Ring Pessary Size Guide 2026 — Sizes 0 to 9 Explained

Choosing the correct pessary size is one of the most important steps in managing pelvic organ prolapse or stress urinary incontinence. A pessary that is too small will not stay in place. A pessary that is too large will cause discomfort and pressure. This guide explains exactly how ring pessary sizes work, what each size means in millimeters and inches, and how to find the right fit for you or your patient.

How are ring pessaries sized?

Ring pessaries are sized by their diameter — the distance across the ring measured in millimeters. Unlike clothing sizes, pessary sizes are numbered from 0 to 9, with each number corresponding to a specific diameter. Size 0 is the smallest at 44mm and size 9 is the largest at 102mm.

The correct size is determined by measuring the vaginal width during a pelvic examination. A healthcare provider — typically a gynaecologist, pelvic floor physiotherapist, or urology nurse — will assess the degree of prolapse and select the smallest size that adequately supports the pelvic organs without causing discomfort.

SciMed ring pessary size chart

Size 0 — 44mm (1.75 inches)
Size 1 — 51mm (2.00 inches)
Size 2 — 57mm (2.25 inches)
Size 3 — 64mm (2.50 inches) — popular size
Size 4 — 70mm (2.75 inches) — most popular size
Size 5 — 76mm (3.00 inches) — popular size
Size 6 — 83mm (3.25 inches)
Size 7 — 89mm (3.50 inches)
Size 8 — 95mm (3.75 inches) — without support only
Size 9 — 102mm (4.00 inches) — without support only

Based on our order data, sizes 3, 4, and 5 account for the majority of pessary orders in the United States — making them the most commonly needed sizes for the average patient.

With support vs without support — does size change?

The sizing system is the same for both ring pessary with support and ring pessary without support. A size 4 with support and a size 4 without support have the same outer diameter of 70mm.

The difference is the membrane. A ring pessary with support has a silicone membrane across the centre that provides additional bladder neck support — suitable for patients who have both pelvic organ prolapse and stress urinary incontinence.

A ring pessary without support is a simple ring with no membrane. It is lighter, easier to self-manage, and recommended for patients with prolapse without significant incontinence symptoms.

How is pessary size measured during a fitting?

During a clinical fitting, the healthcare provider inserts a finger into the vaginal canal and measures the distance from the posterior fornix to the pubic symphysis. The provider will typically start with a size close to this measurement and check the fit by asking the patient to bear down, cough, and walk around.

A correctly fitted pessary should stay in place during these activities without causing pressure or discomfort. One finger should be able to sweep between the pessary ring and the vaginal wall. If the pessary is expelled it is too small. If the patient reports pain it is too large.

Can I self-measure at home?

Self-measurement at home is not recommended for a first-time pessary user. Incorrect sizing can lead to the pessary falling out, causing discomfort, or failing to adequately support the pelvic organs.

However, if you have been previously fitted by a healthcare provider and know your size, you can reorder the same size directly from SciMed Store without a prescription. Many of our customers are experienced pessary users who self-manage their device and simply need to reorder their regular size.

Why choose SciMed pessaries?

SciMed Store is a California-based in-house manufacturer of FDA-approved vaginal pessaries. We manufacture our pessaries at our San Jose, California facility — giving you direct manufacturer quality at competitive prices with no import markups and no foreign tariffs.

We offer the widest size range available from any US supplier — ring pessary with support in sizes 0 to 7, and ring pessary without support in sizes 0 to 9. All orders placed before 2pm PST are dispatched same day from our California warehouse with discreet packaging on every order.

Contact our clinical support team via WhatsApp at +1 669 265 9353 or email sales@scimedstore.com — Monday to Friday, same-day response guaranteed.

Order your SciMed ring pessary today

Ring Pessary With Support — sizes 0 to 7. Recommended for pelvic organ prolapse with concurrent stress urinary incontinence. Shop at scimedstore.com

Ring Pessary Without Support — sizes 0 to 9. Recommended for pelvic organ prolapse without significant incontinence symptoms. Shop at scimedstore.com