1. Marissa Haeny
Is embryo selection ethical?
Introduction
Assisted reproduction has become increasingly popular in the last 30 years. This
references any form of creating a baby other than sexual intercourse, such as artificial
insemination, in vitro fertilization (IVF), intracytoplasmic sperm injection, and
preimplantation genetic diagnosis (PGD) (Purdy 2009). PGD, also called embryo
screening, is a screening test used in determining the presence of genetic or chromosomal
disorders in IVF embryos before they are transferred to uterus (Penn Medicine). PGD is
recommended when there is a history of genetic disorders, one or both partners is a
carrier of a chromosomal anomaly, the mother is of advanced maternal age (typically
defined as 35 or older at delivery), or the mother has a history of recurrent miscarriages
(Penn Medicine). There are several ethical issues surrounding PGD and embryo
selection, but there are two highly controversial ones. The first arises from the need to
create and then select embryos on chromosomal or genetic grounds, while the unselected
embryos typically end up discarded. The second issue deals with the process of selection
itself.
Biological basis of PGD
Since 1990, PGD has been available for screening for single gene and X-linked
diseases in at-risk couples, such as cystic fibrosis, Tay-Sachs disease, hemophilia, and
most neuromuscular dystrophies (Robertson a 2003). Countries such as the United
States, South Africa, and Canada have few restrictions on using PGD, such as if the
parental choice will hard the prospective child (Jordaan 2003). Other countries, including
Germany, the United Kingdom, and Ukraine allow PGD, but only in extreme cases
(Kullmann 2013). The process begins with normal in vitro fertilization, including egg
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retrieval and fertilization in a laboratory (American Pregnancy Association). IVF creates
several embryos at a time, and once the embryos have divided into eight cells, a series of
steps follows. The first step is that one or two cells are removed from a blastocyst
embryo, called an embryo biopsy. The second step is to examine the removed cells for
genetic abnormalities using comparative genomic hybridization (CGH) or fluorescent in
situ hybridization (FISH). These are both cytogenetic techniques used to find anomalies
in the removed cell’s DNA. CGH is used to analyze variations relative to ploidy level and
FISH is used to detect and localize the presence or absence of specific DNA sequences
on chromosomes. After the embryos have been identified as free of genetic problems,
they are replaced into the uterus and implantation is attempted. Additional embryos free
of genetic problems can be frozen for later use, and embryos with problematic genes are
typically destroyed (American Pregnancy Association; Wagner 2005).
PGD can also be used to select for nonmedical traits, such as sex, hearing ability,
height, hair and eye color, and intelligence, among other attributes (Robertson b 2003).
The most common example of using PGD to select for nonmedical traits is sex selection,
where parents have healthy embryos of both sexes, but choose to have a certain sex
implanted over the other. Several countries have banned the use of PGD for sex selection,
such as Canada in 2004, India in 1994, and the United Kingdom in 2003 (“Assisted
Human Reproduction Act”).
Without PGD, embryos with lethal or seriously debilitating genetic abnormalities
can develop, leading to a lower quality of life. The aneuploidy rate is at least 50% in
morphologically normal embryos, for example (Simpson and Carson 2013). However,
just because an embryo has a gene for a certain abnormality doesn’t necessarily mean
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they will develop that characteristic. For example, BRCA is a gene that has been
associated with dramatically increasing the risk of breast cancer, but having it doesn’t
mean someone will definitely have breast cancer (Williams 2010). Also, retinitis
pigmentosa is a disease caused by a recessive allele that causes progressive blindness in
those it affects (Williams 2010). Just because an individual may have the allele for
retinitis pigmentosa doesn’t mean they will be affected by it, they could just be a carrier.
Disrupting the natural process and using PGD could benefit a potential child by ensuring
it doesn’t have any debilitating abnormalities, but it could also prevent an embryo from
developing, even if it never would have developed an anomaly to begin with.
Ethics of discarding embryos
The first ethical issue comes from the process of creating and selecting certain
embryos and discarding others that may have developmental abnormalities. The
arguments on this topic tend to mirror debates on abortion and stem cell research. People
that believe an embryo or fetus is a person from the moment of conception tend to object
to creating and destroying embryos, therefore object to PGD. If personhood begins at
conception, they argue, performing PGD and then discarding embryos that have
developmental abnormalities is equivalent to murder (Petersen 2005). The Roman
Catholic Church is one example of a group of people that holds this view (Briggs 2007).
However, others believe that embryos prior to implantation are too rudimentary in
development to have interests or rights, but that they deserve a special respect as the first
stage toward a new person (Ethics Committee of the American Society of Reproductive
Medicine 2008). People with this view believe that PGD is ethically acceptable when
done for “moral” reasons, such as preventing offspring with serious genetic diseases
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(Robertson a 2003). In such cases where an embryo has a serious genetic disease, PGD
could prevent selective abortions from occurring.
Ethics of nonmedical selection
An ongoing debate surrounding the ethics of selection is whether or not PGD
should be used to select for nonmedical traits. Some opponents argue that selection for
nonmedical traits would create a eugenics mindset that would build a world of designer
children (Robertson b 2003). This would cause certain traits to be labeled as superior and
inferior, which would have many social implications. The most common nonmedical use
of PGD is for sex selection. This occurs when parents have healthy embryos of both
sexes, but choose to have a certain sex implanted over the other (Robertson b 2003).
Some people may wish to choose the sex of their first-born child. In almost all cases, the
sex preference for a first-born child is male due to the cultural norms and sexism set by
many communities (Robertson b 2003). Using PGD for sex selection would reflect the
cultural traditions of male privilege and could reinforce sexism towards women
(Robertson b 2003). If sex selection is carried out on a larger scale, there could be a great
inequality in the sex ratio, as has been seen in China and India (Eckholm 2002, Robertson
b 2003, Sen 1990). While India has legislation that says PGD cannot be used for sex
selection, ultrasound screening and selective abortions are common methods around the
law (Sen 1990).
The other side of the sexual selection debate, though, argues that choosing sex to
balance out a family, or to reverse sex ratio issues could be beneficial (Ethics Committee
of the American Reproductive Society 2001). The case for sex selection for gender
variety in a family is fairly strong, as there is less of a risk of being accused of sexism.
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Parents would select for the sex of their second or subsequent children to have variety in
the family, and not because they think one sex is privileged over the other (Ethics
Committee of the American Reproductive Society 2001). This is also practiced in India
and China, but in a way that incentivizing not aborting a first-born child, should it be
female. In India, an IVF program provides PGD to select male offspring as the second
child of couples that have already had a daughter (Malpani et al. 2002). Because there is a
significant emphasis in India of having a male heir, couples could consider having an
abortion after finding out that they are having a girl. This IVF program aims to eradicate
that issue by essentially incentivizing having a girl to insure the sex of the next child will
be male (Malpani et al. 2002). Similar programs are popping up around China, where
having a son is valued over having a daughter, as the family bloodline passes through the
male heir and men tend to make more money (Branigan 2011).
Taking a position on the issue
In the case of serious genetic issues, PGD should be an ethical practice to ensure a
certain quality of life for any unborn children. This is assuming that a child would not be
able to survive on their own, would have a serious decrease in quality of life, or would
die before adolescence if embryo selection were not to occur. PGD, like most forms of
assisted reproduction, has many benefits and consequences. Firstly, PGD can increase the
quality of life for children, as embryos with severe genetic anomalies would not be
implanted for development. PGD would also decrease the prevalence of severe genetic
disease in our population, potentially eliminating them in the future. However, using
PGD could create a eugenics mindset, as discussed in the section on the ethics of
nonmedical selection. It could also allow people to design their own baby, something
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some groups see as playing God, as discussed in the section on the ethics of discarding
embryos.
Opposition to the position taken above would likely include religious groups that
would argue altering natural human reproduction is wrong and interferes with God’s plan
(see section on the ethics of discarding embryos). They would also likely argue that there
is no difference between embryo selection and abortion, as the chance at life for that
potential child has been taken away. While these arguments are valid, the main reason
why PGD should be used for extreme genetic abnormalities is to ensure a quality of life.
If the child will die a painful death shortly after birth, or will live a few excruciatingly
painful years, we have a moral obligation to act proactively, which means using PGD to
select against the lethal or extremely debilitating diseases. Embryo selection, however,
should not be used for nonmedical purposes, such as selecting for height, hair color,
intelligence, deafness, or blindness.
Learning Plan
Two primary literature articles for the biological basis:
Mastenbroek S, Twisk M, van Echten-Arends J, Sikkema-Raddatz B, Korevaar JC,
Verhoeve HR, Vogel NEA, Arts EGJ, de Vries JWA, Bossuyt PM, Buys CHCM,
Heineman MJ, Repping S, van der Veen F. 2007. In vitro fertilization with
preimplantation genetic screening. New Eng. J. Med. 357(1):9-17.
I chose this source partially because of the titles that almost all of the authors hold. They
range from Ph.D.s to M.D.s to M.Sc.s to M. Arts. The credibility of the authors and the
range of areas of expertise were intriguing. I also chose this article because it nicely
outlines the biology of how IVF and PGD work. Some of its results also found that PGD
“significantly reduced the likelihood of an ongoing pregnancy and live birth in women of
advanced maternal age”, rather than increasing it.
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Staessen C, Platteau P, Van Assche E, Michiels A, Tournaye H, Camus M, Devroey P,
Liebaers I, Van Steirteghem A. 2004. Comparison of blastocyst transfer with or
without preimplantation genetic diagnosis for aneuploidy screening in couples
with advanced maternal age: a prospective randomized controlled trial. Hum.
Reprod. 19(12): 2849-2858.
I chose this article to be my second primary source because it encompasses many topics
within embryo selection and PGD that I have researched, but don’t know many details
about. These topics include FISH, assisted reproductive technology, and advanced
maternal age, among others.
Two review articles for the biological basis:
Wilton L. 2002. Preimplantation genetic diagnosis for aneuploidy screening in early
human embryos: a review. Prenatal Diagnos. 22(6):512-518.
I liked this review article because, like with the primary literature article, it discusses
topics of PGD that I have researched, but would like to know more about. In this article,
these topics are FISH, aneuploidy screening, and embryo biopsies. It is also cited in at
least 68 other peer reviewed and scholarly articles, making it a good starting point to
learn more.
Sermon K, Van Steirteghem A, Liebaers I. 2004. Preimplantation genetic diagnosis.
Lancet. 363:1633-1641.
I especially liked this review article because it uses a feature that not many other articles
do: images and figures. In Figure 1, a cleavage-stage biopsy is shown. Considering this is
a topic I want to learn more about, seeing how the biopsy is done is especially interesting.
They also show images of five-color FISH applied to the nuclei of single blastomeres.
These topics intrigue me, and seeing the images is fascinating.
One experiential way for the biological basis:
One way I could experience the biological basis for embryo screening and PGD is
by talking with a fertility doctor and an OB-GYN. These doctors would be able to explain
to me, in more understandable terms, the whole process of IVF, PGD, and embryo
selection. They could help me understand what is done with embryos that aren’t selected,
even if they don’t have abnormalities.
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Two primary sources for ethical implications
Boyle RJ, Savulescu J. 2001. Ethics of using preimplantation genetic diagnosis to select a
stem cell donor for an existing person. BMJ. 323(7323):1240-1243.
I thought this article would be interesting because it complies research on a very hotly
debated topic: “savior siblings”. This is something along the lines of the plot from My
Sister’s Keeper. This article analyzes the ethical implications behind using PGD to select
embryos for cord blood, blood transfusions, bone marrow donation, and donation of other
body parts.
Botkin JR. 1998. Ethical issues and practical problems in preimplantation genetic
diagnosis. J. Law Med. Ethics. 26(1):17-28.
Something that is intriguing about Botkin’s article is that it analyzes whether or not there
is a demand for PGD. It is also an older article, which gives insight to previous beliefs
and studies on the topic.
One review article for ethical implications
Kahn JP, Wagner JE, Wolf SM. 2003. Using preimplantation genetic diagnosis to create
a stem cell donor: issues, guidelines and limits. J. Law Med. Ethics. 31(3):327+.
I liked this ethical review article because it outlines the issues of using PGD to create
stem cell donors, the current guidelines, and the limits. The authors took it upon
themselves to convene an advisory group to discuss the controversial use of PGD to
create a donor. I like that the article also discusses the history and existing guidelines of
PGD, but also talks about where it could go in the future.
One experiential way for ethical implications
One way I could experientially learn about the ethical implications behind PGD
and embryo selection would be to speak with a human rights lawyer. Because one of the
ethical arguments against PGD is that it is essentially murder (mirroring the debate on
abortion), it would be fascinating to talk with a person who deals with human rights
violations every day.
Three films, books, exhibitions, or performances for ethical implication
1. My Sister’s Keeper – book and film
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a. I have already read this book and seen this film, but those were purely for
the entertainment factor. It would be interesting to go back and read the
book again and watch the movie again and analyze the actions of the
parents from an ethical perspective. It could change my whole opinion on
the book and movie.
2. A Brave New World by Aldous Huxley
a. I have also already read this book, but I read it for my JTerm “Dystopian
Literature” class. We discussed the eugenic society and the implications it
has for our world. We read it as a cautionary tale, but I would like to go
back and read it, wondering about the ethical implications and what it
would take for our world to get to that place.
3. Eugenics: A Reassessment by Richard Lynn
a. This book I have not read. The author argues that condemning eugenics in
the second half of the 20th century went too far and offers a reassessment.
He argues that the technology we have could eliminate genetic diseases,
increase intelligence, and reduce personality disorders, and that all of these
are desirable traits. Reading his argument would be very interesting, as
everything I have read so far states that selecting for those traits isn’t
desirable.
Literature Cited
American Pregnancy Association.Preimplantation genetic diagnosis:PGD. Accessed at:
http://americanpregnancy.org/infertility/preimplantation-genetic-diagnosis/
Assisted Human Reproduction Act. 2004. Accessed at: https://zoupio.lexum.com/calegis/sc-2004-c-2-en
Branigan T. 2011. China’s great gender crisis. The Guardian. Accessed at:
http://www.theguardian.com/world/2011/nov/02/chinas-great-gender-crisis
Briggs S. 2007. The ethics of life. Conscience. 28(3):14.
Eckholm E. 2002. Desire for sons drives use of prenatal scans in China. The New York Times. Jun 21:A3.
Ethics Committee of the American Society of Reproductive Medicine. 2001. Preconception gender
selection for nonmedical reasons.Fertil. Steril. 75:861-864.
Ethics Committee of the American Society of Reproductive Medicine. 2008. Sex selection and
preimplantation genetic diagnosis.Fertil. Steril. 82(1):245-248.
Jordaan DW. 2003. Preimplantation genetic screening and selection: an ethical analysis.Biotech. Law
Report. 22(6):586-581.
Kullmann K. 2013. Genetic risks: the implications of embryo screening. Der Spiegel. Accessed at:
http://www.spiegel.de/international/germany/controversial-pid-embryo-screening-in-germany-a-
882067.html
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Penn Medicine. Preimplantation genetic diagnosis (embryo screening). Accessed at:
http://www.pennmedicine.org/fertility/patient/clinical-services/pgd-preimplantation-genetic-
diagnosis/
Petersen TS. 2005. Just diagnosis? Preimplation genetic diagnosis and injustices to disabled people. J. Med.
Ethics. 31:231-234.
Purdy LM. 2009. Assisted reproduction,prenatal testing,and sex selection, in A Companion to Bioethics,
Second Edition (eds H. Kuhse and P. Singer). Wiley-Blackwell, Oxford, UK.
Robertson JA. a. 2003. Extending preimplantation genetic diagnosis: the ethical debate. Human Reprod.
18(3):465-471.
Robertson JA. b. 2003. Extending preimplantation genetic diagnosis: medical and non-medical uses.J.
Med. Ethics. 29:213-216.
Sen A. 1990. More than 100 million women are missing. New York Review of Books. 37:61-68.
Simpson J. Carson S. 2013. Genetic and nongenetic causes ofpregnancy loss. Glob. Libr. Women’s Med.
Accessed at:
http://www.glowm.com/section_view/heading/Genetic%20and%20Nongenetic%20Causes%20of
%20Pregnancy%20Loss/item/318#31085
Wagner JE. Practical and ethical issues with genetic screening. ASH. 2005(1):498-502.
William S. 2010. Hereditary blindness:the parents’dilemma. The Telegraph. Accessed at:
http://www.telegraph.co.uk/news/health/8046393/Hereditary-blindness-the-parents-dilemma.html