The new guidelines also say that routine Pap screening should begin at age 21. Previously, ACOG had urged a first Pap either within three years of first sexual intercourse or at age 21.
Pap smears can spot pre-cancerous changes in the cervix in time to prevent invasive cancer. Widespread use has halved cervical cancer rates in the U.S. in recent decades.
The change comes amid a completely separate debate over when regular mammograms to detect breast cancer should begin. ACOG says the timing is a coincidence.
The recommendations are published in the journal Obstetrics & Gynecology.