The definitive diagnosis of pregnancy is made by seeing the sac on ultrasound or by checking Bhcg, also called a pregnancy test, in the blood. After a definitive diagnosis is made, an average of 40 weeks pass until birth. This period is roughly examined in 3 periods: the first 3 months, the second 3 months and the third 3 months. After the pregnancy is confirmed, some routine tests are performed on the mother. The most important among these are routine hemogram test, thyroid tests, liver and kidney function tests, heptitis mrker and TORCH panel. Afterwards, one of the genetic screening tests is preferred according to the week of pregnancy.
First 3 Months Screening Test (Double Test)
11-14. It is done between weeks. By measuring nuchal translucency (NT) and looking at two hormones called "PAPP-A" and "free ?-hCG" in the mother's blood, the risk for Down syndrome-Trisomy 21, Trisomy 13 and Trisomy 18 is calculated. It is a screening test with 85-90% accuracy.
Second Trimester Screening Test (Triple-Quadruple Test)
It is preferred in patients who could not have the first trimester screening test. . 15-21st of pregnancy. It is done between weeks. In addition to taking the baby's ultrasound measurements, the risk calculation for Down syndrome-Trisomy 21, Trisomy 13 and 18 is made by checking the free ?-hCG, estriol, AFP (triple test) and Inhibin (quadruple test) in the mother's blood. Only the first trimester screening test is performed. We recommend the second trimester screening test (triple-quadruple test) to our patients who could not have it done. As a result of performing the two tests together and evaluating them separately, 10 out of 100 pregnant women will have unnecessary amniocentesis (due to false positivity). Screening test results are evaluated by your doctor to determine whether you are in the risk group. “Genetic Diagnostic Tests” are recommended for patients in the high-risk group.
Genetic Diagnostic Tests
Genetic diagnosis is made to pregnant women who are found to be at high risk as a result of screening tests, and the chromosomes of the baby are determined and the numerical and structural characteristics of the chromosomes are determined. It is determined whether there is an anomaly or not and the final result is given.
These tests:Chorion Villus Sampling (CVS): 11-14 weeks of pregnancy. Genetic examination is performed by entering the mother's womb with the help of a needle and aspirating the fetal cells from the placenta (the baby's partner) between weeks 20-25.
Amnio synthesis:16-22 weeks of pregnancy. Sampling is done from the amniotic fluid (the fluid in which the baby develops) by entering the mother's womb with the help of a needle between the weeks of pregnancy. It is done by taking a blood sample of the baby.
Pregnancy follow-ups are accompanied by ultrasonography (2-dimensional, 3- and 4-dimensional, color doppler and power doppler examination).
These invasive tests can lead to miscarriage at a rate of 1%. In addition to these tests, genetic screening can be performed with 99.9% accuracy by taking 20 cc of maternal blood and extracting the fetal DNA in it. Currently, especially Tr13, Tr18 and Tr21e sex chromosomes can be examined in England and America. In Turkey, this test can be performed under the names of NIFTY and SERENITY.
18-23 weeks genetic sonogram (detailed ultrasonographic examination): The baby's organ development is examined.
In the last trimester, amniotic fluid evaluation is done with USG and NST. The baby's well-being is evaluated.
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