Prenatal genetic screening is a way for you to determine the chance your baby may or may not have trisomy 21 (Down syndrome) or trisomy 18. Sometimes prenatal screening can tell you about the chance for other genetic conditions, such as trisomy 13 and sex chromosome differences. 

Prenatal genetic screening consists of ultrasound and bloodwork which can only be done at certain stages in the pregnancy.  You may refer to this timeline which shows when prenatal genetic screening and invasive diagnostic tests are available over the course of a pregnancy. 

Below you can find more information about your prenatal screening options, depending on how far along you currently are in the pregnancy. If you are expecting more than one baby (for example, twins or triplets), please visit our page on multiple gestation pregnancies.