Researchers say menstrual blood testing could provide a convenient alternative to cervical screening.
A sanitary pad fitted with a sample strip can detect human papillomavirus, which causes most cervical cancers.
The test allows women to collect samples at home without a clinician.
This could help reach millions who currently skip cervical screening.
Scientists in China compared menstrual blood samples with clinician-collected cervical samples.
The study involved more than 3,000 women with regular menstrual cycles.
Results, published in BMJ, showed high accuracy for detecting serious cervical abnormalities.
Pad-collected samples detected CIN2 lesions with 94.7% sensitivity.
This matched the performance of clinician-collected samples.
Researchers called the method non-invasive and effective.
Cancer Research UK welcomed efforts to improve screening access.
Experts stressed that larger and more diverse trials are still needed.
Eve Appeal said offering more screening options could save lives.
They noted the test would not suit everyone, including menopausal women.
