Testing During Pregnancy


Ultrasound or sonography is an easy, noninvasive way to see internal structures of the baby by sending a high-frequency soundwave through the abdomen.  Sound waves travel through the abdomen and bounce back off structures.  The bounce back waves return to a transducer and are seen as an image on the screen.  This sound is very high frequency and cannot be heard or felt.

There is still controversy about the value of ultrasound in pregnancy but it has become a routine part of care in the United States. 

Benefits of ultrasound:

  1. Dating
  2. Diagnosing early miscarriage
  3. Diagnosing multiple gestations
  4. Diagnosing fetal abnormalities 

Questions have been raised as to the safety of ultrasound but there have been no known adverse effects in the 30 years of use.  The 4D ultrasound, while enjoyable and entertaining, has not been shown to improve pregnancy outcome. FDA recommends against ultrasounds for keepsakes

When indicated for medical reasons, ultrasound is generally covered by insurance. We will schedule appointments for ultrasounds if requested, but you need to understand that insurance may refuse to cover the cost and you may be held responsible.

It is important to understand that this technology has limitations. For example, one study in Boston of over 7,000 ultrasounds identified only half of cardiac lesions. This means at least half of the heart problems were missed on ultrasound.

A normal ultrasound does not guarantee a normal baby!

One Hour Glucola

This is a special test to evaluate how your body metabolizes glucose during your pregnancy. Gestational diabetes affects about 5% of all pregnant women. Predisposing factors are family history, advanced maternal age, and prior medical history. Usually, gestational diabetes is easily managed and it is, therefore, easy to prevent the complications for the baby.

About 28 weeks you will be given a glucose drink. Your blood sugar will be tested one hour after drinking the glucola.

It is important not to fast before this test. About 3 hours before you drink the glucola have a light low-fat, starchy meal such as cereal with skim milk 

Drink the entire bottle of glucola one hour before your scheduled test.  It must be consumed within 5 minutes. The blood work needs to be drawn exactly one hour after completion of the glucola. Failure to follow these instructions will require a repeat of this test.

If your one-hour test is abnormal you will need to do a 3-hour glucose tolerance test to determine if you actually have gestational diabetes.

Three-hour Glucose Tolerance Test 

The three-hour glucose tolerance test is a diagnostic test for gestational diabetes. Gestational diabetes is usually controlled by diet.  Failure to diagnose and control gestational diabetes may result in a poor outcome for your baby.

The test takes some preparation on your part.

The test is scheduled at the laboratory.  For three days prior to the test, you will need to follow the enclosed diet. The night before the test do not eat, drink, chew or smoke anything after midnight.

On the morning of the test, the lab will draw a fasting blood sugar. Then you will be given glucola to drink. Blood will be drawn at 1, 2, and 3 hours after completing the glucola. Plan on eating after completing the test.   

We will call you with the results within 2-3 day if the results are abnormal.

Three Day Sample Diet for Glucose Tolerance Preparation

Breakfast:  1 cup cereal, 1 slice toast with jelly, 1 egg, 1 cup milk, 1 cup juice, 2 tsp sugar
Lunch:  Sandwich with meat and cheese or peanut butter.  Salad, banana, and milk
Dinner:  Meat, 1 cup macaroni and cheese, 1 slice bread, ½ cup vegetables, and 1 cup juice
AM Snack:  fruit
PM snack:  Milk and crackers
Bedtime snack:  ½ cup Jell-O and 1 cup milk

This diet includes daily:

2 cups of juice
4 cups of milk
1 cup vegetables
4 servings fruit
6 slices bread
1 cup cereal
1 cup potato, rice or noodles
3 tsp sugar or jelly

Additional Testing

There are a number of additional tests that may be recommended for you and your baby during the course of your pregnancy.  Many of these will depend on your history, family history or your age at delivery. Often if there is a concern, you will be referred to a genetic counselor and perinatologist for testing and consultation. We will be happy to discuss these tests with you at your visits to the office.

AFP Testing/First-trimester Screen

These tests help identify women who are at increased risk for either Downs Syndrome, Trisomy 13, Trisomy 18, or a neural tube defect. 

Down’s Syndrome is a birth defect that occurs in about 1/800 births that is caused by a chromosomal abnormality.  About 80% of Down’s are born to women younger than 35 years of age.  These babies have abnormal physical features and mental retardation. Many have serious medical problems such as cardiac abnormalities (many of these may be corrected with surgery).

Trisomy 13 and 18 are chromosomal abnormalities that lead to the death of a baby either during the pregnancy or during infancy. There is no treatment for these abnormalities.

Neural tube defects are abnormalities of the brain or spinal cord that occur about 1-2/1000 deliveries. There is a great deal of variability in how badly babies are affected. Many of these babies have mental retardation or significant limitations such as an inability to control their bladder or bowels. They may need surgery, leg braces and physical therapy.

A specialist in high-risk pregnancies will perform the first-trimester screen. This test involves an ultrasound where the skin at the back of the baby’s neck is measured. Those results are combined with a finger stick blood test to screen for Downs, Trisomy 13 and 18, and neural tube defects.

A follow-up blood test will be drawn between 15 and 20 weeks to complete the screen.

An abnormal test does not mean that your baby is abnormal; just that there is an increased risk for a problem. You will be given the opportunity to speak with a genetic counselor and a perinatologist (expert in high-risk pregnancy).  You will be offered additional testing such as amniocentesis or a more comprehensive ultrasound.

A normal test does not guarantee that your baby is normal. It will detect between 80-85% of neural defects and about 40% of Downs Syndromes. Many other sorts of problems are not detected through this testing. This test is primarily recommended for women under 35.  For women who are over 35, amniocentesis or CVS are still considered the “gold standard”.

Genetic Blood Tests

There are now a large number of genetic screening tests that may be run on a woman’s blood during pregnancy.  Some of them are offered routinely such as Cystic Fibrosis screens or screens for Thalassemia or sickle cell anemia. Others such as an Ashkenazi panel are recommended for women of a particular ethnic background. If results are abnormal, you will be referred to a genetic counselor and perinatologist for additional testing.

Genetic Consult

If you will be over the age of 35 or have any type of family history that is genetically linked you will be offered an appointment with a genetic counselor who works with one of our referring perinatologists. Usually, those visits will involve an in-depth genetic history as well as an advanced ultrasound. You will be given information about potential risks for your pregnancy and the testing options that are available.