AFP-TRIPLE SCREEN TEST
The alpha-fetoprotein (AFP) test helps identify a small number of women whose unborn babies may have certain defects such as Down’s Syndrome or an open neural tube defect. This test is available to women who are between weeks 15 and 19 of their pregnancies. A small amount of blood is drawn from a vein in the arm of the pregnant woman and is then tested for a variety of factors. Through this screening test, an open neural tube defect can usually be identified. It can detect approximately 50% of cases of Down’s Syndrome. The downside of the test is that it has a 90% false positive rate. Women who have a positive blood test will need amniocentesis for further evaluation. We will be glad to answer any questions you have concerning this matter.
GLUCOSE SCREENING
During pregnancy, the metabolic system experiences added stress. In some women, this additional stress results in a temporary rise in the blood sugar level. For this reason, your blood sugar level will be tested between 24 and 30 weeks. You will be notified as to when you should schedule your glucose screening. You will be given some Trutol, which is a sweet drink containing a measured dosage of glucose. An hour later, a blood sample will be drawn. You will be notified if your glucose level is elevated. If it is, you should begin following the special diet you will be given and schedule a follow-up blood sugar test.
Please remember that an elevation in your glucose level does not mean anything is wrong with you or your baby. It does mean, however, that you will need to make some changes in your diet, and we will have to do some additional testing.
NON-STRESS TEST (NST)
In the last trimester, you may need a non-stress test (NST). During an NST, two monitor straps are placed around your abdomen to check the baby’s heartbeat and any contractions you might be having. (This is the same type of monitoring you will have in the labor room at the hospital.) This test lasts approximately 20 minutes. You will be monitored while lying in a recliner. If you need this type of test, it may be performed on a weekly basis. You will see the doctor with each scheduled NST appointment.
GROUP B STREP INFORMATION
Group B Strep is normally found in the vagina of 15% to 40% of all healthy adult women. Group B Strep should not be confused with Group A Strep which causes strep throat. GBS does not cause problems for the adult female. Most women carry it and don’t know it.
GBS can cause illness in babies born to women with GBS. Therefore, your HWWC physician will check for GBS between 35-37 weeks. If the test is positive, you will be notified as well Labor & Delivery. You will be treated with antibiotics while you are in labor & delivery. Treatment is not recommended before labor & delivery because the transmission of the bacteria usually would occur during labor and/or delivery.
AMNIOCENTESIS
An amniocentesis may be performed during pregnancy to help determine an inherited, genetic abnormality that the fetus may have. This procedure involves the careful passage of a thin needle through the abdomen of the mother and into the sac of the amniotic fluid surrounding the fetus. (This is done under ultrasound-guidance.) A small amount of the fluid is then withdrawn for analysis.
- WHO SHOULD CONSIDER IT? The principle reasons for genetic amniocentesis are: maternal age of 35 years of older (at time of anticipated delivery), and a previous child with a proven chromosomal abnormality. Other reasons, which rarely occur, include testing for unusual enzyme deficiencies, neural tube (brain and spine) defects, sickle cell disease, and so forth. These often require additional counseling with a geneticist.
- WHAT IS GENETIC AMNIOCENTESIS: Genetic amniocentesis is usually performed on an outpatient basis. This test is able to detect fetal sex and almost all chromosomal abnormalities. It is also able to detect 85 to 90 percent of neural tube defects by taking a sample of amniotic fluid and testing the level of alpha-fetoprotein.
- WHAT ARE ITS LIMITATIONS?
- It cannot detect non-chromosomal congenital abnormalities such as cleft palate, intestinal or cardiac abnormalities, etc., which occur in approximately three percent of pregnancies.
- Its accuracy exceeds 99.9 percent, but cannot be totally guaranteed. There is a very remote possibility of error (one in 10,000 cases) in the interpretation of fetal cells grown from amniotic fluid.
- Fluid cannot be obtained on rare occasions because of technical difficulties or decreased amounts of fluid. The attempt must be postponed if this occurs.
- A second amniocentesis (seven to 14 days later) is needed on rare occasions because cells in the initial sample may not have grown enough to permit valid interpretation.
- WHAT ARE THE RISKS? The principle risk of amniocentesis is spontaneous abortion (miscarriage), which occurs very rarely. Additional risks include, but are not limited to, death, possible fetal or maternal injury, infection or bleeding. Because there is a risk involved, it is important to note that this test is only recommended when there is a specific reason to believe that a detectable genetic disease may be present. The occurrence of these complications in our practice is unusual for several reasons. Most importantly, the physicians who perform this procedure are very experienced practitioners. Secondly, ultrasound is utilized to help determine the gestational age of the fetus, the position of the placenta, and the best area for the proper and safe placement of the amniocentesis needle.
- WHAT IS THE COST? Essentially, there are two categories of charges: the charge for the procedure, and the charge for the laboratory analysis. If you do not have insurance, you will need to pay for the procedure prior to having it performed. If you do have insurance, it will be filed, and you will be billed for the amount not covered by your insurance.
CYSTIC FYBROSIS TESTING INFORMATION
Cystic Fibrosis is a genetic disease that causes breathing problems, lung infections and digestive problems. These problems can require daily medication and respiratory (lung) therapy. Cystic Fibrosis does not cause a person to have learning problems or to look different.
Most people that have a child with cystic fibrosis DO NOT have a family history of cystic fibrosis. Gene carriers have one altered copy of the CF gene and one normal copy. They do not have any symptoms of CF. Individuals with CF have two altered copies of the CF gene. If both parents are CF carriers they have a 1 in 4 chance (25%) to have a child with CF.
Couples with the greatest chance to be a CF carrier that are planning a pregnancy or seeking prenatal care should consider CF Carrier Testing. You should also consider testing if you or your partner has a family member with CF. Testing should be considered if you are partners with an individual with CF or CF carrier.
If you are interested in getting tested you should discuss this with your doctor or genetic counselor. The test will require a blood sample taken from the arm.
For more information about Cystic Fibrosis please contact the following organizations:
Cystic Fibrosis Foundation
6931 Arlington Road
Bethesda, MD 20814
1-800-FIGHT CF
www.cff.org
March of Dimes
1275 Mamaroneck Avenue
White Plains, NY 10605
1-800-MODIMES
www.marchofdimes.com
UAB Department of Genetics
Hugh Kaul Genetics Building
720 20th Street South
Suite 241
Birmingham, AL 35294-0024
(205) 934-4983
