Pre-natal Tests for Disabilities

Pre-natal testing is one way of finding out whether the unborn baby has a disability.

• It may be done by: imaging the fœtus (i.e. producing a picture, which may be still or moving)
• by testing some of the tissues and fluid which surround the fœtus
• by examining a sample of the mother's blood

Purpose of Testing
An ultrasound scan at 11-14 weeks of pregnancy is offered routinely to all pregnant women in New Zealand, both to determine the foetal age, so that a delivery date can be planned, and to check for chromosomal abnormalities such as Down syndrome and spina bifida. At around the same stage a range of tests will be arranged. There are many reasons for these tests:

• If the mother's blood is found to be of a rare type called rhesus negative, and the father is rhesus positive she may need monitoring to avoid problems with future pregnancies. If the father is also rhesus negative, then, there will be no problem at this time or in the future.
• If protein levels in the blood are high, it could be a sign of a condition known as pre-eclampsia, which causes raised blood pressure in pregnant women and can stop the placenta working properly. This is dangerous to both the mother and the fœtus.
• If diabetes is detected because of high blood sugar levels in the mother's urine, then she can be referred to a specialist who can arrange the best possible care for both mother and fœtus. Failure to do this could cause harm to the fœtus
• If it is discovered from blood tests that the mother does not have immunity to rubella (German measles), she will be counselled that she should exercise caution so that she does not come into contact with anyone who has this virus, as it can cause disability in the fœtus; unfortunately, most of the harm to the fœtus will have already occurred before the twelfth week of pregnancy.

Most pre-natal tests are done to find out whether the fœtus has a disabling condition so that s/he can be aborted.

• Specialised ultrasound scans can be used to indicate conditions such as Down syndrome, heart conditions or spina bifida and hydrocephalus
• Specialised maternal blood tests can also indicate these conditions ( Down syndrome, heart conditions or spina bifida and hydrocephalus)
• If it is discovered from blood tests that the mother does not have immunity to rubella (German measles), the fœtus may have already been exposed to rubella and have suffered harm such as deafness, eye disorders, heart problems, bone problems, learning disability and cerebral palsy as a result of such exposure. If this proves to be the case, the mother is likely to be offered an abortion and may even come under pressure to have an abortion.

Virtually the sole aim of the two main diagnostic tests, amniocentesis and chorionic villus sampling, is to detect disability.

Although much is made of "informed choice" for women, in fact, it is frequently assumed that a woman whose fœtus has been found to have a disability will want to have an abortion.

Pre-natal tests are funded by the Government on the basis that they are "worth" the cost because they help "prevent the birth of" disabled babies. In a cost-driven society where governments are already seeking ways of scaling down services to people with disabilities, disabled activist groups are concerned that pre-natal diagnosis and eugenic abortions will lead to the less economically productive in society being regarded as less valuable. 1.2.

Disability action group "No Less Human" has stated:

"It is offensive to suggest that killing disabled babies "prevents disability", it just kills disabled people and it is insulting to say that disabled people may be legally killed to save money. If people are disposable and have to justify their right to life by their productivity or cost, none of us is safe."

Screening tests
Almost all pregnant women now have ultrasound scans and blood tests to measure the amounts of several proteins in the mother's blood which derive not from the mother but from the fœtus. The information from these two screening tests does not give a definitive diagnosis of disability, but it is used to estimate the chance of the fœtus having a disability.

If it is found that the chance the fœtus has a disability is more than 1 in 250, this is defined as "screen positive." One pregnant woman in 20 will fall into this category, but only one in 50 of this group will actually be carrying a fœtus with a disabling condition.3

These tests are safe for the fœtus, but are not as precise as diagnostic tests.

Diagnostic tests
If the tests reveal a "screen positive" result, the mother, particularly if she is in the "older" age range 4, will be offered diagnostic tests such as amniocentesis or chorionic villus sampling, which usually give a more accurate idea of whether or not the fœtus has a disability.

Both these tests are invasive (meaning that they involve taking a sample from inside the womb) and therefore carry a risk of causing miscarriage.

'False positive' and 'false negative'
The terms ' false positive' and 'false negative' always refer to the results of tests taken. This means that of those fœtuses diagnosed after the tests as either having or not having the disability, a certain percentage will be wrongly diagnosed.

False positive means that a fœtus will be said to have a disabling condition but, in fact, it will be found later that s/he will not have that condition.

False negative means that a fœtus will be said not to have a particular disabling condition but, in fact, it will be found later that s/he will have that condition.

Certainly, different studies report different percentages and different tests report different percentages but the point that must be noted is that ALL tests report both ' false positives' and ' false negatives'. i.e. their results are not absolutely reliable.

Built in to pre-natal testing programmes is the aim of discovering disabled fœtuses and then aborting them. This will inevitably mean that a certain number of non-disabled fœtuses will be aborted in error, and others will also die as a result of the test which can cause a miscarriage

Routine tests

"Dating scan"
This is offered to all pregnant women at 12 weeks to check the age of the fœtus. A hand held instrument called a transducer is used to produce a moving picture of the fœtus on a video screen, using high-frequency sound waves. Ultrasound scans are generally thought to be safe for the fœtus. 

However, according to an article in The Lancet, studies in Sweden and Norway have shown that unborn children exposed to only one or two ultrasound scans while unborn are more likely than usual to be left-handed or ambidextrous (i.e. able to use both hands equally well.) This is particularly marked in boys, and may indicate that the scans are causing subtle changes in the fœtus's brain.5

Blood tests
These are offered to all pregnant women at around 12 weeks when a small amount of blood is taken from the woman's arm. They are done to check the mother's blood group, particularly the rhesus factor.

Blood tests are believed to be very safe, with no significant risks for either mother or fœtus. They can be used to predict complications at an early stage, enabling treatment to be initiated before any problems arise.

Urine tests
These tests, offered to all pregnant women, can reveal signs of pre-eclampsia, a dangerous condition for both mother and fœtus which can be treated if discovered early. They can also detect signs of diabetes in the mother, which could harm the fœtus if treatment is not initiated.

There are no disadvantages of urine tests for either mother or fœtus.

"Abnormality" tests
As their name suggests, these tests are done solely to discover whether the unborn fœtus has a disability. They may be divided into invasive and non-invasive.

Non - Invasive Tests

The "abnormality scan" by ultrasound is offered to most (90%) pregnant women at 18-20 weeks. It is similar to the "dating scan" except that the aim is to detect signs which might indicate that the fœtus has Down syndrome, spina bifida or other disabilities.

An "abnormality" ultrasound scan, on average, identifies 50% of "significant" (i.e. "serious") conditions. When ultrasound is combined with a consideration of the mother's age, (Down syndrome is very much more prevalent in the babies of older mothers), an estimation can be made of the chance that the fœtus has a disability.

Mothers whose fœtus has a disabling condition detected or suspected will then be offered invasive diagnostic tests.

Advances in ultrasound technology have given us 4D and 3D scans which provide moving pictures in minute detail of every feature of the fœtus.

These can detect several disabilities including spina bifida, fetal tumours and cleft palate

It is possible that this could lead to pre-natal treatment, but it is very much more likely that it would facilitate abortion of the fœtus.

Another development is the observation that unborn babies with Down syndrome often have no nose bone.

Looking for the absence of this bone could mean that 85% of babies with Down syndrome would be detected, with a "false positive" rate of about 1%, which means that for every 100 babies detected as having Down syndrome one will not actually have it.

Maternal blood tests
Blood tests are the most widely used screening test, offered to 70-80% of pregnant women. They can be used to calculate the chance of the fœtus having Down syndrome, spina bifida, and other more rare disabling conditions.

These tests measure levels of different substances ("markers") which are usually either increased or decreased if the fœtus has Down syndrome or spina bifida.

There is evidence that some "markers" for disabling conditions (i.e. signs which lead doctors to believe that the fœtus has a disability) are not as reliable as previously had been thought. An American study found that although 10-14% of pregnant women have several markers for Down syndrome, fewer than 1% of their babies actually have Down syndrome.

When the mother's age is also taken into account, the levels of these substances can provide an assessment of the chance that the fœtus has a disability.

The markers most frequently measured are:

• Alpha-fetoprotein (AFP). A low level of AFP indicates Down syndrome. A very high level indicates spina bifida or a related disability.
• Human chorionic gonadotropin (hCG). Very high levels indicate Down syndrome.
• Unconjugated estriol (uE3). Low levels indicate Down syndrome.
• Inhibin - A. Very high levels indicate Down syndrome.
• Pregnancy associated plasma protein ( PAPP) which is often found in low levels when the fœtus has Down syndrome.

A "quadruple" blood test can also be done which measures four different markers during the second trimester. If the chance of having a disabled fœtus is assessed as less than one in 250 for a particular woman, it is described as "screen negative" and above this level is "screen positive." Women in the "screen positive" group are then offered invasive diagnostic tests.

Blood tests, plus taking account of the mother's age, detect correctly around 60% of babies with Down syndrome.

However, the maternal blood tests, with no other factor taken into account, are reported to have a "false positive" rate of 8%, meaning that: 8 times out of 100 positive tests, the fœtus will not have the disability which is indicated by the test.

Combined tests
The Nuchal Translucency scan (NT) is done at 11-14 weeks. It is offered to only 10-15% of pregnant women. It uses a high-resolution ultrasound scan to measure the width of a thin layer of fluid between two folds of skin at the back of the fœtus's head.

Babies with some genetic conditions, including Down syndrome, have a thicker layer of this fluid.

The fœtus's heart rate is also measured (babies with Down syndrome tend to have a faster heartbeat than others) and the mother's age is considered. All this information is then combined to provide an assessment of the chance that the fœtus has a disability. It is claimed that this test will detect 78% of babies with chromosomal disorders.

Integrated screening
A combination of Nuchal Translucency (NT) and maternal blood tests may give more accurate results. NT can be combined during the first three months of pregnancy with a blood test called PAPP ("pregnancy associated plasma protein") which is often found in low levels when the fœtus has Down syndrome.

In addition a "quadruple" blood test is also done which measures four different markers during the second trimester. When combined with a consideration of the mother's age, early reports suggest that this may detect 90% of babies with Down syndrome.

However, there is a "false positive" rate of 1-2%. This means that of the babies diagnosed positively as having Down syndrome 1-2% (up to 2 out of 100) actually will not have the disability. This is known as integrated testing also called "OSCAR"- the "One Stop Clinic for Assessment of Risk."

Three-Step or Ultrascreen testing is a series of tests offered between 11-16 weeks and involves Nuchal Translucency screening plus a "triple" blood test (i.e. testing for three different markers.) It identifies the 5% of women who have the highest chance of having a fœtus with Down syndrome. This test has a false positive rate of 5%.(5 out of 100 babies diagnosed by this test as having Down syndrome, will not have the disability)

Invasive Tests
With Chorionic Villus Sampling (CVS), a small sample of cells from the placenta is taken at 11-13 weeks and analysed in the laboratory. As the fœtus and the placenta originate from the same cells it is usually possible to detect whether the fœtus has Down syndrome and other disabling conditions (though not spina bifida.) 

This test can cause the fœtus to miscarry. The miscarriage rate is between 1 - 3%. This means that up to 2 in every 100 babies subjected to CVS screening will die as a direct result of the test.

The aim of this test is to facilitate the deaths by abortion of those babies found to have a disability; if the aim were not present, no babies would die - it is this aim which causes the deaths of both non-disabled and disabled babies. In addition, there is also some evidence that CVS may occasionally cause damage to the unborn child's limbs.

Amniocentesis is usually done at around 18 weeks, though it can be done as early as 13 weeks[a needle is inserted into the womb under ultrasound guidance]. A sample of the amniotic fluid (the fluid that surrounds and protects the fœtus, and which contains cells shed by the fœtus) is removed and analysed in the laboratory. It can usually detect Down syndrome, spina bifida and many other disabling conditions.

According to the Royal College Of Gynaecology (RCOG) guidelines, the rate of miscarriage following an amniocentesis is estimated at about 1%; that is for every 100 women who have an amniocentesis, one will miscarry as a result of the procedure.

Amniocentesis causes the fœtus to miscarry in 0.5 - 1% of cases. Up to 1 fœtus out of every 100 will die as a result of undergoing amniocentesis.

About 400 babies die each year as a direct result of this test, and 100 are found to have Down syndrome, most of whom will subsequently be aborted.

This means that for every one fœtus found to have Down syndrome, four babies not diagnosed with any disability will die as a result of the test.

Occasionally babies are injured permanently or even fatally as a direct result of being stabbed by an amniocentesis needle. In the pursuit of ensuring that no disabled babies are born, the pre-natal testing programme actually causes some previously non- disabled babies to become disabled or to die.

Other Techniques
Recently two additional techniques for detection of fetal cells in the mother's blood have been applied to pre-natal
testing :

• PCR ("polymerase chain reaction") testing uses a chemical reaction to detect whether the fœtus has an extra chromosome (as in Down syndrome).
• "FISH" screening" ("Fluorescence in-situ Hybridisation") also detects an extra chromosome.

It is said that these tests could ultimately be as accurate as amniocentesis.

When a disability is detected
The assumption is frequently made that if a disability is detected, abortion is the logical response.

A study, published in the British Medical Journal, found that parents whose unborn child was diagnosed as having a chromosomal disability were sometimes given "grossly inadequate or frankly misleading information" leading many to abort their babies.

Chris Rudge found out during an ultrasound scan at 8 months of pregnancy that her fœtus had had a brain haemorrhage and could be brain damaged. The doctor said it was a disaster and told her there was really no hope. The doctor then asked if she would abort.

She refused but he asked again, "Are you sure you won't consider a termination?" (i.e., abortion) He asked this question five times, and each time Chris Rudge refused. The doctor also said, "You do realise your fœtus will not look like other children? Its head will be badly disfigured."

Katie Rudges's parents love their daughter and are very proud of all she has achieved, none of which would have been possible had they succumbed to the pressure put upon them by the doctor. ("Thanks for letting me live, Mummy" by Chris Rudge. Take-a-Break 2 August 2001)

It is not unusual for parents to experience pressure to be screened, and to abort if a disability is found. It is reported that abortions are carried out on 92% of babies found to have Down syndrome and 90% of babies with spina bifida.

Reliability of Testing
No pre-natal test is 100% accurate. In every test there is a possibility of: "false positive" results (when a fœtus is reported to have a disability that s/he does not have) "false negative" results (when a disability a fœtus does have is not detected.). Each test has a different rate.

Nuchal Translucency screening for Down syndrome detects 82.2% of babies with the syndrome, but the false positive rate is 8.3%. This means that of every 100 babies diagnosed by this test as having Down syndrome, between 8 and 9 will not have the condition. This error rate results in some non-disabled babies being aborted by mistake.

Although the exact figures are by no means clear, one doctor has suggested that: "..studies show that detecting and eliminating two babies with Down syndrome by screening programmes costs one 'normal' fœtus who succumbs as a result of the programme. The loss of one 'normal' fœtus is thought to be a price worth paying."

The assumption that it is acceptable to kill on the grounds that a fœtus has a disability leads to the deaths of both disabled and non-disabled babies.

It has been found that mothers who received a "false negative" pre-natal test result (i.e. the fœtus had a disability not detected by tests) have higher levels of parenting stress, and also more negative attitudes towards their disabled children than those who either have not had tests or have been given an accurate diagnosis.

These effects persist even up to six years after the birth of the disabled child. Such women may feel anger "stemming from a mistaken belief that screening tests are highly sensitive."

Risks and benefits of testing
Generally non-invasive tests (i.e., ultrasound and blood tests) have no direct dangers to either mother or fœtus. Invasive tests (Chorionic Villus Sampling and Amniocentesis) can cause the fœtus to miscarry. Occasionally babies are injured permanently or even fatally as a direct result of being stabbed by an amniocentesis needle.

Mothers can also be damaged by amniocentesis, and there has been at least one woman who reportedly died in the UK as a result of an infection caused by the amniocentesis needle. ("Pregnant woman killed by Down's test blunder" The Times 20 March 2001)

The vast majority of tests are done solely to detect disability so that the fœtus can be aborted.

Very occasionally, it is possible to help the fœtus because of information gained in a pre-natal test, but in the vast majority of cases there is no benefit to the fœtus, and the tests are done solely to detect disability so that the fœtus can be aborted.

Pre-natal testing in pregnancy is supposed to be entirely optional. All women capable of giving consent can accept or refuse any or all of the (pre-natal) tests offered... Consent should be freely given, without pressure from third parties."

In reality, disabled women and parents who already have one or more disabled children may experience great pressure to have the tests. Caroline Armstrong-Jones, whose daughter India has Down syndrome, says that during her second pregnancy:

"One doctor even admitted he thought I was irresponsible in refusing tests that would determine if my second child had Down syndrome. When I continued to resist, there were the raised eyebrows, the exasperation, the curt, intrusive questioning... with (one) exception ... the medical profession displayed a callously casual attitude to life..." ( "India enriches the lives of those around her" by Olga Craig. The Sunday Telegraph
5 March 2000)

Women who are opposed to abortion and do not want these tests also often experience pressure to have them. Even those who are very knowledgeable medically may be screened without their consent.

Dr. Josephine Treloar who is a G.P. has described her anger at finding that nuchal translucency testing had been done without her consent. The test was described to her simply as "the first trimester scan" with no hint that the key purpose was to detect if the fœtus had Down syndrome. (Venn-Treloar, J. "Nuchal translucency - screening without consent" British Medical Journal 12 September 1998.)

Compulsory Testing
It has been reported that the British Government aims to test every pregnant woman for Down syndrome by 2004. The British Government advice on serum testing for Down syndrome is based on the 1998 Health Technology Assessment report, which concluded that it is "effective" and should be offered to all pregnant women. There are now plans to introduce a national programme of pre-natal testing for Down syndrome.

Economic arguments are sometimes presented to women, to justify pre-natal detection of disability.

A Department of Health spokesperson said, "We welcome any studies which could lead to improved ways of detecting Down syndrome." Economic arguments are sometimes presented to women, to justify pre-natal detection of disability. These claim that as disabled people "cost society a lot of money" it is preferable to detect disabled babies in the womb. They can then be aborted and save the country the money it would have spent in caring for them.

This sort of calculation is highly offensive to born disabled people, and implies not only that their lives have no value, but that they actually have a negative value.

Ethics of testing
Whether or not pre-natal testing is seen as "ethical" depends on the purpose for which it is done. Sometimes it is done to help the fœtus - for instance to diagnose a condition which could be treated in the womb such as spina bifida. However, the vast majority of pre-natal tests aim to detect disabled babies with the aim of aborting them.

Pre-natal tests are sometimes said to be done to "reassure" the mother. However, this begs the question of what will be done if a disability is discovered. There is ample evidence of pressure on women whose unborn babies have been found to have a disability.

No Less Human, a disability rights group, campaigns to protect those they consider to be the most vulnerable of human beings from harm. Pre-natal testing, they believe, sends out a strong message to adult disabled people that society would very much rather that they did not exist. It is clear that disabled unborn children are particularly vulnerable.

Since most screening and diagnostic tests aim to detect disabled babies with the aim of aborting them, No Less Human believes that this can never be ethical, because it involves denying to disabled babies their infinite human worth, and their absolute right to life.

The policy of seeking out before birth and destroying unborn children suspected of having a disability is a form of fatal discrimination.

They consider the policy of seeking out before birth and destroying unborn children suspected of having a disability is a form of fatal discrimination to the individual, and deprives society of a chance to learn the truth about the value of every life.

Evangeline - a case study
Evangeline Edwards, was born with a very rare condition called Thrombocytopenia Absent Radius (TAR) Syndrome in December 1994. Less than fifty children in the UK are thought to have this condition. People with TAR syndrome have a blood clotting deficiency, because they have a reduced number of platelets in the blood. Often blood transfusions are needed, and in the early years, minor injuries may cause major bleeding. In addition the arms are shortened, and the legs are often bowed.

Evangeline's parents, Sue and Evan, found out that she had a disability during a routine scan at 20 weeks into the pregnancy. They were given several different diagnoses, including being told that her chest was so small she would not be able to breathe when born, before tests in London gave more hope.

They were strongly encouraged to consider abortion, which they refused. Sue and Evan did not know for sure what Evangeline's disability was, and whether or not she would survive, until she was actually born.

Evangeline had many hospital stays during her first few years because minor illnesses such as stomach upsets were much more serious for her.

In 2004 Evangeline was reported as doing very well in a mainstream school. She walks short distances with callipers, and uses a wheelchair when she feels she needs it. Life is not always easy for her, but she has a lot of friends and enjoys many activities, including horse riding and attending her local "Out and About" group for disabled and non-disabled young people.

Evangeline is a very bright child, who has had an inquisitive and determined nature since she was born - and even before that! She has a wonderful ability to deal with strangers who ask too many questions, and also has a knack of finding her own ways to do things she wants to do - like playing the piano with her feet!

Evangeline has achieved so much, especially for someone whom doctors, at one point, thought would never breathe alone. Her mother, Sue, says: "Words will never describe how much we love her. She has brought so much joy to our family."

References:

1. Reducing the Risk: Safer Pregnancy and Childbirth" HMSO, London 1978. This DHSS document states "... because caring for the handicapped can impose great burdens on our society the prevention of handicaps ... in addition to its other benefits may save money. The costs of providing amniocentesis for all expectant mothers over the age of 40 years, and maternal serum AFP screening for all pregnant women, would be more than offset by the economic benefits in terms of savings of expenditure on children and adults with Down syndrome and spina bifida."
2. "Costs were overestimated" by Prof. T.M. Reynolds. British Medical Journal 18 November 1995. Prof. Reynolds estimated the cost of detecting a baby with Down syndrome was £40,000. He said "£40,000 to prevent the birth of a baby with Down syndrome to a woman under 30 may be perceived as expensive but is low compared with the costs of caring for someone with the syndrome."
3. "Down's testing can be a lottery" by Nicki Daniels. The Times 5 June 2002
4. The chance of having a baby with Down syndrome rises steeply with the mother's age. At age 20, the chance is one in 1,527. This increases to one in 30 when the mother is aged 44. "Good Birth Guide: Part Two: antenatal tests." The Times 16 July 2002
5. Paneth N, Dept of Epidemiology, College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA. "Prenatal sonography - safe or sinister?" The Lancet 4 July 1998