Tech companies are famous for their lavish benefits, like in-office haircuts, dry cleaning and massages. Now some of those companies are setting off a debate about women and work with a new benefit paying for women on the payroll to freeze their eggs.

Facebook in January began covering up to $20,000 in egg freezing expenses, and Apple said it would start covering egg freezing this January, as first reported by NBC News.

Some doctors say egg freezing could be as influential as the birth control pill in freeing women from the confines of biology. Childbirth coincides with prime career-building years, and balancing both is a perpetual challenge. The cover of Bloomberg Businessweek in April blared, Freeze Your Eggs, Free Your Career.

Yet by paying for women to delay pregnancy, are employers helping them achieve that balance or avoiding policies that experts agree would greatly help solve the problem, like paid family leave, childcare and flexible work arrangements?

Egg freezing seems to put a Band-Aid on the problem of how difficult it is for women to have a career and raise a family concurrently, Seema Mohapatra, a health care law and bioethics expert, wrote in August in a Harvard Law & Policy Review article titled Using Egg Freezing to Extend the Biological Clock: Fertility Insurance or False Hope?

For women whose circumstances have made it unrealistic to have a baby and who are considering egg freezing, the new benefit is likely to be a highly welcome surprise even if in some sense it may seem a logical extension of employee-sponsored health plans that already cover pregnancy, childbirth and some infertility treatments.

Yet workplaces could be seen as paying women to put off childbearing. Women who choose to have babies earlier could be stigmatized as uncommitted to their careers. Just as tech company benefits like free food and dry cleaning serve to keep employees at the office longer, so could egg freezing, by delaying maternity leave and child-care responsibilities.

It is certainly in the employers interest to delay fertility for these women, from a business perspective, said a woman who froze her eggs but would discuss it only anonymously. But in my experience, its more personal: Are you married or not married, and if youre not and youre over 35, its a health thing.

Her employer did not cover her egg freezing, which she said kind of punishes unmarried women.

Ms. Mohapatra, who teaches law at the Orlando, Fla., campus of Barry University, said women who do not fit that profile could feel pressured to use the benefit.

What I worry about is its not going to be just used by that population, she said in an interview, but is going to be used by the population in their 20s and early 30s saying, If I want to be seen as a serious employee and make it to vice president, I cant take maternity leave. Theyre offering this insurance policy to me or else Ill be deemed as being on the mommy track.'

The tech companies emphasized that egg preservation was one of many family-friendly benefits they offered employees, which include perks like baby bonuses to spend on diapers and meals and benefits for adoptive and same-sex parents. We want to empower women at Apple to do the best work of their lives as they care for loved ones and raise their families, the company said in a statement.

Egg freezing has been available for more than a decade, but it had been used mostly for preserving eggs for young cancer patients whose chemotherapy would make them infertile. That changed in late 2012, when the American Society of Reproductive Medicine lifted the experimental label from the procedure after analyzing nearly 1,000 published papers and concluding it could produce healthy babies.

However, the group warned that it is more reliable for women who are younger when they freeze their eggs and that there is not yet strong data on its success, and it stopped short of recommending it for elective reasons.

While a careful review of the literature indicates egg freezing is a valid technique for young women for whom it is medically indicated, we cannot at this time endorse its widespread elective use to delay childbearing, Dr. Samantha Pfeifer, chairwoman of the societys practice committee, said at the time. This technology may not be appropriate for the older woman who desires to postpone reproduction.

Doctors estimate there have been about 2,000 births from frozen eggs, though there is no official data. Women who freeze their eggs when they are younger than 35 have a 10 percent to 12 percent change of giving birth per egg, and women who do it when they are older than 35 have a 6 percent to 8 percent chance or lower, said Marcelle Cedars, director of reproductive endocrinology and infertility at the University of California, San Francisco. Women are advised to harvest and freeze 10 to 20 eggs.

I spend a lot of time talking with couples who go through this to tell them its not a guarantee; its not a baby in the freezer, Dr. Cedars said. If youre ready to have a child, then you should do it. This is just giving women an opportunity that men have always had, to say, Im not really ready right now and Im going to wait.'

Egg freezing is a two-week process involving hormone injections and extraction under sedation, and it takes another two weeks to feel back to normal, Dr. Cedars said. A cycle usually costs $10,000 to $15,000, and many women are encouraged to do more than one cycle to harvest more eggs. Storage costs about $500 a year. Insurance very rarely covers it, though there are also companies outside of tech, like some investment banks and law firms, that do.

There are class and race divides in egg freezing. A planned pregnancy later in life is much more realistic for highly educated, high-income women, according to June Carbone and Naomi Cahn, law professors who write about the gender and class divide in reproduction in other words, the kind of people who work at Facebook and Apple. Working-class women are less likely to be able to afford egg freezing; or to be employed during pregnancy; or to receive paid maternity leave.

If other white-collar companies follow techs lead in offering egg freezing, as they have with other benefits that started in Silicon Valley, that divide could deepen as more women consider the opportunity, or fraught message, when deciding when to start a family.