At what age should a woman start getting Pap (Papanicolau) smears for cervical cancer screening?

Cervical Cancer Screening: Starting Age

Women should begin Pap smear screening at age 21 years, regardless of when they became sexually active or any other risk factors. 1, 2

Evidence-Based Rationale

Universal Age 21 Threshold

• All major organizations—the American Cancer Society, American College of Obstetricians and Gynecologists, and US Preventive Services Task Force—uniformly recommend starting screening at age 21 years with no exceptions for earlier sexual activity. 2
• The USPSTF explicitly gives screening before age 21 a Grade D recommendation, meaning it provides no benefit and causes harm. 2
• This represents a shift from older guidelines (pre-2010) that recommended starting approximately 3 years after first vaginal intercourse but no later than age 21. 1

Disease Burden Supporting Age 21 Start

The evidence strongly supports waiting until age 21:

• Cervical cancer is extraordinarily rare in young women: Only 0.1% of all cervical cancer cases occur in women under age 21. 2
• Among women under 40, only 1% of cases are diagnosed before age 20. 3
• The annual incidence is merely 1-2 cases per 1,000 females aged 15-19 years (rate of 0.15 per 100,000). 2, 3
• Even in the 20-24 age group, the rate is only 1.4 per 100,000 females annually. 3

Harms of Earlier Screening

Screening before age 21 causes more harm than benefit because:

• Most HPV infections and cervical abnormalities in adolescents are transient and regress spontaneously without any intervention. 2
• Unnecessary evaluation and treatment of self-resolving lesions leads to invasive procedures (colposcopy, cervical biopsy) causing vaginal bleeding, pain, infection, and psychological distress. 2
• Treatment procedures like loop excision and cold-knife conization are associated with serious adverse pregnancy outcomes including preterm delivery, low birthweight, and perinatal death. 2

Initial Screening Protocol

Ages 21-29 Years

• Screen every 3 years with cytology (Pap test) alone. 1, 2
• Do not use HPV testing in this age group, either as standalone or co-testing with cytology. 1
• The rationale: HPV prevalence is extremely high in young women but most infections clear spontaneously, making HPV testing unnecessarily alarming and leading to overtreatment. 1

Ages 30-65 Years

Two acceptable approaches exist:

• Preferred: Co-testing with both HPV and Pap test every 5 years. 1
• Acceptable alternative: Cytology alone every 3 years. 1

Critical Clinical Distinctions

Pelvic Exam ≠ Cervical Cancer Screening

A common and dangerous pitfall: Do not conflate the need for a pelvic examination with cervical cancer screening—these are separate clinical activities. 2

• A pelvic exam for IUD placement, contraception counseling, or evaluation of symptoms can be performed without collecting cervical cytology specimens. 2
• Do not screen based on sexual activity history—age 21 is the absolute threshold regardless of when sexual activity began. 2

Implementation Challenges

Despite clear guidelines, providers continue problematic practices:

• Studies show providers continue screening much earlier than recommended despite universal guideline consensus. 3
• From 2000-2010, the proportion of women aged 18-21 reporting Pap testing in the past 12 months decreased from 65.0% to 41.5%, showing movement toward guidelines but still indicating substantial over-screening. 4
• Among women aged 22-30 who should be screened every 3 years, 67% reported screening within the past 12 months in 2010—indicating massive over-screening. 4

When to Stop Screening

Women may discontinue screening after age 65 if they meet all of these criteria:

• Three consecutive negative cytology tests OR two consecutive negative co-test results within the past 10 years. 1
• The most recent test occurred within the last 5 years. 1
• No history of CIN2 or higher-grade lesions in the past 20 years. 1

Important exception: Women with a history of CIN2+ must continue screening for at least 20 years after treatment, even if this extends well past age 65. 1, 2