Aug. 21, 2025
Even though patients who are pregnant may be focused on the pregnancy, childbirth and parenting an infant, it is not the time to gloss over cervical cancer risk and delay diagnosis, according to Alyssa M. Larish, M.D., an obstetrician at Mayo Clinic's campus in Minnesota.
"In fact, there is a higher rate of HPV, the virus leading to cervical cancer, in those who are pregnant than in age-matched controls," says Dr. Larish. "Thus, pregnancy is a time where we can optimize screening. Cervical intraepithelial neoplasia is a slowly progressing lesion that takes about 10 years for the infection to develop into cancer. So we have an opportunity during perinatal care to address this precancerous condition so that it doesn't become cancer."
Unfortunately, 40% of patients diagnosed with cervical cancer have never been screened, according to a 2007 publication in Preventive Medicine. As perinatal care increases contact with the healthcare system and provides Medicaid insurance for many, Dr. Larish considers the antepartum time frame a unique opportunity for screening. This care period also offers a chance to refer patients for colposcopy if the findings meet the threshold dictated by American Society for Colposcopy and Cervical Pathology (ASCCP) for cervical intraepithelial neoplasia (CIN-3), for which all gynecologic patients have a 4% risk. Details about this threshold, which is met if a patient has a 4% or higher estimated immediate risk of CIN-3 or a more advanced condition, appear in a 2020 publication in the Journal of Lower Genital Tract Disease. Mayo Clinic follows the risk stratification approach promoted by the ASCCP.
When to wait and when to move forward with CIN in patients who are pregnant
Margaret E. Long, M.D., an obstetrician-gynecologist at Mayo Clinic in Rochester, Minnesota, and Dr. Larish contend that perinatal diagnosis of cervical cancer or high-grade CIN is preferable to waiting for the postpartum period, due to the opportunity to improve cervical cancer outcomes and the ability to plan follow-up treatments. Importantly, high-grade (CIN-3) lesions require colposcopic surveillance during pregnancy to detect any changes concerning for progression to cancer. If a patient's risk of cancer is lower, the ASCCP does not recommend excisional treatment during pregnancy. As some lesions may regress or resolve in pregnancy, many patients have the option to wait till the postpartum period for colposcopy.
If a physician diagnoses CIN during pregnancy, the lesion does not tend to advance during this period. In fact, at times this lesion may even regress, due to the immunologic changes involved in pregnancy, according to a review publication by Dr. Larish and Dr. Long in a 2024 issue of Obstetrics & Gynecology. Yet patients with a history of cigarette smoking or those diagnosed with HPV 16, a higher risk form of HPV, are less likely to experience CIN regression, says Dr. Larish.
Dr. Larish notes that colposcopic biopsy during pregnancy is safe and unlikely to lead to complications. While the patient may experience increased bleeding during biopsy in pregnancy, she says that clinically important complications — such as the need for blood transfusion — do not increase. She notes that patients who are pregnant and require biopsy commonly experience anxiety and recommends providing ample reassurance that the risk of preterm birth and miscarriage do not increase with this procedure.
However, she and Dr. Long do consider endocervical curettage, which requires a tissue sample from the endocervical canal, unsafe and unacceptable for pregnant patients.
"If you reach up toward the uterus with a scraping tool, it can increase the risk of pregnancy loss," says Dr. Larish. "So we do not recommend this."
Dr. Larish and Dr. Long also recommend that full excisional biopsy, which involves removing a cervical layer to excise a precancer and shortens the cervix, also must be done postpartum.
"The cervix is like a cork or a bottle stopper for the uterus," says Dr. Larish. "Although the risk of pregnancy loss is low with shortening the cervix, it still does add some risk and should be postponed until after pregnancy."
During colposcopic evaluation, Dr. Larish suggests physicians look out for high-grade lesions, which are more likely to progress to cancer, and are identified by these characteristics:
- Plaque-like growth.
- Mosaicism.
- Increased vascularity.
Clinicians who identify high-grade lesions during pregnancy should place the patient under surveillance — which involves further colposcopy, cytology and HPV testing — and seek consultation from maternal-fetal medicine and a gynecologic oncology surgeon. If any lesions appear to progress during pregnancy, the colposcopist should perform a biopsy. If a clinician detects a low-grade lesion during pregnancy, the patient may be reassessed postpartum, says Dr. Larish.
Special circumstances in addressing CIN in patients who are pregnant
In some situations, colposcopy is indeterminate. In these circumstances, a biopsy should always be performed if there is any suspicion of cervical cancer, as the pregnancy or cancer treatment plans might require change if cancer is confirmed. The colposcopist performing a biopsy must carefully select its location, however, as this biopsy may be a one-time opportunity due to potential bleeding, says Dr. Larish.
The infant's delivery method does not affect the status of CIN postpartum, according to a publication in a December 2022 issue of Journal of Gynecology Obstetrics and Human Reproduction. However, if the gynecologist has determined a large, invasive cervical cancer is present, cesarean delivery is advised to prevent seeding of the cancer. If a physician identifies cervical cancer postpartum, Dr. Larish recommends the patient undergo prompt referral to a gynecologic oncologist.
Referral of patients with suspected disease
If a colposcopy for a particular patient who is pregnant proves to be challenging, or if cervical cancer is strongly suspected or confirmed, Dr. Larish suggests referring the patient to a medical center such as Mayo Clinic that performs a high volume of colposcopy and cervical cancer treatments.
For more information
Spence AR, et al. Process of care failures in invasive cervical cancer: Systematic review and meta-analysis. Preventive Medicine. 2007;45:93.
Perkins RB, et al. 2019 ASCCP risk-based management consensus guidelines for abnormal cervical cancer screening tests and cancer precursors. Journal of Lower Genital Tract Disease. 2020;24:102.
Larish AM, et al. Diagnosis and management of cervical squamous intraepithelial lesions in pregnancy and postpartum. Obstetrics & Gynecology. 2024;144:328.
Douligeris A, et al. The effect of the delivery mode on the evolution of cervical intraepithelial lesions during pregnancy: A meta-analysis. Journal of Gynecology Obstetrics and Human Reproduction. 2022;51:102462.
Refer a patient to Mayo Clinic.