NEW YORK (Reuters Health) – Cervical cancer screening should begin when a woman turns 21, according to newly revised evidence-based guidelines issued November 20 by the American College of Obstetricians and Gynecologists (ACOG).

ACOG previously recommended that cervical screening begin 3 years after first sexual intercourse or by age 21, whichever occurred first.

“The recommendation to start screening at age 21 years regardless of the age of onset of sexual intercourse is based in part on the very low incidence of cancer in younger women,” the guidelines state. “It is also based on the potential for adverse effects associated with follow-up of young women with abnormal cytology screening results.”

The updated guidelines also call for women between the ages of 21 and 29 to be screened every 2 years, instead of annually, using the standard Pap test or liquid-based cytology.

Women aged 30 and older who have had three consecutive negative cervical cytology test results and who have no history of cervical intraepithelial neoplasia (CIN) 2 or 3, or cancer, are not HIV infected or immunocompromised, and were not exposed to diethylstilbestrol (DES) in utero may extend the interval between cervical cytology examinations to every 3 years.

Cytology and human papillomavirus (HPV) DNA testing is an appropriate screening strategy for women older than age 30, the guidelines state. Low risk women aged 30 and older who receive negative test results on both cervical cytology screening and HPV DNA testing should wait at least 3 years before being rescreened.