In the doctor`s crowded waiting room, pregnant women gaze at the bulletin board covered with snapshots of happy, healthy babies. That`s all anyone`s hoping for, and odds are they`ll get it. But they have come to hedge their bets.
Through prenatal fetal testing, in some cases as early as 9 weeks into the pregnancy, each woman will learn whether the fetus she carries suffers chromosomal abnormalities that can cause lifelong handicaps or early death, severe deformities or potentially life-threatening flaws to spine or skull. Most of the women will hear good news. A statistically small number, perhaps 3 in 100, will learn of an abnormality and face the question of whether to terminate the pregnancy or prepare for the consequences.
But it is those few, unlucky ones that have fueled the quest by parents and scientists for early answers and in the process raised formidable ethical questions. Insights into fetal health produce troubling dilemmas: How much information is useful and to what end? Is the desire for information worth the risk, however slight, that the procedure itself may endanger the pregnancy?
What defects justify abortion for women willing to go that route? Who can say what level of handicap is ”reasonable” to accept for a child-to-be or the family? Some ethicists go so far as to ask what greater good produced by diversity in humankind is sacrificed in the quest for perfect babies?
”With the technology we have available today, most of the defects we can detect are very serious, life-threatening ones. We`re not seeing a rush by parents to abort a fetus over some slight imperfection,” says Dr. Aubrey Milunsky, director of the Center for Genetics at Boston University School of Medicine and author of ”How to Have the Healthiest Baby You Can.” But genetic and fetal screening technology is advancing rapidly. It is reasonable to expect that in the relatively near future, tests will be available to detect a host of minor medical flaws, ones that could be corrected or treated, or genetic diseases that might not afflict the individual for decades and might be curable by then.
In some cases the current limitations of technology produce more questions than answers. For instance, in the case of Down`s Syndrome, the most common cause of retardation, tests can determine whether the fetus suffers the chromosomal abnormality that causes varying degrees of retardation, but no test yet can determine how severely the fetus is affected. Parents who might consider themselves emotionally and financially prepared to raise a mildly handicapped child might fear the worst–a child suffering profound retardation and physical impairments–and feel compelled to abort instead.
The choices are never easy, rarely clear-cut. A woman in her 30s awaiting the results of her amniocentesis tests, says: ”I don`t know what we`ll do if it comes back Down`s. My husband says he absolutely wouldn`t go through with it, but I feel just the oppposite. So we just don`t talk about it and hope for the best.”
”I couldn`t possibly abort a fetus on the basis of Down`s Syndrome,”
says another mother and career woman in her 30s who underwent testing to screen for ”more serious” flaws. Yet another woman, also a mother and professional, said she had considered the possibility of a Down`s diagnosis and was ready to terminate the pregnancy: ”A close friend of mine had a younger sibling with Down`s, and even though they had a beautiful family life and were very supportive of each other, she confided to me what an incredible hardship caring for the child had placed on everyone for all their lives. She didn`t recommend it.”
Similar issues arise in evaluating a test result indicating spina bifida, a defect in which the spine or skull fails to close completely, usually leading to serious physical disability or death. The severity of spina bifida varies, but in milder cases victims may live active, productive lives, both physically and intellectually. The only way doctors can gauge the severity is to locate the opening on the spine; nerves from that point down are typically affected, so the higher the location of the flaw, the more severe the probable outcome. Again, because the worst-case scenario is so painful to consider, most couples who discover spina bifida in testing choose to abort.
Gender determination made possible by current testing methods perhaps reflects the best and the worst potentials for prenatal technology. Gender is of critical concern to those attempting to avoid serious sex-linked genetic diseases carried in their family. Yet testing for the purpose of arbitrary sex selection–aborting a normal fetus of unwanted gender–is considered by most an outrageous abuse of a science that is intended to alleviate disease and suffering.
”There are ethicists who say we shouldn`t allow testing or abortion for sex selection, but technically, prenatal testing for sex selection is constitutional,” says Dr. James Bowman, a professor at the University of Chicago School of Medicine and member of the Committee on Genetics. ”If we allow abortion on demand, we can`t be squeamish about whether it`s for something like cleft palate or sex selection. Most certainly, I would decry abortion of a fetus because of cleft palate (in most cases still undetectable through tests)–these are minor disorders that can be surgically corrected
–but I would not take away the right of that woman to have an abortion if she chooses. The fact is she can have one, legally, for no reason at all except the simplest one: `I don`t want to be pregnant.` ”
Even in cases where the medical diagnosis of abnormalities is clear and simple, some doctors and prospective parents may have quite diverse opinions on a course of action.
Turner`s Syndrome, for instance, is a chromosome abnormality in females that results in short stature, sterility and stunted growth of sexual organs, mental deficiencies and a variety of physical deformities. With appropriate early medical intervention following birth, including hormone treatments, some of the symptoms can be alleviated, but the condition cannot be cured. Another chromosome abnormality, in which a male carries one X and two Y chromosomes instead of the normal one X and one Y, typically produces tall stature, a tendency toward low IQ and sometimes personality disorders or antisocial behavior.
Neither abnormality is considered life-threatening, but they might be no less devastating to parents unequipped emotionally or financially to deal with the extraordinary lifelong challenge.
”To some parents, any problem is a problem,” says Beth Fine, genetic counselor at Michael Reese Hospital and Medical Center and president of the National Society of Genetic Counselors. Most women who undergo prenatal fetal diagnosis testing abort when the results show any abnormality. ”But there are those who choose to go on with the pregnancy,” Fine says. ”And there are women who wouldn`t consider abortion under any circumstances, who have the testing done to reassure themselves that everything`s okay, or so they can prepare for the outcome, to arrange for the special medical needs of delivery or treatment of the baby, and perhaps to get some of the grieving process over with before the baby arrives.”
Karen Liss, a 42-year-old executive search consultant, felt her unplanned pregnancy was surprise enough; if there was anything unusual about the fetus, she wanted to know sooner than later.
”Because of my age, I was a prime candidate for screening and I chose to have the CVS (chorion villus sampling procedure) because if there had been a real serious mutation, I couldn`t stand to think of the child going through the suffering,” she says. Her test results showed no abnormalities. Her baby is due in August.
Jane, a 39-year-old corporate executive, didn`t want to wait for answers either. Her CVS results showed that the fetus suffered Trisomy 18, a severe chromosomal abnormality that doctors said would likely would kill the fetus before birth, ”but they couldn`t tell me how or when.” She and her husband chose to terminate the pregnancy.
While incidents of genetic defects in the family spur many women to undergo testing, the majority of women do so for simple age-related concerns; the rate of birth defects in pregnancies among women 35 and older, or those with partners 55 or older, increases with each year. For this group of women, the most common anxiety is over the risks of the procedures themselves.
Risk of complications from amniocentesis and CVS procedures are low, but according to statistics, one or two women out of 100 will develop
complications and perhaps lose the pregnancy as a result. Even that simple statistic means something different to every women, depending on her prior pregnancies.
”A woman who`s already had six miscarriages will come to this with an entirely different attitude from someone who`s never had a miscarriage,”
notes Fine.
Nor do the tests eliminate all concern. Current technology can detect only a handful of the thousands of birth defects caused by inherited genes or other genetic mutations. Many defects remain generally undetectable, including blindness, deafness, congenital heart disease and other serious problems, including those caused by environmental factors such as the mother`s drinking, smoking or exposure to hazardous drugs or chemicals.
In instances of pregnancy loss, grief is compounded for some parents by the feeling that the tests they agreed to played a part in the tragedy.
One woman who underwent a CVS at 9 weeks into her pregnancy suffered a miscarriage in her 5th month after a gradual loss of amniotic fluid, accompanied by other health complications doctors said were unrelated to the procedure. An autopsy showed that the fetus was normal but the amniotic sack was infected. Her doctors don`t link the tragedy with the test, yet this woman reflects the uneasiness of many women considering testing: ”You can`t say the procedure caused me to lose my baby, but I personally wouldn`t have the test again for fear of another miscarriage. The risk factors sound so safe, a 1 or 2 percent miscarriage rate, but if it happens to you, that 1 or 2 percent is everything.”
Her fears are common among other pregnant women, even those who wholeheartedly endorse use of the tests.”
”I wanted to know everything I could as soon as I could,” says a woman in her late 30s who lost her baby a week before its due date. She had undergone CVS followed by an alpha fetoprotein (AFP) blood test to detect spine or skull defects. This test came back abnormal. An amniocentesis followed quickly, which determined that the fetus did not have AFP-related problems, but the doctor continued to order frequent ultrasounds for the remainder of the pregnancy ”just to keep an eye on things,” the woman says. The autopsy showed a normal baby but an unusually small placenta, and she still wonders if the CVS or many ultrasounds were to blame.
Perplexing questions arise about tests that identify genes for certain inherited diseases, such as Huntington`s, which may not afflict a person until middle age. Few medical centers offer such tests currently, but the tests exist. So do the ethical dilemmas.
”To elect abortion for a disease that is likely to manifest four or five decades hence is extremely difficult,” says Milunsky. ”First, because by the time it occurs, there may in fact be some treatment or measure that would make life possible. But even right away, it exposes our fundamental sense of human impatience about perfection. The fact is, we all carry some harmful genes, and we cannot rid ourselves of them completely. Nor would we want to, since some of them may actually protect us from diseases worse than the ones they may cause.”
Bowman, too, suggests that our impatience with imperfection may carry a high price tag for future generations. ”In saying we only want a perfect child,” Bowman says, ”we forget the accomplishments of those in our society who have been looked upon as imperfect, we are doing a disservice to the disabled who are living and functioning and contributing. Toulouse Latrec was considered `defective,` but his paintings have given more to this world than all the Nixons and Stalins who might be considered genetically `perfect.` How do we define `imperfect?` ”
Education and personal choice are perhaps the most important factors in maintaining a responsible climate for use of fetal test technology, say professionals in the field. ”Our fundamental thesis is that it is critically important for anyone who plans to have a child to know this information,”
says Milunsky, who advocates testing for most women 35 and over regardless of their attitude toward abortion. ”By not knowing, people don`t remove the chances, they remove the choices.
Fine, however, voices concern over the occasional comment she hears from clients whose doctors have been heavy-handed in prescribing the tests, sometimes even telling the patient that abortion is the only reasonable option if an abnormality is revealed.
”There is no one right answer for all women,” she says. ”Our job is to help people understand their risk of having a child with a genetic disorder or the medical significance of an abnormality. For everything that`s new there are ethical issues, and for every person who walks in there may be a different one.”
TESTING ALLOWS PARENTS TO SPY ON NATURE
A generation ago women talking of fetal diagnosis probably were trying to predict a baby`s sex by the high or low position of the pregnant woman`s bulge. Women today have several medical options for spying on nature in the womb and in the future will likely face, as one researcher put it, ”a cafeteria array” of diagnostic tests designed to monitor fetal health at every stage of pregnancy.
Ultimately scientists hope that advances in genetic research will provide the key to preventing most birth defects while medical science finds ways to reverse or effectively treat those that do occur.
Current fetal diagnosis technology can detect only a few of the thousands of errors in fetal development, but they are some of the most common causes of serious mental and physical defects and infant death:
— Chromosome disorders: The normal cell contains 23 pair of chromosomes; each pair is numbered and when flawed is associated with certain disorders. Down`s Syndro, the most common cause of retardation, results from an extra No. 21 chromosome. Other less common but identifiable disorders result from an extra 13th or 18th chromosome.
Down`s Syndrome causes mental retardation, usually severe enough to require lifelong care. The syndrome typically includes other potentially life- threatening defects in the heart, intestine or nervous system, though in some cases medical care may extend life to old age.
The second most common cause of retardation in males is linked to the Fragile X Syndrome in the sex chromosomes. Other defects in the sex chromosomes typically produce individuals with retardation, learning or personality disorders, stunted sexual development or sterility and a variety of physical deformities. The results of abnormalities in pairs 13 and 18 are so severe that nature itself generally aborts these fetuses spontaneously; 90 percent of those born die by age 1.
— Genetic disorders: Tests can detect cystic fibrosis, a chronic lung and gastrointestinal disorder; Tay-Sachs, a degenerative brain disease; sickle cell anemia, characterized by chronic illness, high risk of stroke or paralysis and a life span of less than 35 years; and thalassemia, another anemia characterized by chronic illness, need for frequent blood transfusions and surgery to remove the spleen, and possibly shortened life span. Some common genetic disorders tests cannot detect include blindness, deafness and congenital heart disease.
— Polygenic disorders: Produced by an interaction of one or more genes and environmental factors as diverse as viruses or vitamin supplements, most
(including cleft palate and club foot, for instance) cannot be identified through tests. The most commonly occurring ones that can be detected include congenital dislocation of the hip, heart abnormalities, some major deformities and pyloric stenosis, an intestinal obstruction. The most serious include neural tube defects such as spina bifida and related disorders linked to incomplete formation of parts of the spine or skull.
Scientists expect in the near future to find a nonintrusive way, such as a routine maternal blood test, to collect fetal cells for analysis. In the meantime, amniocentesis, in use for more than 15 years, continues to be the mainstay of test options. Chorion villus sampling (CVS), still classified as
”experimental” in the U.S., is growing in popularity because of practical aspects of the test.
Both tests collect cells that, when analyzed, provide a blueprint of the fetal chromosomes, making possible determination of fetal gender and detection of chromosomal abnormalities. Both tests also screen for Tay-Sachs and blood disorders such as sickle cell anemia. In addition, the amniotic fluid collected in amniocentesis can be analyzed for evidence of neural tube defects. CVS does not provide that information and can be followed by a special blood test for that purpose.
Though the tests provide much of the same information, the timing and techniques are quite different; for many women CVS seems the more attractive option.
Amniocentesis is performed between the 14th and 16th week after the last menstrual cycle. A thin needle is inserted through the abdomen into the uterus to collect about two tablespoons of amniotic fluid, which contains excess fetal cells. The fluid is replenished in about two days. The fetal cells are then cultured and analyzed in a lab, which takes from two to four weeks. Analysis of the amniotic fluid itself can detect unusual levels of chemicals produced by the fetus, which are indicators of defects such as spina bifida. The procedure takes about 10 minutes and produces only mild discomfort from the needle.
Amniocentesis is safest when done by a specialist using an ultrasound image to avoid touching the fetus with the needle. Under those circumstances, the miscarriage rate is below .5 percent and accuracy is rated at 99.4 percent.
The greatest drawback to amniocentesis is that by the time the results are in, the pregnancy is into the second trimester. At that point abortion requires induction of labor to expel the fetus and placenta.
In contrast, CVS is performed between the 9th and 11th weeks following the last menstrual cycle, results are available within a few days, and any subsequent abortion can be performed by a simple surgical procedure, often done on an out-patient basis. At this point the pregnancy is not visible to others.
In the standard CVS procedure, a thin catheter is inserted through the vagina and cervix into the uterus, where slight suction is applied to collect a sample of the developing placental tissue, or chorion, which contains cells identical to the fetal cells. In an alternate procedure, a transabdominal needle is used to collect the sample. CVS takes about 10 minutes and is generally painless, though frequently followed by mild cramping and spotting. Complications for both procedures include infection, excessive bleeding, leakage of amniotic fluid and spontaneous abortion. Complications from amniocentesis are considered extremely rare; the National Institute of Health has yet to formulate official statistics for the risk factors associated with CVS.
The NIH is scheduled to complete a four-year study of CVS outcomes this year, and the American Medical Association also plans to publish an advisory statement on CVS this summer based on scientific literature and a recent survey of CVS specialists. In several instances severe complications, including maternal death, appear to have been the result of mismanagement of an initial simpler complication such as infection following the CVS procedure, according to Beth Fine, genetic counselor at Michael Reese Hospital and Medical Center and president of the National Society of Genetic Counselors.
CVS specialists, including those at Michael Reese and Northwestern, say the estimated rate of pregnancy loss or complications from CVS is about 2 to 4 percent but that the actual rate may be significantly lower. Because the test is done so early in pregnancy, when the natural miscarriage rate is high, it has been difficult to differentiate between naturally occurring losses and those triggered by the test.
Other tests currently in use:
— Ultrasound: A noninvasive technique in which high-pitched sound waves are directed at the fetus and echoed back to create a visual picture. The procedure is painless, and no ill effects on the mother, fetus or later childhood development have been found. Ultrasound is used to determine fetal age more precisely and to detect gross deformities.
— Alpha fetoprotein blood test: A routine blood test performed on the mother, in which her blood is analyzed for the presence of the chemical produced by the fetal liver and passed into the maternal bloodstream. At 16 weeks there is a predictable level of the chemical in the blood. If the closure of tissue covering the spine or skull is incomplete, unusually high levels of the chemical appear in the mother`s blood. However, high levels may appear with normal babies if, for instance, there are twins or if the fetal age has been miscaluculated. An abnormal reading is typically followed by another test, such as ultrasound or amniocentesis, for more extensive analysis.
— Fetoscopy: Not a routine procedure, fetoscopy is used only when a direct examination of the fetus is needed to determine the presence of a serious deformity or to take a blood or tissue sample from the fetus. A very fine fiberoptic telescope for observing the fetus is inserted through a needle in the mother`s abdomen. An attachment allows for collection of samples.
Insurance policies vary in their coverage of fetal diagnosis costs, often depending on the mother`s age and medical profile. Because CVS remains classified as ”experimental,” many insurance policies reject coverage entirely. Amniocentesis and CVS each may cost as much as $1,000.
