Age to Begin Pap Smear Screening
Women should begin cervical cancer screening at age 21 years, regardless of sexual activity history or HPV vaccination status. 1
Current Consensus Recommendations
All major guideline organizations—the American Cancer Society (ACS), American College of Obstetricians and Gynecologists (ACOG), and U.S. Preventive Services Task Force (USPSTF)—now uniformly recommend starting Pap smear screening at age 21 years. 2, 1 This represents a shift from older guidelines that previously recommended starting 3 years after first sexual intercourse or at age 21, whichever came first. 2
Rationale for Age 21 Start
The recommendation to begin at age 21 is based on several key factors:
Low incidence of cervical cancer in younger women: Cervical cancer is extremely rare in women under age 21, making screening in this population inefficient. 2
Limited utility of screening before age 21: Even among sexually active adolescents, screening does not improve outcomes and leads to unnecessary interventions. 2
High rates of HPV clearance in young women: Most HPV infections in adolescents and young women resolve spontaneously without progressing to cancer, so detecting them leads to overtreatment without mortality benefit. 3
Screening Method for Ages 21-29
For women aged 21-29 years, Pap test alone every 3 years is the appropriate screening method. 1, 3 HPV testing should not be used for primary screening in this age group because HPV prevalence is substantially higher in younger women, leading to excessive false-positives and unnecessary colposcopies without improving cancer prevention. 3
Common Pitfalls to Avoid
Do not screen women under age 21, even if they are sexually active or have multiple partners. 2, 1 Data from 2000-2010 showed that the percentage of women aged 18-21 who had never been screened increased from 26.3% to 47.5%, reflecting appropriate movement toward evidence-based guidelines. 4
Do not screen annually for women aged 21-29 years. The 3-year interval is evidence-based and sufficient. 1 Annual screening in this age group increases costs and harms without improving mortality outcomes. 4
HPV vaccination status does not change screening recommendations. HPV-vaccinated women should follow the same screening schedule as unvaccinated women, beginning at age 21. 1