Depending on when you come to our practice, you may have already completed much of the pregnancy testing and be transferring for maternal or baby complications that require additional monitoring and care. Below are some frequently ordered prenatal tests.
All women in our practice are offered genetic screening for age related risks for infants with chromosomal abnormalities such as Down Syndrome, as well as for other inheritable genetic conditions. You may also be referred to Reproductive Genetics for further testing based on your background, ultrasound findings, age or family history.
Ultrasound & MRI Evaluation
Ultrasound is a common tool that we use to assess fetal growth and wellbeing. Depending on your pregnancy risks and complications, ultrasound screening and monitoring will be offered to evaluate and assess your baby’s growth and development. Most women undergo a detailed evaluation of the baby between 16-20 weeks to assure that the baby is forming correctly. This visit can be quite lengthy (>60 minutes) and if there are multiple babies can take additional time.
For some women a detailed evaluation of the baby’s heart (a fetal echocardiography exam) may also be offered. This test evaluated the structure and function of your baby’s heart. The sonographers within our ultrasound unit are certified in fetal echocardiography.
Regardless of the type of ultrasound testing, a SPA doctor interprets and reviews the images and is always available to discuss ultrasound results.
For some pregnancies evaluation of the fetus or placenta by MRI is recommended as well. This test requires insurance approval and will be scheduled in the hospital. The results will be evaluated by a radiology specialist in fetal MRI and are generally not be available the same day as the exam. Depending on the situation, this testing may be used to aid in planning for both the obstetric and pediatric physicians about your pregnancy. There is no radiation exposure with MRI testing as it uses magnet technology.
Glucose Screening Test
Unless you have already been identified as a diabetic, you will be given a glucose screening test between 24 and 28 weeks (or perhaps earlier if you have risk factors predisposing you to diabetes). Pregnancy is a state in which your body is called upon to make more insulin. Some women cannot keep up with this demand and will develop gestational diabetes. Normal blood glucose levels are important during pregnancy. Gestational diabetics need to adhere to a specific diet and monitor their blood glucose levels. Occasionally, they may be required to begin insulin administration.
To screen for gestational diabetes, you will be given a high glucose beverage (glucola) and will have your blood glucose level drawn one hour later. Although fasting is not necessary prior to the test, only water is allowed after drinking the glucola until your blood is drawn. If the result of your one-hour glucose test is elevated, you will be asked to take a 3-hour oral glucose tolerance test (OGTT). With this particular test, after a fasting blood glucose is drawn, you will drink a larger amount of glucola, and blood glucose samples will be taken after 1 hour, 2 hours, and 3 hours. A diagnosis of gestational diabetes is made if two or more blood glucose levels are elevated.
Healthy babies usually are active. A sudden change in your baby's usual pattern of movement will alert the health care provider that further assessment may be indicated.
You will be asked to lay on your left side (which promotes optimum blood flow to your placenta), and to pay close attention to your baby's movements. The kick count is done at the same time each day. If you notice a marked change in your baby’s movements or if the kick count does not provide ten movements in two hours, you should notify the SPA physician on-call immediately.
Non-Stress Test (NST)
The non-stress test is an easy, non-invasive way to determine if your baby is healthy. It is ordered whenever there is a concern over the status of your baby. It is usually performed once a week, but may be done twice weekly or even more frequently if you are hospitalized.
For a non-stress test, an electronic fetal monitor transducer is applied externally to your abdomen, and a tracing of the fetal heart rate, fetal activity, and uterine contractions is made. The tracing will be studied by a perinatologist who will look for at least two accelerations of your baby's heart rate during a 20-minute period. If these increases in your baby's heart rate are seen, they indicate that delivery of oxygen to your baby is adequate. The NST also can help to assess if you are having contractions.
If accelerations are not seen, a biophysical profile (BPP) may be ordered. The BPP is an ultrasound technique in which your baby's behavior is observed for a 30-minute period. A score is assigned for each of five different parameters: 1) the results of the NST, 2) the presence of fetal breathing movements, 3) fetal body or limb movements, 4) fetal muscle tone, and 5) quantity of amniotic fluid. The total score of the BPP is valuable in helping the physician decide on the best plan of care for you and your baby.
Amniotic Fluid Volume
The amniotic fluid, or "water" surrounding your baby has several important functions: it cushions your baby from injury, helps in maintaining temperature, allows easy fetal movement, and keeps the umbilical cord floating freely. Constant fetal swallowing and urination maintain the level of amniotic fluid. Various conditions may alter the amniotic fluid volume. Amniotic fluid volume is determined by a simple ultrasound examination in which "pockets" of amniotic fluid are visualized and measured.