Deciding to have diagnostic tests

If both parents discover they are carriers, there is a 1 in 4 chance their baby will have the condition. They can choose whether to have a diagnostic test to check if the baby is affected. A woman who knows she is a carrier may also want diagnostic tests if she is not in contact with the baby’s father or he does not agree to be screened. There are two types of test, chorionic villus sampling (CVS) or amniocentesis. (See ‘Experience of having diagnostic tests’). CVS takes a sample of placenta for analysis, whilst amniocentesis takes a sample of the fluid round the baby.

No-one has to have these tests. It has to be a personal decision. Some parents decide they would rather not know, especially if they feel strongly they would never terminate a pregnancy. (See ‘Reasons for deciding not to have diagnostic tests’). Others want a diagnostic test because they expect that they would terminate the pregnancy if the baby has a sickle cell disorder or beta thalassaemia major.

However, some parents want a diagnostic test in pregnancy even though they feel sure they would not terminate the pregnancy. They may prefer to know for certain rather than worrying all through pregnancy whether their child has the condition. Many people also think it is important to prepare emotionally for what they may face.

In her first pregnancy she decided to have CVS so she could prepare for the birth, but she would…

Age at interview 37

Gender Female

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They had CVS to help them prepare for having a baby with beta thalassaemia major. They might have…

Gender Male

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They decided to have amniocentesis straight away. They felt they would want to end the pregnancy…

Gender Male

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Most people we spoke to felt it was worth taking the small risk of miscarriage (up to 1% for both CVS and amniocentesis – NHS Screening programme July 2017) in order to find out.

The risk of miscarriage from CVS was less important than finding out whether her baby had sickle…

Age at interview 41

Gender Female

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Whilst some people decided quickly they wanted a diagnostic test, for others it was a painful process to make up their minds.

She took a long time to decide to have CVS. She became ill with worry and in the end decided it…

Age at interview 24

Gender Female

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Many different factors will affect people’s decision about whether to have diagnostic tests, including their personal knowledge and experience of the conditions, their moral or religious views, their feelings about what they could cope with as parents and their anxieties about what life would be like for the child.

Some people talked about how seeing family members or friends with one of the conditions convinced them they wanted a diagnostic test. We talked to two women who themselves had haemoglobin SC disorder and who both decided to have antenatal diagnosis in some or all pregnancies. They were most concerned about the possibility of having a baby with full sickle cell anaemia, but felt they would manage with a baby with SC disorder like themselves. (See Interview 07 and Interview 03 above).

Parents who already had a child with one of the conditions had different views about whether to have diagnostic tests in future pregnancies, depending partly on how well the child was. It can be difficult for women to consider ending a pregnancy if they already have a child with that condition so some women would prefer not to know but others would consider this option.

After seeing how hard life with beta thalassaemia major is for her son, she wanted diagnostic…

Age at interview 31

Gender Female

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One mother whose own daughter with sickle cell anaemia has been quite well so far knew this might change.

She feels she couldn’t cope with another child with sickle cell anaemia. Her daughter has been…

Age at interview 36

Gender Female

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Religious views were an important factor for many people in reaching their decision. For some Christians and Muslims, their religion meant they could never consider ending a pregnancy. But not all people with religious beliefs felt this way. Some Christians and Muslims, and one Buddhist mother, wanted diagnosis so they had a choice whether or not to terminate, and some Muslim mothers had investigated Islamic teaching on termination. As one mother explained, some Islamic scholars teach that termination for life-threatening conditions is permitted up to 120 days of pregnancy, at which point the soul enters the unborn baby [‘ensoulment’]. After that it is forbidden.

She has heard Islamic religious leaders explain the soul enters the unborn baby around four…

Age at interview 31

Gender Female

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She comes from a strongly Christian family, but she would end a pregnancy if she thought the…

Age at interview 36

Gender Female

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She has talked to an imam and been advised that ending a pregnancy is allowed in Islam if the…

Age at interview 38

Gender Female

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See also sections on:

‘Reasons for deciding not to have diagnostic tests’,

‘Message to other parents’,

‘Deciding what to do after diagnosis’,

‘Values and religious beliefs’,

‘Advising people about their options’

‘Timing and delay’.

If you would like to see more parents talking about their experiences of diagnosis in pregnancy (including diagnosis for other conditions such as Down’s Syndrome), you can visit our Antenatal screening section.