Evidence LibrarySystematic reviewscarrier status
Disclosing to parents newborn carrier status identified by routine blood spot screening

What did we want to know?

The aim of newborn screening is to identify babies who have certain rare but serious conditions. However, some newborn screening programmes also identify newborn babies who do not have these conditions, but are genetic carriers of the conditions. As carriers these babies have an increased chance of passing the conditions on to their children. Also, if a baby is a carrier then it means at least one of the parents is also a carrier. Newborn screening can therefore provide information about not only babies, but also their parents. Indeed, if both parents are carriers, with each of their pregnancies, they have a 1 in 4 chance of having an affected child. In rare cases, if both parents know that they are not carriers, but their baby is found to be a carrier, this can suggest that the man who assumes he is the father, is actually not the biological father. This means that identifying carrier results in newborn screening can reveal non-paternity. Whilst carrier results are complex to explain to and understand, it is considered unacceptable to withhold these results from parents.

Newborn screening programmes in the USA already include tests for several conditions which identify carriers and newborn screening in the UK is expanding to include tests which identify carriers of two inherited conditions: sickle cell disorders (SCD) and cystic fibrosis (CF). Furthermore due to the complex genetics of cystic fibrosis, the meaning of CF results can be uncertain.

There is an urgent need for research about how these results are communicated and understood and the effects they have on families. Depending on the condition for which screening is offered, options include employing tests that do not identify carrier status, if available; identifying acceptable ways of disclosing carrier status; identifying acceptable ways of not disclosing carrier status; or not screening. Currently, there are no screening tests available for sickle cell disorders that do not identify carriers. For cystic fibrosis, the policy decision is between an extended period of testing, and a screening result that is available sooner for most newborns, but inadvertently identifies babies who are carriers.

The aim of this systematic review is to assess the impact of communication about disclosing carrier status following newborn screening; and to collate the relevant evidence about parents’ and health professionals’ views.

Who wants to know?

Clinicians, parents of newborn babies and their families.

What did we find?

We found no studies of the impact of communication, or studies addressing the views of health professionals.

Parents of cystic fibrosis carriers favoured newborn screening and knowing the carrier results, and anticipated telling their child in due course. Cystic fibrosis carrier results led to problems with insurance companies with some families in the USA. A minority of parents used carrier results to inform reproductive planning. When, as part of a trial, children’s carrier results were withheld for four years following newborn screening, parents were angry that they had not been told this and given the opportunity to make decisions about reproductive planning. Discovering their own carrier status could also be an emotional event for parents. Few parents appeared to change their behaviour towards their carrier child. Discussing carrier status with the wider family was perceived as difficult, but necessary.

Initial indication that babies’ results were not ‘normal’ began a roller coaster of emotion for parents; this could also be difficult for the wider family who were simultaneously trying to be supportive. Some parents, even when they were assured that their baby would not be affected by the condition, continued to be concerned.

Parents would like some forewarning of possible results, but not to have ‘too much’ information. Parents favoured having familiar, non-specialists report test results to them; with these non-specialists being sufficiently briefed and not alarmist. The presence of cystic fibrosis specialists to discuss results alarmed parents, as did being giving information about cystic fibrosis at that stage.

There is little or no evidence about how outcomes are influenced by: parents’ previous knowledge of the screened conditions; the methods of communicating test results; or follow-up support.

There is no reliable evidence about the implications for parents of an unclear diagnosis for cystic fibrosis.

What are the implications?

The findings of this review provide some support for a policy decision to use a test for CF which does identify carriers. By including this DNA test early in the screening pathway the numbers of parents experiencing excessive anxiety and having to wait for their babies confirmed result is reduced. However little is known about how to support non-specialists communicating with parents about carrier status or the need for further testing.

There is no support for not disclosing newborn carrier status to parents.

Parents prefer ‘abnormal’ screening results or requests for repeat tests to be communicated by a familiar, non-specialist community/ primary care practitioner. Investment is needed in materials and training to support these health professionals to undertake well a task they may rarely, if ever, encounter. There is a particular need for interventions to support parents who wish to discuss screening results with their wider family.

Parents, older children who are CF carriers, and practitioners should be involved in developing these interventions.

Individual practitioners have a responsibility to forewarn parents about the possibility of ’abnormal’ results or requests for repeat tests and, when they occur, to discuss these with parents themselves rather than referring them to specialist services prematurely.

We recommend:

  • Seeking grey literature through practitioner networks for unpublished studies.
  • Primary research addressing the issue of disclosing non-paternity through identification of carrier status in newborn screening.
  • Research about the implications for parents of an unclear diagnosis for cystic fibrosis and how to provide appropriate follow-up care.
  • Research to explore the views of parents and children, and the possible implications of offering carrier testing for siblings of children who are genetic carriers.
  • Parents and practitioners should be involved in this research.

How did we get these results?

Six studies were synthesised about parents’ views of disclosing carrier status of their newborn child.

This report should be cited as: Oliver S, Lempert T, Stewart R, Kavanagh J, Dezateux C. (2004). Disclosing to parents newborn carrier status following routine blood spot screening. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London.

 

  
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