Frozen Embryo Transfers

Frozen Embryo Transfers

Embryo Cryopreservation and Frozen Embryo Transfer (FET)

Embryo cryopreservation permits selected embryos, not immediately returned to a woman’s uterus, to be frozen for the couple’s later use. When thawed at a later date, these embryos can be placed in the uterus with little or no medication in advance. This is known as a frozen embryo transfer (FET). The babies born after cryopreservation are just as healthy as babies conceived spontaneously.

Explore Your Conception and Fertility Preservation Options
We strive to provide our patients with numerous options at the Aspire Houston Fertility Institute, including cryopreservation and frozen embryo transfer. If you are considering in vitro fertilization, these options may be for you. Embryo cryopreservation allows you to preserve your embryos for later use without any impact on the chance of future successful conception. If you are career-minded, want to focus on personal interests, or are simply not at a point in your life to have a child, embryo cryopreservation allows you to delay the process. If you would like to learn more, we invite you to contact our Aspire Houston fertility clinic.

Frozen Embryo Transfer (FET) – An Indefinite Option

The only fundamental difference between frozen embryo transfer and fresh embryo transfer is that frozen embryo transfers do not require ovarian stimulation. The technique and results are nearly identical. A woman’s embryos can be safely frozen indefinitely through a process known as vitrification (a flash freezing technique which produces no ice crystalization). There are no appreciable differences in the success rates of embryos that have been transferred fresh and those that have been previously frozen and then thawed prior to transfer. The benefits of FET are extending the potential success of an IVF cycle by achieving more than one pregnancy from a single cycle and the option of fertility preservation.

The Treatment Process

The process of a frozen embryo transfer involves synchronizing the uterine lining to match the developmental stage of the embryo or embryos to be transferred. The cycle begins by growing the uterine lining with estrogen to a recommended thickness and appearance on ultrasound. The addition of progesterone advances the lining to match the stage of embryos to be transferred. Once the uterus has been prepared, the embryos are transferred to the uterus in the same way as would occur in a fresh embryo cycle.


Cryopreservation is a technique that involves freezing embryos, sperm, and oocytes (eggs). The technique utilized for eggs and embryos is known as vitrification. Vitrification is a process that allows rapid freezing in solutions that protect against the stresses secondary to freezing (ice crystal formation and osmotic effects from the solutions). The development of this technique has made frozen embryo and egg treatment cycles much more successful than in the past. Today, the pregnancy rates from frozen embryo cycles are comparable to that of fresh IVF cycles.

There are many reasons to consider cryopreservation of gametes (eggs and sperm) and embryos. These include:

  • Embryos remaining from a fresh IVF cycle
  • Preservation of fertility
  • Persons undergoing medical or surgical therapies for other medical problems that could threaten his/her ability to have children in the future
  • Egg and sperm donation

Cryopreservation is a well established technique and is commonly employed in fertility therapy. Our staff will be happy to discuss the process in detail at your consultation.

Contact the Aspire Houston Fertility Institute

We invite you to contact our fertility clinic today if you would like to arrange a consultation with our team. We want you to make informed decisions regarding your fertility options, and will thoroughly educate you on your options. Should you have any questions, we would be happy to answer them. Our goal is to help every one of our patients realize their dreams of parenthood.

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Contact us today if you’re ready to take the next step in your fertility journey.