A Pap smear is a microscopic examination of cells scraped from the cervix.

The Pap smear is performed as part of a gynecological exam. You will lie on a table and place your feet in stirrups to position your pelvis for examination. A speculum (an instrument used to open the walls of the vaginal canal to see the interior) will be inserted into your vagina and opened slightly.

A sample of cells from the outside and the canal of the cervix is taken 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 and sprayed with a fixative, or put in a bottle containing a preservative, then sent to the lab for examination.

The health care provider should be notified if you have had a prior abnormal Pap smear, if you might be pregnant, or if you are taking any medications or birth control pills. You should avoid douching, using tampons, having intercourse, and tub baths 24 hours before the test.

Avoid scheduling your Pap smear while you are menstruating, because blood and cells from the endometrial cavity may obscure the accuracy of the Pap smear. Empty your bladder just before the test.

There may be some discomfort, similar to menstrual cramps, and a feeling of pressure during the procedure. A small amount of bleeding may occur after the test.

The Pap smear can detect cancerous or precancerous conditions of the cervix. A cervical biopsy is usually performed when a pap smear indicates significant abnormalities, or when an abnormal area is seen on the cervix during a routine pelvic examination. The biopsy identifies the abnormality. When a positive pap smear shows minor cell changes or abnormalities, a biopsy probably will not be done immediately, unless there is a reason to believe you may be in a high-risk category. For minor cell changes, it is usually recommended that a repeat pap smear be done in 6 months.

A normal value is negative, meaning there are no abnormal cells present.

Abnormal values are based on the test results. The current system of reporting divides the results into three main areas: benign (noncancerous), precancerous (showing some abnormal cell changes), and malignant (possibly cancerous).

The Pap smear is a screening test. If your pap smear is abnormal, you may require a repeat pap smear or colposcopic evalauation. Your doctor will advise you. See Colposcopy-directed biopsy.

There are no risks involved.

The following drugs may affect Pap smears:

• Colchicine
• Estrogen
• Podophyllin
• Progestins
• Silver nitrate
• Compounds in cigarettes