There is a small risk associated with the CVS procedure. About 1 percent of women who have CVS will have a miscarriage as a result of the procedure. It depends on your particular result. If the test is screen positive for Down syndrome or at increased likelihood for trisomy 18 or Smith-Lemli-Opitz syndrome, an amniocentesis procedure will be offered, sometimes accompanied by a detailed ultrasound examination.
If the test is screen positive for open neural tube defects, a targeted ultrasound examination is most commonly offered, although amniocentesis is often suggested as well. An amniocentesis is a procedure in which the doctor obtains a small sample of fluid that surrounds the developing baby by passing a fine needle through the abdominal wall and into the uterus, under the guidance of an ultrasound scan. The sample is then sent for laboratory testing. This fluid sample can be used to diagnose chromosome problems like Down syndrome and trisomy An amniocentesis is an invasive procedure, which means that there is a small risk of miscarriage about one in associated with it.
Results of the test for Down syndrome and trisomy 18 usually take one to two weeks. FISH results usually take two days. Results for the test for open neural tube defects usually take five to seven days. Ultrasound machines use sound waves to look at the developing baby. This procedure, called sonography, is often used to check fetal age or whether more than one baby is present. Level II or targeted sonography will provide a detailed examination of portions of the baby's body. It cannot be used to diagnose Down syndrome or trisomy 18, but it can often identify spina bifida and various fetal abnormalities that are associated with Down syndrome or trisomy A genetic counselor will be available to discuss your baby's diagnosis in detail and the options available to you.
One option would be to continue the pregnancy and make arrangements for appropriate medical services at and after delivery. Placing the infant for adoption after birth can also be considered. Another option would be a termination of pregnancy. Find A Provider. In The News Media Relations. Site Search. Screening for Down Syndrome. What is Down syndrome?
What is the First Trimester Test? What does the First Trimester Test involve? What does the Integrated Test involve? Why wait until the second stage to have an estimate? What happens if the ultrasound examination shows that I am too late for the first stage of the test? What is the likelihood? The decision as to whether to have invasive genetic testing is up to you.
If a diagnostic test finds a genetic abnormality, the significance of such results should be discussed with experts familiar with the condition, including a medical geneticist and a genetic counselor, as well as your own doctor.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider.
We encourage you to discuss any questions or concerns you may have with your provider. Amniocentesis is a prenatal diagnostic test that can detect significant chromosome problems. Find frequently asked questions regarding Amniocentesis here. Screening is offered for eleven genetic disorders which are more common in individuals of Ashkenazi Jewish descent. Learn more and book an appointment here.
Cystic fibrosis CF is one of the most common life threatening genetic diseases, affecting approximately 1 out of 3, people. Find more info and FAQs here. Fragile X syndrome is the most common cause of inherited mental retardation, affecting approximately 1 in 3, males and 1 in 6, females.
Learn more here. Spinal muscular atrophy SMA is a genetic disease that results in progressive muscle weakness and paralysis. Learn more and find FAQs here. A common complaint of hearing aid users is difficulty using cell phones with their hearing aids. Find strategies to help with this common issue here.
Like amniocentesis, chorionic villus sampling CVS can detect significant chromosome problems, such as Down syndrome. The presence of isolated choroid plexus cysts CPCs on a second trimester ultrasound is a common cause of anxiety. Find frequently asked questions about CPCs. Commonly asked questions regarding Prenatal Tests including, types available, positive screenings, diagnostic testing, health insurance coverage, and more. Prenatal screening tests can identify women at high risk for having a baby with certain types of genetic disorders or birth defects.
Patient Education. Age-Related Risks Generally, the chance of having a Down syndrome birth is related to the mother's age. Causes of Down Syndrome There are three causes of Down syndrome: Trisomy 21 An estimated 95 percent of people with Down syndrome have trisomy 21, meaning they have three number 21 chromosomes instead of two.
Second trimester screening. These are blood tests that also look for certain substances in the mother's blood that may be a sign of Down syndrome. A triple screen test looks for three different substances. It is done between the 16th and 18th week of pregnancy. A quadruple screen test looks for four different substances and is done between the 15th and 20th week of pregnancy.
Your provider may order one or both of these tests. Down syndrome diagnostic tests done during pregnancy include: Amniocentesis , which takes a sample of amniotic fluid, the fluid that surrounds your unborn baby. It is usually done between the 15th and 20th week of pregnancy. Chorionic villus sampling CVS , which takes a sample from the placenta, the organ that nourishes your unborn baby in your uterus. It's usually done between the 10th and 13th week of pregnancy.
Percutaneous umbilical blood sampling PUBS , which takes a blood sample from the umbilical cord. PUBS gives the most accurate diagnosis of Down syndrome during pregnancy, but it can't be done until late in pregnancy, between the 18th and 22nd week. Down syndrome diagnosis after birth: Your baby may get a blood test that looks at his or her chromosomes.
What happens during Down syndrome testing? For amniocentesis: You'll lie on your back on an exam table. Your provider will move an ultrasound device over your abdomen. Ultrasound uses sound waves to check the position of your uterus, placenta, and baby. Your provider will insert a thin needle into your abdomen and withdraw a small amount of amniotic fluid.
For chorionic villus sampling CVS : You'll lie on your back on an exam table. Your provider will move an ultrasound device over your abdomen to check the position of your uterus, placenta, and baby.
Your provider will collect cells from the placenta in one of two ways: either through your cervix with a thin tube called a catheter, or with a thin needle through your abdomen. Your provider will move an ultrasound device over your abdomen to check the position of your uterus, placenta, baby, and umbilical cord. Your provider will insert a thin needle into the umbilical cord and withdraw a small blood sample. Will I need to do anything to prepare for the tests? Are there any risks to the tests?
People with Down's syndrome may be more likely to have other health conditions, such as heart conditions, and problems with the digestive system, hearing and vision. Sometimes these can be serious, but many can be treated. Read more about Down's syndrome. Sadly, most babies with Edwards' syndrome or Patau's syndrome will die before or shortly after birth. Some babies may survive to adulthood, but this is rare. All babies born with Edwards' syndrome or Patau's syndrome will have a wide range of problems, which can be very serious.
These may include major complications affecting their brain. Read more about Edwards' syndrome and Patau's syndrome. A screening test for Down's syndrome, Edwards' syndrome and Patau's syndrome is available between weeks 10 and 14 of pregnancy. It's called the combined test because it combines an ultrasound scan with a blood test. The blood test can be carried out at the same time as the week scan.
If you choose to have the test, you will have a blood sample taken. At the scan, the fluid at the back of the baby's neck is measured to determine the "nuchal translucency". Your age and the information from these 2 tests are used to work out the chance of the baby having Down's syndrome, Edwards' syndrome or Patau's syndrome. Obtaining a nuchal translucency measurement depends on the position of the baby and is not always possible. If this is the case, you will be offered a different blood screening test, called the quadruple test, when you're 14 to 20 weeks pregnant.
0コメント