Reproductive Technologies: VII. Sperm, Ova, and Embryos

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VII. SPERM, OVA, AND EMBRYOS

The technical ability to freeze sperm, embryos, and eventually ova for long periods and then thaw them without destroying their biologic potential offers several new reproductive options for both fertile and infertile individuals. It makes the donation of eggs, sperm, or embryos to treat infertility a more efficient and safe procedure. It also allows individuals and couples to preserve sperm, eggs, and embryos to protect against future reductions in gametic viability due to age, disease, or occupational exposure, and permits posthumous reproduction to occur.

As with any technological deviation from the natural mode of conception, these techniques raise both medical questions of safety and efficacy and ethical, legal, and social questions about prohibition, restriction, or regulation of these practices. Once cryopreservation is medically established as safe and effective, its ethical, legal, and social acceptability depends on a general acceptance of noncoital and assisted means of reproduction, with specific issues relating to the particular technique in question.

Sperm

Cryopreservation of sperm is now well established medically and socially as a commercial enterprise. Sperm banking occurs as an aspect of infertility practice, or as an option for men who foresee damage to their gametes as a result of disease or occupational exposure. In the former case, a commercial sperm bank recruits sperm providers, screens them medically and socially, and usually pays them a fee for their sperm (technically they are vendors rather than donors of sperm though the latter word is commonly used to describe their role). The sperm is then distributed to doctors or others who practice artificial insemination with donor sperm, who in turn resell or distribute it to recipients.

A main legal and ethical issue with regard to this practice is the duty of the sperm bank to screen sperm donors and their sperm for infectious diseases, including the human immunodeficiency virus (HIV). Guidelines of the American Fertility Society, the main professional organization of physicians treating infertility, now recommend that donated sperm be screened for HIV diseases. Because there may be a six-month gap before HIV transmission shows up on antibody screening tests, screening requires that the donated sperm be quarantined for six months so that a second test can be performed on a sample to ensure that it is not HIV-infected. Failure to screen in this way is unethical and could make the sperm bank legally liable for transmission of HIV to recipients and offspring.

There are no laws that restrict to whom sperm banks may sell their sperm, and in the United States, the buying and selling of sperm is not generally covered by federal or state laws against selling organs, though several European countries prohibit the practice. Thus a bank could sell sperm to a single woman or representative organizations for use in inseminating single women. Despite fears that a bank or physician who provides sperm to an unmarried woman could be held liable for financial support of a child born as a result, no such legal liability has yet been imposed. While some persons find artificial insemination of single women to be unethical, and the practice is prohibited in some countries, it can allow women who otherwise could not bear children to reproduce, and unmarried women who are committed to reproduction in this way have been shown to be able childrearers.

Commercial sperm banks also provide service to individuals or couples who wish to store sperm for later use because of treatment of disease, occupational exposure, or fear of later impotence. Because no legislation specifically applies to this practice, its legal status would depend upon basic contract law. The depositor would be entitled to keep the sperm in the bank and retrieve it under conditions specified in the contract of deposit. Thus sperm could be released to the depositor or to his designee posthumously, if that is envisaged, and the bank would perhaps have no obligation to maintain the sperm past a specified time if failure to pay storage charges should occur. Clear specification of rights and duties in the original contract is essential. While posthumous release of stored sperm to the appropriate designee could lead to the birth of a child without a rearing father, this situation is similar to the insemination of an unmarried woman and should be treated similarly. Whether a child born posthumously will be able to share in a deceased's estate is a matter of state inheritance law that does not affect the ethical, legal, or social acceptability of the practice.

The bank would, of course, have a legal duty to return the correct sperm to the depositor. At least one case has arisen in which the bank returned the wrong sperm, which led to the birth of a child who was not of the same race as the depositor. In such instances, suits for damages are likely to be successful. An important issue will concern damages, because there is no way to establish that in fact the lost gametes would have implanted and produced a child. In addition, some states regulate the operation of sperm banks as medical or clinical laboratories to protect the health and safety of consumers of their services.

Many of the issues that arise with commercial sperm banks would also apply to physicians who recruit sperm donors directly. They too would have ethical and legal duties of reasonable care to assure that donors have been tested for genetic and infectious disease. They would also be free to inseminate single women and use sperm posthumously, if that is the clear intention of the parties.

Ova

The ability to freeze and then successfully thaw ova has not yet been developed, due to the larger size of the ovum and the great amount of fluid in it. Once this ability is developed, egg banking will occur.

Frozen ova have less ethical significance than frozen embryos. Once the technical ability to freeze and thaw ova safely is developed, they will play an important role in enabling women to initiate pregnancies through in vitro fertilization (IVF), which involves hormonal stimulation of the ovaries to produce ova, often many more than are needed for fertilization at that time; freezing the extra ova will minimize the need for additional cycles of egg retrieval. Rather than inseminate all eggs retrieved in a cycle of IVF treatment, many couples will prefer to freeze extra eggs, which can then be thawed and inseminated for later attempts at pregnancy. Cryopreservation of ova, rather than embryos, may thus become the preferred method of storage.

Once ova freezing and banking begins, the same issues that currently arise with cryopreservation of sperm will occur. Commercial ova banks, which may be associated with sperm and embryo banks or exist independently, will be established. No doubt such banks will both buy or procure eggs from women and then resell them to doctors and couples in need of an egg donation. The main issues will then concern what the precise arrangement is between the donor and the bank concerning subsequent use, whether the bank will be responsible for genetic and infectious disease screening, and whether the bank will be responsible for any rearing costs of offspring.

With eggs that have been frozen for subsequent use in initiating pregnancy in an infertile couple, the agreement between the woman or couple and the storage facility will be of paramount importance. The depositor of the eggs will be the owner and will control release or discard of cryopreserved ova within the limits of the storage facility's policies. Thus the contract between the depositor and the facility would largely control deposits of eggs prior to disease treatment or occupational exposure or to use then or at a later time. As long as the depositor has paid storage charges, she would be entitled to have the eggs stored, to expect reasonable care to be taken in their maintenance, and to have the eggs released, transferred, or discarded as directed. Posthumous release and use of stored eggs should be as acceptable as posthumous release and use of stored sperm. As with sperm banking, failure of payment could lead to the bank taking the eggs out of storage, but it would not be entitled to transfer them to other persons in lieu of payment unless there were a specific agreement to that effect. Professional or even legislative regulation of ova banking to ensure standards of health and safety can also be expected.

Embryos

Cryopreservation of embryos (sometimes referred to as preimplantation embryos or pre-embryos) is now a well-established adjunct to IVF programs. Standard IVF treatment often produces more eggs than can be safely fertilized and placed in the uterus at one time. Rather than fertilize only the number of eggs that could be safely transferred or fertilize all retrieved eggs and discard the surplus, cryopreservation allows all eggs to be fertilized, a safe number such as two or three placed in the uterus, and the rest frozen for later use. At a later time, the frozen embryos can be thawed and placed in the uterus, donated to others, or discarded. Although the success rate is not as great as with fresh embryos, the pregnancy rate of both fresh and frozen embryos from a single egg-retrieval cycle is 15 to 20 percent greater than the rate from use of fresh embryos alone. Until the ability to freeze and thaw ova is developed, the excess eggs retrieved in a cycle of IVF treatment are likely to be inseminated and then cryopreserved for use during a later cycle.

The main issues that arise with cryopreservation of embryos concern the ethical and legal status of embryos and the locus of dispositional authority over frozen embryos. While some persons have argued that embryos are persons or moral subjects with all the rights of persons, and others claim that embryos are merely tissue with no special status or rights, a wide ethical and legal consensus in the United States, Europe, and Australia views embryos as "deserving of special respect, though not the respect due persons." As a result, embryos may be created, frozen, donated, and even discarded or used in research when there is a valid need to treat infertility or pursue a legitimate scientific goal and rules concerning consent of the gamete providers and institutional review board approval have been followed.

With regard to dispositional authority over frozen embryos, it is now well established that the couple providing the gametes has dispositional authority within the limits of state law and the conditions of storage set by the IVF program or storage facility. If they agree to have embryos created from their gametes cryopreserved, they are owners of the embryos and may decide on any disposition of frozen embryos that their agreement with the storage facility and applicable statutes permit.

Since the frozen gametes are the joint property of the persons providing the gametes, their joint consent is needed for disposition until they relinquish or transfer their dispositional authority to others. To maximize their control over embryos and to introduce administrative efficiency into the operation of embryo banking, they should also give written directions at the time of storage for disposition of frozen embryos in the future if the providers have died, divorced, are unavailable for decision, or are unable to agree between themselves on disposition.

In such cases, the IVF program or embryo bank should be able to rely on this prior agreement in decisions concerning stored embryos. This will give advance control to the parties and clear directions to the bank and minimize costly disputes about what to do with stored embryos. Although no court has yet been faced with a case directly involving a disputed contract, there have been cases recognizing the right of the depositing couple to remove their frozen embryo from a bank against the bank's wishes. There is also legal authority recognizing the validity of such advance contracts for disposition in case disputes arise.

The Davis v. Davis case (1992) illustrates the wisdom of giving effect to the prior agreement. A couple had frozen seven embryos pursuant to their efforts to have children via IVF. They subsequently decided to divorce but could not agree on disposition of the frozen embryos. The husband opposed thawing them and using them to start pregnancy, while the wife insisted that she or another person have them placed in her. The Tennessee Supreme Court finally resolved this issue by ruling that an agreement between the parties for disposition in the case of divorce would have been binding, and that in the absence of such an agreement, the relative burdens and benefits of a particular solution must be examined. In that case if the party wishing to retain the embryos had other means of obtaining embryos, such as by going through IVF again with a new partner, that party's wish to have children could still be satisfied without foisting unwanted parenthood on the party who wished that the embryos not be used. On the other hand, if there was no other way for that party to be reasonably able to produce embryos, so that the existing embryos were the last resort or chance to have offspring, then they should be entitled to use them. In that case, fairness would require that the objecting party not have to provide child support. In the facts presented to it, the court ruled in favor of the husband, who did not want frozen embryos implanted after divorce, because the wife had alternative ways to reproduce.

Ethical and legal codes for assisted reproduction in other countries have not yet addressed the problem that arose in the Davis case. A country could take the position that all embryos must be preserved, or that provision of gametes for IVF is a commitment to have all resulting embryos placed in the uterus. However, the American preference to have the parties control disposition in the case of divorce or disposition by prior agreement might also be recognized, for it maximizes the procreative liberty of the parties directly involved.

The authority of the gamete providers over the disposition of frozen embryos can be limited by law or the policies of the banks or facilities where frozen embryos are stored. For example, some European countries (Spain and Germany) prohibit embryo discard and research, while others (Great Britain, for example) limit the period of storage to a maximum of ten years or the reproductive life of the woman, whichever is longer. While U.S. legislation on these issues is largely absent, the Ethics Committee of the American Fertility Society (1986) has recommended a similar maximum period of storage, and individual embryo banks and programs for religious or administrative reasons have imposed limitations on dispositions that involve discard, donation, or release of frozen embryos to other programs. As long as the storage facility makes clear its restrictions on disposition of frozen embryos, it may impose these restrictions on couples who request storage of embryos at that facility.

Conclusion

Cryopreservation of sperm, ova, and embryos offers individuals options to extend or enhance their reproductive ability and should presumptively be recognized as adjuncts of their procreative liberty. If this view is accepted, principles of informed consent and contract will inform and regulate most of the transactions and activities that occur with cryopreserved gametes and embryos. In some cases legislation to protect the parties' wishes and ensure the health and viability of stored gametes and embryos may also be desirable.

john a. robertson (1995)

bibliography revised

BIBLIOGRAPHY

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Davis v. Davis. 842 S.W.2d 588 (Tenn. 1992).

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Murphy, Timothy F. 1995. "Sperm Harvesting and Postmortem Fatherhood." Bioethics 9(5): 380–398.

Robertson, John A. 1986. "Embryos, Families, and Procreative Liberty: The Legal Structure of the New Reproduction." Southern California Law Review 59(4): 939–1041.

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Encyclopedia of Bioethics