Techniques exist to help couples conceive the baby of their dreams. But is that such a good thing?

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Jennifer Merrill Thompson was confident the baby she was carrying—her second—was a girl. After all, the mom from Vienna, Virginia, had followed the suggestions in the book How to Choose the Sex of Your Baby, which detailed how to optimally time intercourse in order to conceive a girl. So when the sonogram image left no doubt that her daughter was, in fact, another son, a shocked Thompson burst into tears. "I didn't want to be just a mother of boys," she explains.

Although Thompson says she immediately fell in love with her son, she still felt a void that could only be filled by little frilly dresses. Thompson became a mom on a mission, scouring the Internet for a way to guarantee that baby number three would be her dream daughter.

Her quest landed her at the Genetics & IVF Institute in Fairfax, Virginia, where a clinical trial was underway to test the safety and efficacy of a sperm-sorting process called MicroSort. After three rounds of artificial insemination, Thompson finally conceived her little girl. "Our family wouldn't be complete without her," says Thompson, who makes no apologies for taking the extra steps to ensure that her last baby would come home swaddled in pink.

Different Times, Same Hope

Throughout history, parents have tried to influence their children's gender. In ancient Greece, men believed they could father a boy if they had sex while lying on their right side. French men in the 1700s tied off their left testicle in the hopes of producing sons. Library shelves have long been lined with books offering gender-selection folk wisdom, some of it even scientifically based. Still, a couple's odds of naturally conceiving their dream son or daughter remained at about 50/50—until the birth of the first test-tube baby in 1978 ushered in a brave new world of baby-making. Today, thanks to advances in reproductive technology, couples can not only get help conceiving their baby, they can also choose their child's sex. And everyone—from parents and fertility specialists to medical organizations and bioethicists -- has an opinion about whether this progress is a blessing or a curse.

Upping the Odds

The crudest way of choosing a child's gender is through a "selective abortion." Amniocentesis, the early-pregnancy test that screens for genetic diseases, determines the gender of a fetus, and if it's not the "right" one, the mother can then abort the pregnancy. While this method is reportedly used in some parts of the world, it is not common in the U.S., although fertility experts say it isn't unheard of either.

There are three more sophisticated sex-selection methods available to today's moms—each also involving significant drawbacks and ethical considerations. The oldest was developed in the mid-1970s by geneticist Ronald Ericsson, Ph.D. This method relies on the fact that the X chromosomes (female) in sperm are larger and denser than the Y chromosomes (male). Sperm is filtered through a human serum, which separates the faster-swimming male sperm from the slower female sperm. Women are then artificially inseminated with the sperm containing a higher ratio of the desired gender. Although this is relatively affordable (at $2,000 per cycle) and is not medically invasive, it fails as often as three out of 10 times.

A more successful method is preimplantation genetic diagnosis (PGD), a test originally developed to screen for sex-linked genetic diseases, such as hemophilia and muscular dystrophy, which disproportionately affect boys. This process can only be done during in vitro fertilization (IVF), in which a woman's eggs are surgically removed from her ovaries and then fertilized with her partner's sperm in a laboratory dish. In a routine IVF procedure, the fertilized embryos are transferred back to the woman's uterus; but with PGD, one or two cells are removed from each embryo. By analyzing these cells, doctors can tell—with almost 100 percent accuracy—the boys from the girls. The "preferred" embryos are then used in the IVF process, while the others are either donated to another couple or to research, where they are eventually destroyed. (Many people find the destruction of embryos to be morally reprehensible.)

A newer, more promising technique is MicroSort, a variation on the Ericsson method. Sperm is stained with a special dye and then run through a machine that can distinguish male DNA from female DNA in the sperm and sort out the unwanted gender. Women are then inseminated with sperm carrying the chromosomes of their choice. MicroSort has been in clinical trials since 1993. Initially, those trials were only open to couples with histories of sex-linked diseases, but they quickly expanded to include people who wanted to choose their baby's gender. To date, 86 percent of the nearly 800 couples who've conceived through MicroSort have done so for sex selection.

The process is expensive: Each attempt at fertilization through IVF costs from $15,000 to $20,000. And it's far from foolproof: Sperm sorting has up to a 90 percent success rate at helping women conceive girls, but only a 76 percent rate for boys. Still, if the trials prove the method is safe and effective, MicroSort plans to ask the Food and Drug Administration to approve the procedure. If that happens—and if some of the newer sex-selection methods currently being researched come to fruition—picking your child's gender could become as routine as shopping for a luxury car.

A Right to Choose?

There's no consensus on the propriety of "family balancing," as it's called in the fertility industry. A recent survey conducted by the Genetics and Public Policy Center, a division of Johns Hopkins University's Berman Bioethics Institute, found that only 40 percent of respondents supported sex selection for nonmedical reasons. "The idea that you could pick future offspring to meet certain design specifications is troublesome to a lot of people," says Kathy Hudson, Ph.D., the center's founder and director.

Even our nation's medical organizations are divided on the issue. Both the American Medical Association and the American College of Obstetricians and Gynecologists oppose using sex selection for "family balancing," claiming the practice serves no medical purpose. But the American Society for Reproductive Medicine—the organization most fertility doctors look to for ethical guidance—has given the nod to sperm-sorting methods like MicroSort. (The organization does not endorse postconception techniques like PGD that entail the potential destruction of embryos.)

President Bush's Council on Bioethics keeps a close eye on issues like these, but so far it hasn't made any policy recommendations. "We're concerned about the potential for eugenics—the notion that the human race can be improved through genetics and selective breeding," says Gilbert Meilaender, Ph.D., a member of the council and an ethics professor at Valparaiso University, in Indiana. While scientists say we're still far from being able to choose characteristics such as intelligence, hair color, or height, critics say sex selection has us sliding down a slippery slope.

Balanced Family Dynamics

Aside from the broad societal implications of gender selection, there are more immediate concerns. "We need to consider the psychological and emotional effects of this on families," says Linda Applegarth, Ed.D., director of psychological services at the Center for Reproductive Medicine and Infertility, in New York City. She worries that the process could be damaging to kids. "Parents who take these extreme steps to ensure a certain gender most likely have inflated expectations for that child," she says. "What if their daughter hates Barbies? What if their son prefers dance to sports? These parents spent thousands of dollars to get their dream child. That's a tremendous amount of pressure to put on a child." And then there's concern about the impact on other children in the family. "It's like telling your older children, 'Mommy wanted you, but not as badly as I wanted your little brother or sister,'" points out Josephine Johnston, an ethics expert at the Hastings Center, a medical ethics think tank in Garrison, New York.

Still, such considerations don't deter people like Jeffrey Steinberg, M.D., medical director of the privately run Fertility Institutes, who estimates that his company has helped more than 2,000 couples choose a baby's gender since his three clinics began offering PGD for that purpose. "Families want this," Dr. Steinberg says. "It's a matter of reproductive freedom, which we cherish in America." Jennifer Merrill Thompson, who ultimately wrote a book, Chasing the Gender Dream, about her quest for a daughter, agrees. "As the technology becomes more widely available and accepted, I think a lot of kids are going to be conceived this way," she says. And if her daughter someday asks about her birth? "I'll tell her she was conceived as her brothers were. With love."

Sex-Selection Folk Wisdom

Some people tout these no-tech ways for conceiving a son or daughter. We offer no guarantees!

  • Choose the right position. The rear-entry position is supposedly best for couples wanting a boy because it deposits the male sperm closer to the egg and farther away from the vagina's acidic environment. Try the missionary position to go for a girl because shallow penetration makes it harder for weaker male sperm to reach the egg.
  • Go for the "O." (If you want a boy, that is.) When a woman climaxes, the vagina becomes less acidic and more alkaline, which makes it easier for male sperm to survive. Plus the contractions that accompany an orgasm help move the male sperm into the cervix.
  • Monitor the moon. Women's menstrual cycles (and therefore ovulation) can be affected by the monthly push and pull of the moon's electromagnetic field. For a girl, have sex when the moon is full; for a boy, when there's a quarter moon.
  • Watch what you eat. Six weeks before trying for a baby, start a diet rich in potassium (red meats, vegetables, and salt) if you want a boy, or one that's high in calcium and magnesium (milk, cheese, cereals, beans) if you want a girl. These diets are thought to change a woman's pH level, which may determine the gender of the baby she conceives.

A World Out of Whack

Opponents of sex selection worry about what it would do to the natural balance of males and females. In a Cleveland State University study, as many as 94 percent of parents who favored sex selection said they'd want their firstborn to be a son. "A nation of little sisters would negatively affect women's roles in society," says Sujatha Jesudason, director of the Program on Gender, Justice, and Human Genetics at the Center for Genetics and Society, in Oakland, California.

Many think more parents would choose boys overall—a reality that has already had a significant impact on large segments of the world. One study estimates that, globally, there are as many as 80 million fewer females due to selective abortions and infanticide. In China, for example, there are 117 boys born for every 100 girls (the normal average is about 106 boys for every 100 girls). Sociologists think that this imbalance is already creating social havoc in these societies.

Copyright 2006. Reprinted with permission from the July 2006 issue of Parents magazine.

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