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PubMed2006

Feminists on the inalienability of human embryos.

The feminist literature against the commodification of embryos in human embryo research includes an argument to the effect that embryos are "intimately connected" to persons, or morally inalienable from them. We explore why embryos might be inalienable to persons and why feminists might find this view appealing. But, ultimately, as feminists, we reject this view because it is inconsistent with full respect for women's reproductive autonomy and with a feminist conception of persons as relational, embodied beings. Overall, feminists should avoid claims about embryos' being inalienable to persons in arguments for or against the commodification of human embryos.

Commodification↗
PubMed2003

Assisted reproduction--Islamic views on the science of procreation.

The field of assisted reproduction is one of the fastest growing areas in medicine. The development of new and sophisticated techniques all aim to give reproductive technologies and scientists a better understanding of reproductive biology. The development of new techniques may also be able to improve the chances of an infertile couple towards achieving a pregnancy. However the ethics and legality of assisted reproductive technology must not be brushed aside. Islamic scholars whose reference basis resides in the Holy Quran and the Hadith have addressed different issues relating to assisted reproductive technology. Some of the issues remain controversial and need detailed discussion before it can be deemed as appropriate and legible for use as guidelines in the development of the processes involved.

Beginning of Human Life↗
PubMed2004

Mechanisms regulating toxicant disposition to the embryo during early pregnancy: an interspecies comparison.

The dose of toxicant reaching the embryo is a critical determinant of developmental toxicity, and is likely to be a key factor responsible for interspecies variability in response to many test agents. This review compares the mechanisms regulating disposition of toxicants from the maternal circulation to the embryo during organogenesis in humans and the two species used predominantly in regulatory developmental toxicity testing, rats and rabbits. These three species utilize fundamentally different strategies for maternal-embryonic exchange during early pregnancy. Early postimplantation rat embryos rely on the inverted visceral yolk sac placenta, which is in intimate contact with the uterine epithelium and is equipped with an extensive repertoire of transport mechanisms, such as pinocytosis, endocytosis, and specific transporter proteins. Also, the rat yolk sac completely surrounds the embryo, such that the fluid-filled exocoelom survives through most of the period of organogenesis, and can concentrate compounds such as certain weak acids due to pH differences between maternal blood and exocelomic fluid. The early postimplantation rabbit conceptus differs from the rat in that the yolk sac is not closely apposed to the uterus during early organogenesis and does not completely enclose the embryo until relatively later in development (approximately GD13). This suggests that the early rabbit yolk sac might be a relatively inefficient transporter, a conclusion supported by limited data with ethylene glycol and one of its predominant metabolites, glycolic acid, given to GD9 rabbits. In humans, maternal-embryo exchange is thought to occur via the chorioallantoic placenta, although it has recently been conjectured that a supplemental route of transfer could occur via absorption into the yolk sac. Knowledge of the mechanisms underlying species-specific embryonic disposition, factored together with other pharmacokinetic characteristics of the test compound and knowledge of critical periods of susceptibility, can be used on a case-by-case basis to make more accurate extrapolations of test animal data to the human.

Animals↗
PubMed1999

Establishment of a successful donor embryo program: medical, ethical, and policy issues.

OBJECTIVE: To determine how couples prefer to dispose of their extra embryos and to establish a donor embryo program for the treatment of infertile couples. DESIGN: Cohort study. SETTING: University-based IVF program. PATIENT(S): Patients (n = 365) with cryopreserved embryos in storage for >2 years and eight patients who desired donated embryos for transfer. INTERVENTION(S): An IVF ethics committee was formed to discuss the ethical and policy issues involved in starting an embryo donation program and to establish program guidelines. Couples with embryos cryopreserved for > or = 2 years were contacted to determine their desires for disposition of embryos. Potential recipients of donated embryos were identified in our clinic, and donated embryos were transferred to these patients. MAIN OUTCOME MEASURE(S): Desires for embryo disposition and pregnancy rates. RESULT(S): Most couples elected either to continue storage of their embryos for future use (44%) or to discard their embryos (34%). A minority elected to donate their embryos either to infertile couples (11%) or for research (10%). Eight couples have had donated embryos transferred, and four have conceived ongoing pregnancies. CONCLUSION(S): Although only a small percentage of couples are willing to donate their embryos, the resulting number of embryos for use is substantial. Transfer of donated embryos results in a high pregnancy rate and is a cost-effective treatment of infertility.

Cohort Studies↗
PubMed2005

The social implications of embryo cryopreservation.

OBJECTIVE: To summarize the existing literature regarding the social implications of embryo cryopreservation and outline areas in need of further study. RESULT(S): The potential social impact of oocyte cryopreservation has not been investigated. Embryo cryopreservation has been increasingly used to improve the cost-effectiveness of in vitro fertilization (IVF) and expand the options available to infertile couples, yet its widespread adoption has occurred more rapidly than our ability to study the social consequences for the couples and health professionals involved. For maintaining cryopreserved embryos, the existing literature is fragmented and incompletely explores the effects on an infertile couple's psychosocial health and personal relationships, their family planning strategies, or their preferences for the disposition of the embryos. Managing unclaimed embryos continues to create challenges for assisted reproduction professionals. CONCLUSION(S): We currently lack a thorough understanding of the numerous social implications of cryopreservation. Major areas for future research include the impact of stored embryos on couples' fertility intentions and psychosocial health, factors that affect couples' decisions about embryo disposition, strategies to minimize unclaimed embryos, and the consequences of oocyte/ovarian cryopreservation.

Cryopreservation↗
PubMed1999

Regional patterning of reticulospinal and vestibulospinal neurons in the hindbrain of mouse and rat embryos.

The dispositions and axonal trajectories of bulbospinal neurons in the pons and medulla of mouse and rat embryos is described from the earliest times these projections can be labelled retrogradely from the cervical spinal cord. Reticulospinal and vestibulospinal neurons are clustered into identifiable groups, each with a characteristic combination of spatial domain and axon trajectory. The various groups can be labelled retrogradely in a specific developmental sequence. The position of some groups shifts from medial to lateral with development, apparently through cell migration. These observations show that the basic regional organization of the reticulospinal and vestibulospinal projections is similar in mouse and rat and is already established during early stages of axon outgrowth.

Animals↗
PubMed1992

A ray of light about frozen embryos.

The Tennessee Supreme Court's decision in Davis v. Davis, a case that raises the question of how to allocate frozen embryos in the event of divorce, addresses many of the legal issues posed by in vitro fertilization. The decision considers the interests of the progenitors as well as of the children who may result. For example, the court held that gamete providers' discretion regarding the disposition of embryos can be limited only when their decisions would harm the children who might be born. The court also made clear that efforts to seek genetic parenthood are protected only when accompanied by a desire to raise the resulting children, a conclusion that also affects other reproductive technologies. In addition to elaborating an analytic framework, the court set guidelines for resolving disputes when the couples had made no prior agreements, including holding that while the embryos are ex-utero the desire to avoid genetic parenthood almost always trumps the wish to become a parent. The well-reasoned analysis in Davis v. Davis should help shape legal and ethical discussion regarding the use of in vitro fertilization for many years to come.

Civil Rights↗
PubMed2005

Eligibility of cryopreserved human embryos for stem cell research in Canada.

OBJECTIVE: To determine whether cryopreserved embryos in Canadian in vitro fertilization (IVF) clinics available (in theory) for research use are actually eligible (in practice) for stem cell research in accordance with the Assisted Human Reproduction Act, the Canadian Institutes of Health Research's Human Pluripotent Stem Cell Research: Guidelines for CIHR-Funded Research, and the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans. METHODS: Copies of current and past patient information sheets and consent forms for embryo cryopreservation, the future disposition of cryopreserved embryos, and the donation of cryopreserved embryos for research were requested from Canadian IVF clinics. Fourteen of 24 clinics (response rate 58%) provided one or more of the requested documents. RESULTS: A review of the documents currently in use showed that, as of May 2005, all 14 responding clinics require an advance directive for the eventual disposition of cryopreserved embryos. Ten of these 14 clinics allow the donation of cryopreserved embryos for research. Only three of these 10 clinics, however, satisfy in writing the disclosure requirements for embryo research at the time of initial consent for the cryopreservation and future disposition of embryos. Only one clinic specifically identifies the option of embryonic stem cell research. CONCLUSION: Only three of the responding Canadian IVF clinics provide written details about future donation of cryopreserved embryos for research use and about the need for re-contact in accordance with relevant legislation and guidelines. Two of these three clinics, however, include disposition options that may not be legally available. In the event of death or loss of contact, it will not be possible to get project-specific research consent from the legitimate embryo providers as required by law. These same two clinics also fail to mention embryonic stem cell research as one of the research categories. It follows that we have identified only one Canadian IVF clinic with cryopreserved embryos unequivocally eligible for stem cell research, provided the forms we reviewed were used to obtain consent for the cryopreservation of those embryos.

Canada↗
PubMed2003

Factors associated with disposition of cryopreserved reproductive tissue.

OBJECTIVE: To study patient characteristics associated with the preferences for the disposition of cryopreserved semen and embryos in the event of death or divorce. DESIGN: Retrospective exploratory study. SETTING: Tertiary care academic medical center. PATIENT(S): One hundred twelve men banking sperm, 54 female patients (partners of men banking sperm) undergoing in vitro fertilization (IVF), and 112 women undergoing IVF who were not partners of men banking sperm. INTERVENTION(S): Male patients banking sperm and couples undergoing IVF completed a standard consent form detailing their desired dispositions (disposal or release to a surviving party) of cryopreserved sperm and embryos in the event of death or divorce. MAIN OUTCOME MEASURE(S): Effect of marital status, age, reason for sperm banking, infertility diagnosis, partner status (single or significant-other partner) on sperm, and embryo disposition choice. RESULT(S): In the event of death, married men were 5.5 times more likely to release banked sperm to a surviving party than were single men. The estimated odds of giving sperm to a survivor were 1.07 times greater with every 1-year increase in age. The choice of sperm disposal was significantly related to the banking reason for the case of banking prior to chemotherapy and/or radiation for malignancy. In the case of male death, the decisions of couples undergoing IVF for embryo disposition agreed with choices of male patients for sperm disposition approximately 33% of the time more often than by chance alone. CONCLUSION(S): Decisions surrounding disposition of cryopreserved sperm are significantly associated with marital status, age, and reason for banking sperm. Respective choices of sperm and embryo disposition in couples undergoing IVF were similar in the situation of male death.

Adolescent↗
PubMed2003

Dealing with cryopreserved embryos upon divorce: a contractual approach aimed at preserving party expectations.

The development of assisted reproductive technologies, including cryopreservation, or freezing, of embryos created through in vitro fertilization, has given rise to complex legal questions. Because cryopreservation permits indefinite storage of embryos, if couples fail to specify disposition directions, they may disagree regarding embryo treatment upon the occurrence of contingencies such as divorce. Few courts have resolved such disputes, and those that have appear to uphold the rights of the party seeking to prevent implantation in the absence of a written agreement specifying otherwise. In this Comment, Sara Petersen proposes that courts should draw upon contract law principles in determining whether the parties to such conflicts actually reached agreements regarding embryo disposition in the event of divorce. After analyzing existing precedent, the author assesses proposed approaches for deciding which party's interests should prevail and concludes that these methods are inherently ineffective. She then argues that, in an effort to preserve party expectations and to provide fair results, courts instead should examine whether the parties executed binding contracts or achieved mutual assent. Furthermore, she suggests that couples undergoing cryopreservation will be more likely to contemplate and to provide for various outcomes if they know that courts will look at evidence of their conversations and thought processes prior to cryopreserving their excess embryos.

Contracts↗