Equipping parents and doctors to understand the consequences of prenatal genetic screening

Breaking new ground 17. jun 2020 4 min Senior researcher Stina Lou Written by Kristian Sjøgren

Prenatal whole-genome sequencing can provide parents considerable information about possible genetic disorders their unborn child may face throughout life. But how much should doctors say, and how much do parents want to know? Danish researchers have examined this.

“It is probably nothing, but…”

So begins the title of a new scientific article, in which researchers studied the consequences of parents having prenatal genetic testing to identify potential genetic disorders.

The answer may spark joy, but it can certainly have negative effects as well. However, the most problematic results of genetic testing are those in between, with doctors having to say “possibly” and “maybe” about the child’s risk of developing, for example, intellectual disability or autism.

These results put new parents in a difficult situation because the possibility that something may be wrong with their child may be constantly in the back of their minds. In retrospect, many would rather not have known and instead taken things as they come.

“These new genetic tools mean that we have to balance on a knife edge regarding what we tell expectant parents. The information can be useful when parents and professionals can intervene quickly and support the child in case of problems. But it can also be a burden when parents are constantly concerned about whether their child will develop normally,” explains the first author, Stina Lou, Senior Researcher, Department of Public Health, Aarhus University.

The research by Stina Lou and colleagues on doctors’ and parents’ experiences of prenatal genetic testing has been published in Acta Obstetricia et Gynecologica Scandinavica.

Whole-genome sequencing enables better prenatal diagnosis than ever before

Stina Lou's research is part of a larger context in which researchers and doctors at Aarhus University Hospital have thoroughly investigated the significance of being able to use whole-genome-based technologies in prenatal diagnosis.

Ida Vogel, Clinical Professor, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, has led the overall research, which also includes studying the clinical effect.

The doctors found that whole-genome sequencing is extremely effective at making prenatal diagnoses that they had not been able to make previously.

Accurate diagnosis was possible in 25% of 35 prenatal examinations, which would have been impossible just 2 years ago.

Whole-genome sequencing also enables doctors to eliminate many serious disorders that could be connected to a foetal malformation detected by ultrasound scanning.

“The benefits of this new technology will radically improve the opportunities for prenatal diagnosis. But like all technological advances, we need to know both the benefits and the disadvantages of the technology,” says Ida Vogel.

Ida Vogel also says that doctors have taken a huge interest in the subject because they face the challenge of communicating with parents about their child’s risk of various disorders on a daily basis.

Information is not always crystal clear

In the new study, Stina Lou followed 16 couples who had received a prenatal genetic result of unclear or uncertain significance, such as results due to low penetrance or limited evidence about the specific genetic variation detected.

Based on the genetic sequencing, the parents were informed whether their child might have an increased risk of, for example, delayed development, intellectual disability, autism, obesity or a mental disorder.

“The doctors and parents face a difficult dilemma as to how great the risk should be before the doctors should say something. We do not know the answer, but carrying out this kind of research is important, so that, in addition to the benefits, the disadvantages of this new technology are also identified,” says Stina Lou.

Genetic information is not easy to manage

Stina Lou has compiled the numerous interviews with parents into the recently completed study.

None of the parents decided to terminate the pregnancy based on the information they were given.

However, many parents reported that they had difficulty with being told at week 14 of pregnancy that their unborn child had an increased risk of developing autism but might also develop normally.

The problem was the uncertainty.

“A prenatal diagnosis more severely affected some parents than others. If a mother or father had a difficult experience with autism or obesity, this naturally influences their concerns when they are told that their child will potentially experience the same thing,” explains Stina Lou.

Parents are especially attentive to a child with a potential disorder

Stina Lou’s research also shows how many couples deal with getting more information than they might like.

Several of the couples told her that it had helped them to normalize the situation by saying that all children are different and that the normal spectrum also includes a palette of less severe disorders.

The couples also said that they had integrated the information into their everyday lives without letting it control them. They were most concerned immediately after they received the diagnosis and in situations that reminded them of it. This could be, for example, their child not beginning to crawl or walk as early as their peers.

“They maintain that their child is just like any other, but they are attentive if things suddenly move in a different direction. They are also more attentive than the parents who have not received the same information,” says Stina Lou.

Some parents pay the price for others to be reassured

The whole-genome analysis frequently enable doctors to dispel concerns about a wide range of really unpleasant genetic disorders.

Thus, parents can be greatly relieved to be told that at least they do not have a high risk of having a child with multiple disabilities or with a serious and potentially fatal congenital heart defect.

Nevertheless, being informed that one’s child has an increased risk of developing autism or having learning difficulties is not pleasant.

“Eliminating some of the serious issues reduces the concern. But you could say that those who are told about a possible risk of a mild genetic disorder pay the price for the new diagnostic opportunities that enable others to dispel their concerns. We must learn to understand this together with parents so that we develop some guidelines on how best to use the new information we have available,” says Ida Vogel.

Society should decide how to use the information

Stina Lou says that some parents in her study responded that, in hindsight, they would have preferred not to be given this kind of information.

These were primarily the parents of children who had received a prenatal diagnosis of uncertain significance but who had not yet seen any signs of illness.

In this situation, the information had only caused unnecessary worry.

Conversely, some parents also said that, in cases with a serious genetic disorder, they could use the information to deal with the problems very early.

This may involve a special diet or a specific focus on learning how to enhance the development of a child with intellectual disability.

“Drawing definite conclusions from the research is difficult, but it can be used to improve our understanding of what to do when the results are not black or white in connection with prenatal genetic testing. If the test result is normal, it is relatively easy to inform the parents. This is actually also the case if the test shows that a child will develop a well-known serious genetic disorder. But when the answers are not obvious and we cannot say anything with certainty, we must collectively decide as a society when doctors should or should not say something,” says Stina Lou.

“‘It's probably nothing, but …’ Couples’ experiences of pregnancy following an uncertain prenatal genetic result” has been published in Acta Obstetricia et Gynecologica Scandinavica. In 2016, the Novo Nordisk Foundation awarded a grant to Ida Vogel for the project Prenatal Testing in Denmark – Detection, Counselling and Outcome.

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