Why used sanitary pads are being collected in India
Menstruation is considered a taboo to even speak about in India, so imagine the reaction to the idea of collecting women's used menstrual pads.
But that is exactly what health workers did in villages in the West Indian state of Maharashtra - in order to diagnose the possibility of cervical cancer.
More than a quarter of the world's cervical cancer patients are from India.
Yet there are many reasons why women don't go for cervical screening - a lack of adequate infrastructure and facilities in rural areas as well as burdening costs, coupled with unease at undergoing the invasive examination.
"Rural women are shy, fear the test and consider it unnecessary," said researchers writing in the European Journal of Cancer Prevention.
More than 90% of Indian rural women use homemade cloth as a menstrual pad, as opposed to commercial sanitary products.
Researchers from the Tata Memorial Centre and National Institute for Research in Reproductive Health in India found that by analysing these used menstrual pads, they could detect the presence of human papilloma virus (HPV), which can cause cervical cancer.
"It is an easy and convenient way," Dr Atul Budukh, lead researcher from the centre, told the BBC.
"The major roadblock to large scale implementation of the cervical cancer screening programme is the low participation by the women at risk."
As a result, doctors say that most cervical cancer patients are only diagnosed at an advanced metastatic stage or when attending hospital for any other medical check-up.
Deep freeze DNA
For the research, more than 500 women aged between 30 and 50 with no history of any cancer, who were physically and mentally fit and menstruating regularly, provided their pads for analysis during the two-year research period.
These women were asked to store the menstrual cloth on the first day of their periods in a simple ziplock bag and hand it to the local health worker.
The collected menstrual cloth was then stored at -20C and sent to the diagnostic centre in a dry ice container for HPV screening.
Genomic DNA was then extracted from dried menstrual blood, amplified and studied using polymerase chain reaction - a technique used in molecular biology.
Twenty-four women tested positive for HPV and were identified for further treatment, said Dr Bhuduk.
This included a colposcopy - a simple procedure used to look at the cervix, the lower part of the womb at the top of the vagina.
The procedure can confirm whether cells in the cervix are abnormal and require treatment.
The researchers also documented the women's socio-demographic and reproductive history, their bathroom and toilet facilities and the type of menstrual device used.
The study found an urgent need for intensive health education on genital hygiene.
According to the Census of India 2011, more than 41% of the households do not have bathrooms and of those that do, 16% of the rooms did not have a roof.
Dr Budukh said: "Because of the poor conditions of the bathroom or lack of proper toilet facilities, women in rural areas do not have the privacy to wash their genitals."
Poor genital hygiene has been found to be an important factor for the development of dysplasia and cervical cancer, and the use of pads made from reused cloth increases that risk, studies have shown.
Collecting the menstrual cloth was a real challenge, the researchers said, partly because of the myths and superstitions surrounding menstruation among the rural population in India.
For example, menstruating women are generally barred from entering the kitchen, visiting temples and attending religious gatherings.
Myths and superstition
This made it difficult for health workers to collect the pads, especially in the evenings, because it is seen as a bad omen for menstruating women to come out after sunset.
Intensive health education programmes on cervical cancer and how to prevent it were organised for village leaders, social workers and family members of the participants.
They were also informed of the myths surrounding menstruation.
There were some limitations to the study - the transporting of the samples was costly and researchers pointed out that development of a simple mechanism of sending the pads for testing by mail would be more efficient than freezer storage.
Only menstruating women can benefit from this screening method, they also noted.
Dr Budukh and his team say that with an improved system for collecting and despatching menstrual pads for testing and good health education, this could become an effective cervical cancer screening tool.