Prenatal diagnosis makes it possible to identify defects and severe fetal diseases during pregnancy. Among the most commonly used methods are non-invasive: blood biochemical tests and imaging studies, and invasive diagnostics. It is now possible to determine almost precisely whether a foetus is affected by a specific genetic or acquired disorder, rather than relying on an assessment of probability (invasive tests offer this possibility). It usually starts with screening tests, i.e. blood tests and ultrasound, which can indicate the risk of certain diseases or show anatomical abnormalities. Worrying results are a premise for invasive tests. Advancing technologies help detect a wide range of defects and conditions, including:<\/p>\n
\u25cf spina bifida, cleft palate, <\/p>\n
\u25cf Down syndrome, Edwards syndrome, Patau syndrome, Prader-Willi syndrome, Tay-Sachs disease, <\/p>\n
\u25cf sickle cell anaemia, <\/p>\n
\u25cf thalassaemia, <\/p>\n
\u25cf cystic fibrosis, <\/p>\n
\u25cf muscular dystrophy,<\/p>\n
\u25cf anatomical defects, i.e. hydrocephalus, anencephaly, heart defects and amniotic band syndrome,<\/p>\n
\u25cf fetal developmental disorders associated with maternal disease (e.g. diabetes).<\/p>\n
Who should have prenatal screening and when?<\/p>\n
If there is a history of certain genetic conditions in your family or your pregnancy is at risk because of your age, prenatal testing is worth considering. This will reassure the parents-to-be and the doctor that mother and baby are healthy. This type of diagnosis is particularly recommended if: <\/p>\n
\u25cf you are over the age of 35,<\/p>\n
\u25cf the fetus was found to have chromosomal abnormalities in a previous pregnancy,<\/p>\n
\u25cf you have previously given birth to a premature baby or a baby with a birth defect,<\/p>\n
\u25cf there is a history of miscarriage,<\/p>\n
\u25cf you have a history of gestational diabetes,<\/p>\n
\u25cf you have a family history of structural chromosome aberrations,<\/p>\n
\u25cf the child's parent or someone in the family has a genetic disease,<\/p>\n
\u25cf you suffer from diseases such as diabetes, hypertension or autoimmune diseases,<\/p>\n
\u25cf you have been found to have abnormal levels of biochemical markers of pregnancy well-being or an abnormal ultrasound result .<\/p>\n
Even if you or a family member has not been diagnosed with the above-mentioned problems, preventive non-invasive prenatal screening is recommended for all pregnant women. Performed at the right time, they will help to indicate the likelihood of birth defects and prepare for the birth accordingly. The result of the examination will also help to plan medical care in the first months or even to implement treatment at the fetal life stage, if possible. <\/p>\n
The first screening and non-invasive tests, i.e. genetic ultrasound and blood tests, are performed between the 11th and 14th week of pregnancy. This is followed by blood tests in the second trimester, i.e. between 15 and 20 weeks' gestation, and a mid-term ultrasound between 18 and 22 weeks' gestation. If the results are worrying, the doctor may refer you for further invasive tests, including amniocentesis, which can be carried out as early as 13 to 15 weeks of pregnancy (early amniocentesis), although this is usually carried out between 16 and 18 weeks. <\/p>\n
Non-invasive prenatal testing involves determining the risk of a foetus being born with certain genetic abnormalities. The tests analyse small fragments of the baby's DNA that circulate in the pregnant woman's blood or check the levels of several hormones . As they only require a blood draw from the patient, they pose no risk to the foetus. They are screening tests, which means that they do not give a definitive answer as to whether or not the foetus is affected by a genetic disease . The test can only estimate whether the risk of certain conditions is increased or decreased. Such tests include:<\/p>\n
\u25cf double test - - assessment of PAPP-a protein and hCG free beta subunit levels <\/p>\n
\u25cf triple test - assessment in the pregnant woman's plasma of total HCG, alphafetoprotein and free estriol (the quadruple test additionally takes into account inhibin A concentration)<\/p>\n
\u25cf NIPT tests (non-invasive prenatal testing)- assessing fetal DNA in the mother's blood, can be performed from as early as 10 weeks of pregnancy<\/p>\n
In addition to blood tests, a genetic ultrasound is also carried out as part of non-invasive diagnostics, which provides important information about the development and structure of the foetus. In total, this examination is carried out a minimum of three times during pregnancy - once per trimester,. A special ultrasound scanner is used for this examination, which allows the detection of multiple abnormalities. The doctor uses the machine to assess the structure of the baby's body parts and organs, including bones, eyes, nose, ears, chest, stomach, intestines, liver or axial skeleton, arms and legs. Heart function, placental status and amniotic fluid levels can also be assessed.<\/p>\n
If non-invasive tests find abnormalities that require further diagnosis, the pregnancy doctor may refer for invasive tests. These carry a certain risk of complications, estimated at 0.5-3% depending on the method. Possible complications include, but are not limited to, miscarriage, bleeding, intrauterine infection, premature discharge of fetal waters, and the occurrence of uterine contraction activity. However, the benefits of these tests outweigh the risks. Today, examinations are performed by experienced specialists in a hospital setting using modern equipment. Modern techniques are fully optimised with regard to safety. Among the most effective of these are:<\/p>\n
\u25cf Amniocentesis - usually performed around the 16th week of pregnancy, but no later than the end of the 18th week. It involves the collection of amniotic fluid, which contains both free biochemical substances and fetal cells. The fluid is collected under ultrasound guidance through the abdominal layers using a very fine needle . The examination can accurately indicate whether the baby is affected by genetic diseases;<\/p>\n
\u25cf CVS - chorionic villi sampling (CVS) - the collection of the chorionic villi (the tissue from which the placenta is formed) is usually carried out between 8 and 11 weeks of pregnancy, although it can be performed up to week 14 , by needle puncture of the abdominal wall or via a transvaginal route under ultrasound guidance. The sampling needle bypasses both the foetus and amniotic fluid. Local skin anaesthesia is required before the procedure; <\/p>\n
\u25cf Cordocentesis - this test involves the collection of samples by puncturing the umbilical cord. It can be performed after the 18th week of pregnancy. It allows the oxygenation of the baby to be assessed and chromosomal abnormalities to be detected . <\/p><\/p>","protected":false},"parent":0,"menu_order":0,"template":"","blog-category":[],"blog-tags":[],"class_list":["post-247495","blog","type-blog","status-publish","hentry"],"acf":{"blog_clinics":""},"yoast_head":"\n