Harvard Public Health Review: A Student Publication

Commentary

A Discussion of the Ethical and Medical Implications of Prenatal and Preimplantation Screening

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As medicine has lent itself progressively to innovation in the field of antenatal screening at various cellular stages of fetal growth, ethical and moral dilemmas follow these innovations in a parallel fashion. Along with the myriad options currently available in screening a fetus for chromosomal and genetic anomalies, comes the inevitable question of finding the most cost-effective and non-invasive form of screening tailored towards mothers of varying demographics. Currently the legal policies with regards to prenatal screening (a detection of chromosomal aneuploidies often confused with pre-implantation diagnosis) present themselves rather vaguely. Legal policies are ambiguous as the “standard” procedures of management and counseling among mothers with fetuses suffering from these genetic anomalies are still in flux. The ethical precinct of “non-directiveness” in counseling cannot realistically be fulfilled as most genetic counselors cannot maintain an impartial stance throughout a whole genetic counseling session.1

From a medical perspective, prenatal and preimplantation screening seem to be advantageous tools that can aid pregnant women in making informed decisions regarding the fetus’s health, however, the ethical dilemmas surrounding these screening methods and their consequences seem to outweigh the benefits in particular instances. The advantages of these screening techniques in detecting abnormalities range from the detection of chromosomal aneuplodies to major structural anomalies (limb and organ malformations) such as exomphalos, cleft palate, gastroschisis and anencephaly to name a few.2 Prenatal screening varies from pre-implantation screening in its method and in its target of detection.

Prenatal screening follows a series of steps taking place over a time-interval of as early as the 1st week of pre-conception to approximately the 28th week gestation. Initially, the mother’s first prenatal visit involves prescribing her folic acid supplementation (to prevent neural tube defects) along with a panel of tests to confirm her status regarding rubella, syphilis, HIV immunity and Rhesus D status (done to confirm whether an RhD- mother is or is not having an RhD+ baby–to prevent erythroblastosis foetalis from developing in case they have mismatched blood ). This test is followed up by a Down’s Syndrome Screening at the next prenatal visit (in which the baby can also be screened for major structural deformities and trisomies 13 and 18 if the mother wishes to have it done) is considered a non-invasive prenatal test (NIPT) which harnesses the use of cell-free foetal DNA –a major watershed in the field of fetal chromosomal analysis.3 Once NIPT takes place, an invasive testing which is more accurate (in terms of its exclusion of false positives and negatives which occur in NIPT) takes place in the next visit, concluding the screening process.2

Preimplantation genetic screening is only different in the sense that it is a form of screening that takes place at an earlier stage of preconception and targets identification of certain diseases at the cell stage of the embryo (oftentimes the third or fifth day of embryo development). As many other screening techniques it has evolved to evaluate the genetics of the embryo with more accuracy, and currently evaluates all 23 chromosomes utilizing the methods of microarray technology.3 Two methods this microarray technology consists of are analyzing single nucleotide polymorphisms and comparative genomic hybridization. A disadvantage of this screening method is that it uses microarrays which involve amplification of DNA (which can potentially amplify a false result changing the detection of a disease).

Both screening methods offer an endless avenue of possibilities in the way of detecting certain anomalies as they lead to a population of pregnant women who become more cognizant of the well-being of their fetuses. However, the threat of trauma resulting from genetic abortions prevent these methods of screening from being solely beneficial. One main conflict stemming from prenatal screening is that genetic abortion is more psychologically painful than an abortion done due to stillbirth. In the case of an abortion due to stillbirth, the mother has no choice in the matter of a termination to her pregnancy as it has been decided for her. Yet, in the case of a genetic abortion, if her fetus has a genetic defect such as Down’s syndrome or spina bifida, she has to decide whether she must terminate her pregnancy or not.1 If the woman chooses to terminate her pregnancy for these reasons, she can often suffer deleterious psychological consequences due to a sense of guilt. At its worst, this sense of guilt often leads to complex grief reactions in women who choose a termination of pregnancy due to fetal abnormality).1 A complex grief reaction often consists of significant weight loss, significant sleep disturbances, intense feelings of guilt and worthlessness, hallucinations or delusions, and even considerations or attempts at suicide. Essentially, a complex grief reaction can reach into the domain of severe depression.

Another study supporting this outcome, concluded that post-traumatic stress was more frequently found in women who terminated their pregnancy due to a fetal abnormality. Often, these negative reactions to termination also arise from the astonishingly brief amount of genetic counseling that pregnant women receive. One study found that medical professionals spend an average of only 2.5-6.5 minutes discussing genetic counseling with pregnant women.2 Perhaps more confounding than all these reasons, is the quandary of whether the fetus’s quality of life will be compromised if he or she is afflicted with Down’s syndrome and the range to which he or she could be affected by a disease. Should the mother terminate her pregnancy even though she does not know the range of the disease that her child would be afflicted with (the possibility of a milder manifestation of any disease process)?Associated with this reason, is the argument of how disability should be perceived and if a pregnancy should be selectively terminated just because the fetus could suffer the possibility of handicap physically or mentally. Disability activists continue to argue that if there are far fewer handicapped individuals in society, society will be less inclined to ‘value individuals and provide the necessary services for them to survive and thrive’.4,56

Concomitant with these arguments of negative psychological outcomes for women who undergo genetic abortions and moral perception of disability, arises the ethical dilemma from the point of view of a medical professional regarding beneficence and nonmaleficence. One of the core ethical principles medical professional follow, is to do no harm (nonmaleficence) and to act in the patient’s best interest (beneficence). Would it truly be in the patient’s best interest to tell her to terminate her pregnancy? For society, the burden of an impaired individual would be lessened by termination of her pregnancy, but for her and her fetus, would this decision truly be the best? Another ethical contention of nonmaleficence also begs the question of whether fetuses should be selectively eradicated so as to not have any disability.5 Physicians and genetic counselors must do not harm, yet at the end of the day, what constitutes harm cannot easily be defined either by the patient or by the medical professionals involved. Additionally, is genetic abortion at the stage of preimplantation screening more justified than at the level of prenatal screening, since the child to be born is not considered as a fetus (and therefore not a life yet) in the stage of preimplantation screening?

Finally, in the case of NIPT, genetic testing done earlier may allow mothers to more easily follow through with a genetic abortion as the bond between the mother and the unborn child is not as strong at this stage of pregnancy (when the testing takes place).7 Moreover, if NIPT becomes one of the ‘routinized’ sequence of tests that are done in prenatal screening, mothers will not be informed and will not have the independent right of decision to have the test or to not. In the case of low income countries , NIPT may be used to selectively decide the sex of a fetus.1 Apart from this, the steep stratification of society would make it so that the poorer population would not be able to afford the test compared to the higher income families.

Ultimately, the burden falls on the mother of whether she should terminate her pregnancy or not. The psychological trauma also falls on her as she must make the final decision. The mental and social factors compound to make the decision a more difficult one, but genetic screening will continue to advance in its efficacy and accuracy regardless of these issues. Even though these conflicts cannot be avoided, the government, medical institutions, and views upon disability must evolve to fit the advancements of technology in diagnostic screening.

 

Acknowledgements
I thank Teneille Brown for her guidance and her supervision.

 

References

  1. Asbury, B. D. (2016). Fostering Informed Choice: Alleviating the Trauma of Genetic Abortions. Cornell Journal of Law and Public Policy, 293-333. Retrieved September 13, 2017, from http://www.lawschool.cornell.edu/research/JLPP/upload/Asbury-final.pdf.
  2. Jong, A. D., Maya, I., & Lith, J. M. (2014). Prenatal Screening: Current Practice, New Developments, Ethical Challenges. Bioethics, 29(1), 1-8. doi:10.1111/bioe.12123.
  3.  B., B., Ke, R. W., & Kutteh, W. H. (2013). Preimplantation Genetic Screening: A Practical Guide. Clinical Medicine Insights: Reproductive Health, 37. doi:10.4137/cmrh.s10852
  4.  Allyse, M., Minear, M., Rote, M., Hung, A., Chandrasekharan, S., Berson, E., & Sridhar, S. (2015). Non-invasive prenatal testing: a review of international implementation and challenges. International Journal of Women’s Health,113. doi:10.2147/ijwh.s67124
  5. Buchanan A 1996 Choosing who will be disabled: genetic intervention and the morality of inclusion. Social Philosophy and Policy 13, 18–46.
  6. Coghlan, A. (2007). Genetic testing: informed choice or waste of money? New Scientist,196(2624), 8-9. doi:10.1016/s0262-4079(07)62496-8.
  7.  Follow-up of multiple aneuploidies and single monosomies detected by noninvasive prenatal testing: implications for management and counseling. (2016). Prenatal Diagnosis, 36(6), 594-594. doi:10.1002/pd.4839.