) injury soon after delivery with that at long-term follow-up has not been described fully. We aimed to compare results of three-dimensional (3D) transperineal sonographic (TPS) evaluation of the LAM from the period immediately postpartum with long-term follow-up, to determine whether sonographic findings persist over time. Primiparous women (n = 210) who had been examined by 3D-TPS in a previous study to determine LAM trauma 24-72 hours after delivery were invited to participate in a follow-up examination 3-21 months postpartum. We included in this study only women who were not pregnant when approached and who had not given birth in the interim. LAM trauma was diagnosed with 3D-TPS when we observed discontinuity and distortion of the most anteromedial part of the pubovisceral muscle in the coronal C-plane or rendered image. Initial and follow-up 3D-TPS results were compared using Cohen's kappa test for inter-rater agreement. Among the 87 women included in this study we found strong correlation between earlier and later sonographic appearance of LAM: 17/21 women with a sonographic finding of LAM injury in the period immediately postpartum were positive in the follow-up examination, and only 2/66 women negative for LAM damage at the first examination were found to have sonographic evidence of LAM defect at follow-up (Cohen's kappa, 0.805 (95% CI, 0.656-0.954), P < 0.001). Our findings suggest that 3D-TPS of the LAM is a reliable examination. A sonographic finding of LAM defect identified in the period immediately postpartum persists months or years after delivery; therefore, this test may be performed following delivery, or may be delayed without impacting the result. It is likely that this sonographic defect represents real anatomical disruption and is not an imaging artifact.