Yes, it is possible to get a blood test before the baby is born. One common blood test that can be done before the baby is born is called noninvasive prenatal testing (NIPT). This test is performed on a sample of the mother's blood and can detect certain chromosomal abnormalities in the developing fetus, such as Down syndrome, as early as 10 weeks of pregnancy. NIPT is a noninvasive test, which means it does not carry any risk of harm to the developing fetus.
There are also other blood tests that can be done during pregnancy, such as a complete blood count (CBC), which checks for various blood disorders, and a blood glucose test, which screens for gestational diabetes. These tests are typically done as part of routine prenatal care and can help ensure the health of both the mother and the developing fetus.