The American College of Obstetricians and Gynecologists (ACOG) has said women should wait till the age of 21 for their first cervical cancer screening.

And further screenings could be less frequent than previously recommended, says the new guidelines of the association, published in the December issue of Obstetrics & Gynecology.

Most women younger than 30 should undergo cervical screening once every two years instead of annually, and those age 30 and older can be rescreened once every three years.

Women should have their first cervical cancer screening at age 21 and can be rescreened less frequently than previously recommended, according to Cervical cancer rates have fallen more than 50% in the past 30 years in the US due to the widespread use of the Pap test. The incidence of cervical cancer fell from 14.8 per 100,000 women in 1975 to 6.5 per 100,000 women in 2006. The American Cancer Society estimates that there will be 11,270 new cases of cervical cancer and 4,070 deaths from it in the US in 2009. The majority of deaths from cervical cancer in the US are among women who are screened infrequently or not at all. Cervical cancer is a slow growing cancer caused by certain strains of the human papillomavirus (HPV), an extremely common sexually transmitted disease among women and men. HPV also causes genital and anal warts, as well as oral and anal cancer.