I found this and thought it might be helpful to someone who doesn't know what type of tests to expect during pregnancy
Common Tests
Ultrasound
⢠When: Any time during pregnancy.
⢠Why: Used to identify possible structural defects, such as spina bifida, or simply to check the condition of the fetus, such as the age, the rate of growth, the placement of the placenta or the number of babies. Ultrasound can also be used to listen to the fetal heartbeat during labor.
⢠How: Sound waves are bounced off tissues inside the body and changed into pictures of the internal organs. The fetus then appears on a video screen.
Fetal Kick Counts
⢠When: In the second half of pregnancy.
⢠Why: To examine the level of fetus activity.
⢠How: A health-care practitioner or the pregnant woman herself simply measures the length of time it takes for the fetus to make 10 movements. Although it can be done at any time of day, the fetus may be most active in late evening after dinner.
Non-Stress Test
⢠When: Usually performed after 28 weeks.
⢠Why: To measure the fetal heart rate in response to the fetusâ own movements. A rate that quickens when the fetus moves is considered a sign of good health.
⢠How: During this 10 to 30 minute test, a belt is placed around the pregnant womanâs abdomen while she lies down. The woman then pushes a button each time she feels the baby move, prompting a mark to be made on a paper recording of the fetal heart rate.
Contraction Stress Test
This is a forerunner of the Non-Stress Test. It is not frequently used today.
⢠When: In the second half of pregnancy.
⢠Why: To examine how the fetal heart rate reacts to the uterus when it contracts. Poor response can be a sign of fetal distress.
⢠How: The pregnant woman is given oxytocin, which causes the uterus to contract. The response of the fetal heart rate to the contractions is then recorded. To obtain results, the fetal heart rate is measured in response to uterine contractions, which should last approximately 40 seconds. The test can take up to two hours.
Biophysical Profile
⢠When: Usually in the last trimester.
⢠Why: To examine the fetal heart rate, muscle tone, breathing movements, body movement and the amount of amniotic fluid to determine the babyâs state of well-being. An abnormal test may be reason for early delivery.
⢠How: This test is performed with ultrasound. Each of the five areas is given a score. A score of 8 to 10 is normal.
Percutaneous Umbilical Cord Blood Sampling
⢠When: After week 18.
⢠Why: To determine if there might be chromosomal defects, infections or fetal blood conditions.
⢠How: The pregnant woman is given local anesthesia. The doctor uses ultrasound to guide the needle and withdraw a small amount of blood from the umbilical cord. Appropriate tests can then be conducted on the blood sample.
Glucose-Loading Test
⢠When: Routinely performed around 28 weeks.
⢠Why: To determine if there is a high level of blood sugar, which would indicate gestational diabetes. Long exposure to high blood sugar may cause the infant to grow excessively large or may cause the babyâs blood sugar to drop quickly and dangerously after birth. Once diagnosed, a mother can alter her diet and may take insulin to keep her blood sugar from getting too high.
⢠How: The pregnant woman ingests a highly concentrated sugar drink. Then a blood sample is taken to determine how well the pregnant womanâs body utilizes sugar.
Genetic Disorders and Birth-Defects Tests
When Is Genetic Counseling Recommended?
For a list of the risk factors may warrant genetic counseling, click here.
Amniocentesis
⢠When: Recommended at 14 to 18 weeks for women with certain risks.
⢠Why: This test is usually done to obtain information about the babyâs chromosomes. When the level of the motherâs alpha-fetoprotein (AFP) is high for no apparent reason, this test helps to determine whether or not a structural fetal defect may be present. If thereâs a need to deliver early, a test on the amniotic fluid attained through amniocentesis can determine the babyâs lung maturity.
⢠How: The physician inserts a needle into the motherâs abdomen and withdraws a sample of the amniotic fluid surrounding the baby. Appropriate tests are then done on the sample.
Chorionic-Villus Sampling (CVS)
CVS is an alternative to amniocentesis for prenatal diagnosis.
⢠When: At 9 to 11 weeks.
⢠Why: To find out information about the fetal chromosomes.
⢠How: A catheter is inserted through the vagina and cervix and into the uterus to obtain a sample of the placental tissue, which is examined for abnormalities.
Maternal Serum Alpha-Fetoprotein (MSAFP)
⢠When: At 15 to 22 weeks.
⢠Why: AFP levels may be elevated in babies with abnormalities of the brain and spinal cord. The levels may be low in babies with chromosomal abnormalities, such as Down syndrome.
⢠How: This test is performed on a sample of the motherâs blood.

CVS is more commonly performed with a very long needle through the abdomen. This method is safer (lower miscarriage rate) than vaginally.
Testing can be broken down to screening and diagnostic tests.
A screening test will tell you your risk factor for a condition, a diagnostic test will tell you for sure if a condition is present.
For example a glucose challenge test (where you drink the awfully sweet drink and have your blood checked after one hour) is the screeing test.
If you are high risk a ccording to that you are refered to have a glucose challenge test; where you drink the syrup and have 3 blood tests over 3 hours. This is the test that diagnoses diabetes.
Another example of screening is the 18 wk ultrasound.
Ammniocentesis & CVS are diagnostic.
This is great info for first timers.