The Difference Between Frozen & Fresh Embryos
When deciding to undergo in vitro fertilization (IVF), one of the decisions will be whether to use frozen or fresh embryos for the elective single embryo transfer. There are a few factors to consider before making this choice.
When choosing a fresh embryo transfer, it’s necessary to take hormone treatments to help regulate the menstrual cycle. This will stimulate the production of multiple eggs and will help them to mature. The mature eggs can then be harvested and fertilized in the laboratory. The most fully developed embryos can be transferred to into the uterus during the IVF cycles.
During a frozen embryo transfer eggs will have been harvested during a previous cycle and will have undergone a process known as cryopreservation. This method of freezing enables embryos to be stored at -196° Celsius, which keeps them in a suspended state preventing them from deteriorating. They can be warmed to body temperature within 2-3 seconds and are then ready for use.
The advantages of freezing eggs during IVF
The main advantage of freezing eggs during in vitro fertilization is that it saves wasting healthy eggs that have been harvested but not used during a particular cycle. Your eggs can be safely stored while they are most healthy and viable so that if you need to complete further cycles, you have eggs which have the highest chance of successful fertilization.
Do fresh embryos increase the success of pregnancy?
A 2018 study examining 3,000 women undergoing IVF, evaluated whether fresh or frozen embryos are more likely to result in a healthy pregnancy and a live birth. The results showed that there is no significant difference in the success rate of using fresh or frozen embryos.
There is an exception to this, however, in the case of women who suffer from polycystic ovarian syndrome (PCOS). In this condition, the ovaries do not release eggs. Research has shown that women with this PCOS who are undergoing in vitro fertilization cycles are more likely to get pregnant using frozen embryos.
If you are uncertain whether to use fresh or frozen embryos for your single embryo transfer, then discuss your options with your OB/GYN or fertility specialist to make an informed decision.