image_pdfimage_print
Egg Freezing what Do you Hope to Accomplish?

Egg Freezing what Do you Hope to Accomplish?

Egg Freezing what Do you Hope to Accomplish?

The best approach motherhood is to actually try to get pregnant. Though methods of fertility preservation are very helpful, none is a guarantee to make a baby in the future. So the primary advice is “try to get pregnant if you can” after checking different fertility factors (male, tubal and ovarian factors as well preconception screening). If getting pregnant is not feasible in the short term, due to medical or social issues, egg freezing is considered. A reproductive endocrinologist is faced with the challenge of foreseeing if a specific woman, when stimulated and her eggs are harvested and frozen, has a reasonable potential to conceive using these eggs at one time in the future.

Indication for Egg Freezing

Women should consider egg freezing when specific medical or age related situations threatens their ability to have a child in the future.

1. Fertility preservation: When a medical disorder or its treatment can diminish ovarian reserve and reduce the chance for conception e.g cancer treatment (most common is breast cancer), lupus nephritis requiring treatment with chemotherapy, blood diseases requiring bone marrow transplantation, premature ovarian dysfunction and others. About 2 weeks should be available for an egg freezing cycle.

2. Fertility extension (no male partner): women with no male partner and declining the use of donor sperm can freeze their eggs to use in the future when in a committed relationship.

3. Fertility extension (with a male partner): women with a male partner can elect to freeze some of their eggs unfertilized. Unfertilized eggs are under the control of the woman alone, unlike embryos that cannot be used without the consent of both partners.

4. IVF with failed sperm retrieval or ejaculation: In some cases with male factor with failed retrieval of sperm from the testes or failed ejaculation, eggs can be frozen and used later when sperm are available.

5. Children undergoing treatment for cancer and other diseases with the ascent of their parents.

What should you consider before proceeding to egg freezing

i.   Women <38 years with good ovarian reserve: are excellent candidates for egg freezing. Good reserve is indicated by antral follicle count >10 as seen on vaginal ultrasound and AMH levels > 1.75 ng/mL. They will likely produce a good number of oocytes to freeze in a single cycle. These eggs are relatively healthy as they are young. Age <36 years was the best predictor of egg freezing so far in scientific reports.

ii.  Women <38 years with diminished ovarian reserve: are still good candidates for egg freezing. They produce lower number of eggs after stimulation but their oocytes are relatively healthy (chromosomally normal). They can undergo more than one cycle of egg freezing if the first cycle yields <8 mature eggs.

iii. Women 38-40 years with good reserve: can still consider egg freezing with no further delay.

vi.  Women 38-40 years with diminished ovarian reserve: should consider egg freezing with caution. They will not produce a good number of eggs and may require multiple cycles of egg freezing.

V.   Women >41y are not good candidates for egg freezing even if they have a good reserve as the majority of their oocytes are not chromosomally normal. Although pregnancies were reported from vitrified oocytes up to age 44, the chance of pregnancy in quite low in women older than 40.

Realistic Expectations for egg freezing

Not only should the number and quality of eggs be considered, but also the survival of thawed eggs, fertilization and ultimate ability to implant. These issues are very sensitive to the method of ovarian freezing. Vitrification (rapid freezing) is not the method of choice for low temperature storage of eggs due to high survival and subsequently fertilization and embryo development (more details here and here).

Survival on average 85% of virified thawed eggs survive, irrespective of age.

Fertilization approximately 80% of thawed eggs fertilize after injecting each with a sperm (ICSI).

Age specific chance for a live birth after thawing of vitrified eggs can be presented in different ways. The delivery rate is approximately 5 to 15% per thawed egg depending upon the female age at freezing. For example, if eggs are thawed and fertilized and three embryos were transferred to the uterus, the probability of delivery would be 25% at age 30 and 15% at age 40.

If a 35 year old decided to proceed with an egg freezing cycle and produced 10 eggs, 8 eggs were mature and frozen. When she present back 10 years later to utilize her eggs and thaw all of them 7 eggs are expected to survive, 6 eggs are expected to fertilize. If three embryos were transferred her chance for delivering a baby is 20% (the remaining three embryos are frozen). If The first cycle does not succeed and the next three embryos were transferred, her cumulative chance for having a baby from the original egg freezing cycle is approximately 40%.

Sorting through statistics of egg freezing is difficult. No single clinic can present convincing statistic due to small number of egg thaw and transfer (not just egg freezing cycles). Most studies present select donors and selected women and not directly applicable to everyone. And then there is the safety issue and lack of long term follow up data related to safety and health of newborns.

Age is most important predictive  of success of egg freezing followed by method of freezing. Vitrification much better than older slow freezing methods. There is now reasonable body of data, though not definitive, that allows prediction of outcome for egg freezing using vitrification based on age and the expected number of retrieved oocytes. It is neither accurate nor scientific to label egg freezing with terms such as reliable and guarantee. It certainly is not a guarantee of children. What is more productive is to i. try to avoid egg freezing through trying to conceive. If not possible, in a short while, then ii. understand your own personal chances of delivering a healthy baby through egg freezing and if they seem reasonable to you consider the procedure, taking in consideration the limitation of available data and filtering out the marketing hype.

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail
Egg Reserve and Infertility

Egg Reserve and Infertility

Egg reserve means the number and quality of eggs remaining in the ovaries at a given age. It reflects the fertility potential of a woman irrespective of the cause of infertility, even male factor.

Benefits of Testing for Egg Reserve

Testing for egg reserve results should be interpreted with caution. Abnormal values should not be a cause for denying fertility treatment because the predictive power for pregnancy with own eggs is modest. For women, ovarian reserve tests give women insight into the chance of pregnancy with there own eggs. It also may indicate the need to promptly avoid delay in seeking fertility treatment.  For reproductive endocrinologists, the tests have value in designing fertility treatment and selecting the most appropriate fertility treatment protocol. They predict response to fertility medications and allow infertility specialists to select treatment protocol and gonadotropin dose. Egg reserve also predicts the number of eggs retrieved for IVF or egg freezing.

Egg Reserve: Egg Number

Although the number of eggs in the ovaries decrease with age there is significant individual variation in initial number endowed in the ovaries and the rate of decrease. Some young women has low egg number and older with large number of eggs. Ovarian reserve tests are used to estimate this number.

Egge reserve: the number of eggs in the ovaries drops with age

Egge reserve: the number of eggs in the ovaries drops with age

History

Medical history may indicate low egg reserve in women with prior excision of ovarian cysts, endometriosis of the ovaries,  women who smoke and with family history of early menopause

Antral follicle count

The number of antral follicles in the ovaries (the structures that contain the eggs) can be seen and counted using vaginal ultrasound. Performed by an experienced reproductive endocrinologist, it can accurately estimate ovarian reserve. Low count e.g <10 in both ovaries points to low reserve.

Day 3 FSH, Estradiol

FSH is produced by the master gland in the base of the brain. Estradiol is made by the follicles themselves. Measured in the second or third day of menstrual cycle, high FSH (>12) of high estradiol (>75) points to low egg reserve.

Antimullerian Hormone (AMH)

AMH is produced by the cells surrounding the eggs in small follicles and is a more direct measure of egg reserve than FSH. It can be accurately measured any day in the cycle with  little variations in between cycles. Levels <1.5 ng/dL generally indicates low egg reserve. It correlates well with antral follicle count.

Genetic Screening

Low egg reserve in few women is due to a genetic cause. Fragile X syndrome is a genetic disease that causes low egg reserve and mental deficiency in newborn males. Chromosomal abnormalities e.g Turner syndrome, translocations are also associated with low egg reserve. Genetic screening is performed using a simple blood test before starting fertility treatment.

Egg Reserve: Egg Quality

What does egg quality means ?

Good quality eggs are chromosomaly normal (has 23 chromosomes). The most important factor that prevents the achievement of pregnancy or leads to early miscarriage is an abnormal egg (has extra or missing chromosome or piece of a chromosome). Many eggs at any age in any woman are abnormal and the normal eggs are the ones that are successful in being fertilized with sperm, implant and achieve a pregnancy. These errors takes place when the original cell that produce the eggs divide to reduce the number of chromosomes to half. The division (meiosis) is many times unequal leading to an egg with an extra or missing chromosome.

Age and egg quality

The ovary releases better quality age earlier in life and lower quality age later, for unknown reason. Female age is the most important indicator for egg quality, chance for spontaneous pregnancy and after fertility treatment. Older women need to try longer to achieve pregnancy and at an increased risk for miscarriage, ectopic pregnancy and delivering a baby with chromosomal abnormalities e.g Down Syndrome. This effect of age become clinically evident at age 30 or even earlier. Age is more important than the number of eggs in the ovaries. Young women with few eggs in the ovary are more successful in getting pregnant than older women with many eggs in the ovary.

Meiosis

Meiosis

Testing for egg quality: PGD

Age is the only available noninvasive method to estimate egg quality. Healthy eggs cannot be identified using any non invasive method. It is possible to identify chromosomal errors in the egg during IVF fertility treatment after biopsy of the first polar body of unfertilized egg or after removing one cell from an embryo after the egg is fertilized then test this material for chromosomal abnormality. This process is called PGD or preimplantation genetic diagnosis. It is important to remember that PGD is not proven so far as method of enhancing fertility potential. It simply detects if the egg or embryo is chromosomaly normal or not but will not make an unhealthy egg healthy.

Read more about ovarian reserve and low response to ovarian stimulation in my review here.

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail
Egg Freezing

Egg Freezing

Women freeze their eggs for one of two reasons

  1. Elective: freezing eggs to use later on to avoid age related decrease in egg quality and number. This is a fertility solution for fertile women.
  2. Medical indication: women diagnosed with cancer and require surgery or chemotherapy that will reduce ovarian function, egg donation and egg banking, failure of the the male to produce sperm at the time of IVF.

Is egg freezing suitable for me?

You need personalized information about ovarian reserve and reproductive system before deciding on egg freezing. Ovarian reserve is an estimate of the number of eggs in the ovary and their quality. The number of eggs is estimated using vaginal ultrasound for antral follicle count, AMH levels and day 2 or 3 FSH and estradiol. AMH levels > 1.5ng/dL and antral follicle count > 12 indicate decent number of eggs in the ovaries.

Egg quality is reflected by age. The younger the age, the more chromosomally normal eggs are available in the ovary.

Women 38 or younger freezing more than 8 eggs have excellent chance to become pregnant when eggs are thawed, fertilized and transferred to the womb. Live birth rates decline with age but some live births took place from eggs frozen up to age 44.

Approximately 90% of eggs stored using vitrification survive thawing and 75% of them fertilize. Each egg thawed has the potential to produce a baby approximately 10% of the time (5 to 15% depending on age). Commonly, three to four eggs are thawed and two to three embryos are transferred. This will yield a reasonable live birth rate per cycle. The American Society For Reproductive Medicine does not consider egg freezing an experimental technology anymore.

What do I need do to freeze my Eggs?

Ovarian stimulation: using injection medications to recruit multiple follicles and produce multiple eggs, instead of one egg only in a natural cycle. Medicine is self injected daily for approximately 10 days and monitored using estrogen levels and ultrasound every two to three days. A trigger injection is finally given.

Egg retrieval: eggs are harvested under sedation 36 hours after the trigger injection. Eggs are obtained using a needle through the vagina without an incision.

Egg freezing: Vitrification method is used. Four hours after retrieval, Mature eggs are mixed with a cryo-protecting solution. Two to three eggs are placed on a special device cryotop that is sealed and plunged in liquid nitrogen or nitrogen vapor. Immature eggs can also be frozen.

The cycle can be repeated. Also some of the eggs can be fertilized using donor sperm if desired.

What happens after I freeze my eggs?

Frozen eggs Can be stored for a very long time, possibly indefinitely. Eggs can also be transferred to other facilities or countries.

When you are ready, with a partner: try natural conception, investigate other fertility factors, consider fertility treatment or finally use the eggs.

When you are ready, without a partner: try IUI using donor sperm or IVF using donor sperm or fertilize the frozen eggs with donor sperm.

Utilizing your frozen eggs: The steps to utilize your eggs are

  1. Preparation of the lining of the uterus using estrogen (no injections) or during your natural cycle,
  2. Egg thawing in the embryology lab,
  3. ICSI: injection of one sperm into each egg,
  4. Embryo development and transfer is observed in the lab and
  5. Transfer of one or more embryos into the uterus

Is egg freezing safe?

Babies born after thawing the eggs, fertilization and transfer into the uterus do not have higher risk of abnormalities compared to those born from after transfer of thawed embryos or naturally conceived. However, there has not been as much babies born using this technology or long term follow up as in the case of embryo freezing.

Conclusion

If you did not attempt to conceive by age 30 or earlier, consider evaluation of ovarian reserve and egg freezing if you do not intend to get pregnant soon. Obtaining personalized information about egg reserve is the primary step in deciding if egg freezing is suitable for you.

 

Facebooktwittergoogle_pluspinterestlinkedinmailFacebooktwittergoogle_pluspinterestlinkedinmail