SACRAMENTO, Calif. -- A person's biological clock starts ticking as soon as he or she is born, and the older one gets, the louder it beats.

But a Sacramento fertility doctor said he can stop the biological clock and save fertility eggs.

Dr. Robert Green uses technology in a process called vitrification that works by freezing a woman's eggs to match her partner's sperm at a later date.

The technology was originally created for young cancer patients who wanted to preserve their fertility after chemo treatments, but Green said he is now using vitrification for women who chose careers over family but now want to have children.

"So many women today are actually pursuing their career first and then delaying having their children until later," said Green, who works out of Sacramento's Sher Institutes for Reproductive Medicine.

Amber Kraver, 30, was diagnosed with fertility problems and the onset of early menopause five years ago. Amber and her husband, Kevin, decided to turn to Dr. Green and the new technology in hopes of having children.

"I don't have a lot of time left at this age [to have children]," Amber Kraver said. "As a little girl, I just imagined growing up and being able to have children."

Vitrification is an expensive procedure, and fertility expert Dr. Michael Murray said the technology is not ready for "prime time."

"With this new technology, it shows great promise, but it's just not ready for prime time, and the reason is pregnancy rates are at just about 4 percent," Murray said.

Greene said he disagrees.

He said based on previous experience of people doing vitrification, roughly 40 percent of the egg freezing procedures result in the delivery of a healthy baby.

For the Kravers, they said they know there are no guarantees but hold on to hope.

"It's no silver bullet. There is no silver bullet in fertility. But I think that it gives women opportunities and it gives them hope," Amber Kraver said.