Freeze All Embryos Approach May Boost IVF Success
Traditional in vitro fertilization cycles involve the transfer of “fresh” embryos to the uterus within three to five days after egg retrieval. At that time, the best of the unused embryos are frozen through a process called vitrification and stored for future attempts at pregnancy. But recent research has shown that an approach in which we freeze all embryos may be just as successful as a fresh transfer – if not more so.
By freezing all embryos conceived during an IVF cycle, and transferring only when conditions are just right, the odds of success may improve for some women.
Today’s freezing, or vitrification, processes are so advanced, embryos can be stored for decades with no loss in quality. This allows a woman to delay transfer until she and her fertility specialist decide together that conditions are ideal for achieving pregnancy.
Why choose to freeze all embryos?
There are several reasons that a patient and her fertility specialist might choose to freeze all embryos during IVF. For example, it may be the best option for:
- Women who must delay pregnancy due to upcoming medical treatment, such as chemotherapy – It is especially important to freeze embryos or eggs to preserve fertility when the cancer or its treatment jeopardizes the reproductive organs.
- Women who develop many follicles and a high estradiol level during the IVF process – These women may be at risk for ovarian hyperstimulation syndrome, a dangerous condition that can be exacerbated by pregnancy.
- People who wish to use preimplantation genetic diagnosis (PGD) or preimplantation genetic screening (PGS) to test their embryos for chromosomal abnormalities or genetic illnesses – Waiting for the results may be particularly important to families at risk of passing down inheritable, genetic disorders.
- Women who decide to postpone embryo transfer because their uterine lining is less than ideal – The high levels of hormones caused by the IVF process can have a negative effect on the lining of the uterus, reducing the odds that a transferred embryo will implant.
A woman’s age may also be a factor. One recent study1 of more than 16,000 IVF cycles found that a freeze-all approach is associated with improved ongoing pregnancy rates in women over the age of 35. Freeze-all IVF achieved success rates of 46% in this age group, as compared to a 33% success rate with fresh transfers.
The same study found that women of all ages who had high progesterone levels before egg retrieval also had better success with a freeze-all approach. Among these women who were younger than 35, freeze-all success rates were 47%, compared to 38% with fresh transfer. Women in this group who were older than 35 had a 45% success rate when they chose to freeze all embryos, compared to a 30% success rate with fresh transfers.
Is freeze-all IVF right for you?
Your fertility specialist will help you make the decision to freeze all embryos or perform a fresh transfer, based on your unique circumstances and risks, as well as the effect of your IVF cycle on your hormone levels and uterine lining.
To learn more about freeze-all IVF, contact our New York fertility center.