There are signs of change, though, and one of the most surprising may be in the matrimonial market. Four years ago, the Haryana government started its “No Toilet, No Bride” campaign, painting walls across the state with the slogan: “I won’t allow my daughter to marry into a home without toilets.”

Today, as 23-year-old Nimmi Singh, who is now engaged to be married, insists, a groom with a loo is essential. Her family in the city of Rohtak rejected two bathroom-less grooms before locating a family willing to install one in time for the wedding.

“It’s a matter of pride,” she said. “Why should I have to go to the fields?”

And in Delhi, marriage brokers — who provide a popular service in a country where arranged marriages are still the norm — confirm that many families will now ask whether the groom’s family has a bathroom of its own before going ahead with nuptial negotiations.

Meanwhile, in the southern state of Tamil Nadu, an inventor is hoping to usher in a separate but equally important revolution. A few years ago, A. Muruganantham made news with his campaign to create a low-cost sanitary napkin that could be used by poor women in both urban and rural India. He pursued a “Gandhian operation” to make cheap sanitary napkins: women would use his company’s technology to set up their own manufacturing units at home, much as the charkha was used to spin homespun cloth two generations ago.

He isn’t alone — Procter & Gamble has entered a partnership with the Ministry of Health & Family Welfare’s National Rural Health Mission to produce inexpensive sanitary napkins for rural women in the northwestern state of Rajasthan.

A recent survey by the nongovernmental organization Plan India indicated how great the need for innovations of this kind are here. It found that 68 percent of rural women in India could not afford something as basic as a sanitary napkin. It also found that reproductive tract infections were 70 percent more prevalent among women who lacked access to such hygienic supplies for that time of the month.

Women like Asha Bibi, 46, who lives in the village of Baharpur in Uttar Pradesh, consider commercial brands of sanitary napkins unaffordable.