Child screening in Europe has reduced the number of babies born with Down syndrome

The growth of antenatal screening in Europe has reduced the number of babies born each year with Down syndrome (DS) on average by 54%, according to a new study published in the European Journal of Human Genetics by researchers from Massachusetts General Hospital (MGH) and international groups Down syndrome. In a study published in 2016, the same team found that 33% fewer babies are born with DS each year in the United States as a result of pregnancy termination.

The researchers spent three years collecting data from multiple records and databases in every European country to estimate the number of babies born with DS and the total number of people with DS in Europe. the crowd.

People with DS were counted sporadically, inconsistently, or not at all, depending on the country. But without a proper estimate, it is impossible for policymakers and advocacy groups to determine how many facilities and support services are needed for the Down syndrome population. “

Brian G. Skotko, MD, MPP, Medical Generator, MGH and Lead Author

The researchers used statistical modeling to generate estimates in countries where there were gaps in data. “This data is as close to accurate as possible,” Skotko said. The data are described both in the study and in an associated information sheet.

Equally important, however, was the study to establish a baseline of DS birth rates and termination rates of pregnancy prior to the widespread adoption of new noninvasive prenatal screens (NIPS). The new screening tests can detect the appearance of a chromosomal position in a fetus as early as nine weeks after gestation, after which an expectant couple can opt for a definitive genetic test. As NIPS becomes widely available, it is expected that fewer babies with DS will be born.

NIPS was introduced in the US in 2011 but has not yet been widely covered by national healthcare systems in European countries. “Countries involved in funding decisions for NIPS should definitely be talking deeply about the impact it has on the country’s population Down syndrome,” said Skotko, whose sister 40-year with DS. Countries also need to create an appropriate support and information infrastructure so that expectant couples can make informed decisions about NIPS and subsequent pregnancies.

The researchers found a wide variation in DS birth rates among European regions. From 2011 to 2015, the highest decline in DS births was due to fertile terminations (71%), followed by Northern Europe (51%) and Eastern Europe (38%). However, there were significant differences among countries, from no reduction in the percentage of babies born with DS in Malta, where pregnancy prevention is severely limited, to an 83% reduction in Spain. .

The termination of DS-related pregnancy termination is influenced by several factors. Some countries, such as Denmark, offer free access to antenatal screening, but there may be cost barriers for couples in other countries. The religious and cultural benefits of a country also play a part, as do a country’s policies regarding the way prospective couples are consulted about antenatal screening and DS. Parental decisions can also affect the chances of people with DS living a vibrant, productive lifestyle within a country. “In the U.S., people with Down syndrome have good opportunities to get an education, fall in love, and find satisfying jobs,” Skotko says.

The modeling study also estimated the number of people with DS currently living in each country. The declining number of DS births is offset by people with DS living longer than ever before – to an average age of around 60 in countries with resourceful health care systems. In Europe there were 27% fewer people living with DS in the total population in 2015 (and 21% fewer people with DS in the US) as a result of selective pregnancy termination from previous years.

Skotko and his international colleagues hope that the European and US studies will pave the way for governments and DS agencies to work together and share best practices on thoughtful ways to implement NIPS and support for couples who receive a prenatal DS diagnosis. “Massachusetts, for example, has a unique network of parents who are willing to talk about their live experiences in raising children with Down syndrome to expectant couples,” Skotko says. “That nonprofit has trained parent groups in Brazil, Japan and elsewhere so they don’t have to restart the wheel.”

The researchers are designing a similar modeling study in Australia and New Zealand, and will continue to update each country’s data to measure the impact of different antenatal testing policies and NIPS as it becomes more widely available. This research is unfunded; Skotko and his colleagues have voluntarily given the time to conduct these analyzes. “We just feel it’s so important to bring the right numbers of citizens to countries with Down syndrome,” says Skotko.


Massachusetts General Hospital

Magazine Reference:

of Graaf, G., et al. (2020) Estimate of the number of people with Down syndrome in Europe. European Journal of Human Genetics.