Frozen Donor Egg IVF
Bay IVF - Advanced Reproductive Care                                Palo Alto  650-322-0500


Frozen Donor Egg IVF

Frozen Donor Egg IVF is an alternative to "fresh" (non-frozen) Donor Egg IVF treatment. Just as the "fresh" Donor Egg IVF, it can be a highly successful treatment for patients who no longer have sufficient quality eggs within their ovaries.

You choose your frozen donor eggs from a donor egg bank catalog. This is similar to choosing donor semen from a sperm bank.

Once you select the egg donor of your frozen eggs, the egg bank will ship your selected frozen eggs to our Clinic. The egg banks our embryologists recommend are Fairfax Egg Bank, Donor Egg Bank USA at California Cryobank, and Cryos International-USA.

Probability of Success
The likelihood of a successful pregnancy depends primarily on the fertility potential of the egg donor who provided your frozen donor eggs, rather than your uterine receptivity or age.

The probability of a successful outcome with frozen donor eggs approaches the success of using "fresh" donor eggs.

Treatment Efficacy
Over the years, we have streamlined and simplified our fertility treatments to minimize interference with your lifestyle. A cycle of Frozen Donor Egg IVF requires only 3 to 4 brief visits to the Clinic, and most patients will be able to continue their everyday lifestyles during their treatment.

Frozen Donor Egg IVF Offspring
Children conceived with the help of either "fresh" or frozen donor egg treatment are genetically linked to the male partner and the egg donor, but the female partner is the one who becomes pregnant, nourishes the baby throughout the pregnancy, and experiences the childbirth.

The baby would get one set of genes from the dad and another from an egg donor, but you, mom carrying the pregnancy, would make that baby your very own. There is a whole new science of epigenetics that describes how our environment modifies the gene expressions and possibly the genes themselves.

The epigenetic marks transmitted from the mother are a fine-tuned mechanism to control gene activation during the complex process of early embryogenesis. And this maternal influence continues throughout the pregnancy. You will imprint yourself onto the baby! By the time your son or daughter is born, that baby will be biologically yours.

"Fresh" and Frozen Egg Donor IVF Comparison
In "fresh" Donor Egg IVF, the egg donor undergoes ovarian stimulation and an egg retrieval. The eggs are inseminated with partner (or donor) sperm, and fertilized eggs are cultured in the laboratory. The resulting embryo(s) is/are transferred into the recipient mother’s uterus after hormonal preparation (synchronization with embryonic development).

In a Frozen Donor Egg IVF, the egg donor’s ovarian stimulation and egg retrieval have already taken place. The eggs have been vitrified (cryopreserved, frozen) by the egg bank for use in future treatment(s). The recipient mother does not need to synchronize her treatment with the donor’s.

In both types of donor egg treatments, egg donors are tested for genetic and infectious diseases as well as being psychologically screened.

Advantages of Frozen Donor Egg IVF
The advantages of Frozen Donor Egg IVF are possible lower treatment cost than "fresh" Donor Egg IVF, shorter treatment length, and, possibly, not having to decide what to do with too many extra embryos that might be left over after a successful "fresh" Donor Egg IVF treatment.

Advantages of "Fresh" Donor Egg IVF
The advantages of "fresh" Donor Egg IVF are typically a very high success probability and possibly having enough extra frozen embryos improving the chances for a genetic sibling in the future.

Treatment Logistics
The rate of development of embryos from frozen donor eggs may be unpredictable, and it may not be possible to match the recipient's uterine lining development with the development of the embryos.

This is resolved by thawing and inseminating the frozen donor eggs and freezing (vitrifying) the resulting embryos. The frozen embryos are thawed and transferred into the uterus in a subsequent Frozen Embryo Transfer.

A large majority of embryos will survive the vitrification and thawing process. The implantation rate of the thawed embryos is equal to the "fresh" embryo implantation rate.

Obstetrical Care
Once your Frozen Donor Egg IVF treatment at Bay IVF is completed (approximately 6-8 weeks into your pregnancy), the pregnancy becomes indistinguishable from conception through intercourse, and your obstetrical care should be no different than if you conceived without any treatment.

To maximize the probability of success, Frozen Donor Egg IVF should not be used for severe male factor infertility or when PGT procedure is added to the treatment.


Frozen Donor Egg IVF Procedure


Frozen Donor Egg Procedure


Frozen Donor Egg IVF is a two-stage treatment. The first phase consists of development and freezing (cryopreservation) of embryos.

  1. Obtaining donor eggs from an egg bank
  2. Thawing of vitrified donor eggs
  3. Fertilization of eggs (Intracytoplasmic Sperm Injection)
  4. Culture of embryos
  5. Cryopreservation (vitrification) of embryos
  6. Embryo storage


The second stage consists of thawing and a uterine transfer of embryos.

  1. Preparation of recipient’s uterus
  2. Thawing and culture of cryopreserved embryos
  3. Assisted embryo hatching
  4. Embryo transfer
  5. Implantation


Stage One: Development and Storage of Embryos


  1. Obtaining Donor Eggs from an Egg Bank

    Once you have finalized the selection of your donor eggs, the egg bank will communicate with our Clinic, and our Embryology Laboratory will make preparations to receive your eggs. After their vitrification in the egg bank, eggs are stored and transported in liquid nitrogen containers. Once your eggs arrive at Bay IVF, they will be kept in liquid nitrogen storage until it is time to thaw them.

  2. Thawing of Vitrified Donor Eggs

    Since it is expected that not all vitrified eggs will survive the vitrification-thawing process and since not all thawed eggs will fertilize or develop into healthy embryos, you will be purchasing a cohort of eggs. You should expect to receive between 5 and 8 vitrified eggs.

    Such a cohort will likely produce 1-3 good quality embryos suitable for transfer, though some may produce more for your potential future use.

  3. Fertilization of Eggs

    The male partner collects a semen specimen by masturbation the day of thawing your eggs. The highest quality sperm are extracted from the semen, and Intracytoplasmic Sperm Injection (ICSI) is performed. In ICSI, a single sperm is inserted into an egg. ICSI is necessary for the fertilization of vitrified/thawed eggs.

  4. Culture of Embryos

    Evidence of fertilization can be seen the next day, 16 hours after ICSI. The fertilized eggs are transferred into a growth medium and continue to be cultured in our laboratory.

    A normally fertilized egg (zygote) will show two pronuclei representing the genetic material from the egg and sperm.

    The following day, embryos should divide into 4 cells, the day after into 8 cells.

    This picture shows a morphologically exquisite, day three, 8-cell embryo. At this stage, human embryos are still microscopic and invisible to the naked eye.


Eight Cell Embryo


By the fifth to seventh day after the insemination, embryos should reach the blastocyst stage (80 or more cells).

This picture shows an advanced stage of blastocyst development. Notice the central fluid-filled cavity. The cells within the blastocyst have already differentiated into the inner cell mass (at seven o’clock) that will give rise to the fetus and the trophectoderm cells that will form the future placenta.




  1. Cryopreservation of Embryos

    Embryos that develop normally are cryopreserved (vitrified). Preparation for the freezing process involves removing water from within the embryos and replacing it with cryoprotective substance to prevent ice crystal formation during vitrification and subsequent thawing. The embryos are then flash cooled to −196 °C (−321 °F). Such rapid freezing (vitrification) prevents damaging water crystal formation.

  2. Embryo Storage

    Following the vitrification process, the embryos are transferred to a liquid nitrogen storage chamber in our Center. Theoretically, there is no limit on the length of storage, but conceiving past the age of 40 may result in a high-risk pregnancy.


Stage Two: Thawing and Uterine Transfer of Embryos


  1. Preparation of Recipient Mother's Endometrial Lining

    There are several different forms of endometrial lining stimulation protocols, each with many modifications. Your treatment is always individualized.

    There are several different forms of endometrial lining stimulation protocols, each with many modifications. Your treatment is always individualized.

    Below is an example of endometrial stimulation protocols used at Bay IVF. Your cryopreserved embryo transfer cycle may take less or more time to complete.

Endometrial Stimulation Example


Endometrial Stimulation Example


The treatment begins by taking oral contraceptives. They are started within the first four days of the beginning of a menstrual cycle. A few days after the last pill, you will have a menstrual period, and the endometrial stimulation will begin at that time.

Oral and subcutaneous injection medications are used to prepare your endometrial lining for the transfer of the frozen-thawed embryos. The endometrial lining preparation is straightforward, and you should not expect any side-effects.

  1. Thawing and Culture of Cryopreserved Embryos

    You will need to decide and communicate to us how many vitrified/thawed embryos you would like to transfer. Please let us know if you need help with this decision.

    Most patients should select one or two embryos for the thaw and transfer to eliminate the risk of a high order multiple pregnancy (triplets or more). With this approach, most pregnancies from cryopreserved embryos are single baby pregnancies.

  2. Assisted Hatching

    Assisted hatching is a laboratory procedure used to create a "weak spot" in the eggshell of an embryo. Since embryo freezing commonly hardens the embryo eggshell, assisted embryo hatching is always a part of the Frozen Embryo Transfer treatment.

    This picture shows an embryo after assisted embryo hatching with an opening breaching the eggshell at 12 o’clock position.


Assisted Hatching


  1. Embryo Transfer

    Transfer of cryopreserved embryos into the uterus is identical to "fresh" embryo transfer: Just prior to the embryo transfer, the embryos are placed into the tip of a thin embryo transfer catheter. The catheter is then passed through the cervical canal to within 15 mm of the top of the uterine cavity, and the embryos are gently released.

    Having done thousands of embryo transfer procedures, Dr. Polansky will precisely place your embryo(s) within the endometrial cavity. The embryo transfer usually takes only a few seconds to complete, and no resting is required afterward.

  2. Implantation

    After the embryo transfer, the endometrial lining gently holds the embryos within the top of the uterus. There is no restriction on your physical activity.


Hatching Blastocyst


This picture shows a healthy blastocyst in the process of "squeezing out" of its eggshell. Once fully hatched, it will stay in the uterus unattached for one to two days and then implant.

A blood pregnancy test is done ten days after the embryo transfer. If the pregnancy test is positive, an ultrasound examination is scheduled two weeks later to visualize the implantation site and to look for a heartbeat within the embryo. Once a heartbeat is seen, there is a 95% probability that the pregnancy will continue to a baby.

There is no increased risk of birth defects in pregnancies from cryopreserved embryos compared with conceptions conceived through intercourse or using "fresh" embryos.


Pregnancy Ultrasound


This ultrasound picture shows a six-week pregnancy. The pregnancy sac is 25 mm in diameter. The baby inside the sac is only 13 mm long, and yet it is already possible to distinguish the head and the "tail" portion of the baby’s body and to see the cardiac activity.



Supplementation of estrogen and progesterone must continue until the placenta produces enough of its own estrogen and progesterone to sustain the pregnancy. You will be closely monitored for 6 to 8 weeks as this transition takes place. Once all medications are discontinued, you will be referred to your OB doctor for the remainder of your obstetrical care.

At this point, your pregnancy becomes indistinguishable from conception through intercourse, and your obstetrical care should be no different than if you conceived without any treatment.

Please use the following links for financial information about Frozen Donor Egg IVF and to schedule a consultation.


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