NEW DELHI, India — When 39-year-old Michael Kuykendall approached the Indian consulate for a visa last year, he faced no real problems.

Sure, he had to re-apply for a medical visa instead of a tourist permit when he revealed that he was traveling to New Delhi to fertilize a donor egg for a local surrogate mother. But in those days, that was just a formality.

When it came to take his 6-week-old daughter, Isabella, home last month, however, everything had changed. In January, India adopted new regulations to govern the booming surrogacy business.

The new rules effectively bar gay couples and single parents from the trade — mandating that only heterosexual couples who have been married for at least two years are eligible for the newly created surrogacy visa.

“I felt like they were almost hostile towards me,” Kuykendall, who is gay, said about his exit interview at New Delhi's Foreigners Regional Registration Office (FRRO) last month.

“You go to an interview with some lady, and she really grills you. She belittles you. She makes you feel small about yourself.”

A police officer back home in Milwaukee, Wisc., Kuykendall didn't take too much of that before he pulled out Isabella's US passport and told the immigration officer in no uncertain terms that she might be able to delay his exit, but there was no way she was going to stop him. The circumstances of his private life were “none of her business,” he said.

Not everybody is that confident of his rights. “The guy ahead of me was in there for more than an hour, and he came out in tears,” Kuykendall said. “I told myself, 'That's not going to be me.'”

Surrogacy professionals in India say the government remains flexible with regard to patients who had transferred embryos to surrogates before the rule change. But the changes nevertheless pose a huge threat to one of India's fastest growing medical tourism offerings.

“The new home ministry rules have come as quite a surprise to doctors, the medical fraternity and clients who are overseas,” said Amit Karkhanis, a lawyer whose practice focuses on the surrogacy industry.

“It's definitely going to have an impact on the surrogacy market in India. The immediate fallout is that a lot of people are going to Thailand now. A lot of foreigners are reconsidering their decision to come to India.”

Official data is not available. But industry estimates suggest that some 50,000 people visit India annually seeking surrogate mothers, resulting in around 2,000 births per year. Gay couples and singles previously accounted for more than a third of that trade.

“There's no official study,” said Ramasubramanian. “At least 30-50 percent of the patients who come to India for surrogacy will be affected. The reason is because we are looking at large volumes of single and gay parents who are coming to India for surrogacy.”

One of the largest surrogacy clinics has a waiting list of more than 200 people who say that they are keen to come to India for surrogacy if the new regulations barring gays and singles are relaxed. And there are hundreds of babies already on the way and scores of surrogates waiting for embryo transfers.

“The situation has already arisen where parents [who have already engaged a surrogate] want to come to India to pick up their children but their visa is refused initially,” said Hari G Ramasubramanian, a partner at the Chennai-based Indian Surrogacy Law Center. “What we've seen is that on an appeal basis most of the cases are allowed to come back.”

The new visa rules mark a step backward for gay rights in India, which decriminalized gay sex in 2009 and has witnessed a steady, albeit slow, growth in the acceptance of homosexuality.

But they will also cost India a significant source of foreign exchange and cut a deep slash in one of the few industries that gives poor women without marketable skills an opportunity to earn the kind of money that can help them propel their children into the middle class.

From start to finish, a surrogacy procedure in India runs nearly $30,000 — about a third of what it might cost in the United States. The low costs mean higher volumes, especially for the larger, dedicated players, such as the New Delhi-based Surrogacy Center of India and the Akanksha Infertility Clinic in Anand, Gujarat.

“We do about 60 [embryo] transfers for surrogacy every month,” the center's head Shivani Sachdev Gour said. Although not every transfer results in a completed pregnancy, that's serious volume.

“We had 291 babies delivered by surrogacy last year, and we've delivered more than 550 babies by surrogacy to date,” he added, suggesting that her clinic shared in nearly $9 million in revenue from the surrogate business in the year before the rule change.

Doctors aren't the only ones to benefit.

Some have suggested the so-called “rent-a-womb” industry exploits poor women, but it's lucrative enough that many surrogates opt to do it more than once. They even recommend it to other women who badly need money to change their lives.

Surrogates employed by the surrogacy center, for example, earn around $6,000 for bringing babies to term, as well as room and board during their pregnancies.

That amounts to about 50 percent more per month than two such mothers had been earning as cooks, and then enough to cover their living expenses for a year after the baby's birth. But many surrogate mothers leverage the extra income to offer a better opportunity for their own children.

“I'm using the money for my son's studies,” said 25-year-old Manisha Thapa, who is eight-months pregnant. “My son is in the fourth grade. The private school where I'm sending him costs around $100 to $150 including fees, books and tutoring.”

And that's the real secret of the surrogacy trade. It's not trading one life for another. It's delivering one life to make many lives better.