SCIENCE: BRAVE NEW BABIES

Sharla Miller always wanted a baby girl, but the odds seemed stacked against her. Her husband, Shane, is one of three brothers, and Sharla and her five siblings (four girls, two boys) have produced twice as many males as females. After the Millers' first son, Anthony, was born in 1991, along came Ashton, now 8, and Alec, 4. Each one was a gift, says Sharla, but the desire for a girl never waned. "I'm best friends with my mother," she says. "I couldn't get it out of my mind that I want-ed a daughter." 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 from her home in Gillette, Wyoming. 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?"

The brave new world is definitely here. After 25 years of staggering advances in reproductive medicine--first test-tube babies, then donor eggs and surrogate mothers--technology is changing baby-making in a whole new way. No longer can science simply help couples have babies; it can help them have the kind of babies they want. Choosing gender may obliterate one of the fundamental mysteries of procreation, but for people who have grown accustomed to taking 3-D ultrasounds of fetuses, learning a baby's sex within weeks of conception and scheduling convenient delivery dates, it's simply the next logical step. That gleeful exclamation, "It's a boy!" or "It's a girl!" may soon just be a quaint reminder of how random births used to be.

Gender selection is one of many advanced techniques doctors have developed to assist in conception. As the technologies spread, they've fueled a worldwide boom in assisted-reproduction treatments (ART). Couples from disparate cultures, nationalities and religions all share at least one thing: a powerful drive to have children of their own genetic stripe, which often compels them to go to extraordinary lengths--traveling great distances and spending huge amounts of money on treatments.

Doctors in a handful of countries--including India, South Korea, Israel, Italy and the United States--have begun to cater to this international clientele. "Our technology is only six months behind that of the West," says Dr. Hrishikesh Pai, an infertility specialist at the Lilavati Hospital in Mumbai, India, which reports a steady rise in foreign patients. "The Internet has given us a chance to convey this to the West." Steinberg's clinic, which has an office in Mexico, will soon perform its 100th PGD sex-selection procedure. A third of them were performed for couples who had traveled from Hong Kong, Egypt, Germany and other countries.

Infertility medicine, which makes it possible for mothers in their 60s to give birth, gay and lesbian couples to conceive their own genetic offspring and (perhaps in the not-too-distant future) bereaved parents to clone their lost child, is already prompting a legislative backlash in some countries. Gender selection may only worsen matters by galvanizing opponents of ART. Already, many couples are forced to travel far and wide for access to the latest procedures. In the near future they almost certainly will have fewer places to go.

Despite the moral murkiness of gender selection, demand for the service seems to be taking off. People query their doctors and visit catchy Web sites like choosethesexofyourbaby.com and myboyorgirl.com--many of them offering money-back guarantees. In the past six months Steinberg's site has had 85,000 hits. And PGD isn't the only ticket to selection for a boy or a girl. At the Genetics and IVF Institute in Fairfax, Virginia, a U.S. Food and Drug Administration clinical trial of a sperm-sorting technology called MicroSort is underway. The clinic has recruited hundreds of 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 (graphic). PGD, though, is by far the most provocative gender-selection technique. 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."