Screening for cervical cancer involves sampling cells from the cervix and the area around it. Screening has been shown to decrease the morbidity and mortality from this disease – which is more common in younger women than older ones – and is therefore highly recommended.
Once the cells are collected, a Pap smear, an HPV test, or both are performed in the laboratory. The Pap smear checks for precancerous or cancerous cells. The HPV test checks for the presence of human papillomavirus (HPV), which can cause cervical cancer.
Cervical cancer screening begins with a speculum examination, which allows the doctor to see the opening of the cervix. A few cells are then scraped off the cervix and placed on a glass slide to be examined. This scraping is generally done with a wooden or plastic spatula, which does not enter the cervix. The scraping may cause mild bleeding. However, since this bleeding is caused by a confirmed trauma to the cervix, bleeding from this procedure does not render a woman niddah.
Occasionally, a cotton applicator (Q-tip) or small brush is inserted a little way into the mouth of the cervix to sample cells from the endocervix, or cervical lining. This does not constitute sufficient opening of the cervix to render the woman niddah, even according to the most stringent definition.
A woman who will have cervical cancer screening during her shivah neki’im (seven clean days) should perform a bedikah in the morning, prior to her procedure. She may then omit further bedikot that day and even on the next day and attribute staining to the procedure. (Ideally, a woman who follows Ashkenazi rulings should avoid having this procedure during the first three clean days, when rules of attributing stains to a lesion are more stringent.)
As above, staining from these tests does not make a woman niddah. A woman should consult a halachic authority if any questions arise, or if the procedure is performed on the fifth or sixth day and she is concerned about her seventh-day bedikah.