by Dr. Louis Weckstein
Last week I was visited by 6 Popsicle Kids in my office. This is what one of the mothers called her child who came from a frozen embryo transfer (FET). As IVF technology becomes more successful, we are transferring fewer embryos and having more excess embryos to freeze. This allows patients to have a second attempt at IVF, or the opportunity to come back for more children in the future, at a much lower cost.
The first baby born from a frozen embryo was in 1984. Since that time hundreds of thousands of babies have been born from frozen embryos. In some IVF centers (like our own) pregnancy rates with frozen embryos are now equivalent to fresh embryos. On average, 50% of IVF cycles in women under the age of 35 have extra embryos to freeze.
Embryos can be successfully frozen anytime from one day after fertilization through the blastocyst stage (5 -6 days after fertilization), with most centers now freezing at the blastocyst stage. Embryos can be frozen with a very slow programmed freeze, or a quick freeze, vitrification. Many centers see superior thawing and success with vitrification.
In most centers a frozen embryo transfer cycle costs a fraction of a fresh IVF cycle (15-25%). Another advantage of frozen embryo cycles is that they are much simpler for the patient than fresh IVF cycles, with fewer visits and less injections. Most centers will have the patient take natural estrogen and progesterone to hormonally prepare the uterine lining for the embryo transfer. This can even be done without any injections. Some centers will use a natural cycle (but many have found inferior pregnancy rates with natural cycles). After a couple of weeks on the hormonal preparation the patient comes to the center for usually just a single visit for an ultrasound and blood test, and if things are optimal, the frozen embryo transfer is scheduled a few days later. The thawing process is fairly simple and usually takes an hour or so. Many centers recommend transferring only 1-2 frozen embryos with high success rates. Typically 90 – 95% of blastocyst embryos survive the thaw.
Some recent studies even suggest that pregnancies are lower risk and babies born from frozen embryo transfers are healthier than from fresh IVF cycles.
With current trends in IVF pregnancies, I know we will have a whole new generation of Popsicle Kids in the future.
Dr. Louis Weckstein is a leading Reproductive Endocrinology and Infertility specialist at the Reproductive Science Center of the San Francisco Bay Area, where he has served as the medical and IVF director since 1997. Dr. Weckstein has particular interest and experience in all aspects of IVF, including Egg Donation and fertility in older women. He loves his job and is very appreciative to be able to work in a field where so many couples have been helped to achieve their dream of having a family.
