Researchers say testing menstrual blood could provide a simple alternative to cervical cancer screening.
A sanitary pad fitted with a sample strip can detect human papillomavirus, the main cause of cervical cancer.
Women could use the test at home without a clinical appointment.
Scientists in China compared menstrual blood samples with clinician-collected cervical samples.
The study involved more than 3,000 women aged 20 to 54.
Researchers published the findings in BMJ.
The pad-based test detected high-grade cervical abnormalities with 94.7% sensitivity.
This matched the accuracy of samples collected by clinicians.
Specificity was slightly lower, but negative results were equally reliable.
Experts say the approach could help reach women who skip screening appointments.
Cancer Research UK welcomed efforts to improve access.
Researchers stressed the method still needs larger and more diverse trials.
Charities said offering multiple screening options could save lives.
They noted the test would not suit everyone, including menopausal women.
