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Maternal Blood Screening
Now is the time to think about having a maternal blood screening test, which is performed between weeks 16 and 18 of pregnancy. Also known as a maternal marker screen or serum screen this blood test is offered to all pregnant women and serves as a way to assess risk for birth defects. A positive result means there is a level of risk for birth defects, and an amniocentesis may be ordered for further testing.

What Is The Test Looking For?

This blood test is a simple process that measures the levels of certain hormones present in your blood. Doctors will look at the results and look for high or low results. These results, when combined with your age, weight, race and any health issues, give the doctors a level of risk for birth defects that could affect your baby. Birth defects include chromosomal defects like Down’s Syndrome, Neural Tube defects like Spina Bifida, congenital heart defects and abdominal wall defects.

How Accurate Is The Test? 
This test isn’t a diagnosis for a problem but rather a screening for risk. An abnormal test result doesn’t tell your doctor your baby has a birth defect but rather, is at risk for one. Even if you test abnormal, you could still have a perfectly healthy baby. However, the tests do help to target at-risk pregnancies at a rate of 70% and more.

What if the Test is Abnormal? 
An abnormal test result doesn’t necessarily mean your baby is at risk for a birth defect. It could mean your pregnancy is further along than thought, or further behind, resulting in abnormal hormone levels. Or it could mean you’re having multiple births.

If you’re test results aren’t in the range the doctor would like, you might be sent for amniocentesis, which is the sampling and testing of amniotic fluid surrounding your baby (discussed in the week 15 newsletter). The fluid contains proteins and other factors that give doctors a closer look into your baby’s health.

General Introduction to Pregnancy
Your Changing Body + Pregnancy
Your Baby’s Development
Potential Pregnancy Complications
Labor and Delivery
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General Introduction to Parenting
Child Nutrition
Childcare and Education
Sleep in the Early Years
Baby Milestones
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