Pelvic organ prolapse in nulliparae

Background Pregnancy and childbirth are thought to be the strongest environmental risk factors for pelvic organ prolapse, but prolapse does occur in nulliparae. Aim To characterise prolapse in vaginal nulliparae. Material and methods This was a retrospective study using archived clinical and imaging data of 368 vaginally nulliparous women seen between 2006 and 2017 at two tertiary urogynaecological centres. Patients underwent a standardised interview, clinical examination and 3D/4D translabial ultrasound. Volume datasets were analysed by the second author, blinded against all clinical data, using post‐processing software on a personal computer. Significant prolapse was defined as Pelvic Organ Prolapse Quantification system stage ≥2 for the anterior and posterior compartment, and stage ≥1 for the central compartment. On imaging, significant prolapse was defined as previously described. Results Of 4297 women seen during the inclusion period, 409 were vaginally nulliparous, for whom 368 volume data sets could be retrieved. Mean age was 50 years (17–89) and mean body mass index 29 (16–64). Eighty‐one (22%) presented with prolapse symptoms. On clinical examination, 106 women (29%) had significant prolapse, mostly of the posterior compartment ( n  = 70, 19%). On imaging 64 women showed evidence of significant prolapse (17%), again mostly posterior ( n  = 47, 13%). Rectovaginal septal defects were even more common in 69 (19%). On multivariate analysis we found no differences between true nulliparae ( n  = 184) and women delivered exclusively by caesarean section ( n  = 184). Conclusions Prolapse occurs in vaginal nulliparae, but it has distinct characteristics. Rectocele predominates, while cystocele and uterine prolapse are uncommon. Pregnancy and caesarean delivery seem to have little effect.