Testing

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Genetic Testing

AFP Test. Triple marker screening (the expanded AFP test) is a screening test for women who are in their second trimester of pregnancy. This test will help your provider detect an increased risk for Down Syndrome, neural tube or abdominal wall defects and other chromosome-related abnormalities. It is only a screening test, not a definitive diagnostic test.

A positive result does not necessarily mean that there is an abnormality present. Many times this is caused by incorrect dating of the fetal age. So it is important to be as accurate as possible when determining date of conception. The increased risk of a positive result may require additional genetic counseling and a more detailed ultrasound examination. You and your provider may want to consider having an amniocentesis performed to more clearly identify the baby’s genetic disorders.

A negative result does not necessarily mean that there are no abnormalities present. Read that statement again. This result indicates that the risk of the fetus having Down Syndrome is not greater than that of a 35-year old woman and that the risk of a neural tube defect is no greater than that of the general population.

Most often, the AFP test provides reassurance that you baby probably will not have a serious defect. If abnormal results are detected, you and your doctor can manage your pregnancy more effectively and can plan your delivery to optimize the outcome of the pregnancy.

Amniocentesis. This is an invasive test in which a small amount of amniotic fluid which surrounds the fetus is removed from the uterus through a thin needle. An ultrasound of the fetus is performed while the needle is in the uterus to help guide the positioning of the needle. This procedure carries with it increased risk for damage to the fetus and/or a complete miscarriage. It should only be conducted after a thorough dialogue with both our physician and the specialist who will be performing the procedure.

A partial list of the chromosome abnormalities that can be diagnosed with this test are:

• Down Syndrome
• Neural Tube Defects (such as spina bifida)
• Cystic Fibrosis
• Sickle Cell Anemia
• Tay-Sachs Disease

Down Syndrome.

Down syndrome is a chromosome abnormality that causes mental retardation and certain types of other birth defects. The fetus has three, not the normal two, copies of chromosome 21. Down syndrome affects approximately one in every 800 newborns. The chance to have a pregnancy with this abnormality increases with the increased age of the mother, particularly if you are 35 or older.

Neural Tube Defects.

A neural tube defect result from a failure of the neural tube to completely close during early fetal development. One common defect of this type is spina bifida. Spina bifida is an opening on the spine that exposes nerve tissue and can lead to paralysis and mental retardation.

Cystic Fibrosis.

This can be diagnosed either with the amniocentesis test, or more frequently with a simple blood test. This test is 99% accurate. If you are tested positive, then you have a mutation in the CFTR gene and are considered a carrier. Your health will not be directly affected if you are a carrier. Your partner should also be tested. If he also is tested positive then he is a carrier too. When both parents are carriers of the mutated CFTR gene, then your baby has a 1 in 4 chance of being affected the cystic fibrosis (CF).

CF is more common in the Caucasion population than in other ethnic groups. The most common problems of CF are chronic lung infection and poor absorption of food because of the accumulation of thick mucus in the lungs and pancreas of the individual. At this time there is no known cure; the median life expectancy is about 30 years.

Sickle Cell Anemia.

This can be diagnosed either with the amniocentesis test, or more frequently with a simple blood test called the hemoglobin electrophoresis test. You and the the baby’s father each contribute genes that combine to form the baby’s genetic makeup. If one of the parents’ genes given to the baby has this abnormal hemoglobin deficiency then the baby will have sickle cell trait. If both of the parent’s genes given to the baby have this abnormal hemoglobin deficiency then the baby will have sickle cell anemia.

Only individuals with sickle cell anemia will experience the effects of the disorder. This disorder produces abnormal hemoglobin which result in the red blood cells being crescent or sickle shaped, not round. These sickle-shaped blood cells become hard and sticky and have difficulty passing through small bllod vessels and capillaries. They clog the flow and break apart. This is what causes the pain, damage and anemia.

Tay-Sachs Disease.

This is a fatal disorder that most often occurs in members of the East European Jewish community. When born, the baby appears normal; but after six months the infant begins to develop mental retardation. This is followed by paralysis, blindness and seizures. Death usually occurs by the age of five or six.

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Gestational Diabetes (Diabetes of pregnancy)

You will have a one-hour glucola test between your 24th and 28th weeks of pregnancy to screen you for gestational diabetes. This type of diabetes can present serious health risks to you and your baby. This screening test will determine if you are at risk for gestational diabetes and if you need a more comprehensive 3-hour glucose tolerance test.

If you do have gestational diabetes as determined by the 3-hour test, you will be referred to a special program that helps you with your diet so that your sugar levels remain normal throughout the remainder of your pregnancy.

Preparing for the one-hour glucola test:
1) On the day of your test, eat light, well-balanced meals. Avoid concentrated
sweets. DO NOT EAT OR DRINK ANYTHING for two hours before the test.
2) At our office SIGN IN AT THE LAB. Since this will take an hour to complete,
please arrive before 10:30 AM in the morning and before 3:30 PM in the
afternoon.
3) The lab tech will give you a sweet drink called “glucola”. Exactly one hour after
you drink the glucola your blood will be drawn.
4) Do not eat, drink, smoke or chew gum during this hour. Keep your activity to a
minimum during this test.

We will contact you if the results of the test show a need for additional testing.

Preparing for the three-hour glucose tolerance test:
1) Eat your normal meals on the days leading up to the test. FAST FOR 12 HOURS
BEFORE YOUR MORNING APPOINTMENT. Sips of water only.
2) At our office SIGN IN AT THE LAB for this morning test. It will take three
hours to complete.
3) The lab tech will take a blood sample before giving you the “glucola” to drink.
Your blood will be drawn three additional times; at 1 hour, at 2 hours and finally
at 3 hours.
4) Do not eat, drink, smoke or chew gum during this test. You may want to bring
a book or something else to help you pass the time. Keep your activity to a
minimum during this test.

We will contact you with the results of this test and advise you of the next step.

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Group B Strep

Group B Strep is a type of bacteria that is normally found in the vagina and/or rectum of some women. It is not a sexually tranmitted disease. It can, however, in some cases cause serious infections to the newborn baby as it passes through the birth canal. We will order this test in the 35th or 36th week of pregnancy. If the test is positive, meaning that the Group B Strep bacteria is present, IV antibiotics will be started when you are admitted to the hospital for the delivery to help prevent this infection in the newborn.

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Non-Stress Test

Why am I having a Non-Stress Test?

Your doctor or midwife may recommend that you have a non-stress test during the later stages of your pregnancy. There are a number of reasons why this test may be ordered:

• High blood pressure or diabetes
• If your baby seems to be moving less than usual
• If you are past your scheduled due date
• If you’ve had difficulties/complications in one of your earlier pregnancies
• If both of us want reassurance that your baby is doing well

What exactly is a Non-Stress Test?

It is a safe, easy and painless way to check on your baby’s well-being before it is born. This test normally takes between 20 and 40 minutes to perform, depending on the activity and sleep pattern of the unborn baby. Two small monitors are placed on your abdomen and attached to an electronic measuring device. One of the monitors will measure your contractions while the other one will monitor baby’s heart rate. The evaluation of these two activities will help the provider evaluate baby’s condition.

Based on this evaluation, you may be sent home with detailed instructions on what to do over the next period of time. You may also be admitted for the health of you and the baby.

Is there any other testing to be done like this?

Your doctor may request that an AFI and a BPP be done. An ultrasound is done to determine the amount of amniotic fluid that surrounds your baby. This Amniotic Fluid Index will tell the physician if the baby and placenta are making enough fluid. Additionally, a BioPhysical Profile, consisting of the NST, the AFI, and observations of both baby’s arms/legs movement and large body movements (the chest muscles, which are a reflection of baby’s ability to breathe) will tell the physician whether the circulation to the baby is adequate.