Screens for: Chromosomal and genetic problems as well as some blood disorders in your baby including some infections.
Who does it:This is typically done by a maternal fetal medicine specialist (MFM) or an OB/GYN.
How it is done: With ultrasound guidance a small needle is placed into the uterus to obtain a sampling of blood from the umbilical cord.
When is it done: Not until after the 18th week of gestation.
Accuracy: Virtually 100%, barring lab error.
Risk to mom: Procedure can be uncomfortable, cramping may occur afterwards.
Risk to pregnancy/baby: There is about a 1-2% risk of miscarriage.
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