In the first six months of 2019 the programme studied results from 42,138 newborns, 352 more than the 41,786 studied in the same period last year, according to the data coordinated by the Neonatal Screening Unit in the Department of Human Genetics of the Ricardo Jorge National Health Institute (INSA). In 2017, the figure was 41,689.

To find a higher total than that for the first half of this year you have to go back to the first half of 2016, when 42,758 infants were studied.

In terms of annual totals, last year saw 86,827 newborns, up from 86,180 in 2017. That was down from 87,577 in 2016, which in turn was up from 85,056 in 2015.

According to the Ricardo Jorge Institute, more than 3.8 million children have been screened in the 40 years that the heel prick test has been part of universal health procedures. A total of 2,132 children with rare genetic diseases were detected in this way, ensuring that treatment could be initiated swiftly.

Of those cases, 779 involved metabolic diseases, 1,304 of congenital hypothyroidism and 49 of cystic fibrosis, according to the institute.

The programme began in in Portugal in 1979 with the screening for phenylketonuria, which is relatively prevalent in Portugal, with one case for each 10,867 births. Two years later the test began to include congenital hyperthyroidism, whose prevalence is one case per 2,892 births.

The heel prick text is normally performed between the third and sixth day after birth, and involves taking a few drops of blood by pricking the baby's foot.

Although it is not mandatory, coverage is currently 99.5%, with the mean time of the start of treatment for any diseases found just 9.9 days. When the programme started, coverage was 6.4% and treatment started on average after 28.5 days.