Egg freezing: how many eggs should you freeze?

Oocyte cryopreservation, or egg freezing, is now routinely offered in the field of assisted reproductive technologies. Once considered experimental, this procedure is now approved as a standard treatment of care for fertility preservation in women who wish to delay having children.

Women are born with all of the eggs they are ever going to have, and as women get older, the amount of viable eggs goes down. These changes start in women in their early 20s, but accelerate at the age of 30. Fertility goes down the quickest from age 35 onward. Breakthroughs in recent technologies, however, now allow women the option of retrieving and freezing unfertilized eggs during an in vitro fertilization cycle. While the quality of eggs continually decreases with age, the quality of frozen eggs is tied to when they were retrieved and cryopreserved. In other words, the chances of success are tied to the age you are when you actually freeze the eggs, not the age you are when you implant embryos created from the frozen eggs. This is a huge breakthrough for women wishing to delay childbearing without compromising their chances of having a biological child.

One excellent question most patients ask is how many eggs should I freeze? In a recent study, Dr. Ana Cobo and colleagues from the IVI clinics in Spain looked at the optimal number of oocytes needed in order to obtain a live birth. They analyzed data from 1,468 women who underwent egg freezing for social reasons. In total, 137 (9.3%) returned to use their eggs. Overall survival rate was 85.2% (95% CI 83.2 – 87.2).

The results suggest that in women 35 years old and younger, at least 8 mature (metaphase II) oocytes are needed in order to obtain a reasonable likelihood of pregnancy and live birth. In patients 36 and older, more mature oocytes are needed (11 or more) to reach the same live birth outcome. As the number of mature oocytes that are frozen increases in both groups, so does the likelihood of a live birth outcome. This may mean, especially in patients 36 years and older, more than one egg retrieval will be needed to obtain the optimal number of oocytes. For many patients, it may be prudent to plan on banking eggs in 2 or more cycles of IVF stimulation for the best probable outcome.

For many women, knowing that there is an “insurance policy”, of sorts, on their reproductive timeline is a big relief. Many women want to delay childbearing for a variety of reasons. With egg freezing, women are able to bank their future reproductive chances while they are still at their optimal reproductive age, thereby maximizing future success of having a baby.

To see a fertility specialist who can answer all of your questions about egg freezing, make an appointment at one of InVia’s four Chicago area fertility clinics.