Advanced Fertility Center of Chicago Blog

What are the issues with freezing eggs to preserve fertility?

Can you freeze eggs in an attempt to preserve fertility for a future pregnancy?

• Yes, egg freezing (oocyte cryopreservation) is being done – some women freeze eggs to try to reduce the impact of aging on fertility
• Success rates for IVF with fresh eggs are high in young women
• Success rates for IVF using frozen eggs are generally much lower – but are improving. This technology is rapidly evolving.

There is currently controversy about:

• Who should be offered egg freezing?
• What should women of different ages be told about their chances for having a baby with frozen eggs?
• Are women who freeze eggs well informed about the chances to have a baby in the future with their frozen eggs?

What do recent studies show regarding pregnancy success rates using frozen eggs?

Egg freezing is relatively new

• IVF with fresh eggs has reportedly resulted in the birth of about 3 million babies worldwide
• IVF with frozen eggs has resulted in the birth of about 2000 babies worldwide
• Studies continue to investigate whether the older “slow freezing” technology or the newer method of “vitrifying” eggs will be better

Older studies

• Studies from the 1990′s to early 2000′s showed pregnancy success rates with frozen eggs of about 2% to 10% (live birth rate per embryo transfer cycle).

Recent studies

• A recent study from an Italian group found similar fertilization and embryo development rates of vitrified versus fresh eggs. Vitrification is a relatively new freezing method.
  • This study involved 40 cycles in women (average age 35.5)
  • The ongoing pregnancy rate (beyond 12 weeks of pregnancy) with vitrified eggs was 30% per cycle.
  • This is a good rate since only 3 eggs can be inseminated under Italian law.
    • Study by L Rienzi, et al, Human Reproduction; January 2010

• A 2009 study of 23 IVF cycles using frozen eggs (average age 31.5)
  • There were 14 pregnancies, 1 miscarriage and 13 ongoing pregnancies (57% per transfer)
    • Study by J Grifo and N Noyes, Fertility and Sterility; May 2009

• A large multicenter Italian study compared IVF using fresh vs. frozen eggs
  • Italian IVF clinics tend to have lower success rates because only 3 eggs can be inseminated per cycle (by law)
  • They compared 2209 cycles with fresh eggs to 940 cycles with frozen eggs
  • The success rate was halved using frozen instead of fresh eggs
  • 748 thawing cycles in women less than 39 years old (average age 33.6)
    • Live birth rate per transfer with frozen eggs was 13.3% (age < 39)
  • 192 thawing cycles in women 39 and older (average age 40.5)
    • Live birth rate per transfer with frozen eggs was 8.1% (age 39+)
  • Study by A Borini et al, Fertility and Sterility; January 2010

(continue reading…)

Our society has undergone significant change since the 1960s. Women’s liberation is definitely a good thing. Women can now do pretty much anything that a man can do. However, the one thing that they cannot do is delay childbearing as long as a man can.

Our society has evolved and many women are pursuing advanced educations and career advancement – and delaying childbearing as a result. However, in general women should be more knowledgeable about the impact of delaying childbearing on fertility potential.

Fertility specialists know this is a problem. We commonly see women in their late 30s and early 40s that are very bright and well-educated who are surprised and very disappointed when told that it may be very difficult (or impossible) to get pregnant and have a baby using their own eggs.

I like to use a “garden” analogy when discussing infertility with patients. The uterine lining is the “garden”  and the embryos are the “plants”. As women age, the garden is rarely the problem – the plant is often the problem. This is why using donor eggs is so successful regardless of the age of the recipient woman. (continue reading…)

We know that chromosomal abnormalities in eggs are responsible for fertility problems – particularly when the woman is in her late 30s or 40s.

• An abnormal number of chromosomes is referred to as aneuploidy
• Aneuploidy causes the increased rate of miscarriage with aging
• Aneuploidy is responsible for most of the decline in fertility with advancing age (both with and without IVF)

In recent years research has shown the importance of a structure in the egg called the meiotic spindle. This spindle is involved with aligning chromosome pairs so proper division of pairs can occur during egg maturation.

• As women age they are more likely to have an abnormal spindle apparatus that does not efficiently line up chromosomes prior to division
• This causes a higher likelihood for an unbalanced chromosomal situation in the mature egg – and then in the embryo

A recently published study (referenced below) might help us to understand why some women have more chromosomally abnormal eggs at a given age. This study was performed in mice, but may well have relevance for human reproduction as well (in many ways we aren’t as different from mice as we might like). (continue reading…)

Age and female fertility and waiting to have babies

• A recent report on the average age at first childbirth from the CDC’s National Center for Health Statistics showed that as of 2006, women in the US waited an average of 3.6 years longer to have their first baby, as compared to 1970.

• There is not enough discussion in our society about the effect of age on fertility.

• Women’s liberation is a good thing and women have made very significant advances over the past 40 years. Many women are pursuing advanced education and careers.

• However, there is a potential “disconnect” involved. Women are waiting longer to have children – but many are not educated about what that delay can do to their fertility.

These days, many couples try to have their first child when the woman is in her mid-to-late 30s. Some will get pregnant easily, and others end up needing fertility treatments. (continue reading…)