Why is prenatal testing done?
Prenatal testing is offered to women during pregnancy to determine if the fetus has a possibility to be born with a genetic condition or birth defect. Performing prenatal testing may be important to women who might want to explore who know their babies are already at risk and want to make the best decisions for better outcome of their baby. Different prenatal testing options are available according to the trimester that the mother is in.
So, who is prenatal testing offered to?
Even though prenatal testing is offered to all women, as the age of a mother increases, the chances of having a baby with chromosomal abnormality increases. So, the age of a mother is the most common reason for prenatal testing. Family history or a previous child with a genetic condition, parents who are known carriers of a specific genetic mutation, abnormal ultrasound findings and screening tests are some other reasons that women may be offered screening tests.
Remember screening tests are not "diagnostic (disease proving)"
Screening tests only identify women who have an increased chance of having a baby, with certain chromosomal abnormalities. They dont "identify" birth defects such as genetic diseases. Results that reveal levels over a "cut-off" are called positive results and these women then undergo further testing. These tests are able to screen many cases at risk but please note, that these too can miss a high risk case where the woman may get a "negative screening" result.
Another type of testing is diagnostic testing, it can determine exactly if the fetus/baby has a certain genetic condition or birth defect.