Rhonda and Gerry Wile hold their baby, Blaze Xennon (Fabien Charuau for The Wall Street Journal)

On their third trip to India, Rhonda and Gerry Wile finally heard a sound they thought they might never hear: the heartbeat of their unborn child.

Four nerve-racking months after that joyful ultrasound moment, their son arrived on Aug. 26 at 10:22 p.m. weighing 2.7 kilograms and sporting wisps of dark hair. They named him Blaze Xennon Wile, the middle name chosen from a book of baby names that gave its meaning as "from a foreign or faraway land."

"It seems unreal. We hold him and kiss him a thousand times a day," Mr. Wile says. "It's so lucky that it worked out for us."

For the Wiles, a married couple who live in Arizona, the birth was the culmination of four years of trying to conceive. Theirs was a path marked by wrenching disappointment, a failed pregnancy, many hours on the Internet -- and long airplane trips. The determination to produce a child that is at least partly their genetic offspring led them finally on a high-tech passage to India, where they hired a surrogate to bear their baby.

No official agency keeps track of the number of would-be parents who travel to India for surrogacy. But the proliferation of clinics around the country providing such services gives some idea of the rising demand for surrogates: women who bear children on behalf of other people, often in return for money, a practice that is legal in India.

According to Hrishikesh Pai, a Mumbai-based in-vitro fertilization specialist and vice-president of the Indian Society for Assisted Reproduction, India now has about 350 facilities that offer surrogacy as a part of a broader array of infertility-treatment services, triple the number in 2005. Last year, Dr. Pai says, about 1,000 pregnancy attempts using surrogates were made at these clinics. This year, he estimates the figure will jump to 1,500, with about a third of those made on behalf of parents from outside India who hired surrogates.

Rudy Rupak, president of PlanetHospital, a California-based medical-tourism company, says that in the first eight months of this year he sent 600 couples or single parents overseas for surrogacy, nearly three times the number in 2008 and up from just 33 in 2007. All of the clients this year went to India except seven who chose Panama. Most were from the U.S.; the rest came from Europe, the Middle East and Asia, mostly Japan, Vietnam, Singapore and Taiwan.

Mr. Rupak says that because of growing demand from his clients for eggs from Caucasian women, he's started to fly donors to India from the former Soviet republic of Georgia, where he has connections with clinics. The first woman arrived last month. A PlanetHospital package that includes an Indian egg donor costs $32,500, excluding transportation and hotel expenses for the intended parent or parents to travel to India. A package with eggs from a Georgian donor costs an extra $5,000.

In India, there are critics of surrogacy who contend it treats children as a "commodity" and exploits some women. "They are using the vulnerability of the poor. Making (a woman) a child-producing machine is not acceptable to us," says Ranjana Kumari, president of WomenPowerConnect, a coalition of 800 organizations across India that lobbies government on women's issues. "There should be controls so it is not an open market as it is at the moment."

Since 2005, the practice of surrogacy has been operating under guidelines established by the Indian Council of Medical Research, a government body. But a new law is in the works that aims to regulate the surrogacy industry by standardizing such things as contract terms and surrogate compensation, which currently ranges from about $2,000 to $10,000. To avoid potential legal disputes, it will also govern what parental information is given on birth certificates. What's more, the new law, which could be introduced in Parliament as early as December, would require clinics to register surrogacy cases and report their outcomes. "At the end of the day, we're going to have statistics, which is very important," partly because of the implications for India's burgeoning medical-tourism industry, says Kamini Rao, a fertility doctor in Banglalore who helped draft the legislation.

For the Indian surrogates themselves, it's an experience often fraught with emotional conflict. In most cases, the egg comes either from the woman who wants to become a mother but can't carry a child, or from an egg donor. The egg is then fertilized with sperm from the intended father, or a sperm donor, and implanted in the womb of a surrogate who bears the child. Sometimes, no money changes hands, particularly when a friend or relative acts as the surrogate. Alternatively, it's a commercial transaction, which is almost always the case in India for would-be parents from overseas.

Surrogacy itself is often maligned in India's multireligious society as a peculiar form of prostitution. Fearing social censure, many surrogates hide their pregnancies from relatives and friends by moving away temporarily on the pretext of having secured a job elsewhere. What's more, some doctors prefer to separate the surrogate from her family to insure she gets the proper nourishment, while avoiding risks to the fetus such as sexually transmitted diseases and secondhand cigarette smoke. The family is allowed to visit her in her quarters, but even so it can be a lonely time for the woman.

Still, it's a way to raise money in sometimes desperate circumstances. Take Sudha, a 25-year-old mother of two who now works as a maid in Chennai earning $20 a month. She owes moneylenders about $2,700, borrowed to pay bribes to secure a government job as a streetsweeper, which never materialized. A neighbor told her she could earn about $2,000 at a local clinic by bearing a child for an infertile couple. She gave birth in July 2008 -- and is haunted by the memory. "Whenever I have free time and I lie down, I think about the child. I pray that the child is safe and happy and is taken care of well."

Sudha, who like other surrogates asked that only her first name be used, has reduced her debt to about $600, but the family still struggles to eat. One solution, her husband Umat says, is for Sudha to act as a surrogate again. But he adds that he "won't force her if she says no."

For other women, like 29-year-old Lakshmi, a pregnant surrogate in Chennai who already has an 11-year-old daughter, a 12-year-old son, an alcoholic husband and a $4,000 debt, having someone else's child sounded like a better option than her other plan: selling a kidney. A doctor advised her that with a single kidney left, "I might live for a shorter time. I have a daughter. I have to get her married...I prefer" to be a surrogate, she says.

Some middle-class Indian women, too, are becoming surrogates. In Bangalore, a cash-strapped high-school-educated wife, who earns about $20 a month selling Oriflame brand cosmetics, waits for a call from a local clinic that she has been chosen as a surrogate. Her husband, an office manager, owes more than $30,000, borrowed to start a company that faltered, and the couple can't repay the loan.

For the would-be parents, this passage to India can be stressful, even if they are well organized. Among the foreign couples who began their odyssey on the Internet, some never dreamed that in a world of instant messaging they would be tearing their hair out over delayed transmissions of a scan or fretting about the health of a surrogate halfway around the world. Add to that the unfamiliar environment, language barriers and potential legal risks of doing it in India.

Michael Bergen and Michael Aki, a gay American couple who got married in 2004 and work as graphic designers in Massachusetts, decided to try surrogacy in India after they waited unsucessfully for three years to adopt a child in the U.S. To hire a surrogate, "we looked at Panama and the Ukraine," recalls 39-year-old Mr. Bergen. "But India had better infrastructure, more high-tech facilities and the healthier lifestyle. (Most women) don't smoke, they don't drink and they don't do drugs."

Mr. Rupak's PlanetHospital steered the couple to the Rotunda -- The Center for Human Reproduction, a Mumbai clinic that has been upfront about marketing its services to the overseas gay community. Its Web site highlights a video of a gay Israeli couple who made headlines after taking home a baby from the Rotunda last year.

By email, the American graphic designers chose an anonymous Indian egg donor from profiles provided by the clinic that included the women's education levels and current family status. Then the couple spent four days in India in July 2008. Both wanted to be a genetic father, so they each gave a sperm sample. The pair, concerned that the agreements they were given to sign with the surrogate and the clinic were too vague, spent $3,000 in legal fees to have a U.S. lawyer rewrite them. In retrospect, Mr. Aki, 43, wonders whether the revised contracts would have been honored in India's byzantine legal system anyway. Luckily, the process went smoothly. Using eggs from the same donor so that the offspring would be kin, doctors fertilized them with the respective sperm of the two men and implanted the embryos in two separate surrogates. Both women became pregnant, almost simultaneously, on their first try. This year, Mr. Aki became the father of Rose, born March 24, and Mr. Bergen became the father of Eva, born April 12.

With travel costs, Mr. Bergen estimates the couple spent about $60,000 in all, including compensation of $10,000 for each surrogate. That's roughly half what he thinks the total cost would have been in the U.S.

For others, money is no object. Last year, a former U.S. investment banker in her early 40s, who asked that her name not be used, spent $128,000 to reach her goal. She approached a dozen fertility clinics in India for help. Despite her age, she and her husband wanted to try with her eggs. In the initial attempt, a doctor implanted several embryos in two separate surrogate mothers. That failed. In the second round, the doctor relied on three surrogates. Still no pregnancy. In the third round, he repeated the procedure with two additional surrogates. Bingo. The seventh surrogate gave birth to healthy twin girls.

It's the kind of determination that Rhonda and Gerry Wile understand. She's a 39-year-old blond registered nurse. He's a hefty 43-year-old fireman. Originally from Canada, they married in 2000 and resettled in Mesa, Arizona, three years ago.

The couple started trying to conceive in mid-2005. After several months, Ms. Wile consulted a specialist who found a problem: She has two small wombs instead of a single one. Two months later, though, she was thrilled to find out she was pregnant. But she soon learned the fetus had no heartbeat, and she had to undergo a drug-induced abortion.

Next the couple tried artificial insemination. It failed. They started to consider other options. They ruled out adoption, discouraged by the red tape. A doctor, meanwhile, had recommended surrogacy, and Ms. Wile saw a TV program about surrogacy in India on "Oprah" in October 2007. The Wiles then trawled the Internet for information. In January 2008 they settled on Surrogacy India, a newly established private Mumbai clinic. They liked the quick response to their questions and the clinic's policy of encouraging surrogates to move into designated quarters with their families during the pregnancy, rather than splitting them apart.

"It's been hard for me, being a woman," Ms. Wile said during a trip to India last April. "I've always believed that part of my job as a woman is to have a child." For her, surrogacy seemed as close as she could get to creating a child. The price was also right. "We didn't want to go broke" and "bring a child into the world bankrupt," she added.

The Wiles figured it would cost them between $50,000 and $80,000 for each attempt if they had used a surrogate in the U.S. By comparison, they spent a total of about $50,000 on three attempts in India, including travel expenses for four round trips to India, $550 for the baby's birth and a few days' hospital stay and $5,625 paid to a woman they call "KT," who carried their son.

Initially, Ms. Wile was determined to use her own eggs. From Arizona, over the Internet, the couple picked a potential surrogate and a backup surrogate, just in case, from photos and information such as educational background and family medical history provided by Surrogacy India on a special secure Web site. The Wiles flew to India in April last year, with Rhonda prepped with fertility drugs, a prelude to retrieving eggs from her body. Her eggs were fertilized with Gerry's sperm and transferred to a surrogate but no pregnancy resulted. They tried again in September with a new batch of Ms. Wile's eggs, a second trip to India and a different surrogate. That effort also failed.

"What's more important," Mr. Wile remembers he asked his wife, "having a family, or having a child of your own?"

They decided that if they were to have a family, it would be with a donor's eggs. In October, the Wiles selected an Indian egg donor over the Internet using the clinic's Web site. Then they picked out a new surrogate, KT, a married woman with the Indian equivalent of a seventh-grade education who has two small boys of her own. In her profile, KT described herself as having a "supporting nature" and listed her motivation for becoming a surrogate as "financial, to educate (my) kids." (To lessen any bond the surrogate might form with the child, doctors in India generally discourage the practice of egg donors and surrogates being one and the same.)

Donor eggs fertilized with Mr. Wile's sperm were implanted. This time it worked. The Wiles used Skype from Arizona to talk with the surrogate through an interpreter. In April, the couple made their third trip to India to meet KT face-to-face. "We wanted to see an ultrasound and hear our baby's heartbeat," Mr. Wile says. (Requests to interview KT for this article were declined.)

A month or so before the birth, they finished the nursery in their Mesa home and held a baby shower. Mr. Wile bought the baby a set of golf clubs. Despite the ultrasound, they didn't know whether they would be bringing home a boy or girl; to discourage the selective abortion of girls, Indian law prohibits disclosure of a fetus's gender.

Mr. Wile says: "We've had a very good experience with surrogacy and we're definitely going try it again." They will have to find yet another surrogate, though. Mr. Wile says KT declined to carry a second baby for them.

The couple kept a detailed account of their journey on a blog, which they hope will help others in a similar predicament. "We both plan to let our child know how he was conceived," Ms. Wile says, and that he came from "someone else's tummy."

—Anjali Athavaley contributed to this article.