What is the procedure for performing a Pap (Papanicolaou) smear?

How to Perform a Pap Smear

The Pap smear is obtained by using a Papanicolaou paddle rotated 360° to sample the entire exocervix, followed by a cytobrush to collect an endocervical specimen, with liquid-based cytology preferred over conventional smears. 1

Pre-Procedure Considerations

Timing and Patient Preparation:

• Postpone the Pap test if the woman is menstruating (for conventional cytology) and reschedule at the earliest opportunity 1, 2
• The presence of mucopurulent discharge should not delay testing; carefully remove the discharge with a saline-soaked cotton swab before specimen collection 1, 2
• The sequence of Pap testing in relation to collection of other cervicovaginal specimens does not influence results 1

Collection Technique

Optimal Device Selection:

• The combination of cytobrush (for endocervix) and spatula (for ectocervix) is superior for quality Pap smears 3
• The Cervex-brush (broom) alone performs poorly and is associated with absent endocervical cells, limited/unsatisfactory results, and obscuring inflammation 3
• Cytobrushes and brooms improve the number of satisfactory Pap tests compared to spatula alone 1

Specimen Collection Steps:

1. Ectocervical sampling: Use a Papanicolaou paddle rotated 360° to sample the entire exocervix, ensuring complete coverage of the transformation zone 1
2. Endocervical sampling: Use a cytobrush to collect endocervical specimens; this device may cause bleeding, particularly in patients with STIs 1
3. Target the transformation zone and squamocolumnar junction: Most precancerous changes occur in this area, making adequate sampling critical 4

Important Technical Points:

• Warn patients about possible light bleeding or spotting after the Pap test due to cytobrush use 1
• The sequence of collection (ectocervix first vs. endocervix first) does not affect quality indicators in conventional Pap smears 3

Specimen Processing

Liquid-Based Cytology (Preferred Method):

• Liquid-based cytology is preferred because it produces fewer inadequate readings and false-negative results 1
• Liquid-based preparations are an acceptable alternative to conventional Pap tests with similar test-performance characteristics 1
• Additional benefit: STI testing can sometimes be performed on the same specimen 1

Conventional Cytology (Alternative):

• If using conventional smears, directly smear the slide and immediately fix before air drying 1
• Verify with the laboratory whether they use 1- or 2-slide Pap tests (endocervical/ectocervical specimens on one slide or separated) 1

Special Populations

Pregnant Women:

• Screen at the same frequency as nonpregnant women 1
• Use a swab and Ayre's spatula for obtaining Pap tests 1
• Cytobrushes are NOT recommended in pregnancy 1

Quality Assurance

Provider Training and Documentation:

• Health-care providers who receive basic retraining on Pap-test collection obtain more satisfactory test results 1
• Document Pap-test results, type and location of follow-up appointments, and results clearly in the clinic record 1, 2
• Develop protocols to identify women who miss follow-up appointments 1, 2

Common Pitfalls to Avoid:

• Do not use the broom device alone—it has significantly higher rates of absent endocervical cells 3
• Do not delay testing for mucopurulent discharge; simply remove it first 1, 2
• Do not use cytobrushes in pregnant women 1
• Ensure immediate wet fixation for conventional smears to prevent air-drying artifact 4