Regulating Preimplantation Genetic Diagnosis in the United States

The Limits of Unlimited Selection

M. Bayefsky, B. Jennings

• Publisher: Palgrave Pivot
• Year: 2015
• ISBN:
  9781137515445
• Topic: Politics & International Relations
• Subtopic: Politics
• Index: Politics & International Relations

Reproductive technology allows us to test embryos' genes before deciding whether to transfer them to a woman's uterus. Embryo selection raises many ethical questions but is virtually unregulated in the United States. This comprehensive study considers the ethical, medical, political, and economic aspects of developing appropriate regulation.

1

Introduction

Abstract: In this chapter, we lay out the potential and actual uses of preimplantation genetic diagnosis (PGD). We include an explanation of the medical process and current limitations of reproductive medicine and genetic sequencing technology, as well as a presentation of existing empirical data on the use of PGD in the United States. We then briefly summarize the ethical dilemmas surrounding various uses of PGD, including nonmedical sex selection, selection against adult onset diseases, selection for a tissue match for a sick sibling, and selection for a disability such as deafness. The chapter also includes a description of the current regulatory landscape for PGD in the United States as compared to two Western European countries (the UK and France), and ends with a discussion of the relationships between health care financing in the United States, insurance coverage of PGD, and the current dearth of regulation.

Bayefsky, Michelle and Bruce Jennings. Regulating Preimplantation Genetic Diagnosis in the United States: The Limits of Unlimited Selection. New York: Palgrave Macmillan, 2015. DOI: 10.1057/9781137515445.0003.

As science and medicine rapidly advance, philosophers, social scientists, and policymakers struggle to apply ethical and policy frameworks to the use of new technologies. Ordinary citizens also struggle with the moral, religious, and personal implications of biotechnology. Sometimes, as with human reproductive cloning, there is a strong public response, numerous state bans, and a general consensus that a particular procedure is deeply problematic from an ethical and social point of view. Other times, as with stem cell research, public opinion is divided on the question of whether the application is acceptable, and the government intervenes to draw moral lines in the sand and restrict public funding for research. In yet other situations, the public is undereducated, federal and state governments are silent (or paralyzed), and medical technology continues to advance relatively unfettered by moral and regulatory restraints.

This latter pattern has been the case in the United States with the technology that is the subject of this book: preimplantation genetic diagnosis (PGD). PGD is a procedure performed on embryos following in vitro fertilization (IVF) or on polar bodies (to preclude an X linked disorder) in order to obtain genetic information prior to uterine implantation. Couples wishing to benefit from PGD may decide to go through the process of IVF even though they are not infertile. Normally, several embryos are created for PGD and some are selected for transfer into the uterus, while others are discarded, including those in which no genetic abnormality was found.¹ Although the ethical dilemmas and implications surrounding the use of PGD are significant and have been the subject of scholarly exploration, the technology continues to be unregulated by either federal or state law.

PGD was first successfully used in 1989 as an alternative to prenatal genetic testing, which can pose an anguishing decision concerning abortion. Initially, it was designed to identify a small number of serious genetic disorders that would cause chronic illness and/or foreshorten life (such as cystic fibrosis, fragile X, beta thalassemia, Tay-Sachs, and sickle cell anemia). But as genetic science and technology have advanced, PGD has come to be used for a broader range of conditions and purposes. PGD thus raises a number of provocative bioethical issues that are both philosophical and ethical, including the definition of disease, the specter of eugenics, the rights of parents to decide the genetic makeup of their children and governments to restrict the procreative freedom of its citizens. Even beyond these powerful questions, PGD differs from other controversial innovations in medical technology in its ability to impact the future of our species. By testing embryos’ genes and choosing to implant some embryos rather than others, doctors and scientists make permanent changes in the genetic makeup of future generations. Given the far-reaching consequences of this technology, it is imperative that we carefully examine the ethical implications of its various potential applications before deciding whether and how to restrict its use.

This book will explore the numerous ethical issues surrounding the use of PGD. Rather than attempting to resolve these moral issues or end debate, however, we aim to lay out the competing values and moral views at stake. Above all, we focus on the question of the governance of genetic technology in the case of PGD: should PGD be regulated in the United States, and if so, how could this be done in the context of current medical, political, and economic realities? We do not take this current context to be immutable, however, as it reflects the views and interests of the relevant stakeholders and the general populace, and these factors are contingent and dynamic. Our analysis will draw upon interviews with fertility specialists, patient advocates, philosophers, and representatives of physicians’ associations, along with survey data on the public’s views on PGD. Our goal is to provide an account of the pertinent ethical questions, the regulatory options in the current practice of PGD, and the barriers to developing regulations for PGD in the United States.

Preimplantation genetic diagnosis: the technique and its uses

Preimplantation genetic diagnosis is the technique used during in vitro fertilization (IVF) to check an embryo’s genes for heritable conditions. Prospective parents² who know that they are carriers of a particular heritable disease, such as cystic fibrosis, can choose to undergo fertility treatment in order to guarantee that the disease will not be passed on to their child. Alternatively, they may conceive a child naturally, screen the fetus genetically via chorionic villus sampling at week 10 or amniocentesis at week 16, and decide whether to terminate the pregnancy if the fetus tests positive for the disease. The decision to have an abortion can be very difficult, and using PGD to select for a healthy embryo allows couples at risk for having a child with a genetic disease to avoid recourse to abortion.

In order to utilize PGD, a couple must go through an IVF cycle, which involves several steps. After consultation with a fertility specialist, the woman self-administers daily hormone injections in order to stimulate her ovaries to produce multiple eggs, rather than a single egg per ovulatory cycle. She comes in for check-ups every two—three days and a doctor or nurse performs transvaginal ultrasounds in order to monitor the growth of the eggs and time the egg retrieval. When the eggs are ready to be retrieved, the woman takes additional hormones to trigger ovulation. Then, under general anesthesia or a combination of local anesthesia and sedation, her doctor collects the eggs from follicles which have reached the size that typically indicates maturity (18–22 mm in diameter). The egg retrieval involves using transvaginal ultrasound to guide a needle through the wall of the vagina into the ovary, where the fluid within each follicle is aspirated.³

Next, an embryologist examines the content of the aspirated fluid and fertilizes the eggs that have indeed reached maturity with sperm collected from the patient’s partner or a donor. To perform PGD, the resulting embryos are incubated for two—three days and then one or two cells are taken for DNA testing. One or more embryos that are deemed healthy after genetic testing are subsequently transferred into the uterus.⁴ If the any of the embryos successfully implants in the uterus, the woman becomes pregnant.

While PGD was originally intended for couples seeking to avoid passing on a genetic disease, the capacity to screen embryos prior to implantation lends itself to uses apart from having a healthy child. For example, couples in which one or both partners are deaf or of very short stature (dwarfism) have asked fertility specialists in the United States to use PGD to select for a child with deafness or dwarfism.⁵ Furthermore, parents of sick children in need of a stem cell transplant but unable to find a suitable donor have done PGD in order to give birth to a child who can serve as a tissue match for his or her sibling (a “savior sibling”). This application is known as Human Leukocyte Antigen (HLA) typing, after the antigen that must match the sick sibling’s antigens in order for a stem cell donation from the younger child’s (sometimes referred to as the “savior sibling”) umbilical cord blood to be accepted.⁶

In the United States, the most common uses of PGD are for the purpose of selecting an embryo without a specific genetic disease for implantation. However, PGD is also relatively commonly used for the purpose of elective sex selection.⁷ Couples seeking to have a child of a preferred sex can utilize IVF techniques even when they are not infertile, and they can have PGD performed so that only the embryos of the preferred sex will be transferred into the woman’s uterus. Finally, as our ability to sequence DNA rapidly and test for specific genes advances, it will be possible to use PGD to select for and against an even wider range of conditions or even certain traits.

Recent developments in genetic sequencing technology render the possibility of greatly expanding the conditions for which PGD is used extremely probable, if not inevitable. In January 2014, Illumina, Inc., the world’s leading seller of gene sequencing technology, released a next-generation sequencing tool called the NextSeq 500 System, which can sequence a whole human genome in one day. Illumina’s portfolio of sequencers also includes the HiSeq X sequencer, which is the world’s first system to sequence whole genomes for under $1,000.⁸ Fertility centers and laboratories are already using next-generation whole-genome sequencing as a more cost effective and reliable way to perform preimplantation chromosomal screening (PGS) or single-gene PGD.⁹

In addition to having the scientific capacity to use advanced genetic sequencing technology for PGD, doctors and scientists now have the FDA’s implicit approval. In December 2013, the FDA approved Illumina’s next-generation MiSeqDx system, which was designed specifically for clinical laboratories. In a perspective piece in the New England Journal of Medicine, FDA Commissioner Margaret Hamburg and NIH Director Francis Collins highlighted the significance of this development, writing that FDA approval will allow “any lab to test any sequence for any purpose.”¹⁰ PGD will surely be one of the many genetic techniques that are revolutionized by rapid whole-genome sequencing.

Next-generation sequencing will be attractive to fertility specialists and patients in need of PGD due to its ever-decreasing costs, accuracy, and speed. Currently, patients who use PGD must wait a whole month to transfer embryos to the ut...

Table of contents

• Cover
• Title
• 1  Introduction
• 2  The Ethics of PGD and Its Relevance to Regulation
• 3  Drawing Ethical Lines
• 4  Regulating PGD in Practice
• 5  Paying for PGD
• Bibliography
• Index