Fresh vs. frozen
During IVF, the couple has the option of choosing fresh or frozen embryos. The clinic creates multiple embryos by combining sperm and egg samples in a special petri dish. Fresh embryos are transferred immediately after the fertilization process. The clinic would then freeze the best remaining embryos for future use. Embryos can be frozen at different stages of development. The clinic then thaws the embryo before implantation to complete a frozen embryo transfer. Choosing frozen embryos over fresh ones has some differences, including an extended implantation period.
Why choose a frozen embryo?
Frozen embryos play an essential role in IVF. For cycles that have failed, frozen embryos are available to try again. These embryos also help with delaying pregnancy. Some women may prefer to pursue other endeavors before starting a family. Others may have health concerns but still hope to start or grow a family in the future. Frozen embryos also have some health benefits. Repeated fresh embryo transfers increase the risk of ovarian hyperstimulation syndrome.
Do frozen embryos take longer to implant?
After the fertility doctor transfers the embryo, these cells take some time to implant. On average, a fresh embryo transfer takes about 1-2 days to hatch. Hatching and implantation can take about 5-7 days. Frozen embryos can take as long as 5 days to hatch, extending the transfer period further. Frozen embryos will take longer to implant because there is simply a longer timeline. This extra time is an advantage as the uterus can recover from excess hormone treatment.
Does delayed implantation matter?
Studies show that both fresh and frozen transfer offer successful pregnancy outcomes. However, there are some advantages to frozen embryos. These advantages may impact the overall success of the IVF cycle. For instance, the clinic can perform preimplantation genetic testing (PGT) to find the best viable embryo. PGT helps patients with multiple failed cycles or a preexisting genetic condition that may be passed on to the child. The clinic needs additional time to complete the test and frozen embryos makes the process easier. Frozen embryos are also more cost-effective per cycle compared to fresh embryos. Best of all, the delayed implantation gives a little extra time to recover from the rigors of IVF. Overall, patients do have to wait longer to confirm pregnancy with frozen transfers.