Through her 20s and early 30s, pediatrician Kristie Manning was so neck-deep in medical school and training that she had no time to focus on having children. Still single, the Pleasanton, Calif., native isn't ready to start a family by herself.
So she bought herself some time. In May, facing the biological threshold of age 35, when a woman's fertility takes a steep dive, she went to the California Pacific Fertility Center in San Francisco and had 14 eggs removed and frozen for future use.
For Manning, those eggs represent an insurance policy of sorts. Even though she's not sure if she will ever use them. Even though there's no guarantee any of the eggs will one day provide a baby. Even though she paid dearly for them.
That $12,000, she says, bought peace of mind. "I don't know what the future holds, but I feel like I can look back years from now and know no matter what happened, that I did what I could," she said. It also means that if she meets a potential partner, there's less pressure to jump into a relationship just to have kids: "I can think more about if he's the right person."
Manning is among a small but growing number of women who have seized on recent advances in "oocyte cryopreservation" to widen the window of time for starting a family.
Over the past decade, clinics that provide reproductive services such as in vitro fertilization have offered egg-freezing to women facing chemotherapy for cancer or other medical issues that could affect their fertility. In the past few years, however, the technology has improved to the point that it's no longer deemed "experimental," and clinics have begun touting it as an option for women who delay starting families in order to pursue advanced degrees, build their careers or meet a suitable partner.
About half of all women over 40 have fertility problems, according to the American Society of Reproductive Medicine, and older eggs carry increased risks of chromosomal abnormalities that can cause miscarriage and birth defects. For this reason, women in this age group have much more success using donor eggs when undergoing in vitro fertilization, the Centers for Disease Control reports.
Egg-freezing allows women to preserve their own genetic material for future in vitro fertilization, an option that in some ways gives them more control over their reproductive futures.
"The technology has come so far so far that we think it's like (the introduction of) birth control pills in the 1950s," said Dr. Mary Hinkley of the Reproductive Science Center in San Ramon, Calif.
The focus on egg-freezing as a mainstream fertility treatment began after the American Society of Reproductive Medicine in October 2012 removed the "experimental" label and deemed the procedure as safe and effective for producing healthy pregnancies as IVF procedures using live eggs.
The ASRM's move spurred an uptick in women choosing egg-freezing, including at the Stanford Fertility and Reproductive Medicine Center, said Dr. Lynn Westphal.
Women who wait until they are 40 to try bearing children must face the likelihood that "probably half their eggs will be chromosomally abnormal," Westphal said. "Any woman in her early 30s who is not sure when she wants to have her children should think about it."
She and other doctors have become more insistent about making this recommendation since the development of a technique called vitrification — or flash freezing. It has "made all the difference" in preserving women's eggs, Westphal said. In the past, the slow-freezing method caused ice crystals to form that damaged the membranes of delicate egg cells.
Egg-freezing also doesn't buy women unlimited time to become a parent. While women's wombs don't age nearly as quickly as their eggs, pregnancy puts a strain on a woman's body at any age. Risks for diabetes and high blood pressure increase in women in their late 40s, Westphal said. Clinics typically won't transfer embryos to women past their early to mid-50s.