There are common tests done during each trimester of pregnancy. You may feel confused or overwhelmed by these tests. What follows are the standard tests administered to most women. Depending on your health or situation, you may be given additional testing.
At each visit, you will be asked for a sample of urine. This is done to check for several things, including sugar, protein and bacteria. Sugar can be an indication of gestational diabetes. Bacteria can be a sign of a urinary tract infection. Protein can indicate preeclampsia or a kidney problem, particularly if protein is found in combination with high blood pressure.
First Trimester:
During your first visit, several blood tests will be done. One will be your blood type and RH factor. This is done to determine if your blood is RH positive or negative. If your RH factor is different from the baby’s, problems can result. In general, the difference won’t be a problem in the first pregnancy, but can cause serious problems in the second pregnancy, including losing the pregnancy. After your baby is born, you will be given an injection to prevent these problems.
Your glucose level will also be tested. This test checks to be sure you are metabolizing sugar and screens for the risks of gestational diabetes. Your blood will be checked for immunity to Rubella, or German Measles. If you are not immune, you will be given a vaccination in the hospital after your baby is born. Exposure during pregnancy can be very dangerous and it’s not considered safe to be vaccinated during pregnancy.
Your iron levels will also be tested. Low levels can be an indication of anemia. If this is the case, you will be given iron supplements. Hemoglobin will also be measured. This shows the ability of your blood to carry oxygen in the red blood cells. If the level is below 10g, it can also be an indication of anemia.
You will also be tested at this time for several sexually transmitted diseases. These diseases can increase your risk of miscarriage or premature birth, if left undetected. You may be tested for hepatitis B, gonorrhea, chlamydia and HIV.
Second Trimester:
Most pregnant women will get an ultrasound around 18 to 20 weeks. Ultrasound confirms the gestational age of your baby and will detect the presence of more than one fetus. The location and condition of the placenta and amniotic fluid are also checked. Measurements are taken and the anatomy of the baby is checked for abnormalities. As an added bonus, you may get to find out the gender of your baby.
You will be offered a blood test known as a triple or quad screen. This is a screening test for possible genetic disorders, including Down’s Syndrome, Trisomy 18 and Spina Bifida. The values of the blood test are combined with the mother’s age to determine the risk for these disorders. The test is able to detect between 60 and 80% of babies with these disorders. Be aware that this test has a relatively high incidence of false positives, particularly with Down’s Syndrome. This is because the test relies on accurate dating of the pregnancy and the age of the mom.
Between 24 and 28 weeks, you will likely be given a glucose tolerance test. You will be given a glucose solution to drink. An hour after drinking it, your blood will be drawn. If an abnormal result occurs, don’t panic. You will be brought back for a three hour test to be sure. This test is done to check for gestational diabetes.
Third Trimester:
Between 35 and 37 weeks you will probably be given a Group B Strep test. GBS is a bacteria that is present in the vagina of 1 out of 4 women. This bacteria can cause an infection in the baby during birth. The test is done with a swab from the vagina and the rectum. If GBS is present, you will be given antibiotics during labor to prevent transmission to the baby.