Prenatal Diagnosis: Making complex choices
Copyright Sarah J Buckley 2016
This article is supplied for personal use by members of www.gentlenaturalbirth.com and may not be circulated in any way without Sarah’s specific permission Previously published in Gentle Birth Gentle Mothering (2005) and updated for 2016.
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Pregnant women are being offered an increasing number of tests to assess the wellbeing of themselves and their babies, with many of these tests now integrated into routine prenatal care. There has similarly been enormous growth in the number of tests and choices around “prenatal diagnosis”: the testing of babies in the womb for genetic abnormalities. In particular, tests for Down syndrome have proliferated, leading to extremely complex decision-making in the earliest weeks of pregnancy with sometimes difficult and long-lasting consequences. This chapter presents important information for expectant parents and highlights the often-neglected personal and emotional aspects of this complicated issue.
You’ve never received bad news in the doctor’s office before, and this was even worse because it was about your unborn baby. Your doctor was kind and gentle, and there must have been a lot of talking, as you were in there for over thirty minutes, but all you can remember is a creeping numbness, a fog that thickened around you, and the words “blood test,” “high risk,” and “Down syndrome.”
That evening you try to retrieve some detail for your partner, but the day is still foggy, and you have little memory of the pretest counseling that the doctor said she gave you before the test. The figure “one in three hundred” comes to mind, but this doesn’t make sense: how can there be all this worry over such a small number?
Eventually you find the brochure in your purse. Your doctor called it invasive testing, and said it was the next step, if you want to take it. In the brochure it is called amniocentesis, which means taking a sample of your baby’s waters. “Poor baby,” you tell your belly as you absorb the information, “the test might kill you, or else you might have Down syndrome. Then we would have to choose whether or not to get rid of you ourselves.”
That night you dream of a field of babies: perfect pink chubby babies, skinny grey babies with horrible deformities, Chinese babies, African babies, Romanian babies, and they all want to come home with you. In the morning you can hardly remember how it felt to simply enjoy your pregnancy. Your belly has become a heavy weight that you find yourself supporting as you go through that difficult day.
Welcome to the brave new world of prenatal diagnosis, where we are given information that is unprecedented in human history, and choices that can be as painful as they are complex.
Prenatal diagnosis—the detection of abnormalities of babies still in the womb—is driven by the increasing expertise of medical technology, but it is clearly sanctioned by Western societies. In a 1999 U.S. survey, more than 80 percent of respondents indicated that the benefits of prenatal testing were equal to, or greater than, the costs,1 and selective abortion for prenatal abnormalities is legal in most developed countries. It seems that we have decided, collectively as well as individually, that we want to avoid the difficulties of raising children with disabilities—particularly, in our society, children with intellectual disabilities. However, for prenatal diagnosis to contribute to this end, some of us must choose to terminate our wanted pregnancies.
Prenatal diagnosis can open a veritable Pandora’s Box for the woman and her family, and also raises wider, profound ethical and philosophical questions. For example, how can we call ourselves a tolerant and inclusive society—a society that celebrates difference—when we have an entire industry directed toward eradicating babies who have obvious differences? And our values are portrayed very starkly when we specifically target babies with Down syndrome (Trisomy 21), a condition that is not usually fatal, but is associated with intellectual disability and with characteristic physical features that our society does not recognize as beautiful.
Some of the personal impact of prenatal testing is illustrated in the story that opens this chapter. Whether this baby is affected (a one-in-three-hundred chance, in this scenario) and aborted; is affected and kept (as perhaps one in ten affected babies are2); miscarries as a result of the procedure (about a one-in-one-hundred chance with amniocentesis) or is unaffected (299 chances out of 300, before the amniocentesis), the mother has been through a difficult process.
Most women who opt for these tests are unaware that they are entering an emotional minefield with consequences that may last for years. Many are also unaware that the tests that they are accepting will not detect all, or even most, abnormalities in their unborn babies.
These forms of prenatal testing can detect only abnormalities in the chromosomes: the small strands of DNA in the cell center that act as templates for growth and development. Chromosomal abnormalities are present in around 40 percent of children with intellectual disabilities: the other 60 percent (including conditions such as autism and cerebral palsy) cannot be diagnosed before birth with our current forms of prenatal testing.
Chromosomal abnormalities also account for only a small minority of physical congenital abnormalities, which affect around two to three in one hundred babies overall at birth.3
Recent research also shows that the majority of pregnant women are not well informed before or after they undergo tests for prenatal diagnosis.4, 5 In a recent survey of U.S. obstetricians, almost one-quarter of the respondents reported that they did not routinely discuss screening with the women under their care,6 and a U.S. review has suggested that pediatricians and residents lack essential knowledge of genetics and communication skills for effective counseling of patients.7 Both Australian8 and Canadian health professionals9 have also been shown to have a variable knowledge of these complicated issues.
Furthermore, a U.S. survey found that more than one-third of primary care physicians admitted to being biased when counseling women with a prenatal diagnosis of Down syndrome.10
Screening versus diagnostic tests
Our mother-to-be has accepted a screening test for her baby. Like one in twenty of the women who opt for the second trimester maternal serum screen (STMSS—a blood test at fifteen to eighteen weeks, also called a “triple” or “quadruple” screen)—she received a screen-positive result, with all the anxiety that accompanies this news.
However, only around one in fifty women who test positive will actually have an affected baby; the remaining forty-nine have had what is called a “false positive” result. As well as this, with a average detection rate of 60 to 70 percent, STMSS will fail to detect around one in three babies with Down syndrome. Detection rates for spina bifida, the other major condition that may be discovered with STMSS, are around 70 percent, which means that, similarly, one in three affected babies will not be detected with this test.3
Why is this widely used test so inaccurate? The major reason is that it is not a diagnostic test—that is, it can’t give a definite diagnosis for the baby. It is a prenatal screening test, designed to give an indication of risk so that the next step—a diagnostic (and invasive) test of the baby’s cells by amniocentesis or chorionic villus sampling (CVS)—can be targeted to women who are more likely to be carrying an affected baby.
Limiting these diagnostic tests is desirable because they carry their own risks, especially the risk of causing a miscarriage, as we will discuss. An ideal prenatal screening test will be sensitive (that is, detect as many affected babies as possible) and specific (that is, having few false positive results), which means that the least number of healthy babies will be exposed to the risks of invasive testing. Researchers are currently attempting to increase the sensitivity and specificity of prenatal test by increasing the number of components that are tested in the mother’s blood. Triple-, quad-, and even penta-screens (testing five blood components) are now available, but note that the usefulness of the test depends on the sensitivity and specificity of each component.
These prenatal screening tests have been promoted as a “no-risk” test to women (especially younger women) who may not consider themselves likely to have a baby with Down syndrome and may not consider invasive testing because of the risk of miscarriage. For example, women under the age of thirty-five have a generally low chance of giving birth to an affected baby, but because the majority of babies are born to these younger women, they also give birth to the majority of babies with Down syndrome.
Screening tests can tell an individual woman whether she has a higher-than-average chance of carrying an affected baby, and she can be offered a diagnostic test when her risk is over 1 in 250 to 300. This is approximately double the normal risk, as approximately 1 in 600 pregnant women overall carry a baby with Down syndrome. In this way, screening tests can increase the overall numbers of Down syndrome babies detected and aborted, because around 70 percent of Down syndrome babies are born to women under thirty-five.
Several studies have found that serum-screening tests are more likely to be false positive in specific situations. Researchers have, for example, found that women who are vegetarian,11 smokers,12 from different ethnic groups,13 and/or who have had a false positive result in a previous pregnancy14 may require adjustment of their serum markers to avoid an excess of false positive results. Mothers who carry a female baby are also more likely to receive a false positive test result.15
Overall, however, the most common reason for inaccurate test results, including false positives, is an error in dating the pregnancy. Accurate dating is important, because levels of the substances that are tested depend on the age (gestation) of the baby. Between 20 and 40 percent of women with screen-positive results will be found to have normal levels when their pregnancy is more accurately dated by ultrasound scan.16
Currently, 99 percent of U.S. obstetricians report offering STMSS (triple or quad tests) to women under their care, making it the most common screening test.6 However, there are two other screening tests that are increasingly used to detect babies with Down syndrome. The first is an earlier blood test, performed at around ten weeks and known as first trimester maternal serum screening (FTMSS). First trimester screening analyzes one or two components of the mother’s blood and has, in some studies, given results as accurate as triple or quad screening, although it cannot detect defects like spina bifida.
The second early prenatal screening test is a specialized ultrasound, known as nuchal translucency testing, which measures the thickness of the skin fold at the back of the baby’s neck at eleven to fourteen weeks. This can be used in combination with first and sometimes second trimester screening to enhance sensitivity and specificity, as I discuss below.
The newest and perhaps most radical chromosomal testing involves analysis of the tiny amount of fetal DNA that enters the mother’s blood. Still too expensive for routine use (over $1000 per test), cell-free DNA is 99% accurate and can be detected ion a simple blood test around 12 weeks. Most concerning is the potential for testing without counseling or true informed consent. Further, the likelihood is that this “cell-free fetal DNA” (cfDNA) testing will eventually be cheap enough to be offered universally, creating the possibility, as one expert described, of “Down syndrome genocide” (Kesby G, quoted in Smith 2013).
Ultrasound and Nuchal Translucency
Nuchal translucency (NT) is a very specific test; it requires a trained operator and dedicated equipment, including a sophisticated computer program to analyze the data, which includes the mother’s age and the baby’s exact gestation.
Like the serum screening tests, NT gives an estimate of risk of Down syndrome rather than a definite diagnosis. NT detects around 60 percent of babies with Down syndrome, with a 5-percent false positive rate, meaning that around one in twenty women will have a positive result on NT but a normal baby. An increased NT measurement may also indicate other less common abnormalities such as heart defects, trisomy 18 (Edwards syndrome) and trisomy 13 (Patau syndrome), which, like Down syndrome, involve an extra copy (“trisomy”) of one of the 23 pairs of chromosomes. However, because NT is performed while the baby is still small and undeveloped, the ultrasound performed with NT testing cannot be expected to diagnose abnormalities of the body, gut, kidneys, heart, and spinal cord, and an eighteen-to-twenty-week scan would still be necessary for this reason.
NT uses ultrasound, which has not, I believe, been adequately shown to be safe for our offspring long-term. Recent research, which compared multiple scans with single scans in pregnancy and followed the offspring up until eight years of age, has produced some reassurance; however, as the researchers state, “ . . . our results do not lessen our need to undertake further studies of potential bio-effects of prenatal ultrasound scans.”17
Ultrasound machine output intensities continue to increase, even since this study was conducted, and questions about non-right-handedness associated with ultrasound exposure have not been resolved. (For more information on ultrasound, see chapter 5 in Gentle Birth, Gentle Mothering, also available as ebook and audio) XXhyperlink
Early detection, early relief?
These new, early tests are believed to benefit women, because the whole process (screening, diagnosis, and possibly termination) can then take place at an earlier stage of pregnancy, perhaps even before the woman has shared her news. CVS, as a diagnostic test, can be performed from ten weeks, and a termination, if chosen, can also be done at an earlier stage of pregnancy.
However, early screening is advantageous only if CVS is readily available: according to one survey, only 2 percent of U.S. obstetricians have this skill, compared with 37 percent who perform amniocentesis. And because of the complexity of these procedures and the time needed to make these major decisions, many women who have undergone first trimester screening or NT do not actually have a termination until after sixteen weeks.18
The complexity of prenatal screening is increasing, because researchers are looking at different combinations of first and second trimester screening, and NT. Currently the best figures for detection of Down syndrome are produced through two-step integrated testing (IT), a resource-intensive protocol that detects 90 to 96 percent of affected babies, with a false-positive rate of 2.6 to 5 percent, respectively,19, 20 Higher detection rates are associated with higher false-positive rates, as explained below. Integrated testing involves serum screning at ten weeks, NT at eleven to fourteen weeks, and finally the fourteen-week STMSS. When all these results are back (after a long wait), the woman will receive her risk estimate and can then decide whether she wants to proceed with amniocentesis.
Other combinations are less sensitive and have higher false-positive rates, but may be easier and less costly to administer. Stepwise sequential screening protocols allow women to know their first trimester results at the time, thus avoiding weeks of uncertainty, and contingent sequential screening regimes offer further tests only to women with high-risk results on early tests. Serum integrated testing involves first and second trimester blood tests but without NT.
In the United States, the American College of Obstetricians and Gynecologists (ACOG) recommends offering screening to all women regardless of age, with combined FTMSS and NTS recommended for women who begin obstetric care early in pregnancy.21 The U.S. Preventive Services Taskforce currently recommends STMSS for all low-risk pregnant women who have access to counseling, and invasive testing for women over thirty-five or at high risk of carrying a baby with Down syndrome.22
In Canada, the Society of Obstetricians and Gynaecologists of Canada (SOGC) has also recommended that every woman be offered high-quality screening to assess risk, with diagnostic tests limited to women with screen-positive results or aged over forty.
These complex and prolonged testing regimes are argued to be cost-effective, based on the premise that money will be saved through aborting babies with Down syndrome, who are estimated to cost an extra U.S.$762 758 each (adjusted to 2006 dollars) for lifelong care.23 In the United States, it is said to be cost-effective to spend more than U.S.$2.5 billion annually to detect and abort around 7,500 babies with Down syndrome by offering FTMSS and NT to all pregnant women.24
In the UK, where this testing is funded by the state, Alfirevic and Nielson ask:
What is the importance of establishing top quality Down’s syndrome screening programmes, relative to other priorities in the maternity services—notably tackling inequalities and ensuring that all women in labor have enough midwives to meet their needs?25
Diagnostic and invasive testing: amniocentesis and chorionic villus sampling (CVS)
Amniocentesis and CVS are invasive tests because they involve invading the pregnant mother’s womb to take a sample of the amniotic fluid and developing placenta (respectively) to test for genetic abnormalities.
Because of this, both tests carry risks to the baby and, to a lesser extent, to the mother.
Amniocentesis is usually performed at fifteen to sixteen weeks. In amniocentesis, around one to two tablespoons (1/2 to 1 ounce, or 15 to 30 ml) of amniotic fluid is taken with a needle under ultrasound guidance, and the baby’s cells, which are floating in the fluid, are removed and grown (cultured) in the lab. The baby’s chromosomes, which are part of the nucleus of the cell, are tested for abnormalities, including Down syndrome.
Results are usually available in about two weeks, although new technologies such as fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR) can be performed without cell culture, reducing the waiting time to a few days but also reducing the number of abnormalities detected.
It is estimated that these tests will miss around one in one hundred abnormal results, with 30 to 45 percent of these carrying a significant risk of fetal abnormality.26 Amniotic fluid can also be tested for alpha feto-protein (AFP), which indicates neural tube defects (NTDs) in the baby’s brain and spinal cord, including spina bifida. AFP is a simpler test, and results are usually available within a day or two. If AFP levels are high, a detailed ultrasound is recommended to give more information.
Amniocentesis is recognized to increase the risk of miscarriage by between one in fifty and one in two hundred overall, and this miscarriage can occur up to three weeks after the procedure, or even later. In one study involving women under thirty-five 35?, the majority of procedure-related miscarriages occurred after twenty-eight weeks.27
More experienced operators tend to have lower miscarriage rates, and rates are lower when ultrasound guidance is used.28 One large study indicated that the risk of miscarriage might be higher among older women; women who have experienced bleeding in the pregnancy; and women who have had more than three previous early miscarriages or abortions, a late miscarriage or abortion, or both.29 In this study, women over forty had a risk of miscarriage after amniocentesis of around 5 percent, whereas those over forty who had also experienced bleeding had a 10 percent chance of miscarriage. Women over forty with previous miscarriages or abortions, as cited earlier, had a 20-percent chance of miscarriage after the procedure.29
It is noteworthy that, with STMSS and follow-up amniocentesis, miscarriage will be caused in one normal baby for every one to two aborted babies who would have otherwise been born with Down syndrome.2
Leakage of the amniotic fluid through the vagina (even though amniocentesis is performed through the mother’s abdomen) will occur for about one in one hundred women. And although it is a rare occurrence, the amniocentesis needle can scrape or even penetrate the baby, and the consequences, which may be severe, may not be detected before birth.30
Studies have suggested that newborn babies who have been exposed to early invasive testing—CVS or amniocentesis before 13 to 14 weeks — may have impaired lung growth and development,31, 32 even up to age one,31and may also have a higher risk of congenital abnormalities,33 including a higher risk of musculoskeletal deformities such as club foot and hip dislocations..34
Amniocentesis between fourteen and fifteen weeks may increase the risk of newborn pneumonia, meconium aspiration, and tachypnea (rapid breathing),34 and amniocentesis may also increase newborn respiratory distress.35 A large European study has also suggested that amniocentesis may increase the risk of prematurity by more than 50 percent.36 Ironically, prematurity is a significant risk factor for physical and intellectual impairment, including cerebral palsy, making further research in this area important.
Amniocentesis is also invasive for the mother, as it involves penetration of her uterus. Possible complications include infection of the baby’s sac and fluid (chorioamnionitis), which will usually cause miscarriage. More severe infections can cause septic shock and serious illness and can, very rarely, be fatal.37
CVS involves taking a sample of the baby’s developing placenta under ultrasound guidance, via either the mother’s abdomen or her vagina, at around eleven to twelve weeks. CVS is a newer test and has extra risks, compared to amniocentesis. First, the miscarriage rate from the procedure is higher—between one in twenty-five and one in one hundred overall.38, 39 Difficulties with the procedure, or with lab analysis, are more common with CVS than with amniocentesis, occurring between 2 and 6 percent of procedures, and a repeat CVS (or amniocentesis at a later time) may be necessary.3 Repeated testing increases the risk of miscarriage.
It is also possible that the cells removed by CVS will be reported as normal when the baby actually has an unusual (and usually milder) “mosaic” form of Down syndrome, where only some cells carry the extra chromosome.. Alternatively, the baby may be unaffected yet have some abnormal mosaic cells, giving a false positive result on CVS. Mosaicism affects around 1 percent of CVS test results.40
CVS was designed so that women could have this diagnostic test early in pregnancy, when a termination, if chosen, is more straightforward. However, a major disadvantage of this earlier diagnosis is that some affected babies would have been naturally miscarried within a few weeks. This is especially true for Down syndrome babies, of whom one in four (25 percent) will be miscarried between ten and fourteen weeks, and another one in four (23 percent) will be miscarried before the end of pregnancy.2 Research has even suggested that those Down syndrome babies who are detected prenatally may be miscarried at a higher rate (50 percent overall) than Down syndrome babies who are not detected on prenatal screening.41
CVS may also cause damage to the baby. Early studies have suggested that babies exposed to CVS before ten weeks may have a small but increased risk of limb deformities (CVS is now performed at eleven to twelve weeks), and other studies have noted increased numbers of CVS babies with clubfoot and malformations of the jaw and gut, as well as hemangiomas (strawberry birthmarks).42
One small study has reported an increased risk of high blood pressure and preeclampsia (toxemia) later in the pregnancy when the baby’s placenta has been penetrated during CVS (which is a necessary part of the procedure) or amniocentesis.43 Mixing of fetal and maternal blood is likely during amniocentesis or CVS, so anti-D (Rhogam) should be administered to mothers with an Rh-negative blood group to prevent blood incompatibility problems in future pregnancies.
Another irony of both amniocentesis and CVS is that both procedures involve ultrasound, giving the mother the opportunity to see her baby, yet at the same time she is expected to consider abortion. As one mother shared, “I was simply able to see her, reinforcing the love that they told me was for the wrong baby.”44
Brave new world
Against these very quantitative analyses, Elkins and Brown argue:
. . . individuals with Down syndrome have come to be recognised, over the last three decades, as bringing a valuable quality of life into our society. They are well known for the joy and love they bring to their families. They remind us that the definitions of normalcy are artificial and fragile . . . In short, individuals with Down syndrome teach the rest of us how to cope, to grow, to overcome and to understand humility, gratitude and joy.45
In the research and published material about prenatal diagnosis, the perspectives of those affected by conditions such as Down syndrome have rarely been considered. Most of the prenatal diagnosis information leaflets, designed to help prospective parents decide about testing, paint a very negative and outdated view of Down syndrome.46, 47
Alderson examines our presumptions about the value and quality of life with Down syndrome through her interviews with five affected adults.48 Her interviewees show insight and enjoyment of life, sensitivity to social prejudice, and painful awareness of the issues around testing and selective abortion for Down syndrome babies. There is more excellent and realistic literature written by parents, caregivers, and individuals with Down syndrome.49–51
A recent paper suggests deeper ethical issues for us all to consider. In the United Kingdom, Reynolds sent a questionnaire comprising nineteen clinical scenarios, including prenatal testing for Down syndrome (which was not identified as such), to forty randomly chosen research ethics committees.52 More than half of the respondents expressed the opinion that prenatal screening for a condition with the clinical features of Down syndrome was unethical. When it was disclosed that confirmatory testing could cause the miscarriage of normal babies, only 14 percent remained in favor of screening.
Diagnosis and Counselling
After so many decisions and tests, you might hope that the results from amniocentesis or CVS would be clear and the decision, whatever it is, would be straightforward. Unfortunately, this is often not the case. For all the babies with a clear diagnosis of Down syndrome, there are as many again with other chromosomal abnormalities, many of which carry an uncertain outcome.
For example, around one third of abnormalities reported involve the sex chromosomes, which can give subtle or unknown levels of abnormality.3 Rothman, who conducted extensive interviews with women who had experienced prenatal diagnosis, notes that parents can be incapacitated by uncertain diagnoses.53 Other research shows that many women will choose to terminate their pregnancy rather than live with such uncertainty.54
New gene technologies such as FISH and PCR, mentioned earlier in relation to shorter testing times, are less likely than traditional chromosomal testing to give uncertain diagnoses because they are used to test for a narrow and specific range of abnormalities.;
Such tests will not, for example, detect less common abnormalities in the sex and other chromosomes, but are as accurate in testing for Down syndrome as traditional chromosomal testing. In most places, comprehensive chromosomal testing follows FISH and PCR results. Choices may be made simpler by using only these methods, if available, to test for Down syndrome although rare conditions may not be diagnosed.
Obviously there is a great need for high-quality counseling both before and after testing. Specialized genetic counselors are the appropriate professionals, and a counseling session—ideally provided to all women considering testing—is essential for those with positive screening or diagnostic tests.
Note however that genetic counselors area part of the industry of prenatal diagnosis, whose purpose is to reduce the number of live-born babies with Down syndrome. This may make it difficult for them to provide impartial information. One analysis of all the written information provided by caregivers and counselors in the UK showed very little information about, and a negative attitude toward, people with Down syndrome. This complaint is echoed in a survey of 141 U.S. mothers who chose to continue their affected pregnancies.55 Thornton notes, “High uptake of prenatal blood tests suggests compliant behavior and need for more information.”56
In some places, parents of children with Down syndrome are attempting to redress the imbalance by becoming proactively involved in educating expectant couples.57
Termination after prenatal diagnosis
Prenatal diagnosis, and the industry that supports it, is based on the premise that the majority of women with affected babies will decide to terminate their pregnancies. Although women may consider this when they are choosing whether to have the screening test, they are unlikely to realize (or to be told) exactly what this entails until they actually confront this situation for themselves.
Early termination, involving a straightforward procedure (scraping or suction to remove the lining of the womb and baby), is possible only up to around fourteen weeks. Following a CVS at eleven to fourteen weeks, and then a two-week wait for results, women may end up with little time to consider their choices, and may even miss the possibility of an early termination.
Later termination may involve induction of labor, which can be as long and difficult as a full-term labor, and the baby may be born alive but obviously unable to survive. Alternatively, saline may be infused into the amniotic fluid (which also stimulates labor) or a lethal injection may be administered to ensure that the baby is stillborn. In one trial involving the drug misoprostol, the average time from induction to delivery for a mid-pregnancy termination was eighteen to thirty hours, depending on the method of induction.58
Most U.S. centers offer a “dilate and evacuate” termination when the pregnancy is around fourteen to eighteen weeks, which usually involves preliminary softening of the cervix, then a general anesthetic for the mother while the surgeon extracts the unborn baby (fetus) in pieces.
Dilate and evacuate procedures have been favored over induction methods because it has been presumed that this technique will reduce maternal trauma by preventing contact with the baby. However, one study has suggested that maternal grief over a one-year period is equivalent for the two procedures.59
If termination is considered after amniocentesis at fifteen to sixteen weeks plus two weeks for results, not only will the mother be feeling her baby moving, but by twenty weeks the baby is only a few weeks away from the time when it could survive with intensive care—around twenty-four weeks. Furthermore, terminations of babies at advanced gestations may require more difficult abortion techniques as well as death certification, naming, and a funeral, depending on legislation in the place of birth.
Early termination has been the goal of prenatal diagnosis programs, with the presumption that it will be less traumatic for the mother than a later termination. However, although termination for fetal abnormality in the first trimester is medically less complicated than later in pregnancy, there is little evidence that the distress for the woman is any less. Some women interviewed by Rothman felt that seeing the baby afterward, which is possible only after a late termination involving an induced labor, was (or would have been) helpful in their grieving process.53
One post-mortem survey found a diagnostic error in one baby out of 128 diagnosed by amniocentesis or CVS, and three normal babies among 215 aborted because of abnormal ultrasound results.60 And although termination is regarded as the end of the process of prenatal diagnosis, a small U.S. study suggested that one third to one half of women may still be experiencing despair, with up to one-half reporting difficulty coping twelve months later,59 and a UK survey found that one in five women who underwent later termination were still significantly distressed two years later.61
Eve’s apple: the consequences of knowing
Pregnant women are the target, and supposed beneficiaries, of this large and increasingly complex industry, yet there is surprisingly little written about their experiences and opinions. Technological obstetrics makes the assumption that more knowledge is better, but, like Eve’s apple, the knowledge that we gain through prenatal diagnosis can cast us from our pregnant paradise, with major and long-lasting consequences for mother, baby, and family.
Research suggests that most women around the world have a difficult time making sense of this complex area, especially the crucial distinction between screening and diagnostic tests. Perhaps this reflects the difference between our intellectual understanding of, and our emotional reaction to, a positive screening test.
For example, a health professional reported that she felt that her positive screening result was
. . . [a] disaster.” That evening she was unable to sleep, and felt like crying desperately. The next day she described herself as being “out of control.” Simply having technological information did not prevent a strong emotional reaction.62
Another woman in her second pregnancy
. . . described the four weeks of waiting as the most difficult of her life. She was nervous, tearful and hypersensitive, and she decided to abort the fetus if it was abnormal . . . serum screening had struck her down . . . she could not believe in a healthy baby before she held it in her arms.63
Women have described their reactions to a positive screening result as: “tragic,” “it was a shock,” “I was deeply worried,” “everything went dark,” and “it was a slap in the face.”64
Others have shared:
I was totally shattered, frightened out of my wits.65
I said to the midwife who told me the results: it’s all gone wrong, it’s all gone wrong. I don’t want to know about it anymore.65
Even when the results are reported as normal, many mothers still remain anxious. One mother, who said that she had been “totally reassured” by a normal amniocentesis result, asked for a pediatrician to check her baby for Down syndrome immediately after the birth.66
For the women whose babies are found to be abnormal, the decision becomes, as Rothman calls it, “the tragedy of her choice”53—to terminate a wanted pregnancy or to continue with the knowledge that her baby will be affected, and with the possibility of a stillbirth or a child with a lifelong disability. Research indicates that maternal grief may be the same whether a baby with a lethal abnormality is aborted or stillborn.67, 68
One has to also wonder at the consequences for the ongoing mother-baby relationship when mothers have experienced this degree of “false positive” stress over the wellbeing of their baby. Ordinarily, such anxiety would mobilize a mother’s protective instincts, and she would draw closer to her baby. However, this protective instinct is difficult to express when the mother is also considering abortion, and she is likely to protect herself through emotionally distancing from her baby and her pregnancy—to “not want to know about it anymore,” as the woman just quoted puts it—at least until reassuring results are received.
Some women report that this distancing has affected their relationship with their children long after birth, and that this anxiety or detachment, based on fear of abnormalities, can recur in subsequent pregnancies.64, 69 As midwife Anne Frye comments, “Nature never intended that parents would have such information, pregnancy as a time of unconditional attachment is severely disrupted by the technology available today.”70
This difficult emotional situation, which pulls women in two directions, is echoed in the literature of prenatal diagnosis, which refers, for example, to “therapeutic termination” of babies with abnormalities, as though the abortion is curing an illness, rather than enacting a socially sanctioned form of eugenics. Is it any wonder that, following a termination, women experience “conflicting feelings of relief, guilt, doubt, loss of self-esteem and moral bewilderment”?71
When parents make the decision to terminate, often they describe it as being in their abnormal baby’s best interests,72 which may be true in a society that is bent on eradicating individuals with conditions such as Down syndrome. As one woman said, “I didn’t want to give up my baby, yet I had to because I knew what the future held for all of us if I kept her.”44
Ironically, the stress that prenatal screening and diagnosis generates may create further risks to mother and baby. Research into the long-term effects of pregnancy stress concludes
. . . pregnant women with high stress and anxiety levels are at increased risk for spontaneous abortion and pre-term labor and for having a malformed or growth-retarded baby . . . 73
According to these authors (and the many papers that they review), offspring whose mothers were stressed in pregnancy may have delayed development, with alterations in brain and hormone systems as well as increased susceptibility to stress throughout their lives.
Even more worryingly,
Huizink74 has demonstrated that maternal stress in the first half of pregnancy is an important predictor of problematic infant behaviour. This was found especially for pregnancy-specific anxieties such as fear of the baby’s health and fear of [pain during] delivery.75
One also wonders about the effects of prenatal diagnosis on the child themselves. Are we, at some level, accepting the view that our children are commodities that we can subject to a quality control test and reject if faulty? How will our children feel if they discover that our acceptance of them was so conditional? How will these experiences affect our subsequent role and expectations as parents?
Prenatal diagnosis is also said to benefit women through forewarning of their baby’s abnormality. This may be true for some women,76 but others may resent their loss of enjoyment of pregnancy.64 Discovering the baby’s problems during pregnancy is also a very different experience from discovering this at birth, when Mother Nature hormonally primes new mothers to fall in love with their babies. Some parents have also appreciated the opportunity to recognize their baby’s disability themselves, even days after the birth.77
This chapter has focused mainly on the experience of women whose screening result is positive, especially false positive. However, the promise of prenatal diagnosis—to prevent the birth of babies with abnormalities—also has an influence on those who receive a “false negative result”—that is, their test is normal but they give birth to an affected baby.
In one study, parents of Down syndrome babies who had been misdiagnosed as normal had more problems adjusting, including more feelings of stress, blame, and anxiety, than those who did not have a test.78 Such parents are increasingly litigating for “wrongful birth,” with successful cases in many countries in recent years. Such litigation further pressures both caregivers—for whom non-directive counseling is already challenging79—and their clients toward routine testing.
A further irony is that most women choose to have prenatal screening to receive reassurance that their baby is healthy. Yet for all the stress, time, and money that are consumed by the prenatal diagnosis industry, neither these tests, nor any other pregnancy tests currently in use, can tell us with certainty that our babies are normal and healthy. Major conditions such as cerebral palsy and autism cannot be detected by any existing method, and physical abnormalities involving the heart and kidney, some of which are severely disabling, are also unlikely to be picked up through prenatal screening.
New uses for the information gained from these tests are also developing, with the discovery that low-risk women with extreme levels of STMSS markers may have increased risks of complications in later pregnancy. These risks include premature labor; growth restriction; and perinatal death; all due to deficits in placental function, which may be clarified by further testing.80 The cost of this information, in terms of anxiety and increased testing, versus the benefits for mother and baby are not yet clear, as these conditions are not treatable except by monitoring and possible early delivery in extreme cases.
The trick of technology
Prenatal diagnosis represents incredible and continuing advances in technology, yet there is a sleight of hand—a trick, perhaps—that is being played on pregnant women. We are told that prenatal diagnosis will increase our choices, but as these tests become routine, women are feeling that they have less choice to refuse the testing. We are already, through social attitudes, individually responsible for our children’s development, and now we are also becoming responsible for producing a healthy baby at birth.
As one woman comments,
I knew it was my responsibility to make sure I was not going to give birth to a handicapped child. But that meant taking the risk of losing a healthy baby. I am responsible for that too.81
Finally, as we look more deeply, the parallels between prenatal diagnosis and medicalized childbirth become increasingly obvious. Both industries are centered on high technology and its superior knowledge, and both consider women’s own feelings and instincts about their body and their baby to be of lesser importance. Melinda Reist, in her important book on this topic Defiant Birth, calls this “The benevolent tyranny of expertise.”82
Women who choose either path are at risk for a cascade of intervention—from induction to cesarean or from screening to abortion—with pressure to conform to medicalized ideas of “the right decision” at each point. As one woman notes, “ . . . once you’ve got onto the testing trap you have to get to the end.”44
Where does this end take us, as individuals and as a society? Does prenatal diagnosis represent liberation, or the beginning of a slippery slope toward selecting babies on the basis of socially acceptable characteristics? How will the “new genetics” impact prenatal diagnosis, with the huge amount of information that will soon become available about our unborn babies? And does it, as Rothman suggests, make every woman feel that her pregnancy is “tentative” until she receives reassuring news?
The answers to these and other questions are as yet unknown, but what is certain is that this technology will become more sophisticated in the coming years, and our choices more complex. Mother Nature, like many women who are enrolling in these tests, does not know whether to laugh or cry.
Update for 2016
There is rapid change in the field of prenatal diagnosis. In particular, non-invasive prenatal testing (NIPT) and especially cell-free fetal DNA, (cfDNA, mentioned under “Screening vs Diagnostic tests”) is becoming less expensive (Currently $800-2000 in US and cheaper elsewhere) and therefore more commonly used. It is generally done between 10 and 14 weeks, depending on the specific test and manufacturer.
cfDNA gives over 95% accuracy in some situations (see below), but it is not fully accurate in diagnosing chromosomal conditions. Therefore, it is used as a screening test, not a diagnostic test. It is likely that this will soon be used as the main screening test, replacing blood tests and likely the 11-13-week Nuchal Translucency Scans.
This is a beneficial development. Because of greater accuracy, there will be fewer women with “false positive” results: that is women with healthy babies who are told their baby is at high-risk of being affected by Down syndrome or other common chromosomal abnormalities. Fewer babies will therefore are exposed to diagnostic tests – CVS and amniocentesis—with their increased risks of miscarriage.
However, there are some other issues with cfDNA. It is an easy pregnancy test, with just a simple blood test and this makes it more likely that women may be offered this without the necessary informed consent, support and counselling.
In addition, cfDNA does not detect the breadth of chromosomal abnormalities that conventional testing does at present. For example, although it is used for Trisomy 18 (Edward’s syndrome) and Trisomy 13 (Patou syndrome), it seems to be less accurate for these and other chromosomal abnormalities apart from Down syndrome (Trisomy 21).
It is possible that cfDNA testing will develop to be more accurate and comprehensive in the future. However, this development also has risks and benefits, including the huge ethical questions involved with discovering an unborn baby’s genetic susceptibilities. For example, parents could know if their female baby carries the BRAC genes that will increase her breast cancer risk, and have to make complex and difficult choices based on other future risks that are difficult to quantify.
Finally, most of the research on cfDNA has been conducted on women with babies at high risk of abnormalities. Studies show that, for low-risk women, half of all positive tests are false positive, with a healthy baby. (See SMFM link below)
Society of Maternal-Fetal Medicine (SMFM, 2009) https://www.smfm.org/publications/183-cell-free-dna-screening-is-not-a-simple-blood-test%5Bsmfm.org%5D
CfDNA reviews: http://www.ncbi.nlm.nih.gov/pubmed/25639627
Mayo clinic on prenatal testing: http://www.mayoclinic.org/diseases-conditions/down-syndrome/basics/tests-diagnosis/con-20020948
Current ACOG recommendations: http://www.ncbi.nlm.nih.gov/pubmed/26287791
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