Family Preparation

Congratulations on your pregnancy! Pregnancy is an exciting time, but it can also be filled with questions and concerns about the health of your developing baby. Most babies are born healthy. However there is always a small risk for genetic conditions to occur, regardless of age or family history. ClariTest, a non-invasive prenatal screen, can be an important step in building your family and can provide you with valuable information and peace of mind as you plan for your future.

  • ClariTest™ Non-Invasive Prenatal Screening
    • ClariTest™, a non-invasive prenatal screen, can be an important step in building your family and can provide you with valuable information and peace of mind as you plan for your future. ClariTest™ is a simple blood test that screens for the most common chromosome abnormalities caused by extra or missing genetic information in the baby’s DNA including Down syndrome, trisomy 18, trisomy 13, monosomy X, and certain microdeletions.
  • WHAT ARE CHROMOSOME ABNORMALITIES?
    • Chromosomes are structures found in our cells that carry our genetic information. Normally, we have 46 chromosomes in our cells, which come in pairs. We inherit 23 chromosomes from each parent. The chromosome pairs are numbered from 1 to 22. The 23rd pair is the sex chromosomes. Females generally have two X chromosomes and males generally have one X and one Y chromosome. Health and development problems can occur when there are extra or missing chromosomes or pieces of chromosomes.
  • MICRODELETIONS
    • The term “microdeletion” refers to a small missing piece of a chromosome. Some microdeletions are known to cause specific genetic syndromes with major health impacts to the baby, including intellectual disabilities, heart and other birth defects, immune system problems, trouble feeding, and other complications that may need immediate care upon birth. The chance of having a baby with a microdeletion syndrome does not increase with the age of the mother and is equal across all ages.
  • IS ClariTest™ RIGHT FOR ME?
    • This screening test is usually offered to pregnant women identified by their doctor to have an increased chance of a fetal chromosome abnormality. It may be an option for you to consider if you have a confirmed singleton or twin pregnancy of at least 10 weeks gestational age and meet any of the following criteria:
      • You are considered to be of advanced maternal age at time of delivery (35 years or older for a singleton pregnancy or 32 years or older for a twin pregnancy)
      • You have an abnormal or “positive” serum screen
      • Your ultrasound shows concerns or abnormalities with fetal growth and/or development
      • You have a personal or family history suggestive of trisomies 21, 18, 13, or other sex chromosome abnormalities
  • CONDITIONS SCREENED FOR IN ClariTest™
    • Today there are a number of genetic testing options available for expectant women and their healthcare providers. ClariTest may provide a clearer picture of chromosomal health—detecting even small abnormalities with a high degree performance, including a low false positive rate compared to other NIPTs, and the lowest test failure rate in the industry. ClariTest can have “false negative” or “false positive” results. Diagnostic tests, such as CVS and amniocentesis, provide definitive diagnostic information and are recommended to confirm any abnormal NIPT result.
  • MATERNAL SERUM SCREENING
    • Any pregnancy can be at risk for birth defects including those that are not inherited from a child’s parents. Conditions like Down syndrome, Open Neural Tube Defects (ONTD), and Trisomy 18 can affect any pregnancy, but a number of tests exist that can tell you the risk of one of these defects affecting your pregnancy and your child.
  • WHAT IS DOWN SYNDROME?
    • Down syndrome is the most common cause of severe mental disability, caused by an extra chromosome number 21 in a developing child’s cells. It is often associated with physical problems such as heart defects or difficulty with sight and hearing. It is usually not inherited, so a baby can be affected even if there is no history of Down syndrome in the family. In an unscreened population, about 1 in 700 (1.4 in 100) babies are affected by Down syndrome. There is no way to assess the degree of handicap before a child is born. About 9 of 10 babies with Down syndrome will survive their first year and nearly half of these will reach age 60.While a woman of any age can give birth to a baby with Down syndrome, the risk of having an affected child increases as the woman’s age increases. For this reason, age is one of the factors used in determining the risk of your pregnancy and whether you may be offered subsequent diagnostic testing following the results of your serum screening.
  • WHAT ARE OPEN NEURAL TUBE DEFECTS (ONTD)?
    • There are two main kinds of open neural tube defects (ONTDs): spina bifida and anencephaly. Open spina bifida is a defect where a baby has an opening in the spine that can cause damage to the nerves that control the lower part of the body. This can cause weakness or paralysis of the legs, as well as bowel and bladder problems.Closed spina bifidais a defect where the spinal opening is covered with skin or thick tissue. This accounts for about one in five babies born with spina bifida. While closed spina bifida cannot be detected by blood tests, the condition is often less severe than open spina bifida.Babies with spina bifida are more likely to suffer from a condition called hydrocephalus, where fluid collects on the brain. This condition can potentially lead to mental disability, but it can be treated surgically.
      Anencephaly is a defect that is nearly always fatal. Babies born with this condition have a large part of their skull missing, and their brain is not properly formed.
  • CAN OTHER ABNORMALITIES BE IDENTIFIED?
    • The risk of two other disorders can be estimated through maternal serum testing.Trisomy 18is a rare and usually fatal disorder caused by an extra chromosome 18 in the cells of a developing baby. The risk of Trisomy 18 can be estimated using PAPP-A, AFP, uE3 and total ß-hCG.Smith-Lemli-Opitz syndrome(SLOS) is a genetic disorder that may cause developmental problems in a baby including mental retardation and poor growth. SLOS is caused by errors in how the baby synthesizes cholesterol. The risk of SLOS can be estimated using AFP, uE3 and total ß-hCG.The results of Trisomy 18 and SLOS testing are reported only if the risk of a disorder is high.
  • WHAT DOES A SCREEN POSITIVE RESULT FOR DOWN SYNDROME MEAN?
    • A screen positive result means that you are at high risk for having a baby with Down syndrome. If you receive a screen positive result, you will be offered genetic counseling, and you will be given the option of diagnostic testing like CVS or amniocentesis to determine whether baby has Down syndrome. A result is called screen positive if the risk of Down syndrome in your pregnancy is greater than or equal to a threshold value as determined by the type of serum test:
      Combined First Test – 1 in 200
      Quad Test – 1 in 270
      Integrated Test – 1 in 190
      Serum Integrated Test – 1 in 270
      Sequential Test (first trimester testing only) – 1 in 30
      Sequential Test (first and second trimester testing) – 1 in 200

      Note that a screen positive result does not necessarily mean that your baby will have Down syndrome. Most women with screen positive results do not have a pregnancy with Down syndrome.

  • WHAT DOES A SCREEN POSITIVE RESULT FOR OPEN NEURAL TUBE DEFECTS MEAN?
    • A screen positive result means that you have an increased risk of having a baby with an open neural tube defect. If you receive a screen positive result, you will be offered genetic counseling, as well as an ultrasound scan examination at 18 to 20 weeks of pregnancy and the option of an amniocentesis. These tests will be organized by your doctor.
  • WHAT DOES A SCREEN NEGATIVE RESULT MEAN?
    • If the risk of Down syndrome is below the threshold risk level for the screening test, then the result is called screen negative and a diagnostic test will not be offered.Although a screen negative means that you are not at high risk of having a baby with Down syndrome or an open neural tube defect, a screen negative result does not completely rule out the possibility of a pregnancy with either of these abnormalities. This is because a screening test cannot completely distinguish an affected pregnancy than an unaffected one.
  • WHAT IS CHORIONIC VILLUS SAMPLING (CVS)?
    • If you receive a screen positive result in the first trimester, you may be offered chorionic villus sampling (CVS), a procedure where a small amount of placental material is extracted to provide a sample of genetic material from the fetus. If the test is performed between 10 and 12 weeks into the pregnancy, it can be performed either transcervically or transabdominally. If the test is performed after 12 weeks, however, it must be performed transabdominally.There is a small risk of miscarriage associated with CVS (less than one percent of women have a miscarriage as a result of the procedure.) Test results are usually available in five to seven days with a detection rate greater than 99% for chromosomal abnormalities like Down syndrome and Trisomy 18. Follow-up evaluation to rule out increased risk for open neural tube defects is indicated after 15 weeks.
  • WHAT IS AMNIOCENTESIS?
    • Amniocentesis is a second trimester procedure where a doctor obtains a sample of the amniotic fluid that surrounds a developing fetus for laboratory testing. The sample can be used to diagnose chromosomal abnormalities like Down syndrome and Trisomy 18 as well as open neural tube defects.Amniocentesis is an invasive procedure, and there is a small risk of miscarriage (less than 1 in 200) associated with it. While no test can guarantee that your baby will be free of birth defects, a negative result on your amniocentesis will almost certainly rule out chromosomal abnormalities like Down syndrome and Trisomy 18.
  • WHAT ARE THE ADVANTAGES OF RISK ASSESSMENT?
    • Maternal serum screening and risk assessment provide you and your doctor important information about your pregnancy and your developing baby. If your baby is found to have a serious birth defect, counseling will be offered to explain how your child’s physical and mental development will be affected. You may wish to discuss the individual capabilities and potential of children with birth defects with your doctor or genetic counselor. They will be able to discuss different options available to you and your partner.