Purpose
Hysterectomy may be a risk factor for pelvic organ prolapse (POP). We assessed the risk of recurrent POP (operations and visits) after hysterectomy among women with previous POP. We also studied patient and operation related risk factors for POP recurrence.

Methods
This retrospective cohort study included 1697 women having previous POP diagnosis or POP at the time of hysterectomy (FINHYST 2006 cohort). Follow-up was until the end of 2016. The data was derived from the Finnish National Care register linked to the cohort. Hysterectomy approaches and other demographics were compared to the risk of a prolapse diagnosis and/or surgery. Cox regression model was used to identify hazard ratios.

Results
Following hysterectomy, a total of 280 women (16.5%) had a POP reoperation and 359 (21.2%) had an outpatient visit due to POP. Vaginal vault prolapse repair was the most common POP reoperation (n = 181, 10.7%), followed by anterior wall repair (n = 120, 7.1%). Median time to POP reoperation was 3.7 years. Hysterectomy approach did not affect reoperations or visits. Previous cesarean section and anterior repair during hysterectomy were associated with decreased risk, whereas concomitant sacrospinous fixation and uterus prolapse as the main indication led to increased risk of anterior/vault prolapse reoperations. Concomitant posterior repair decreased posterior reoperations and visits, but uterus weight over 500 g caused a fivefold increased risk of posterior prolapse visit. Residential status was associated with elevated risk of any POP reoperations and visits.

Conclusions
Approximately one out of five women suffering from POP ensue POP reoperation or visit after hysterectomy. These high rates are independent on hysterectomy approach, but probably indicate that hysterectomy may worsen previous pelvic floor dysfunction.