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.