Genetic tests in pregnancy when and why?

There is % 3 major fetal abnormalities that can be seen in delivery time. Half of them can be detected at delivery time and the cause is genetic abnormality.

Overall newborn can have chromosomal abnormality ratio is 1/160 . In the first trimestr most of the  reason of abortion depends on choromosomal abnormality .

Every pregnant must be checked about genetical  tests. But the accuracy is not % 100.

The blood test that is done in 11-14 weeks of pregnancy which combined transvaginal ultrasound of baby nuchal translucency.The accuraccy rate is % 80.

The other test can be done at 15-22 weeks of pregnancy .They are been doing from mother blood. And some proteins ( alpha feto protein,estradiol,total hcg ) have been checked. This is triple test. İf inhibin A added to this test accuraccy rate raised to % 81.

Most power test is NIFT test can be done at 10-22 weeks of pregnancy . In the mother blood baby blood has been evaluated. The accuracy rate is % 99.