Embryo freezing, also known as embryo cryopreservation, can be used as a form of fertility preservation for people who are not yet ready to have children. Some people also freeze their embryos when more embryos are created during an IVF cycle than can be used in that cycle. Once the couple is ready to get pregnant, the embryos can be thawed and transferred to the uterus. Below, we will take a look at the frozen embryo transfer timeline.

Frozen Embryo Transfer Timeline

Pretesting

‍The doctor may recommend that you undergo a hysterosonogram or hysteroscopy to examine the inside of the uterus before performing a frozen embryo transfer. This can identify the presence of uterine abnormalities that could prevent implantation or cause miscarriage. Your doctor will evaluate whether or not pretesting is necessary in your particular case based on your medical and reproductive history, and whether you have been tested in the past.

‍Hormonal Preparation

‍Hormonal preparation is used to prepare the uterus to receive the embryos. Unlike in a fresh IVF cycle, the frozen embryo transfer timeline is more relaxed, because the embryo transfer only becomes time-sensitive once progesterone is started. The usual medications used and the timelines for the medications are as follows:

• Two weeks of daily Lupron injections to suppress the pituitary gland
• Estrogen pills to help build up the uterine lining so it will be ready to support the embryo
• Progesterone is given via injections and vaginal gel for several days to mature the uterine lining and make it receptive to the embryo; it will be continued for at least the first few weeks of pregnancy

In some cases, it is possible to monitor the natural development of the uterine lining, instead of supplementing with fertility medications. However, the frozen embryo transfer timeline is much more unpredictable and tricky with this method, which is one reason that medication is usually preferred.‍

Frozen Embryo Thawing and Transfer

‍Once estrogen is started, the doctor will use blood tests and transvaginal ultrasound to monitor the development of the uterine lining; the timing of the medications can be adjusted based on that information. Since IVF1 freezes embryos at the blastocyst stage, or after 5-6 days of development, progesterone must be given so that the uterine lining is compatible with a blastocyst. If you are interested in fertility preservation. Dr. Randy Morris would be happy to hear from you. To schedule your consultation today, please click below and enter your information or call IVF1 at (630) 357-6540.