Photo: Mauricio Alejo

Suzanne LaJoie is luminously pregnant at 43, thanks to donor eggs from someone she trusts implicitly: herself. Five years ago, LaJoie, an ob-gyn in New York City, began to worry about her prospects for having kids. "I felt enormous pressure," she says. "So I thought about what I might tell a patient in a similar situation." Then she booked an appointment to freeze her eggs, increasing her odds of having a child with her own—and her future husband's—DNA.

LaJoie's baby will be one of about 2,000 kids worldwide born since 1997 from once-frozen eggs, a number that has grown nineteenfold in the past six years. According to many experts, the technology is finally ready to do what it has always promised: stop time until a woman is ready to be a mother.

For decades science struggled to perfect a method for freezing eggs. Because they're essentially large cells filled with water, the trick is to freeze them without forming ice crystals that can damage genetic material. The first technique that achieved success—reducing an egg's temperature slowly over a few hours—is a cumbersome process. More recently, however, doctors have started using a process called vitrification that flash-freezes the egg in a matter of seconds.

The largest clinical trial to date followed 600 women who had been implanted with either fresh or vitrified eggs, and found no difference in their results: Just over 40 percent in each group got pregnant. LaJoie's reproductive endocrinologist, Alan Copperman, MD, calls the technology a paradigm shift: "As part of checkups, doctors are now asking single women in their 30s, 'Are you interested in talking about egg freezing?'"

But as Zev Rosenwaks, MD, director of the Center for Reproductive Medicine and Infertility in New York City, points out, women shouldn't put all their eggs, so to speak, in this new basket. The viability of any egg is unknown until it's fertilized, so it's impossible to tell whether you've frozen enough until you need them. At more than $10,000 a cycle, that's an expensive gamble.

Nevertheless, Nicole Noyes, MD, a founder of the fertility clinic at New York University's Langone Medical Center, argues that it's time to stop thinking of the procedure as experimental. The change in perception, she says, will make freezing more widely available and advance the field.

LaJoie, for one, doesn't need convincing. Her baby is due this month.

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