Screening tests are routinely done during prenatal care appointments and include urine and blood sampling from the mother. Additional testing is optional for mothers over the age of 35, those with high-risk pregnancies or a history of genetic defects. Screening tests during pregnancy reassure and keep mothers informed about their developing baby.
Significance
According to the Mayo Clinic, prenatal care and screening tests are able to show if the baby has the potential to have certain conditions, however this is not a definitive diagnosis. The American College of Obstetricians and Gynecologists says percent 2 percent to 3 percent of babies are born with congenital defects. Additional testing may be offered to the mother if initial tests raise concerns.
Urine Tests
Each prenatal visit requires a urine screen to check for sugar or proteins which are signs of conditions such as gestational diabetes, bladder or kidney infection or preeclampsia. Preeclampsia is a condition that can cause poor fetal growth, seizures or coma.
Blood Tests
A hemoglobin test with a blood sample is conducted in the first and third trimesters to verify that the mother is not anemic. An antibody screen test with a blood sample in the first trimester and end of the second trimester determines blood type compatibility between the mother and developing baby. This test is also known as the Rh factor antibodies screen. A platelet count test requires a blood sample in the third trimester to verify the mother has adequate blood-clotting ability. This becomes important during delivery.
Glucose Test
A glucose tolerance test in the second trimester will test for gestational diabetes in the mother. Gestational diabetes can be dangerous for the health of the baby and also increase the baby's birth weight.
Ultrasound
All mothers receive a minimum of one ultrasound, generally around 20 weeks of pregnancy to make sure the fetus is developing properly. At this time, the gender of the baby may be determined if the genitals are viewed. Depending on the health care provider, additional ultrasounds may be required to calculate a delivery date, view the position of the baby or monitor high-risk pregnancies.
Genetic Testing
Additional screening tests may be requested by the physician to determine if genetic disorders exist in the developing baby. The tests include amniocentesis and chorionic villus sampling. Amniocentesis involves collecting a sample of amniotic fluid to detect chromosome disorders. Chorionic villus sampling involves collecting placenta tissue through the cervix to test for chromosome and other genetic disorders. According to the American College of Obstetricians and Gynecologists, 1 in 378 women age 35 years old have babies born with the chromosomal disorders that cause Down's syndrome.
Tags: blood sample, developing baby, Additional testing, American College, American College Obstetricians, babies born
