Test to detect fetal abnormalities
A simple blood test would be sufficient to track down any chromosomal abnormalities present in the fetus, thus allowing pregnant women to avoid amniocentesis. It is called Praenatest and is a test approved by Swissmedic, the Swiss institute for therapeutic agents, which gives a few days is proposed in Switzerland. "It is a test that allows, in an absolutely non-invasive way, to identify if a chromosomal anomaly is present in the fetus: the trisomy of chromosome 21 on which Down syndrome depends", explains Giuditta Filippini director of ProCreaLab, the molecular genetics laboratory of the center for reproductive medicine Procrea in Lugano which promotes the new test in the Canton of Ticino.
"This analysis allows the presence of a supernumerary chromosome 21 to be identified with high sensitivity. Until now there were not many alternatives: non-invasive analyzes such as ultrasound and tests carried out on the mother's blood, such as the measurement of nuchal translucency and biochemical tests as part of the first trimester test - they could only indicate the level of risk of a trisomy 21. A definitive diagnosis, however, came only through a CVS or an amniocentesis: invasive analyzes that can also involve risks of abortion. fetal loss every 200 cases ".
The Preanatest is performed after the eleventh week of pregnancy and consists of a sample of 20 milliliters of maternal blood which contains a fraction of the genetic material of the fetus (DNA) due to the cell turnover of the placenta. "The DNA is sequenced and amplified to allow the calculation of the number of chromosomes. And trisomy 21 is characterized precisely by a different number of chromosomes. This test has a predictive capacity of around 95 percent and eliminates the risk of abortion", explains Doctor Filippi.
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This new test is not performed indiscriminately for all pregnant women, but is indicated if the woman belongs to a group with a high risk or if, after an ultrasound examination or a blood test, a trisomy 21 should be suspected. in the child. "It should also be borne in mind that this type of analysis cannot diagnose some rare forms of trisomy 21 and is not indicated in the case of a twin pregnancy", concludes Filippi.
The Praenatest is offered in Switzerland at a cost of 1,550 CHF, approximately 1,250 euros.
See also:
- Longer life for mothers over 45
- Caesarean section: opportunities, risks and abuses
- Give birth with serenity. From choosing the hospital to returning home
- Vegan nutrition. Possible choice in pregnancy
