A Neural tube defect (NTD) is a defect in the spinal cord or brain that occurs very early in fetal development. It is uncommon and occurs in about 1 in 1000 babies.
The cause is partially genetic and partially due to folic acid deficiency. Taking folic acid supplements early in the pregnancy (or better yet, before you are pregnant) will significantly reduce your baby’s risk of developing NTD.
The second trimester screening blood test, or “quad screen,” done when you are 15 to 20 weeks pregnant, will reveal this defect if your baby has it. The quad screen is also used to look for the presence of genetic conditions such Down syndrome.
If your blood test shows an elevated risk of your baby having NTD, an ultrasound and sometimes an amniocentesis will be recommended in order to definitively show whether or not your baby has a defect.