How do you complete a Pelvic Organ Prolapse-Quantification (POP-Q) exam?

How to Perform a POP-Q Examination

The POP-Q exam is performed by identifying six specific vaginal points (Aa, Ba, Ap, Bp, C, D) and measuring their position relative to the hymenal ring during maximal straining, ideally with the patient standing and with an empty bladder to avoid underestimating prolapse severity. 1

Patient Preparation and Positioning

• Empty the bladder completely before examination – a full bladder significantly underestimates prolapse severity, with mean differences of up to 2.3 cm between full/supine and empty/standing positions 2
• Position the patient standing whenever possible – standing position reveals significantly more prolapse than supine lithotomy (mean difference of 1.4 cm), and patients examined only in supine position may be understaged by 1-2 stages 2
• If standing examination is not feasible, use modified lithotomy position as an alternative 3

The Six Measurement Points

Anterior Compartment

• Point Aa: Located 3 cm proximal to the external urethral meatus on the anterior vaginal wall 1
• Point Ba: The most distal (most dependent) position of the remaining anterior vaginal wall between point Aa and the vaginal cuff or anterior vaginal fornix 1

Posterior Compartment

• Point Ap: Located 3 cm proximal to the hymen on the posterior vaginal wall 1
• Point Bp: The most distal position of the remaining posterior vaginal wall between point Ap and the vaginal cuff or posterior vaginal fornix 1

Apical Compartment

• Point C: The most distal edge of the cervix or vaginal cuff (after hysterectomy) 1
• Point D: The posterior fornix (location of uterosacral ligament attachment to cervix) – omit this measurement in women who have had a hysterectomy 1

Measurement Technique

• Ask the patient to perform maximal Valsalva or straining maneuver to elicit the prolapse to its maximum extent 1
• Measure each point's position relative to the hymenal ring (the reference point = 0):
  • Points above the hymen are recorded as negative values
  • Points below the hymen are recorded as positive values
  • Points at the hymen level are recorded as zero 1

Additional Measurements Required

• Genital hiatus (GH): Measured from the middle of the external urethral meatus to the posterior midline hymen 1
• Perineal body (PB): Measured from the posterior margin of the genital hiatus to the midpoint of the anal opening 1
• Total vaginal length (TVL): The greatest depth of the vagina when point C or D is reduced to its normal position 1

Practical Measurement Options

• Traditional method: Use a centimeter ruler (such as POPstix®) to measure each point 3
• Digital assessment (DPOP-Q): Measure your index finger with a ruler beforehand, then use finger segments as measurement units during examination – this method has excellent inter-observer reliability (κ = 0.94), is significantly faster, less uncomfortable for patients, and cost-effective 3

Recording and Staging

• Record all measurements on a standardized grid with the six points plus the three additional measurements 1
• Staging is determined by the most descended point:
  • Stage 0: No prolapse
  • Stage 1: Most distal point is >1 cm above the hymen
  • Stage 2: Most distal point is ≤1 cm above or below the hymen
  • Stage 3: Most distal point is >1 cm below the hymen but not completely everted
  • Stage 4: Complete vaginal eversion 1
• Prolapse typically becomes symptomatic at Stage 2 or higher (when any point reaches within 1 cm of the hymenal ring) 1

Common Pitfalls to Avoid

• Examining only in supine position with full bladder – this combination produces the greatest underestimation of prolapse severity and may miss 1-2 stages of prolapse 2
• Not achieving maximal straining – inadequate Valsalva will underestimate the true extent of prolapse 1
• Forgetting to omit point D in post-hysterectomy patients – this measurement is anatomically impossible after hysterectomy 1