Prenatal Diagnostic Tests and the Social, Legal, and Ethical Implications
Introduction
Jackie and Michael are expecting their first baby. Jackie is 32 years old and is in good health. She is 15 weeks pregnant and wants to do everything possible to ensure a healthy baby. Even though they do not have risk factors within their families, she and Michael decide to have an amniocentesis.
The results indicate that their baby is a female with Turner Syndrome. This condition is caused by a missing X chromosome and results in short stature, ovarian failure, and medical problems involving the heart, thyroid glands, and kidneys. Some of these conditions can be treated and managed with great success. The question that arises after diagnoses is whether or not they will choose to terminate the pregnancy with an abortion or carry the child to full term.
The availability of methods that determine the genetic predisposition of a fetus gives rise to a whole array of questions and issues that must be confronted as we develop policies to deal with genetic testing. In this essay, I will present current and future methods for prenatal diagnosis, ethical concerns and related problems dealing with this new technology, my personal opinion on the issue, and finally, future goals in the science of genetics.
All of us are potential carriers of several deleterious recessive genes that could be lethal to our offspring if combined with another recessive allele carrying the same fate (IOM 1994). The chances of a genetic disease being passed on are 1 in 100 Americans born today (March of Dimes 1997). Because of the risks involved, many people are having prenatal tests to examine the genetic makeup of their fetuses. For many couples, this option enables them to ensure they will have healthy children that they might not have had because of a history of inherited diseases. This information relieves a lot of parental anxiety and unfulfilled expectations of an impaired child.
People who may be especially interested and advised for testing might include couples with a family history of genetic disease, those that might have a birth defect, pregnant women over the age of 34, couples who already have a child with a genetic disorder, and couples concerned about specific disorders that occur more frequently within their ethnic group (March of Dimes 1997).
Techniques
Currently, there are four prenatal diagnosis techniques used. The first, and safest method, is an ultrasound. It is noninvasive and can assess and evaluate gestational age, fetal position, growth, development, and any structural birth defects. When performed by highly skilled operators, abnormalities can be detected with as high as 90% accuracy (IOM 1994).
The next technique routinely performed for prenatal diagnosis is amniocentesis. A long needle is inserted into the mother’s uterus to withdraw a sample of amniotic fluid containing cells shed by the fetus. The cells are cultured and analyzed for chromosome abnormalities. Despite the lengthy time in obtaining results because the cells need to be cultured, this method has become widely accepted as a safe and accurate way to determine genetic disorders.
Chorionic Villus Sampling (CVS) is yet another technique that can be performed very early on in gestation-between 9 and 12 weeks. A catheter is passed through the cervix into the uterus, and a sample of the chorionic villus surrounding the sac, which protects the fetus, is obtained. Large amounts of DNA are gathered and analyzed within 24 hours. Because of the quick results and use early on in pregnancy, abnormalities can be identified and used to make more acceptable decisions about selective termination of the pregnancy. Abortion is also much safer at this early stage (Weatherall 1991).
The last method involves fetal blood sampling and is called percutaneous umbilical cord sampling (PUBS). A needle is inserted into the umbilical cord and fetal blood is obtained and evaluated for metabolism or hematologic abnormalities (IOM 1994).
In addition, a couple of new technological advances may become combined with prenatal diagnosis in the near future. First, the use of dot-blot technology could be used to detect point mutations more easily and more accurately. CVS and PUBS methods are still used to obtain the DNA samples; however, the DNA is then simply spotted on a nylon filter, probed with oligonucleotides, and non-radioactively labelled with probes to identify genetic diseases (Weatherall 1991).
Another advancement on its way combines prenatal diagnosis with in vitro fertilization. This technique would involve acquiring a number of fertilized ova and analyzing them for a particular genetic disorder before implanting a healthy one into the uterus. This approach may be more acceptable to couples who oppose abortion (Weatherall 1991).
Pros and Cons
Although many of these options for prenatal diagnosis are being used and benefited from by amiable couples wishing to have healthy children, opponents of these genetic tests are not giving up without a fight. They bring up many concerns and issues that must be dealt with if we are to evolve in the science of genetics.
Many opponents believe in the preservation of all life, and until we come up with cures to all genetic diseases, terminating the lives of inflicted fetuses will remain prevalent in our society. Besides the fact that eliminating a human being that cannot be cured violates the principles of medicine, prenatal diagnosis combined with the option of terminating the pregnancy raises two more issues: selective breeding, or eugenics, and value judgements.
The first, eugenics, might include using abortions as a means of eradicating a disease and eliminating an entire population that did not fit into society’s criteria for an ideal community. Also, specific physical characteristics, such as eye color and IQ, will eventually be obtainable. Will we, as a society, emerge into a supremacy in which those with bad genes will be scorned.
A second problem that might need to be addressed involves value judgments. Prenatal tests are being used more and more. Parents are choosing to abort a child based on any indication of a birth defect, no matter what the severity. The Institute of Medicine recommends that prenatal diagnosis not be used for minor conditions or characteristics (Botkin 1995). But who decides what a minor condition is? Different views depend on the couple’s race, culture, education, religious beliefs, and economic status. The decision will also depend on what information about the abnormality is presented to them and how they interpret the data.
Undoubtedly, these problems address the need for ethical and legal standards. A parental crusade for the perfect baby is well on its way. While we must uphold the freedom of choice, we must decide what is best for society as a whole.
While there are opponents to the use of these tests, more people are in favor of them. Prenatal testing and selective abortion to avoid a seriously genetically impaired child is widely accepted in the United States. It was determined that 79% of Americans believe abortion should be available for a fetus with a severe abnormality (Botkin 1995). Some believe that the birth of a child with a severe genetic disorder may bring the mother and/or family distress, psychological harm, emotional harm and suffering, loss of a child, loss of opportunities, loss of freedom, isolation, and financial expenses (Morejon 1996).
An additional potential threat that could present itself with the birth of a defective child may be the quality of the relationship between parents and the child. For instance, a child may be subjected to activities that do not necessarily benefit the child because of the parents’ lack of preparation for dealing with the child. Also, the child’s personal freedom may be restricted or his/her condition may lead to fragile treatment.
Societal discrimination also makes raising a child much more difficult, not only for those actually having a genetic disease, but also for individuals who have a predisposition to one. The latter refers to late onset disorders in which the person may be symptomless until later on in his/her life. There has already been over 200 reported cases cases of genetic discrimination involving health insurance, employment, and adoption (Arc 1997). A key element that must be remembered, however, is that just because we may have the gene for a disease doesn’t mean we will get the disease. Many other physical and environmental factors contribute to the development of the disease.
According to Francis Collins, Director of The National Center for Human Genome Research, all of us carry probably 4 or 5 really fouled up genes and another couple of dozen that are not so great and place us at risk for something (Arc 1997). If this is true, everyone is genetically impaired and could be subject to discrimination.
My Beliefs
My personal opinion coincides with the majority of the population. Although my ideal scenario would be carrier screening of all at risk couples before conception, I believe in the use of prenatal tests to determine severe abnormalities in a fetus. I would never want to subject any child to a disease in which the consequences are severe and detrimental as well as something the child has no control over. I cannot bear the thought of any child suffering needlessly because of an unforeseen deleterious inheritance from it’s mother and father.
To me, the benefits far outweigh the consequences of bringing a helpless baby who may surcome to a serious and fatal destiny into this world . Until we can intervene with effective treatments, I believe testing is necessary.
Upon completion of the Human Genome Project, a worldwide effort to map out the entire sequence of human genes, we will be able to develop these treatments. New diagnostic and prevention techniques will enable us to detect genes leading to disease. The knowledge will bring about an increased availability of genetic testing and gene therapy. Along with this profound discovery, the field of genetics will give rise to an even more debated issue. Government intervention of standards and policies will be called upon to regulate genetic testing.
To prepare citizens for informed personal decision making, public education and counseling will become vital to understand these new genetic concepts. We will also need to rely on our pre-existing knowledge and values if this emerging technological field is to be dealt with appropriately. My outlook for the future is optimistic. We will be able to cure diseases we never dreamed possible, and the lives of humans will be improved eminently.
References Cited
Arc. Genetic Discrimination. Obtained from WWW 10/09/97: https://www.the.arc.org/depts/gbr03.html
Botkin, Jeffrey R. Fetal Privacy and Confidentiality. Hastings Center Report, Sept.-Oct. 1995:32-39.
Institute of Medicine. Assessing Genetic Risks. National Academy Press, Washington, D.C. 1994.
March of Dimes Birth Defects Foundation. Genetic Testing and Gene Therapy: What They Mean to You and Your Family. Obtained from WWW 10/09/97:https://ubeclu.unibe.ch/insel/GENETEST.HTML
Mattei, Jean-Francois. Prenatal Diagnosis. World Health, No. 5, Sept.-Oct. 1996:22-23.
Morejon, Diana Punales. Commentary. Hastings Center Report, May-June 1996:21-22.
Weatherall, D.J. The New Genetics and Clinical Practice. Oxford University Press, 1991.
While most prenatal tests are routine and pose no known harm to you or your baby, there are riskier or less common genetic screenings that you may want–or need–to consider. Your doctor might recommend these procedures if you'll be 35 or older on your due date; if you've had an earlier screening that indicated an increased likelihood of a chromosomal or genetic problem; if you've had a prior pregnancy with a child with a birth defect; or if you or your partner has a chromosomal abnormality, has a genetic disorder, or is a carrier for an inherited disorder.
"The biggest question I think women need to ask before doing some of the more dangerous but accurate prenatal tests is what will they do with the knowledge," says Robin Elise Weiss, LCEE and author of The Everything Getting Pregnant Book. "If you aren't planning to act on it and it won't help plan for a safer birth, it may not be worth the risk."
Here's an at-a-glance guide to four diagnostic tests.
Method: An ultrasound-guided needle is inserted through the abdomen into the amniotic sac to extract a small amount of amniotic fluid. The test should be administered by a physician who is experienced in performing the test and a registered diagnostic medical sonographer.
Accuracy: Nearly 100 percent for 95 percent of chromosomal disorders.
Pros: Performed at 15 or more weeks, an amnio is used to detect chromosomal defects, neural tube defects, certain diseases and chemical problems, and to assess a baby's lung development.
Cons: Rarely, the test can cause infection in the womb, rupture of the membranes, pre-term labor or injury to the baby. Miscarriages occur in about one out of 200/250 women.
Considerations: Even if you wouldn't terminate a pregnancy no matter what the results, an amnio can help you better plan for a child with special needs or a special delivery. For example, knowing that you're having a baby with special needs will allow you to arrange for specialized childcare assistance or in-home help. Or if your child has a severe physical defect that would alter the mode of delivery, you can make sure that there will be an intensive care pediatrician on hand when the baby is born, says Vivian M. Dickerson, MD, FACOG and medical director of women's health programs and care at Hoag Hospital at University of California, Irvine.
Method: A small catheter is threaded into the cervix though the vagina, or via a needle inserted through the abdomen, to extract a small sample of fetal cells from the chorionic villi — fingerlike projections on your placenta.
Accuracy: About 98 percent accurate at detecting 95 percent of chromosomal disorders.
Pros: Can be performed early — between eight and 12 weeks — before the embryo becomes a fetus. CVS is used to detect Down syndrome, cystic fibrosis, hemophilia, Huntington's disease, sickle-cell anemia, thalassemia, muscular dystrophy and hundreds of other genetic disorders.
Cons: Miscarriages occur in about one out of 100 women, although some of those may not be caused by the CVS itself. "When you do a procedure at 11 weeks, you're going to see more spontaneous pregnancy losses that may or may not have anything to do with the procedure, just because it's earlier," Dickerson says.
Considerations: "Obviously, there's always a small risk, but it's a very small risk, and the information we find is very helpful," Dickerson says.
Method: An ultrasound-guided needle is inserted through the abdomen into a blood vessel of the umbilical cord to extract a tiny sample of fetal blood.
Accuracy: The test is not performed nearly as often as amnio or CVS, so there's no definitive research on its reliability, but it's thought to be highly accurate.
Pros: Performed after the eighteenth week, PUBS is used to diagnose several blood and skin diseases that amniocentesis can't detect. It's also used to check abnormal amniocentesis results, diagnose causes of growth retardation late in pregnancy or indicate if the baby has been infected by a potentially harmful disease.
Cons: Poses risks slightly greater than amniocentesis and is associated with a slight additional risk of premature delivery or early rupture of the membranes.
Considerations: PUBS isn't indicated for routine prenatal diagnosis and is used in very specialized situations, Dickerson says.
Method: Using an ultrasound, a physician measures a tiny fold of fat at the back of the baby's neck (babies with abnormalities tend to develop more fluid in this area, making the space larger). The doctor inputs the measurement, the baby's age and your age into a computer that calculates your baby's statistical likelihood of having a chromosomal abnormality.
Accuracy: Although a nuchal fold scan won't give you the near-definitive diagnosis that amnio and CVS can, it can help you determine whether you want to undergo additional testing.
Pros: Performed between 11 and 14 weeks, there are no risks to you or your baby.
Cons: Until recently, the test was only performed at major medical centers, although it's becoming more widely available. Doctors have to be thoroughly trained to ensure accuracy because it's such a tiny measurement.
Considerations: Nuchal translucency screening should only be done when it is combined with a blood test. And when deciding who should administer any of these tests, Dickerson recommends calling local hospitals for recommendations or choosing a maternal fetal testing center, which focuses on these procedures full-time.
Vaginal Discharge
Feeling better yet? Now that you're just a week away from the second trimester, you should be feeling pretty good soon (after all, the second trimester doesn't get its reputation for being the easiest and most comfortable of the three trimesters for nothing). But if you're not feeling better yet, don't worry. While most early pregnancy symptoms will probably soon be behind you, some women find that nausea and fatigue linger into the fourth and even fifth months. And unfortunately, for some women, those and other usual first trimester suspects (such as bloating, constipation, headaches, and breast tenderness) can continue to some extent throughout pregnancy.
Of course, even though the second trimester is known as the trimester of smooth sailing, it doesn't mean you'll be symptom-free in the near future. Far from it. Something else you might have noticed recently is an increase in your vaginal discharge. Known in medicalese as leukorrhea (try getting that right in a spelling bee), this perfectly normal discharge is thin, milky, mild-smelling (sometimes even odorless), and can be expected to increase as your pregnancy progresses. Leukorrhea is caused by the stepped-up production of estrogen (your other pregnancy hormone pal) as well as the increased blood flow to the pelvic area. Its purpose is noble: to protect the birth canal from infection and maintain a healthy balance of bacteria in the vagina. Unfortunately, in achieving its noble purpose, leukorrhea can make a mess of your underwear.
If it'll make you more comfortable, you can use a panty-liner (never a tampon) to absorb the discharge. But don't take it any further than that. Never douche while you're expecting. Actually, it's really never a good idea to douche; douching can upset the normal balance of microorganisms in the vagina and can lead to vaginal infections. Douching can also force air into the vagina during pregnancy, which can be dangerous.
—————
This section is empty.
—————
—————
