We recently reported on a new study that came to a rather surprising conclusion: infertile women are much better off using fresh eggs than frozen eggs from donors for in vitro fertilization (IVF). But why is that the case and just how does it affect these women?

The popularity of frozen eggs has been rising in recent years — and it’s easy to see why. Whereas women might have to wait months for fresh donor eggs, frozen eggs can be kept around until someone comes calling for them, and so many IVF centers have created donor egg banks that are specifically dedicated to frozen eggs, according to a CBS News report.

But new research from the Center for Human Reproduction in New York City has some unfortunate news for those who have been using or intend to use frozen eggs: there’s a significant lower rate of pregnancy and delivery than fresh eggs after an IVF, and so patients may want to think long and hard before immediately opting for the frozen eggs.

In the case of fresh eggs, the woman who is getting the IVF is matched with a donor, whose eggs are fertilized with the sperm of the woman’s partner, and then those fertilized eggs are transferred into that woman’s uterus. However, it may take months for a woman to get matched up with fresh eggs, whereas frozen eggs can be kept on hand whenever they are needed, giving women a wider field to choose from when it comes to donors and allowing the process to be much smoother and quicker.

But it means a lower success rate — significantly so. The study, which was published in the Journal of the American Medical Association, involved 11,000 IVF procedures — 20 percent of which used frozen eggs — finding that the live birth rate was 56 percent for fresh eggs, and just 47 percent for frozen eggs.

But is the difference big enough for a woman to give up all the flexibility and choice she would have with the frozen eggs? That will be up to the individual.