First Trimester Screen For Down Syndrome

Patient: If my blood work came back abnormal ( a 1 in 58 chance of having a baby with DS ) and my ultrasound showed no markers and a completely healthy, on-track baby, do I still have a 1 in 58 chance of having a baby with DS?

Doctor: I can understand how terribly distressing the situation must be for you. If the blood tests say the chances are 1 in 58 that you could have a baby with downs syndrome then it is a very significant risk. Downs syndrome is a condition arising out of an extra chromosome no. 21 and results in a mentally retarded child.If you are in the first trimester of pregnancy you can wait till 16-18 weeks of pregnancy to do a more exhaustive congenital anomaly scan. You may also opt for more invasive testing I.e chorionic villus biopsy or amniocentesis to do DNA testing of the baby. These tests are more reliable and will give you more information so that you may make an informed decision about the same. Chorionic villus biopsy is basically a procedure that involves taking a small piece of the placental tissue for examination. It is done after 9 weeks of gestation. Amniocentesis involves taking a sample of the waters surrounding the baby for fetal cells whose DNA is then tested.The chances of fetal injury or miscarriages as a result of these invasive procedures is around 1 in 100. The other disadvantages of further testing is that you delay the decision of termination of pregnancy by another 2 weeks. A second trimester termination is generally more traumatic for the mother as it is like a mini labour. You will have to carefully weigh the pros and cons of your situation before you make the choice of what to do next. Consult with your obstetrician or fetal medicine specialist about the same and discuss the options you have.