How can feminine fertility be preserved?

There are multiple procedures that can be indicated when preserving fertility, and these may be classified depending on the age of the patient:

      • Prepubertal: these techniques are indicated in girls that still  have not reached puberty  and have to undergo through treatments which may jeopardize their future fertility, such as oncologic therapies. As puberty has not been reached in these patients, there will not be a natural ovarian functionality; there will be no ovulation. Therefore, those techniques based on hormonal treatments, such as oocyte extration, will not apply to this patients. 

 

      • Postpubertal: these patients have already reached puberty and have a natural ovarian functionality. Procedures may be sub-classified depending on:
        • If ovarian stimulation is indicated; consists of a hormonal treatment aimed to increase the number of follicles grown during the menstrual cycle.

Depending on whether a masculine sample (semen) is available or not, fertility will be preservated with one technique or another. 

        • If ovarian stimulation is not indicated. The diagnosis may not be compatible with this hormonal treatment, or requires a very quick solution, in which case this treatment will not be indicated due to insufficient time.

 
Some procedures might take place simultaneously with the treatments that are compromising this fertility, though, in the vast majority of the cases, the procedures will be done prior to the situation in which fertility is endangered in order to avoid this reduction on fertility or to preserve some of the previos fertility.

As well as there are procedures that have proven to be successful, some of them are still experimental (indicated with *).

For more information on each procedure, click on its name in the bright boxes!

 

 

 

 

Oocyte vitrification

Oocyte vitrifications is a technique based on a  ultrafast freezing  that consists on using cryoprotectant substances to protect the oocyte of the damage that this accelerated freeze may cause.

  • Ovarian stimulation 

    In natural cycles only one oocyte ovulate. With a hormonal treatment based on follicle-stimulating hormone (FSH) we aim to reach an ovarian hyperstimulation; the growth of multiple follicles in each cycle.

  • Oocyte retrieval

     Once these follicles have the right size (≈ 22 mm), they are collected via puncture and suction of the ovarian contents through the abdominal cavity. This surgery takes places under anesthesia. The content is collected in test tubes and handed to the embryologist. 

  • Selection

    In the IVF laboratory, the retrieved oocytes are evaluated. Those which have adequately madurated are selected, as well as those who have not achieved this maturity, or have degenerated, are disregarded. Before freezing, oocyte must undergo through  denudation; its granulosa cells must be eliminated.

  • Vitrification

    This techniques consists on dehydrating the oocytes by introducing them in increasing concentrations of cryoprotectant. Its aim is protecting the oocytes from the extreme temperatures achieves during freezing, preventing the cristallyzation of the cell, that leads to its death.
    Afterwards, the oocytes are retrieved and placed in a strip, named cryotop, that will be immersed in liquid nitrogen (-196ºC) and, next, stored in freezing tanks.

Other preservation techniques

 

 

Embryo vitrification

 Embryo freezing or vitrification is a protocol aimed to preserve embryos in optimal conditions for a later use. 

  • Stimulation, retrieval and selection

    These three stages are identical to those in  Oocyte vitrification; stimulation is used to ensure the growth of multiple follicles, followed by their retrieval and the selection of those that have an adequate maturity.

  • Sperm sample

    A semen sample is collected from the patient, whether by masturbation or surgical intervention. Spermatozoa obtain their fecundative capacity by a capacitation process, during which they will obtain the adequate motility and characteristics to fertilize the oocyte.

  • Fertilization

    The next stage consists on the union between the oocyte and the spermatozoa. It may be accomplished in a more “natural” way by a conventional In Vitro Fertilization (IVF), in which these oocytes are submerged in a solution of spermatozoa, therefore this sperm will have to find its way to the oocyte to achieve fertilization. The alternative is to use a intracytoplasmatic sperm injection (ICSI), in which the spermatozoa will be directly inserted in the oocyte’s nucleus. 

  • Embryo culture

    Once this fertilization is accomplished, embryo are left to grow, maximum 6 days, in a medium with adequate conditions for their survival. Their development will be monitored and those with better evolution and quality will be stored and freezed .

  • Vitrification

    Essentially, this vitrification stage is also identical to the one used for oocytes. However, the difference lies in the number of oocytes and embryos placed in each strip (or cryotop); while multiple oocytes may be freezed in one strip, embryos must be freezed separately, each one in a different strip, with a maximum of two per strip. 

Other preservation techniques

 

 

Oophoropexy

Also referred to as Ovarian Transposition , this procedure consists on moving the ovaries out from the radiation field
in order to maintain its functionality.

  • When do we use it?

    This technique is used when the ovaries are inside the radiation field. The goal is to protect these ovaries from the gonadotoxic effects of oncologic therapies, such as radiotherapy, and to prevent an ovarian failure.

  • How is it done?

    This surgical intervention consists on moving one or both of the ovaries out of the pelvis and attach them to the abdominal wall, in order to reduce the incident radiation.  It is achieve by a laparoscopic technique; by an incision on the abdomen.

  • Principal complications

    1. Vascular lesions which may block the blood suply and cause an ovarian failure

    2. Triggering ovarian cysts formation, which may interfere with pregnancy.

    3. Triggering adhesions formation, fibrous bands formed between the pelvic organs provoking their adherence and a loss on their functionality.

    4. Ovarian failure by scattered radiation.

  • Statistics

        ■  Radiation level on the ovary: 5-10%

        ■  Prevention capacity: 16-90% (depending on dosage, scattering, vascular damage and age)

Other preservation techniques

Some experimentation has taken place with the cryopreservation of the entire ovary, claiming this would allow to recreate the procedure if any malfunction would occur.

  • Statistics

    It is considered an experimental technique. Due to the high success and survival rates in other cryopreservation techniques, as those dealing with oocytes, this procedure will be performed as a last resource, in the mentioned situations.

 

Ovarian tissue cryopreservation

A biopsy
is required in order to freeze this ovarian tissue; it is based on the extraction of a slice of tissue that contains the oocytes precursors cells . This tissue will be processed before freezing.

  • When do we use it?

    This procedure is conducted in the following situations:

      Childhood cancer: When girls must go through an oncological treatment before having reached puberty, not having the ability to ovulate.

      When the ovarian stimulation is contraindicated, or there is insufficient time to conduct that, due to a need of oncological treatment.

  • Retrieval

    This technique is based on an ovarian cortex biopsy in order to retrieve a section of tissue, containing the oocytes precursors. This tissue will be dissected and thinly sliced in strips.

  • Cryopreservation

    Those ovarian tissue strips, namely know simply as strips, will be immersed in solutions to protect them from quick-freezing and, finally, freezed in liquid nitrogen, inside special containers.

  • Fertility re-establishment

    After thawing, several strategies may be carried on to restore the patient’s fertility:

      A. Orthopic transplantation: Consist in reintegrate this ovarian tissue on a close-upon range to the ovary, or even inside this same ovary, if available.  With this procedure it is viable:

         – Achieving a natural fertilization, in rather remotely situations.

         – Restoring functionality in the ovary to retrieve the oocytes.

      B. Heterotopic transplantation: In this occasion, the tissue will be reintegrated on a distant range from the ovary, for instance the underarm. This strategy aims to recover the functionality in the ovary and, therefore, to achieve the oocyte’s retrieval.

      C. Follicle maturation: Another strategy to conduct might be an in vitro follicle maturation, found in the tissue, to pursue an in vitro fertilization.

  • Technical complexities

    ■  Dealing with a whole tissue means dealing with a thicker sample and different cell types.

      As this is performed in patients with cancer, the sample may contain cancerous cells.

Other preservation techniques

Hormonal suppression

This procedure entails using hormones for the purpose of stopping the ovarian functionality.

  • When do we use it?

    Indicated to women, past the age of puberty, whoSe utiliza en mujeres que, ya habiendo alcanzado la pubertad, wo must undergo medical treatments which may induce an early ovarian failure.

  • How does this work?

    Some hormones (GnRH) are given to the patient a few days before starting her medical treatment, or on the first days.

    GnRH is responsible for stimulating the synthesis of the other hormones involved in the menstrual cycle (LH and FSH). Its administration aims to cause a “temporary menopause”; ovaries will stop being stimulated during this hormonal suppresion treatment. That way, the number of harmed oocytes will be reduced.

  • Facts

       ■  It is recomended using this procedure as support, complemented by others with higher success rates, such as oocyte or embryo vitrification.

       ■ There is still some disagreement regarding the efectiveness of this technique on its own.

       ■ May cause menopausal symptoms

Other preservation techniques

Radical trachelectomy

Also known as Radical cervicectomy; Is a surgical intervention consisting on the removal of the cervix and the sorrounding lymph nodes.

  • When do we use it?

    It is indicated in patients suffering from cervical cancer in early stages.

  • How does this work?

    The intervention consist on the removal of the cervix, and the surrounding lymph nodes, a través through the vagina or the abdominal cavity. Once removed, the uterus is connected to the remaining vagina, with a special band acting as cervix and creating an opening to imitate the natural anatomy of the woman’s reproductive tract.

  • Disadvantages

      This procedure only applies to cervical cancer early stages.

      May result in spontaneous abortions in future pregnancies.

Other preservation techniques

 

Gonadal protection

Used during radiotherapy treatments in order to preserve the patient’s fertility by preventing direct damage to genital organs.

  • When do we use it?

    It is indicated in patients requiring radiotherapy treatments on or around the pelvic area.

  • How does this work?

    The procedure is based on the placing of a shield on the pelvic area during the radiotherapy session, covering the genital organs. 

  • Types of shield

    Two types of shield may be used:

    Shadow shields: these are placed hanging above the patient’s body so its shadow covers the pelvic area in order to protect it.

    Contact shields: these are opaque shields placed directly on the pelvic area. May, or may not, be shaped to adapt to the anatomy. 

Other preservation techniques

What?

What is feminine fertility preservation?

When?

When, and why, is fertility compromised?

How?

How to preserve fertility?

   

“Brindemos por las mujeres fuertes: Que las conozcamos. Que las seamos. Que las criemos.