Researchers say testing menstrual blood could offer a simple, non-invasive alternative to cervical screening.
A sanitary pad with a blood sample strip can detect human papillomavirus, the main cause of cervical cancer.
The test could be used at home and may help reach women who avoid clinic-based screening.
Scientists in China compared menstrual blood testing with clinician-collected cervical samples.
The study involved more than 3,000 women aged 20 to 54 with regular menstrual cycles.
Researchers published the findings in BMJ.
Menstrual blood samples detected significant cervical abnormalities with 94.7% sensitivity.
Clinician-collected samples showed a similar sensitivity of 92.1%.
Although specificity was slightly lower, negative results proved equally reliable.
Referral rates for further testing matched those of standard screening.
The authors said the method could replace or complement existing screening programmes.
Cancer Research UK said the approach looked promising but needed further trials.
Experts stressed the test may not suit everyone, including menopausal women.
The Eve Appeal said offering screening choices could improve participation.
