Pregnancy Testing, Sonograms, and Ultrasounds

Sonogram or Ultrasound: 18-20 weeks

At eighteen-twenty weeks a routine ultrasound is scheduled. Ultrasounds are done in our office. An ultrasound is a physical exam of the fetus. The ultrasound pictures provide valuable information about the baby’s health and well being. You must come to the office with a FULL bladder or the sonographer will be unable to do your ultrasound. Some insurance companies do not pay for ultrasounds so you should check with your insurance plan to see if it is a covered benefit.

Glucose Tolerance Testing

At twenty-four to twenty-eight weeks you will be screened for gestational diabetes. Diabetes occurs when there is a problem with the way the body uses insulin. When insulin is not used properly, the level of glucose (sugar) in the blood becomes too high. Because the hormones of pregnancy increase the body’s resistance to insulin, approximately 3% of pregnant women will develop diabetes during pregnancy. This condition usually subsides after pregnancy, but women who have had gestational diabetes are more likely to develop diabetes later in life.

You will be given a bottle of glucose to drink before coming in for the test. Drink the full bottle 45 minutes before you arrive. You need to have your blood drawn exactly one hour after finishing the drink. Please be in the office on time to have your blood drawn. Do not eat foods with sugar content 2 hours before drinking the glucose. Please advise the front desk upon your arrival of the time you finished the drink. If the test is elevated, further testing will be done. You will also be screened for anemia at this time. If you are diagnosed with gestational diabetes, there will be follow up testing done after your baby is born.

Tdap Vaccination: Late in the second trimester or third trimester

Pertussis (also called whooping cough) is a highly contagious disease that causes severe coughing. In newborns, pertussis can be a life-threatening illness. Infants are at risk of getting pertussis until they can be vaccinated at 2 months of age. Getting your Tdap shot is the most important step in protecting yourself and your baby against whooping cough. Your doctor and nurse will review current recommendations.


If you are Rh negative (O-, B-, A-, AB-), you will receive a Rh injection in your hip around 28 weeks. Only 15% of women are Rh negative. This means if your baby’s blood is Rh positive, you may form antibodies that fight against your baby’s blood. The injection can prevent sensitization for up to twelve weeks. You will have this injection again after delivery if your baby is Rh positive.

Group B Streptococcus (GBS): 35-37 weeks

GBS is a type of bacteria that can be found in up to 40% of pregnant women. A woman with GBS can pass it on to her baby when she is pregnant or to her baby during delivery. Most babies who get GBS from their mothers do not have any problems. There is a small percentage that will become sick. This can cause major health problems or even threaten the baby’s life. GBS is one of many bacteria that do not usually cause serious illness. It is found in the digestive, urinary, and reproductive tracts. In women, it is most often found in the vagina and rectum. A culture will be done at around 36 weeks to check if GBS is present in your vaginal tract. If GBS is present, you will be treated with antibiotics during your labor.

Further Education

The internet can be a source of excellent pregnancy related information. When reviewing information on your computer, do consider the source. Try to avoid unknown sites, and sites trying to sell you products.

Websites that you may find useful include: