Prenatal Diagnosis

Prenatal testing is testing for diseases or conditions in a fetus or embryo before it is born. The aim is to detect birth defects such as neural tube defects, Down syndrome, chromosome abnormalities, genetic diseases and other conditions. It can also be used to determine the sex of the unborn baby.

Diagnostic prenatal testing can be by invasive methods or non-invasive methods. An invasive method is when probes or needles are inserted into the placenta, e.g. amniocentesis, which can be done from about 14 weeks gestation, and usually up to about 20 weeks and chorionic villus sampling, which can be done earlier (between 9.5 and 12.5 weeks gestation) but which is slightly more risky to the unborn child. Non-invasive methods, called “screens”, can only evaluate risk of a condition and cannot determine 100% if the fetus has a condition. Non-invasive techniques include examinations of the mother’s womb through ultrasonography and maternal serum screens (i.e. Alpha-fetoprotein) If an abnormality is indicated by a non-invasive procedure, a more invasive technique may be employed to gather more information.

Most often this is performed to test for birth defects. Common procedures include amniocentesis, sonograms, nuchal translucency testing, or genetic screening. The tests can be used to check for conditions such as Down syndrome, spina bifida, cleft palate, genetic diseases (as Tay Sachs disease, thalassemia, cystic fibrosis, and fragile x syndrome.

There are three purposes of prenatal diagnosis: (1) to enable timely medical or surgical treatment of a condition before or after birth, (2) to give the parents the chance to abort a fetus with the diagnosed condition, and (3) to give parents the chance to “prepare” for a baby with a health problem or disability, or for the likelihood of a stillbirth.

Having this information in advance of the birth means that healthcare staff can better prepare themselves (have suitable treatment ready ) and parents (providing counselling) for the delivery of a child with a health problem.

Il professor Claudio Giorlandino dirige il centro di eccellenza di diagnosi prenatale presso Artemisia Main Center Roma.