Medical and Social Oocyte Freezing

Medical and Social Oocyte Freezing

Medical and Social Oocyte Freezing

Why Is Egg Freezing after IVF So Important?

A woman’s age is the most important factor that affects fertility. A woman is born with all of the eggs she will ever have and as she grows up, due to ovulation and the natural process of cell loss called atresia, her egg count declines. In addition, her egg quality will diminish due to the accumulation of chromosomal abnormalities in an egg over time and because of this woman’s chance of conceiving decreases gradually from age 30-35. And after age 40, sharp decline is observed in the fertility rate leading to decreased conception and high miscarriage rates. Freezing eggs can help to preserve your ability to have a child in the future since the number and quality of eggs are frozen in time.

The Indian Scenario

Multiple studies have shown , that SouthEast Asian women and Indian women, have a lower ovarian reserve (less number of eggs in the ovary). On an average the fertility potential of a36 year old Caucasian woman, matches that of a 30 year old Indian woman, meaning thereby that fertility reduces 6 years earlier in an Indian woman compared to her Caucasian counterpart. Hence, it becomes all the more important to be aware of one’s own individual fertility potential and ovarian reserve, and consider the option of Egg Freezing in fertility treatment, if the reserve is low and immediate pregnancy is not desired.

Should I Freeze My Eggs?

Although what should be the best time to have a baby is a personal decision, it takes significant thought and consideration.

A woman may choose to freeze eggs for a number of reasons:

  • Timing: You may not be ready to start a family now because of various factors or priorities like education, career, travel, money or some other obligations. Or perhaps, you may not have found the right partner yet or maybe, you just aren’t ready.
  • Family Building: You may already have a child or two but by the time you want to have more your fertility may be affected.
  • Undecided: You may not know now if you want a child (or more children) in the future.
  • Medical: Certain medical conditions may hamper your ability to have children, such as primary ovarian insufficiency, endometriosis and cancer treatments.

What is the IVF egg freezing process?

  • The purpose of egg freezing is to save the eggs in a given cycle that would have been lost in the natural process of cell loss and ovulation.
  • At Xenith IVF Center in Pune, we do this by administering hormonal injections for about 8-10 days. These hormones (also called gonadotropins) are naturally present in the body and are essentially the very same ones that your brain releases to stimulate the eggs in your ovary.
  • Since we want more than just one egg to develop in the ovary, you will take higher doses of such hormones than your brain ordinarily produces.
  • During this period, you’ll have to make 5–7 short office visits at IVF Centerto monitor the response and follicle growth . You would be required to have a blood test and an ultrasound. At these visits, your doctor would assess your response to the medication and would make adjustments depending on how your eggs are growing.
  • Once the number and size of the eggs in the ovary are deemed sufficient, the retrieval process is carried out.
  • You will need mild anesthesia so that you do not feel anything and the entire procedure would take about 15-20 minutes.
  • At Xenith IVF Center, we use an ultrasound probe in the vagina attached with a needle. A very small puncture is made through the vaginal wall which then enters the ovary. The fluid from what are called follicles, which enclose the eggs, are sucked out through this very thin needle. The fluid is then handed off to the embryologist in the embryology lab.
  • The embryologist examines the fluid under the microscope to evaluate for the presence of these microscopic eggs and freezes the eggs that appear viable with the most sophisticated vitrification protocol.
  • When you are ready to have a child, your frozen eggs will be thawed and fertilized in our lab. The resulting embryo can then be transferred into your uterus.

How long can the eggs remain frozen? Is Egg Freezing Safe?

An extensive study of over 900 babies born from the fertilization of previously frozen eggs revealed no increased risk of birth defects when compared to the general population. Other studies have found no increased rate of chromosomal abnormalities or pregnancy complications in babies born from frozen eggs. Based on scientific data as well as our own ample experience, there is no damage that results from the long-term storage of frozen eggs. Human eggs are likely to remain frozen and viable indefinitely.

Xenith Advanced Fertility Centre is one of the best IVF centers in Pune with state of the art equipment. We specialize in IVF egg freezing treatments. Call us today to book you appointment.

Medical and Social Oocyte Freezing

What are the specific steps in IVF embryo freezing?
  • Embryos are removed from the 370C incubator and placed in a weak solution of CPA’s at room temperature. Embryos spend 8 minutes in this solution, which is enough time for the water and CPA’s to equilibrate. When first in the CPA solution, embryos initially shrink (as water leaves the embryo) and then re-expand as the CPA’s enter the cells.
  • Embryos are placed in a stronger CPA solution and allowed to equilibrate for just 1 minute.
  • Each embryo is loaded up into a fine straw which has been pre-labeled with identifying and tracking information. The label has information on the individual(s) that created the embryo (full names and date of birth), tracking information for any sperm and/or oocyte donor used, and the date of the freezing procedure and the status of the embryo at the time of freezing.
  • The straw is sealed at both ends and plunged into liquid nitrogen at a temperature of -1960C. It will remain at this deep sub-zero temperature until the individual(s) that created the embryo request for it to be warmed.
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    How are frozen embryos stored and monitored?

    The air that we breathe contains a gas called nitrogen. This gas makes up about 78% of the air around us. If nitrogen gas is cooled, it becomes liquid at -1960C. This liquid is very stable and easy to work with. In the laboratory we have large tanks filled with liquid nitrogen in which we store frozen embryos. Each tank is in effect like a large thermos flask since it is vacuum lined. All patients have designated storage spaces within a tank, where their embryos are kept. The straws that contain the embryos are color-coded and labelled with precise and unique identifying information as described above.

    The tanks that contain frozen embryos are monitored continuously. Each tank gets a physical inspection twice a day, looking for problems or signs of wear. The quantity of nitrogen in the tank is assessed as a means of monitoring for a possible slow leak or an impending tank failure. The nitrogen in the tank is topped up once or twice a week, since it continuously evaporates at a slow rate (if a tank was not filled regularly, the nitrogen would evaporate entirely in about 6 weeks).

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    How long can embryos be stored?

    No one knows what the maximum storage period might be. Procedures for human embryo freezing were developed in 1984 and only went into widespread use in the late 1980s. This means that the longest time a human embryo has been stored is 25-30 years and, typically, patients that have left embryos in storage for this long are not coming back for them. Some patients have come back after 10-12 years and the embryos have been thawed successfully and created healthy babies. Beyond this time frame, we don't know how long an embryo will remain viable, but it is possible that, kept in liquid nitrogen, an embryo may be viable indefinitely.

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    How are embryos thawed?

    The process of embryo freezing has already been explained. Thawing the embryos is simply a reversal of the freezing procedure.

    When an embryologist removes embryos from the freezer, a second ............. person is required to witness the act, and verify the identity of the embryos before they can be thawed. Under no circumstances can a lone embryologist remove embryos from the freezer without another .................. person to confirm correct identification.

    The embryos coming out of the freezer (at –196°C) are warmed to room temperature in 3 seconds. This rapid thaw method minimizes damage to the embryo from ice that could form during warming. The embryologist has to remove the antifreeze from the embryo and replace the water that was removed at the time of freezing. This is done by incubating the embryo in decreasing concentrations of the antifreeze, and increasing concentrations of water. Over a period of 20 minutes, the embryo is stepped through different solutions, until finally the antifreeze is gone and all the water has been replaced.

    The thawing procedure is performed at room temperature, and once complete, the embryo is warmed up to body temperature (37°C). It can be ready for transfer in as little as 40 minutes after leaving the freezer.

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    Can freezing damage my embryos?

    While every care is taken to protect the embryos during the process, some embryos may have one or more dead cells after they have been thawed. At Xenith, using the vitrificationmethos we have excellent survival rate after warming vitrified embryos. We consider a warmed (thawed) embryo as having a normal chance of implanting after transfer.

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    Am I more likely to have a child with a genetic or congenital abnormality because I'm pregnant after a frozen embryo transfer?

    Even after 20 years, there are few studies in the scientific and medical literature concerning outcomes after embryo cryopreservation. However, the few studies that have been published are thus far very reassuring. Children born from frozen embryos do not seem different from children born from embryos that had not been frozen. Even if an embryo loses some cells during thawing this does not cause any abnormalities. Freezing does not cause or introduce genetic abnormalities.

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    What are my options for using the embryos?

    We hope that most couples will be able to use the embryos to have a healthy baby. Patients undergoing frozen embryo transfer make up about one fourth of the patients visiting our office. Some are thawing embryos after failing to become pregnant during their IVF cycle, and some are using the embryos a year or more after a successful IVF cycle, to have a second or third child.

    You may be surprised to learn that there are a significant number of people who do not want to use their frozen embryos to become pregnant. These are typically people that have completed their families and are not interested in having any more children. As per the current guidelines, all embryos in frozen storage for more than 5 years have to be destroyed if not claimed by the couple till then. Nonetheless, it is very important for all couples and individuals to think about what they might eventually do with excess embryos in the future should they find themselves in this situation. Some may want to freeze some eggs rather than fertilizing all eggs up front. Although a potentially costlier solution, it could help to avoid having to make an impossible choice at some future point.

    Frozen embryos can also be donated for research studies. Embryos donated for research will be thawed and used in a scientific study, and discarded after a few days. A research study might look at new ways of freezing or thawing embryos, new ways of growing embryos in the laboratory or at the genetic make-up of the embryos. The studies will not benefit the patient that donates the embryos, but the research may benefit other IVF couples in the future.

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    How are embryos destroyed when patients request disposition?

    A formal request to destroy the embryos must be received in writing from the patients. The request must be signed by both partners and notarized, or witnessed by a member of our staff. Once the laboratory has received the disposition notice, no action is taken for 30 days. This gives the couple a cooling off period and an opportunity to change their decision.

    When the 30-day waiting period has passed, the Embryologist and the Clinical Doctor, take responsibility for carrying out the patients' wishes. They fill out a form indicating that they have checked the disposition request and are in agreement that the patient wants the embryos discarded. They locate the embryos in the storage tank and double check the identity with the paperwork. The embryos are then thawed and discarded. The paperwork is complete when both sign, attesting that they performed and witnessed the destruction according to the patients' wishes. The paperwork is kept in the laboratory files and a copy filed in the medical record of the patient.

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    Can I donate my embryos to another infertile couple?

    Yes, it is possible to donate embryos. This process is referred to as embryo donation.

    There are many advantages to embryo donation, including giving another couple the chance to have a child and avoiding having to discard the embryos that took so much effort to create. Couples wanting to donate surplus embryos can donate them anonymously to other couples through Xenith. Your Physician can explain the process to you. We always take consent from the couple before donating any surplus embryos and the embryos are donated or disposed only as per the wishes of the couple.

    The couples donating and those receiving the embryos do not meet each other and only the consents are taken with complete counselling.