How is a ring pessary measured for proper fit?

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Last updated: June 18, 2025View editorial policy

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From the Research

A ring pessary is measured for proper fit by a healthcare provider who selects the largest size that remains comfortable while providing adequate support, with the most recent study suggesting that the levator hiatal area (HA) measured by transperineal ultrasound can be used to estimate the appropriate ring pessary size 1. The fitting process begins with a pelvic examination to assess the vaginal anatomy and degree of prolapse.

  • The provider then inserts different sized pessaries, starting with an estimated size based on the width of the vaginal introitus (typically measured by finger widths) or by using the distance between the pubic symphysis and posterior fornix.
  • A properly fitted pessary should sit comfortably behind the pubic bone and across the posterior fornix, with enough room to allow a finger to pass between the pessary and vaginal wall.
  • The patient should not feel the pessary when properly positioned, and should be able to walk, sit, void, and have bowel movements without discomfort. After insertion, the patient is typically asked to stand, cough, strain, and walk around to ensure the pessary stays in place and remains comfortable.
  • The fit is considered successful if the pessary adequately reduces the prolapse, remains in position during physical activity, and causes no pain or discomfort.
  • Follow-up appointments are essential to check for proper fit and to monitor for potential complications such as vaginal irritation or ulceration, with studies suggesting that factors such as genital hiatus width, total vaginal length, and vaginal introitus width can influence the size of the ring pessary chosen 2. It is also important to consider the patient's individual characteristics, such as their history of hysterectomy and stage of prolapse, when selecting the type and size of pessary, as these factors can affect the success of the fitting trial 3, 4.
  • A study published in 2022 found that a Valsalva HARP ratio of ≤5.00 was the best cut-off for predicting successful trials, and that unsuccessful fitting trials due to dislodgment or failure to relieve POP symptoms were associated with a small ring pessary with respect to the levator HA 1. Overall, the key to a successful ring pessary fitting is to select the largest size that remains comfortable while providing adequate support, and to consider the individual patient's characteristics and anatomy when making this selection, as supported by the most recent and highest quality study 1.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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