Diagnosing Down Syndrome

Diagnosing Down Syndrome

It is a known fact that early detection and screening of Down syndrome can lead to several benefits. You may also prevent several complications by knowing the condition early on, before it can lead to other problems in the body. Diagnosis is done through a variety of ways. Here are the details on how you can stay ahead for immediate treatment.

Expanded AFP Screening

Expanded AFP Screening is a basic blood test, performed between 15 and 20 weeks of pregnancy. The results of the blood test are combined with the age of a woman to measure the personal risk of bearing a fetus with Down syndrome. The blood test also gives information regarding the risk of open neural tube defects, trisomy 18 and abdominal wall defects. There is an 85% rate of detection among women below 35 years old for developing neural tube defects, as well as a 60% risk for both Down syndrome and trisomy 18. The detection risk will be higher among those beyond 35 years old. 

As a screening test, getting a positive test result means that the person has a bigger risk of developing a genetic abnormality. Birth defects cannot be diagnosed, and the fetus cannot be checked if there are any birth defects present. Women having an abnormal expanded AFP or those who are about to become 35 years old during delivery time can undergo CVS or chorionic villus sample or amniocentesis. The tests can diagnosis disorders in the chromosomes, but not all birth defects, having a high degree of certainty. 

Nuchal Translucency Screening

Nuchal Translucency Screening or NT is a new non-invasive diagnostic test done early during pregnancy to check whether or not women have an increased risk for Down syndrome, as well as other birth defects. Performance of NT screening is from 11 to 14 weeks of pregnancy. It is provided to women of all ages. The screening is also done through a very detailed ultrasound exam of the nuchal area, which is a fold of skin at the back of the fetus's neck. The results are combined with the age of the mother to know if there is an adjusted risk for Down syndrome. The rate of Down syndrome detection is around 80%. The woman may have CVS or amniocentesis for diagnosis, based on the findings. 

Amniocentesis

Amniocentesis is usually done to find chromosomal problems like Down syndrome. The procedure is done to find other diseases like Tay-Sachs disease, sickle cell disease and cystic fibrosis if the fetus is found to be at risk. Amniocentesis procedure for genetic testing is usually done between 15 to 20 weeks of pregnancy. A needle is inserted through the abdomen to take some amniotic fluid via the guidance of ultrasound. 

CVS

CVS or chorionic villus sampling is like amniocentesis which identifies problems with chromosome, like Down syndrome. It is more advantageous than amniocentesis since it is done earlier during pregnancy, at around 10 to 12 weeks. During the procedure, a small piece of tissue is taken from the placenta. Via ultrasound guidance, the tissue is taken via a needle through the abdomen or via a catheter inserted through the cervix. The tissue is cultured. The results will arrive in about 2 weeks. 

Ultrasound

Ultrasound is done to check the status of pregnancy, taking into consideration factors like fetal size, due date and number of gestations. Ultrasound can give information regarding the possible birth abnormalities in a fetus. A comprehensive ultrasound exam may be required before other tests are to be done.