Two years ago Sharla, who had her fallopian tubes tied after Alec's birth, began looking into adopting a baby girl. In the course of her Internet research, she stumbled upon a Web site for the Fertility Institutes in Los Angeles, headed by Dr. Jeffrey Steinberg, where she learned about an in vitro fertilization technique called preimplantation genetic diagnosis. By creating embryos outside the womb, then testing them for gender, PGD could guarantee -- with almost 100 percent certainty -- the sex of her baby. Price tag: $18,480, plus travel. Last November Sharla's eggs and Shane's sperm were mixed in a lab dish, producing 14 healthy embryos, seven male and seven female. Steinberg transferred three of the females into

Sharla's uterus, where two implanted successfully. If all goes well, the run of Miller boys will end in July with the arrival of twin baby girls. "I have three wonderful boys," says Sharla, "but since there was a chance I could have a daughter, why not?" TOP

Throughout history, humans have wished for a child of one sex or the other and have been willing to do just about anything to get it. Now that gender selection is scientifically feasible, interest in the controversial practice (banned, except for medical reasons, in the United Kingdom) is exploding. Despite considerable moral murkiness, Americans are talking to their doctors and visiting catchy Web sites like www.choosethesexofyourbaby.com and myboyorgirl.com -- many of them offering money-back guarantees. In just the last six months, Steinberg's site has had 85,000 hits. At the Genetics and IVF Institute (GIVF) in Fairfax, Va., an FDA clinical trial of a sophisticated sperm-sorting technology called MicroSort is more than halfway to completion. Through radio, newspaper and magazine ads ("Do you want to choose the gender of your next baby?"), the clinic has recruited hundreds of eager couples, and more than 400 babies out of 750 needed for the trial have been born. Other couples continue to flock to older, more low-tech and questionable sperm-sorting techniques like the Ericsson method, which is offered at about two dozen clinics nationwide. By far, the most provocative gender-selection technique is PGD. Some clinics offer the procedure as a bonus for couples already going through fertility treatments, but a small number are beginning to provide the option for otherwise healthy couples. Once Steinberg decided to offer PGD gender selection to all comers, he says, "word spread like wildfire." TOP

The ability to create baby Jack or baby Jill opens a high-tech can of worms. While the advances have received kudos from grateful families, they also raise loaded ethical questions about whether science is finally crossing a line that shouldn't be crossed. Even fertility specialists are divided over whether choosing a male or female embryo is acceptable. If couples can request a baby boy or girl, what's next on the slippery slope of modern reproductive medicine? Eye color? Height? Intelligence? Could picking one gender over the other become the 21st century's form of sex discrimination? Or, as in China, upset the ratio of males to females? Many European countries already forbid sex selection; should there be similar regulations in the United States? These explosive issues are being debated in medical journals, on university ethics boards and at the highest levels in Washington. Just last week the President's Council on Bioethics discussed proposals for possible legislation that would ban the buying and selling of human embryos and far-out reproductive experimentation, like creating human-animal hybrids. While the recommendations -- part of a report due out this spring -- do not suggest limiting IVF or gender selection, the goals are clear: the government should clamp down before technology goes too far. "Even though people have strong differences of opinion on some issues," says council chair and leading bioethicist Leon Kass, "all of us have a stake in keeping human reproduction human." TOP

After their first son, Jesse, was born in 1988, Mary and Sam Toedtman tried all sorts of folksy remedies to boost their chances of having a girl. When Jesse was followed by Jacob, now 10, and Lucas, 7, it seemed clear that boys would be boys in the Toedtman family. Sam has two brothers and comes from a line of boys 70 years long. So, after a lot of serious thinking, the Toedtmans decided to enroll in GIVF's clinical trial of MicroSort for "family balancing." That's the popular new term for gender selection by couples who already have at least one child and want to control their family mix. Since MicroSort's family-balance trial began in 1995, more than 1,300 couples have signed on -- almost 10 times more than joined a companion trial aimed at avoiding genetic illnesses that strike boys. GIVF is actively recruiting new candidates for both trials. In 2003 a second MicroSort clinic was opened near Los Angeles, and a third is planned for Florida this year. GIVF hopes MicroSort will become the first sperm-sorting device to receive the FDA's stamp of approval for safety and effectiveness. "This will completely change reproductive choices for women, and that's very exciting," says MicroSort's medical director, Dr. Keith Blauer. "We hope to make it available to as many couples as possible." TOP

The MicroSort technology -- created originally by the Department of Agriculture to sort livestock sperm -- works by mixing sperm with a DNA-specific dye that helps separate X's from Y's (graphic).The majority of couples who use MicroSort for gender selection have no fertility problems and use standard artificial insemination to conceive. The technique is far from perfect: most participants have to make more than one attempt, each costing at least $2,500, to get pregnant. And not all end up with the gender of choice. At last count, 91 percent of couples who requested an "X sort" gave birth to a baby girl and 76 percent who chose a "Y sort" produced a boy. It worked for the Stock family. Six-month-old Amberlyn was spared the debilitating neuromuscular disorder that plagues her brother, Chancellor, 7. The Toedtmans were lucky, too. Though it took three tries to get pregnant, Mary finally delivered a girl, Natalie, last April. "She's a total joy," she says. TOP

Determined as she was, Toedtman says she would not have felt comfortable creating embryos to ensure that Natalie was Natalie and not Nathaniel. But a small number of others, knowing that their chance of success with PGD is exponentially better, are becoming pioneers in the newest form of family planning. Available at a limited number of clinics nationwide, PGD was designed and originally intended to diagnose serious genetic diseases in embryos, like Tay-Sachs and cystic fibrosis, before implantation. Over the last decade the technology has allowed hundreds of couples, many of whom have endured the death of sick children, to have healthy babies. Today, some doctors are using PGD to increase the odds of successful IVF pregnancies by screening out chromosomally abnormal embryos. Some of those patients are asking about gender -- and it's their right to do so, many doctors say. After an embryo screening, "I tell them it's normal and I tell them it's male or female," says PGD expert Yury Verlinsky of the Reproductive Genetics Institute in Chicago. "It's their embryo. I can't tell them which one to transfer." TOP

It's one thing to allow infertile couples to choose gender after PGD. Creating embryos solely to sort boys from girls sets off ethical and moral alarm bells. In the last year or so, several clinics have begun to offer the procedure for gender balance without restrictions. Steinberg, of Fertility Institutes, says his team methodically debated the pros and cons before doing so. The logic, he says, is simple: "We've been offering sperm sorting for 20 years without any stipulations. Now, in 2004, I can offer almost 100 percent success with PGD. Why would I make it less available?" Steinberg's clinic, which also has offices in Las Vegas and Mexico, will soon perform its 100th PGD sex-selection procedure. So far, about 40 babies have been born, every one of them the desired sex. It's unclear how many couples will actually want to endure the hefty cost, time commitment and physical burden of fertility drugs and IVF just to ensure gender. But the idea is intriguing for a lot of couples. "I've had friends and neighbors discreetly inquire," says Dr. David Hill, head of ART Reproductive Center in Beverly Hills, Calif., where about 5 to 10 percent of patients are requesting PGD solely for sex selection. Hill has no problem offering it, but he respects colleagues who say no. "This is a really new area,'' he says. "It's pretty divided right now as to those who think it's acceptable and those who don't."

Dr. Mark Hughes, a leading PGD authority at Wayne State University School of Medicine in Detroit, is one of the latter. "The last time I checked, your gender wasn't a disease," he says. "There is no illness, no suffering and no reason for a physician to be involved. Besides, we're too busy helping desperate couples with serious disease build healthy families." At Columbia University, Dr. Mark Sauer balks at the idea of family balance. "What are you balancing? It discredits the value of an individual life." For those few patients who ask for it, "I look them straight in the face and say, 'We're not going to do that'." And at Northwestern, Dr. Ralph Kazer says bluntly: " 'Gattaca' was a wonderful movie. That's not what I want to do for a living." TOP

One of the most vexing concerns is what some consider gender selection's implicit sexism. When you choose one sex, the argument goes, you reject the other. In Asia girls have been aborted or killed, and populations skewed, because of favoritism toward boys. Could the same thing happen here? GIVF's Blauer says the vast majority of MicroSort couples want girls, not boys, though that could change if Y-sort statistics improve. At Hill's clinic, about 65 percent request boys; at Steinberg's, 55 percent. "It's not going to tip the balance one way or the other," he says. But what if a couple doesn't get the boy or girl they desire? PGD comes as close as it gets to guaranteeing outcome, but there remains the thorny question of what to do with "wrong sex" embryos. Opponents worry that they'll be destroyed simply because they're male or female, but the options are identical for everyone going through IVF: discard the extras, freeze them for later use, donate them or offer them up for scientific research. As for MicroSort, of the more than 500 pregnancies achieved so far, four have been terminated at other facilities (GIVF won't perform abortions) because of "nondesired gender," says Blauer. "It's important to realize that couples have reproductive choice in this country," he says, but "the vast majority of patients want another healthy child and are happy with either gender."

Just beyond these clinical worries lies a vast swamp of ethical quandaries and inherent contradictions. People who support a woman's right to choose find themselves cringing at the idea of terminating a fetus based on sex. Those who believe that embryos deserve the status of personhood decry their destruction, but gender selection could result in fewer abortions. Choosing sex can skew male-female ratios, but it might also reduce overpopulation. Requesting a girl could mean she will be more desired by her parents, but it's also possible she'll grow up and decide she'd rather have been a boy. "Children are going to hold their parents responsible for having made them this way," says bioethicist Kass, "and that may not be as innocent as it sounds." TOP

And then there is the most fundamental conflict of all: science versus religion. One Korean-American couple with two daughters has been on both sides. Feeling an intense cultural pressure to produce a son, the woman, 31, attended a MicroSort information session, where Blauer reviewed the technique. Intrigued, she went back for a second session and convinced her husband to come along. When it was time to move forward, though, a greater power took over. "I don't think God intended us to do that," she says. "We decided we should just pray about it and leave it up to God." TOP

There are no laws against performing gender selection in the United States. Many people believe that the safety and effectiveness of reproductive technologies like PGD should be regulated, says Kathy Hudson, of the Genetics and Public Policy Center at Johns Hopkins, which recently polled 1,200 Americans on the topic. But, she says, many Americans "are uncomfortable with the government being the arbiter of how to use these technologies." Meanwhile, fertility doctors look to the American Society for Reproductive Medicine for professional standards. John Robertson, head of ASRM's ethics committee, says preconception techniques like MicroSort "would be fine once safety is established." So far, MicroSort reports, 2.4 percent of its babies have been born with major malformations, like Down syndrome, compared with 3 to 4 percent in the general population. But until the trial is completed, there are no definitive data. As for PGD, the ASRM currently discourages its use for sex selection, but Robertson says he wouldn't rule out the possibility that it might become acceptable in the future. TOP

So what, in the end, should we make of gender selection? Will programming of human DNA before birth become inevitable? "I learned a long time ago never to say never," says Rick Myers, chief of Stanford's genetics department. Still, he says, traits we're all worried about, like height, personality and intelligence, aren't the products of single genes. They're cooked in a complex stew of DNA and environment -- a stew that boggles scientists, even those with IQs so high you'd swear they were bioengineered. And even if we could create designer Uma Thurmans, would we want to? Sharla Miller and Mary Toedtman say absolutely not. "That's taking it too far," says Miller. TOP

We wouldn't be human if we didn't fantasize about the sci-fi universe around the corner. Steinberg, who has worked in IVF since its conception in the 1970s, remembers finding notes on his windshield in the early days that said, test-tube babies have no soul. The very idea of creating life outside the womb "was unthinkable," he says. And yet, some 1 million test-tube babies later, the practice has become routine. The same will likely be true of gender selection, says Robin Marantz Henig, author of the new book "Pandora's Baby," a history of IVF. "The more it's done," she says, "the less you're going to see concerns."

Lizette Frielingsdorf doesn't have any. She and her husband have three boys -- Jordan, 8, Justin, 6, and Jake, 5 -- and one MicroSort girl, Jessica, who just turned 2. "I call her my $15,000 baby. We felt like we won the lottery," says Frielingsdorf. "Probably once a week someone will say, 'You got your girl. How did you do that?' and I'll say, 'Here's the number.' I want others to experience the same joy we have." No doubt, many will.  NEXT