Your doctor will probably choose to perform several standard tests during your pregnancy.  Every woman's pregnancy is unique, but there are a group of fairly standard tests that you will probably receive.

You will receive a blood test that will tell your doctor if you are anemic or if you have a low platelet count.  Your hemoglobin and hematocrit levels will tell your OB/GYN if you are anemic.  If your blood count is low and you are anemic, you will be treated most commonly with iron to raise it prior to delivery.  If your platelet count is low, your ability to clot is diminished.  Since a woman can lose up to half a liter of blood during delivery, a lack of blood clotting can result in death.

Early in your pregnancy you will receive a blood test to determine your blood type - if you need a blood transfusion at any time, there will be no question as to what your blood type is.  You will receive an antibody screen as well, since antibodies can cause blood diseases in both you and your baby.

During your pregnancy you will receive several urine tests.  Your doctor is looking for any UTI's (urinary tract infections) as well as an excess of protein or sugar.  If your urine test shows you have a urinary tract infection, you will be placed on antibiotics.

At the beginning of your pregnancy you will be tested for Syphilis, Hepatitis B, AIDS, Gonorrhea and Chlamydia.  These diseases can be dangerous if not deadly for both mother and child.

Your OB/GYN will give you a blood test to determine your Rh type.  If you are exposed to another person's red blood cell markers, your body may develop antibodies against them.  So, if during labor your body is exposed to your baby's blood (75% of all mothers have evidence of exposure to their baby's blood after delivery), you may develop antibodies to these red blood cell markers.  Remember, 50% of your baby's genes come from Dad.  If you are Rh negative and Dad is Rh positive, exposure to your baby's blood may result in your development of antibodies.  Your body may send these through the placenta in future pregnancies to "attack" an Rh positive baby's blood. 

If it is determined that you are Rh negative, you will probably be given RhoGAM at 28 weeks and within 72 hours of your baby's delivery.  RhoGAM is Rh immunoglobulin.  It absorbs the positive Rh blood cell markers of your baby, blocking the formation of mom's Rh antibodies and therefore protecting your baby.

You may be screened for the presence of rubella antibodies.  If you have no antibodies against rubella, you will be immunized for it after your baby is born.  You cannot receive this immunization during pregnancy because it is a live-borne virus and can be transmitted to your baby.  If it is determined that you have no antibodies for it, you will be advised to stay away from young children who may have it, as well as anybody who is suffering from rubella syndrome.

Some women carry a bacterial strain called Group B Streptococcus.  Surprisingly, up to 25% of women carry this bacterial strain.  GBS causes no harm to Mom, but can cause sepsis in your baby and result in death - particularly if your baby is premature.  Testing is done four weeks prior to delivery or during any sign of pre-term labor.  This is a culture taken from both the vaginal and rectal areas.  If your test is positive, you will be given intravenous antibiotics during labor to prevent infection in your newborn. 

You will receive a test for gestational diabetes around your 24th to 26th week of pregnancy.

Many OB/GYN's will perform one to two ultrasounds routinely during prenatal care - although some do not perform them at all.  An early ultrasound will help to determine the accuracy of your due date, whether you are carrying multiple fetuses, or if anything looks abnormal.  Some doctors will perform a second ultrasound several months into the pregnancy to rule out any abnormalities that may have occurred during your baby's growth.  This is normally the ultrasound where many excited parents find out the sex of the baby.