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Fertility preservation

Fertility preservation means storing/preserving sex cells or tissue for use at a later point to help achieve pregnancy. This can be done either for medical or “lifestyle” reasons.

Fertility preservation is made possible by the latest cryopreservation (freezing) methods.

Fertility preservation – social freezing

Fertility preservation as a lifestyle procedure

Introduction

At birth, a female baby has approximately 2 million egg cells (oocytes) in her ovaries. This number will drop significantly before puberty to approximately 400,000 cells. In the subsequent fertile phase, women lose about 1000 oocytes per month. While the remaining number of oocytes decreases, their quality is reduced at the same time. A 30 year-old woman may have one in two or one in three oocytes with normal chromosomes, in a 40 year old woman however, this number is reduced to one in five or six oocytes.

Spontaneous pregnancy is only possible in about 10 % of women in their early 40s. It is rare for a woman aged over 45 to give birth to a child.

Thanks to modern freezing techniques, it is now possible to preserve egg cells in order to postpone a wanted pregnancy to a later point in life. This requires that the “fertility preservation” takes place at a time when the quality of the oocytes permit an acceptable pregnancy rate.

The best time is therefore when the woman is in her late 20s or early 30s. Experience shows, however, that very many women only start to seriously consider having a child in their mid 30s.

Procedure

Of course, it is possible to principally remove the one oocyte growing in the natural cycle and preserve it. However, this is not advisable for the following reasons:

  • it cannot be guaranteed that every cell will withstands the freezing and thawing
  • it cannot be guaranteed that it will be possible to fertilize the cell
  • it cannot be guaranteed that the developing embryo will also become implanted
  • it cannot be guaranteed that a miscarriage will not occur subsequently.

If you also considers that only about 30 % of eggs in a 30 year old woman will develop to an embryo capable of development (blastocyst), it becomes clear that a higher number of oocytes should be retrieved and frozen. For the embryo transfer of a blastocyst (for a 30 year-old woman) the probability of pregnancy is expected to be 35 %. If two blastocysts are transferred, a success rate of 50 – 60 % can be expected. The overall pregnancy rate from from the transfer of three sets of two blastocysts is a good 90 %!

However, it must be borne in mind that transferring two embryos is associated with a relatively high risk of twins. We therefore strongly prefer SET (Single Embryo Transfer). We recommend that approximately 30 oocytes be retrieved and frozen.

For this purpose, hormonal stimulation takes place in the first half of the cycle. Depending on the type of stimulation and dose, this will permit the retrieval of 5 – 15 (20?) oocytes per cycle. Because the high-dose stimulation typically used for IVF is associated with risks which make stimulation especially unsuited as a solution for an elective procedure like fertility preservation, we recommend the type of low-dose stimulation used for mini-IVF.

You will have to plan for 4 – 6 treatment cycles to obtain 30 oocytes. Each treatment costs approximately 1200.00 Euros plus long-term storage costs of approximately 300.00 Euros per year.

If you compare this with the potential cost of IVF for a patient who only learns at the age of 40 that fertilisation will no longer work with her own eggs, this is clearly a good investment. Conventional IVF costs approximately 4000.00 to 5000.00 Euros including medications and offers a success rate of 15 % in a patient aged 42 – 43 years.

Risks

Stimulation with clomifene and what is known as low-dose gonadotropin therapy are only associated with minor risks. Some feeling of fullness can be expected. Hyperstimulation is rare, and when it does occur, it is only of short duration (lasting for a few days).

Fertility preservation or fertility protection for medical reasons

Introduction

At birth, a female baby has approximately two million egg cells (oocytes) in her ovaries. This number will drop significantly before puberty to approximately 400,000 cells. In the subsequent fertile phase, women lose about 1000 oocytes per month. While the remaining number of oocytes decreases, their quality is reduced at the same time. While a 30 year-old woman may have one in two or one in three oocytes with normal chromosomes, in a 40 year old woman, this number is reduced to one in five or six oocytes.

Spontaneous pregnancy is only possible in about 10 % of women in their early 40s. It is rare for a woman aged over 45 to give birth to a child.

Unfortunately, a woman may suffer illnesses before she has made any plans for a family, the treatments for which may be life saving but also have a considerable impact on fertility. These conditions include cancer and endometriosis. Occasionally, there is only a short amount of time available between the diagnosis and the start of treatment (chemotherapy, radiotherapy or surgery).

In these cases, a decision should be taken as quickly as possible as to whether oocytes are to be preserved by freezing. Thanks to modern freezing techniques, it is now possible to preserve oocytes and thus to achieve pregnancy after undergoing treatment and after a certain waiting period has passed.

Endometriosis

Endometriosis is a disease which commonly affects fertility in a variety of ways:

  • If there is a mechanical obstruction affecting the transportation of semen and oocytes.
  • Inflammatory substances in the area surrounding the endometriotic lesion affect egg cell quality and the ability of the mucous lining in the uterus to hold embryos.
  • The surgical removal of endometriotic lesions always involves the loss of healthy tissue as well.

Mechanical fertility problems resulting from endometriosis can be treated with test tube fertilisation (IVF).

However, the loss of tissue from the ovaries cannot be reversed.

The earlier the onset of the disease, the longer it persists and the more radical the required treatment, the less likely it is that the woman will be able to become pregnant the natural way.

The disease is often diagnosed at a time when family planning has not yet been considered.

Cancer

If a woman suffers from cancer before or during her fertile years, her personal life planning is put at risk by the chemotherapy and/or radiotherapy she will need to undergo.

Maintaining fertility, fertility preservation

Appropriate steps can be taken to attempt to preserve the woman’s ability to conceive once she has recovered from her illness.

There are various approaches that can be taken depending on the age of the woman, the time to treatment, whether the woman currently has a partner and other factors.

Occasionally, it is sufficient to temporarily shut down the ovaries so that they are not attacked as aggressively by the chemotherapy. There are surgical procedures that can be performed to move the ovaries within the body to better protect them from radiotherapy.

Alternatively, ovarian tissue can be removed in the hope that egg cells can later mature from it or that this tissue will start to function again after reimplantation.

However, the cryopreservation (freezing) of egg cells is the simplest way to preserve fertility. Using the “slow cooling” approach which is still widespread in Germany, only (pre)inseminated egg cells can be preserved effectively. This means that this type of fertility preservation only makes sense if the woman has a steady partner with whom she would also like to have a child in the future.

Only vitrification permits the cryopreservation of non-inseminated egg cells with a very high survival rate. This enables women who do not yet have a partner or are not yet sure that they would like to have a child with their current partner to have their non-inseminated eggs preserved over a period of years.