The Pap smear is a screening test for cervical cancer. Cells scraped from the opening of the cervix are examined under a microscope. The cervix is the lower part of the uterus (womb) that opens at the top of the vagina.
How the Test is Performed
You lie on a table and place your feet in stirrups. The doctor or nurse gently places an instrument called a speculum into the vagina to open it slightly. This allows the doctor or nurse to see inside the vagina and cervix.
Cells are gently scraped from the cervix area. The sample of cells is sent to a lab for examination.
How to Prepare for the Test
Tell your doctor or nurse about all the medicines you are taking. Some birth control pills that contain estrogen or progestin may affect test results.
Also tell your doctor or nurse if you:
- Have had an abnormal Pap smear
- Might be pregnant
Do not do the following for 24 hours before the test:
- Douche (douching should never be done)
- Have intercourse
- Use tampons
Avoid scheduling your Pap smear while you have your period (are menstruating). Blood may make the Pap smear results less accurate. If you are having unexpected bleeding, do not cancel your exam. Your doctor will determine if the Pap smear can still be done.
Empty your bladder just before the test.
How the Test will Feel
A Pap smear may cause some discomfort, similar to menstrual cramps. You may also feel some pressure during the exam.
You may bleed a little bit after the test.
Why the Test is Performed
The Pap smear is a screening test for cervical cancer. Most cervical cancers can be detected early if a woman has routine Pap smears.
Screening should start at age 21.
After the first test:
- You should have a Pap smear every 3 years to check for cervical cancer.
- If you are over age 30 and you also have HPV testing done, and both the Pap smear and HPV test are normal, you can be tested every 5 years. (HPV is the human papillomavirus, the virus that causes genital warts and cervical cancer.)
- Most women can stop having Pap smears after age 65 to 70 as long as they have had three negative tests within the past 10 years.
You may not need to have a Pap smear if you have had a total hysterectomy (uterus and cervix removed) and have not had an abnormal Pap smear, cervical cancer, or other pelvic cancer. Discuss this with your doctor.
A normal result means there are no abnormal cells present. The Pap smear test is not 100% accurate. Cervical cancer may be missed in a small number of cases. Most of the time, cervical cancer develops very slowly, and follow-up Pap smears should find any changes in time for treatment.
What Abnormal Results Mean
Abnormal results are grouped as follows:
ASCUS or AGUS
- This result means there are atypical cells, but it is uncertain or unclear what these changes mean
- The changes may be due to HPV
- They may also mean there are changes that may lead to cancer
LSIL (low-grade dysplasia) or HSIL (high-grade dysplasia):
- This means changes that may lead to cancer are present
- The risk of cervical cancer is greater with HSIL
Carcinoma in situ (CIS):
- This result most often means the abnormal changes are likely to lead to cervical cancer if not treated
Atypical squamous cells (ASC):
- Abnormal changes have been found and may be HSIL
Atypical glandular cells (AGC):
- Cell changes that may lead to cancer are seen in the upper part of the cervical canal or inside the uterus
When a Pap smear shows abnormal changes, 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.
For minor cell changes, doctors will recommend another Pap smear in 6 to 12 months.
Follow-up testing may include:
- Colposcopy-directed biopsy
- An HPV test to check for the presence of the HPV virus types most likely to cause cancer
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American College of Obstetricians and Gynecologists. Practice Bulletin No. 131: Screening for cervical cancer. Obstet Gynecol. 2012;120:1222-1238.
American College of Obstetricians and Gynecologists. Practice Bulletin No. 99: Management of abnormal cervical cytology and histology. Obstet Gynecol. 2008;112:1419-1444.
American College of Obstetricians and Gynecologists. Committee Opinion No. 463: Cervical cancer in adolescents: screening, evaluation, and management. Obstet Gynecol. 2010;116:469-472.
Saslow D, Solomon D, Lawson HW, et al. American Cancer Society, American Society for Colposcopy and Cervical Pathology, and American Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer. CA Cancer J Clin. 2012;62(3):147-72.