Fertility and Fertility Preservation-Beware of What You Read

Fertility treatment especially assisted reproductive technology-IVF enabled many women to achieve pregnancy even those with the most difficult cases of infertility. Advances include ICSI-injection of a single sperm into an egg ,  PGD-biopsy of embryos and polar bodies for genetic diagnosis, of specific genetic diseases, prolonged culture of embryos to blastocyst stage-day 5 to 7 and TESE-surgical sperm retrieval.

Meanwhile, a new host of fertility treatments emerged in the past 10 or so years that were not thoroughly studied including egg freezing, ovarian tissue freezing and transplantation, IVM-in vitro maturation of oocytes, PGS-preimplantation genetic screening for chromosomal abnormalities in the emryo or oocyte and generation of ‘artificial’ eggs or sperm. These procedures carry great promise to advance reproductive options for men and women and can be tailored to their medical or social circumstances.

Potential issues with new reproductive technologies include efficacy, short and long term risks to the mother and children. The American Society for Reproductive Medicine-ASRM states that “procedures for the diagnosis or treatment of infertility will be considered experimental or investigational until the published medical evidence regarding their risks, benefits and overall safety and efficacy is sufficient to regard them as established medical practice”

Information disseminated about fertility procedures online and in lay press are sometimes inaccurate or convey unrealistic expectations. Recently, a same sex couple curbside me to recommend a physician to harvest one partner bone marrow to produce artificial gametes that can then be used with the other partner gametes. When I explained to them that this experimental and was never accomplished in humans, they were very  dismayed and disappointed, confirming that they read about the procedure  online.

Looking at published studies discussing new reproductive technologies one can infer

Egg freezing

Still considered investigational by the American Society for Reproductive Medicine. Not suitable for all patients based on their ovarian reserve. No large studies comparing the efficiency of egg freezing in comparison to the established technology of embryo freezing. No long term follow up data for children conceived using thawed oocytes.

Ovarian stimulation in estrogen sensitive cancers

Using conventional protocols for ovarian stimulation in breast cancer and other estrogen sensitive cancers was not studied in terms of its effects on cancer recurrence. Using special protocols to reduce estrogen exposure during stimulation was not studied long enough. In short and intermediate terms, however, it does not appear to increase recurrence.

Ovarian Tissue Freezing

This is the most investigational technique for fertility preservation. Ovarian tissue is harvested and frozen for later transplantation. Only sporadic case reports were published. It is considered in women with very high risk for ovarian failure e.g. after chemotherapy. There is also the risk for transmission of malignant cells within the graft at the time of transplantation. The outcomes of children conceived after transplantation is unknown.

In vitro maturation

Immature eggs are not suitable for fertilization with sperm. Immature eggs can be harvested, matured in the lab then fertilized or frozen. ‘Cultivating’ very immature eggs from primordial follicles in the lab is experimental and was not done in humans yet. Immature eggs obtained after short period of ovarian stimulation can produce a viable children.  This procedure is more applicable to women with very good ovarian reserve. The long term safety of the procedure is not known yet.

Pre-implantation genetic screening for aneuploidy

Many eggs in every woman are not chromosomally normal-having an extra or missing chromosome-egg quality. Fertilization of these eggs result in chromosomally abnormal embryos. The majority of abnormal embryos do not implant or are miscarried. Testing of embryos to select the normal ones was suggested as a method to increase the pregnancy rate. This is yet to be proven in a peer-reviewed scientific publication. The exact embryo stage to test and the method of testing are still debated.

Artificial gametes

The concept that eggs and sperm can be generated from human embryonic stem cells was shown in mice. The function of the resulting gametes is unknown. This was never accomplished in humans. If functional gametes can be produced from other cells, likely applying this technology in medicine will require another decade or more.

Beware of what you read

Many new reproductive technologies are available to address one or more medical or social issues related to reproduction. Some of these technologies are experimental, not efficient or their outcomes not studied long enough to ensure its safety. They may be applied in limited or monitored settings e.g research or for those that at risk for loosing their fertility and have no other options. Detailed discussion with woman / couple is essential to ensure that the they have realistic expectations concerning their outcomes and that uncertainty about their safety is clearly explained.

Read more at http://nycivf.org

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