Pregnancy Forum - 15 Week Appointment

Why did the doctor say you needed an amnio? they normally don't tell you this until they find something wrong during the level II u/s.

you are a worrier and you need to talk to your doctor about all of this. if you are this stressed out about everything it's not good for you or the baby. your doctor can talk to you and maybe you won't be so stressed out about every little thing that you hear.

here is a little info on the screening they will do when you have the blood test. If you dont' get a call that is pretty much good news....

Maternal Blood Screening for Down Syndrome and Neural Tube Defects

Health care providers offer their pregnant patients a screening test that identifies pregnancies at higher-than-average risk of certain serious birth defects, including neural tube defects such as spina bifida (sometimes called open spine) and some chromosomal disorders (Down syndrome and trisomy 1 Cool

. This blood test, which can provide valuable information about a developing fetus, has a number of names including maternal serum (blood) screening test, multiple marker screening test, triple screen, quad screen and others. It’s important to understand that, in most cases, an abnormal test result shows an increased risk, but not a definite problem with the baby. Further testing usually rules out the suspected problem.

What does this test measure?
This test currently measures the levels of three or four substances in the mother’s blood.

When maternal blood testing first began in the early 1980s, the test measured only alpha-fetoprotein (AFP), a substance produced by the liver of the fetus. Some of this protein is excreted into the amniotic fluid surrounding the fetus. AFP also passes into the mother’s bloodstream, where its concentration rises gradually until late in pregnancy.

Along with maternal serum alpha-fetoprotein (MSAFP) levels, the test now also measures the levels of two pregnancy hormones called estriol and human chorionic gonadotropin (hCG). When the test measures the levels of these three substances, it is often called the triple screen.

Many laboratories in the U.S. measure the level of a fourth substance in the mother’s blood called inhibin-A. The addition of inhibin appears to make the test more accurate in detecting pregnancies at risk of Down syndrome. The test is called the quadruple screen when it measures the four substances in the mother’s blood. Researchers continue to study other substances in the mother’s blood, which eventually may be added to the blood test to improve its ability to detect birth defects.

The laboratory calculates a woman’s individual risk of neural tube defects (NTDs), Down syndrome and trisomy 18 based upon the levels of the three or four substances plus the woman’s age, weight, race, and whether she has diabetes requiring insulin treatment. These last three factors influence MSAFP levels.

When during pregnancy is the maternal serum screening test done?
This blood test most often is done between 15 and 18 weeks after the last menstrual period. The results usually are available within one week. Researchers also are exploring approaches for earlier screening.

Does an abnormal test result mean the baby has a birth defect?
No. This test cannot diagnose a birth defect, it only can indicate an increased risk. An abnormal screening test result simply means that additional testing is needed. Out of every 100 women who take a maternal serum screening test, about 5 to 7 will have an abnormal result. However, only about 1 to 2 percent of women whose test results show an increased risk of Down syndrome will actually have a baby with Down syndrome. Similarly, only a very small number of women whose test results show an increased risk of spina bifida and related birth defects will actually have an affected baby (a woman’s doctor can give her a better estimate of the risk to her baby, based on her test results).

For many of the rest, the abnormal test result simply indicates that the fetus is either a few weeks older or younger than originally thought. Because the range of normal results varies with the weeks of pregnancy, it is very important to know the accurate gestational age of the fetus. The gestational age of the fetus should be confirmed by ultrasound if there is any question about it. Another common cause of an abnormal test result is a multiple pregnancy (twins, triplets, etc.).

It’s important to remember that follow-up (diagnostic) tests usually show that a baby does not have Down syndrome, trisomy 18 or an NTD. Pregnant women who do not understand that most women with abnormal test results have healthy babies may experience much unnecessary anxiety.

What fetal problems can cause abnormal maternal serum screening test results?
Neural tube defects (NTDs). High levels of one of the measured substances, MSAFP, suggest an increased risk of NTDs. The neural tube is the embryonic structure that develops into the brain and spinal cord. If the neural tube does not close properly during the fourth week after conception, birth defects such as spina bifida and anencephaly will result. About 2,500 babies are born in this country each year with these birth defects.

Spina bifida, often called open spine, affects the backbone and, sometimes, the spinal cord. Children with the severe form of spina bifida have varying degrees of leg paralysis and bladder and bowel control problems. Anencephaly is a fatal condition in which a baby is born with a severely underdeveloped brain and skull.

The causes of NTDs are not thoroughly understood. Scientists believe that genetic and environmental factors act together to cause these malformations. About 90 to 95 percent of babies with NTDs are born to couples with no family history of these abnormalities.

Studies show that, if all women consumed the recommended amount of the B vitamin folic acid before and during early pregnancy, up to 70 percent of NTDs could be prevented. The March of Dimes recommends that all women of childbearing age take a multivitamin containing 400 micrograms of folic acid daily, and eat a healthy diet including foods rich in folic acid. Foods that contain folic acid include: fortified breakfast cereals, beans, green leafy vegetables, orange juice and peanuts. (Any woman with a history of nut allergies should avoid eating peanuts or peanut products at all times, not just when pregnant or breastfeeding.)

Abdominal defects. Certain uncommon birth defects of the abdominal wall also can raise MSAFP levels, as can certain rare kidney and bowel defects. In rare instances, the MSAFP level is elevated because the fetus is dying or dead.

Down syndrome. Low levels of MSAFP and estriol, along with high levels of human chorionic gonadotropin (hCG) suggest an increased risk of Down syndrome. About 1 in 800 babies is born with Down syndrome, which is caused by an extra copy of chromosome 21. Affected children have characteristic facial features, mental retardation and, often, heart defects and other problems.

Trisomy 18 (Edward syndrome). Low levels of MSAFP, estriol and hCG suggest an increased risk of this less common chromosomal abnormality, which affects about 1 in 3,000 babies. Affected babies, who have an extra copy of chromosome 18, have severe mental retardation, heart defects and numerous other birth defects. Most die in the first year of life.

The risk of Down syndrome, trisomy 18 and other chromosomal problems increases with a woman’s age. Pregnant women who are 35 years of age and older generally are offered prenatal testing with amniocentesis or chorionic villus sampling (CVS) to diagnose or, far more likely, rule out these disorders. If the maternal serum screening test shows that a woman under age 35 has a risk that equals that of a 35-year-old woman (about 1 in 270), she also will be offered follow-up tests.

What tests are recommended following an abnormal maternal serum screening test?
After an abnormal test result, the next step usually is an ultrasound examination. This test uses sound waves to take a picture of the fetus. Ultrasound can help determine the gestational age of the fetus and show if a woman is carrying twins. If either of these factors accounts for the abnormal test result, no further testing is needed. Ultrasound also can detect some serious birth defects.

If the ultrasound does not provide an explanation for an abnormal test result, additional diagnostic testing is recommended. If the maternal serum screening test shows that a woman is at increased risk of Down syndrome or trisomy 18, her health care provider will offer her amniocentesis. In this test, the doctor inserts a thin needle through the abdominal wall and into the uterus to withdraw a few teaspoons of amniotic fluid. Fetal cells contained in the amniotic fluid will be tested for Down syndrome and other chromosomal abnormalities. Amniocentesis is more than 99 percent accurate in diagnosing or, far more likely, ruling out Down syndrome.

If the maternal serum screening test shows that a woman is at increased risk of having a baby with an NTD, her provider may recommend a detailed ultrasound examination (sometimes referred to as a targeted, comprehensive or level II exam), amniocentesis or both. A targeted ultrasound examination of the fetal skull, spine and other organs can quite accurately detect or rule out serious NTDs. It also may help predict the severity of NTDs. If this type of ultrasound examination is not available, or if more information is needed after an ultrasound examination, amniocentesis often is recommended to measure the level of AFP and another substance called acetylcholinesterase in the amniotic fluid. When amniocentesis is done to help detect NTDs, cells from the fetus usually are tested for chromosomal abnormalities because they sometimes can accompany an NTD or an abdominal wall defect.

The maternal serum screening test leads to the prenatal diagnosis of about 95 percent of cases of anencephaly, 85 percent of cases of serious spina bifida, as well as 65 percent of cases of Down syndrome (about 75 percent of Down syndrome cases if the quadruple screen is used).

What are the benefits of the maternal serum screening test?
For the great majority of women, the screening test provides reassurance that their fetus does not appear to have certain serious birth defects. Test results also can help a woman manage her pregnancy more effectively. For example, finding the correct gestational age helps determine whether the fetus is growing at a normal rate. And detecting a multiple pregnancy allows for special care.

When an NTD or other problems are diagnosed or suspected, a couple can discuss all their options with their health care provider. They can plan for delivery in a specially equipped medical center so that the baby can have any surgery or treatment required soon after birth.

In a 1991 study supported by the March of Dimes, David B. Shurtleff, MD, and others at the University of Washington in Seattle, found that cesarean delivery before the onset of labor appeared to reduce the severity of paralysis in babies with spina bifida. If a baby is prenatally diagnosed with spina bifida, a woman can discuss with her health care provider the possibility of a planned cesarean.

In some cases, there is no clear-cut explanation for an abnormal test result. Abnormal results have been linked with pregnancy problems such as placental abruption (in which the placenta peels away from the uterine wall before delivery), preeclampsia (pregnancy-related high blood pressure), preterm labor, low birthweight, and fetal or infant death. If a woman has an unexplained abnormal maternal serum screening test result, her health care provider may monitor her carefully in the last trimester of pregnancy. She may need more frequent prenatal visits and various tests of fetal well-being, such as ultrasound.

Some women over age 35 may choose the maternal serum screening test to provide more information on their risk of having a baby with Down syndrome before deciding whether or not to proceed with amniocentesis. Because amniocentesis poses a small risk of miscarriage, some women choose to avoid the procedure. If the screening test shows that a woman is at low risk of Down syndrome, she may choose not to have amniocentesis. However, it is important to note that this approach does not guarantee that the baby will be free of chromosomal defects. Additionally, amniocentesis and CVS can diagnose or rule out many other chromosomal defects besides Down syndrome and trisomy 18. The screening test does not test for these additional chromosomal disorders, nor can it definitively diagnose or rule out Down syndrome or trisomy 18, as amniocentesis and CVS can.

Can maternal blood screening be done in the first trimester?
Several studies recently reported that a screening test done between 10 and 14 weeks of pregnancy may be as accurate as the maternal serum screening test done in the second trimester. The first-trimester blood test measures the levels of hCG and a substance called pregnancy-associated plasma protein A. An ultrasound examination of the fetal neck was done along with the blood test. This approach detected about 75 percent of fetuses with Down syndrome. When both the first- and second-trimester screening tests were done, more than 90 percent of affected fetuses were detected. Although promising, first-trimester screening is not yet the standard of care nor is it widely available in most parts of the country.

Women who receive abnormal results on a first-trimester screening test may be offered a prenatal test called chorionic villus sampling (CVS), which is done between 10 and 12 weeks of pregnancy. In this test, the health care provider inserts a thin tube through the vagina and cervix or through a needle in the abdomen to take a tiny tissue sample from outside the sac where the baby grows. Like amniocentesis, CVS is highly accurate in diagnosing or, far more likely, ruling out Down syndrome and other chromosomal birth defects.

not written by me.