Second Trimester Tests
Prenatal tests can help you and your baby stay healthy during the rest of your pregnancy. You might not have all of the tests discussed here. Or your health care provider might ask you to have others, depending on your age and your family background. As always, everything is done to ensure the health of you and your baby.
AFP and Triple Marker Tests
You may have an AFP (alpha-fetoprotein) or a triple marker test. These screen your growing baby for signs of certain birth defects. If the results are higher or lower than normal, other tests such as amniocentesis or ultrasound may be needed.
Amniocentesis
Amniocentesis tests for genetic problems and certain birth defects. A sample of fluid that surrounds your baby (amniotic fluid) is removed and tested. Your health care provider will talk to you about the risks of this procedure.
Ultrasound
Ultrasound is a harmless test. It bounces sound waves off your baby's body. The echo of the returning waves creates an image of the growing child. Ultrasound may confirm your due date, show the baby's growth, and rule out certain health problems. It can also show whether you are having twins.
If You Are Rh Negative
You'll be given a second blood test near your 28th week. If you have not formed Rh antibodies, you will be given an injection of RhoGam. This medication prevents Rh antibodies from forming. You will be treated every time fetal blood might mix with yours (for instance, after an amniocentesis or after your baby's birth).
Blood Glucose Screening
Blood glucose screening is a test for gestational diabetes. With this disease, changes in your body during pregnancy produce too much sugar in the blood. This can be controlled with diet and, if needed, medication. To do the screening, the patient is given a test dose of sugar (either a special drink or jelly beans), and the blood is tested one hour later. If the blood sugar is too high, a glucose tolerance test is ordered. If the glucose is very high, the diagnosis of gestational diabetes is made without further testing. You may be told to stop eating 8 to 12 hours before your glucose tolerance test.