Common surgical procedures used to diagnose and treat precancerous cervical lesions do not decrease women's chances of becoming pregnant, according to a study that followed nearly 100,000 women for up to 12 years.

To the contrary, researchers found that women who had one of these procedures were actually more likely to become pregnant than women who did not have a procedure. The new Kaiser Permanente study is published in PLOS ONE.

According to the Centers for Disease Control and Prevention, about 3 million women in the United States will have an unclear or abnormal pap test each year. Many of them will go on to have a diagnostic colposcopy and biopsy to determine if they have pre- cancerous lesions on their cervix. If these lesions are found, the women may have a LEEP procedure, cryotherapy or another surgical procedure to remove the cells so they don't progress to cervical cancer.

"This is great news for the millions of women who have one of these procedures, but still want to have a family," said Allison Naleway, PhD, lead author and senior investigator at the Kaiser Permanente Center for Health Research in Portland, Oregon. "There was a fear that these procedures could weaken the cervix, and reduce fertility, but our study suggests that this is not the case."

The researchers examined medical records for 4,137 women between the ages of 14 and 53 who were members of the Kaiser Permanente health plan in the states of Oregon and Washington between 1998 and 2009 and who had had a cervical treatment procedure. They followed the women for up to 12 years after the procedure to find out if they became pregnant. The researchers compared those women to 81,435 women in the health plan who did not have a cervical treatment procedure and 13,676 who had a colposcopy or biopsy diagnostic procedure.

Fourteen percent of women who had cervical treatment procedures got pregnant, compared to 9 percent of women who did not have a procedure and 11 percent of women who had a biopsy or colposcopy. After adjusting for age, contraceptive use and infertility, women who had a treatment procedure were still almost 1.5 times more likely to conceive compared to untreated women. Pregnancy rates among women who had a biopsy or colposcopy were the same as rates among women who had a surgical treatment procedure. For more information, contact: 

"While the data we collected did not include sexual history, it is possible that the women who had these procedures may have been more sexually active than the untreated group, and that would explain the higher pregnancy rates," Naleway said.

This is the largest study to date to examine whether these surgical procedures decrease fertility. Other, smaller studies have relied on patient recall and survey data rather than examination of medical records, which was what Naleway used for her study.

Researchers also examined whether these procedures affected birth outcomes such as preterm delivery. Results of that study are expected later this year.

This study was funded by a grant from GSK, which makes Cervarix, a vaccine to prevent cervical cancer.

Authors include Allison Naleway, PhD, and Sheila Weinmann, PhD, of the Kaiser Permanente Center for Health Research; Geeta Swamy, MD, and Evan Myers, MD, MPH, of Duke University Medical Center in Durham, North Carolina; and Girishanthy Krishnarajah, MPH, MBA, Bhakti Arondekar, BPharm, MBA, PHD, and Jovelle Fernandez, MD, PhD, of GlaxoSmithKline, in Philadelphia.

Naleway, Weinmann, Swamy and Myers received funds from GSK to work on the study. Swamy and Myers also received additional consulting fees from GSK not related to the study.