A Pap smear is an examination under the microscope of cells scraped from the tip of the cervix. The cervix is the lower part of the uterus (womb) that opens at the top of the vagina.
The Pap smear is done as part of a gynecological exam. You will lie on a table and place your feet in stirrups to position your pelvis for examination. The health care provider will insert an instrument (speculum) into your vagina and open it slightly to see inside the vaginal canal.
The health care provider will take a sample of cells from the outside and just inside the opening of the cervix (cervical canal) by gently scraping the outside of the cervix with a wooden or plastic spatula, then inserting a small brush that looks like a pipe cleaner into the canal.
The cells are placed on a glass slide, or put in a bottle containing a preservative, and then sent to the lab for examination.
Tell your health care provider if you:
Within 24 hours of the test, avoid:
Avoid scheduling your Pap smear while you have your period (are menstruating), because blood and cells from the uterus may affect the accuracy of the Pap smear. Empty your bladder just before the test.
You may have some discomfort, similar to menstrual cramps, and a feeling of pressure during the procedure. You may bleed a little bit after the test.
The Pap smear can detect cancerous or precancerous conditions of the cervix. Most invasive cancers of the cervix can be detected early if women have Pap tests and pelvic examinations.
Screening should start within 3 years after first having vaginal intercourse or by age 21. After the first test:
Women who have had a total hysterectomy (uterus and cervix removed) and have not had any previous history of cervical dysplasia (abnormal cells), cervical cancer, or any other kind of pelvic cancer, may not need to have Pap smears.
A normal value is negative, meaning there are no abnormal cells present.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The current system divides the abnormal results into these main areas:
When a Pap smear shows abnormalities, further testing or follow-up is needed. The next step depends on the results of the Pap smear, your previous history of Pap smears, and risk factors you may have for cervical cancer.
This may include:
For minor cell changes, doctors usually recommend having a repeat Pap smear in 3-6 months.
There are no risks involved.
The Pap smear test is not 100% accurate. Cervical cancer may be missed in a small number of cases. Fortunately, cervical cancer develops very slowly in most women and follow-up Pap smears should identify worrisome changes in time for treatment.
The following drugs may affect Pap smears:
ACOG Practice Bulletin No. 99: management of abnormal cervical cytology and histology. Obstet Gynecol. 2008;112(6):1419-1444.
ACOG Committee on Gynecological Practice. ACOG Practice Bulletin No. 109: Cervical Cytology Screening. Obstet Gynecol. 2009 Dec;114(6):1409-1420.
Noller KL. Intraepithelial neoplasia of the lower genital tract (cervix, vulva): etiology, screening, diagnostic techniques, management. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM. Comprehensive Gynecology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2007:chap. 28.