Socially frozen eggs?

It is an unusual perk - and probably not a completely altruistic one.

According to a NBC News report, the US company Facebook covers egg-freezing for non-medical reasons. A spokesperson confirmed the company had launched the scheme in January.

The IT company Apple has also announced a similar benefit for its employees from next January.

According to NBC news, it is part of the companies' plans to increase the number of female employees.

It is said they want to give their employees the opportunity to concentrate on their careers first and to have children later in life.

Save it for later

The method of freezing eggs - "oocyte cryopreservation" as it is known medically - was originally developed for cancer patients needing chemotherapy or radiotherapy.

These life-saving procedures destroy oocytes and can - with a lot of bad luck - make a woman infertile.

Egg freezing offers a chance to preserve viable eggs so that women can have children at a later date.

The method can also be useful for women who avoid having children because they feel they haven't found the right partner yet.

Or for those who want to have a career first. And that is what is called "social egg freezing."

If you decide to have eggs frozen, you are given hormone injections which stimulate the ovaries to mature multiple eggs. Other medication triggers ovulation.

Then, through a small procedure, the eggs are removed using an ultrasound guided needle through the vagina.

The eggs are immediately frozen using cryoprotectants - substances that inhibit the formation of ice crystals inside the cells, and this keeps them viable.

Later, whenever you decide you want to get pregnant, the eggs are thawed and fertilized using in vitro fertilization (IVF).

Success rate unknown

But there is no guarantee that the eggs will survive years of freezing, and unsuccessful fertilization is also common.

Katrin van der Ven, a senior physician at the department of obstetrics and gynecology at University Hospital Bonn, says the success rate of an fertilization depends on the age of the woman when the egg was removed. "The younger the better," she says.

Women who have their eggs frozen before the age of 30 have the best chances of getting pregnant later on.

Doctors use a relatively new freezing method called vitrification.

"Studies have shown that eggs frozen with that method show the same fertilization rates as fresh oocytes," van der Ven says.

But she stresses there are no long-term studies on the method yet as it is relatively young.

"We can only say that it is a promising method. We don't know what the long-term chances are."

No guarantee

An in vitro fertilization (IVF) does not offer a 100 percent chance of pregnancy.

According to the German IVF index, 93 percent of all fertilizations in 2012 were successful, so that an embryo could be transferred into the woman's womb. Fifteen percent of all resulting pregnancies, though, ended in a miscarriage.

The age of the father also plays a role.

Sperm from younger men have higher chances of fertilizing eggs.

"We also know that certain genetic diseases occur more often if the father is older," van der Ven says.

So freezing eggs may not be enough - as the woman's partner, the child's father, also ages.

"A good alternative"

Katrin van der Ven has two children and says she struggled to balance her career and her family lives for many years.

Freezing eggs "is not the ideal solution," she says, but "for a person who is concerned, it is indeed a good alternative."

In fact, she says, women who want to have children and success in their jobs "may have no other choice these days."

It may become a necessity

Politicians from the conservative German Christian Democratic party have described the scheme at Facebook and Apple as "an indecent proposal."

Ethicist Joachim Boldt, a deputy head of the institute for ethics and history in medicine at the University of Freiburg, warns there may be certain expectations linked with any such offer.

"If a company pays for this procedure and an employee wants to have children in her 20s anyway, the question might arise: 'Why is she not deferring her desire to start a family until later?'" he says.

"We have to watch out"

Boldt says the main question is why it is being left to individuals to solve this issue, which should be solved by society as a whole.

"The fact that women can't combine a career and motherhood is a problem in our society," he says, but adds that Scandinavian countries have found a solution.

Scandinavian countries manage to balance their professional ambitions and family lives with childcare centers and part-time work, Boldt says.

"Part-time work is widely accepted in Scandinavian countries, whereas in Germany it is often seen as a lack of commitment to your job."

"Social egg freezing is not wrong as such," says Boldt, "but we have to be careful."