Glossary of Terms

Maternal-Fetal Medicine Consultation: This is a discussion visit with the maternal-fetal medicine (MFM) doctor. The doctor will review your medical and pregnancy history and make recommendations for your care. If you are pregnant, the consultation may include having an ultrasound.

Genetic Counseling Consultation: This is a discussion visit with the genetic counselor. The genetic counselor will review your family, medical and pregnancy history. Based on this information, the genetic counselor will explain what genetic tests are available to you and help you decide if you want to have any testing. If you have had a genetic test ordered through your referring doctor’s office, the genetic counselor will review the results with you and offer additional testing, if indicated.

Genetic Screening Tests

First Trimester Screen or Nuchal translucency (NT) Screen: Includes an ultrasound measurement of the back of the baby’s neck AND measurement of pregnancy hormone levels in your blood. This screening test can be done between 11 and 14 weeks after the last menstrual period. The results indicate whether the baby is at higher or lower chance for having Down syndrome, trisomy 18, or trisomy 13. (The result is not 100 percent accurate. An abnormal or high risk result means that you should consider diagnostic genetic testing to get more information. A normal or low risk result is reassuring, but there is still a chance the baby could have one of the conditions listed above). Results are usually available in two to three days.

AFP Tetra Screen: Blood is drawn from your arm at 15 to 21 weeks after the last menstrual period to measure pregnancy hormone levels. The results indicate whether the baby is at higher or lower chance for having spina bifida, Down syndrome or trisomy 18. (The result is not 100 percent accurate. An abnormal or high risk result means that you should consider diagnostic genetic testing to get more information. A normal or low risk result is reassuring, but there is still a chance the baby could have one of the conditions listed above). Results are usually available in two to three days.

Cell-Free DNA Screening or Non-Invasive Prenatal Screening (NIPS): Blood is drawn from your arm as early as 10 weeks after the last menstrual period to measure the amount of DNA fragments in a sample of your blood. Some of the DNA is maternal (yours) and some of the DNA is fetal (the baby’s). The results indicate whether the baby is at higher or lower chance for having Down syndrome, trisomy 18 and trisomy 13. Screening for fetal gender, and sometimes other chromosome conditions, can also be done through this test. (The result is not 100 percent accurate. An abnormal or high risk result means that you should consider diagnostic genetic testing to get more information. A normal or low risk result is reassuring, but there is still a chance the baby could have one of the conditions listed above). Results are usually available in eight to 10 days.

Carrier Screening: Blood is drawn from your arm to determine if you are more likely or less likely to be a carrier of an inherited condition. In most cases, carrier screening is checking for conditions that are inherited in an autosomal recessive way. These are conditions that result when a person inherits one gene for the condition from his/her mother and another gene for the condition from his/her father. Carriers themselves do not have any symptoms of the condition, but the children of two carrier parents are at risk for being affected with the condition. Some inherited conditions are more common in certain ethnic groups. For example, cystic fibrosis is more common in Caucasians, sickle cell anemia is more common in African-Americans, and thalassemia is more common in Asians. Results are usually available in one to two weeks.

Diagnostic Genetic Tests

Chromosome Testing: Determines whether there are extra or missing chromosomes, or rearrangements between chromosomes. Chromosomes are the packages of genetic information (DNA) that we inherit from our parents. Typically, each of us should have a total of 46 chromosomes in every cell of our body. Medical problems, birth defects and/or mental retardation can occur when there is an extra or missing chromosome, or when there is an extra or missing piece of chromosome. One of the most common conditions caused by having an extra chromosome is Down syndrome, also known as trisomy 21. Chromosome testing of a fetus is accomplished through CVS or amniocentesis. Results are usually available in 10 to 14 days. Chromosome testing through a blood sample is also available for couples who have had several pregnancy losses.

FISH (fluorescence in situ hybridization) Testing: Checks for certain chromosome conditions. Most often, the test is ordered to check for Down syndrome (trisomy 21), trisomy 18 and trisomy 13 and conditions caused by extra or missing X and Y chromosomes, such as 45,X (also known as Turner syndrome). FISH testing of a fetus is accomplished through CVS or amniocentesis. The result is usually available in two to three days, and it is considered to be preliminary. A final result is usually available seven to 10 days later.

Microarray Analysis: A deeper level chromosome test that checks for extra or missing pieces of chromosomes that cannot be detected by routine chromosome testing. This testing is typically offered in situations when routine chromosome testing may not offer as much information as is desired. Microarray analysis of a fetus is accomplished through CVS or amniocentesis. Results can take five to seven days or up to two to three weeks, depending on the situation.

DNA Testing: Checks for changes in the DNA sequence of a particular gene or set of genes. This testing is necessary for conditions caused by mutations within a particular gene, such as cystic fibrosis or muscular dystrophy. DNA testing of a fetus is accomplished through CVS or amniocentesis. The timing of results varies.

Sonogram (Ultrasound)

Comprehensive/Targeted Sonogram: Provides a detailed look at a baby’s organ development and growth. The clarity of the ultrasound pictures depends on how many weeks pregnant you are and other factors, such as your weight and how much amniotic fluid is around the baby. Ultrasound is not capable of detecting all birth defects and/or all genetic conditions.

3D/4D Sonogram: Sometimes, special techniques using 3D sonography may be helpful in visualizing certain birth defects or parts of the baby that may otherwise be difficult to see. Examples include facial abnormalities, abnormalities of the hands and fingers, as well as certain types of brain and heart abnormalities.

Fetal Echocardiogram (Fetal Echo): A specialized targeted evaluation of a baby’s heart. Not all heart defects can be detected with sonography, however a fetal echocardiogram provides the best chance of finding an abnormality if one is present. Certain babies have a greater chance of having a heart defect. Your doctor will recommend a fetal echocardiogram if your baby is at risk of a heart defect.

Procedures

Chorionic Villus Sampling (CVS): A procedure where a small sample of tissue (chorionic villi) is removed from the developing placenta for genetic testing. CVS is performed between the 10th and 13th week after the last menstrual period. There are two ways to perform CVS: transcervically (through the cervix) and transabdominally (through the abdomen). The cells of the chorionic villi are used for chromosome testing and/or other genetic testing you choose to have based on your particular needs. Chromosome results are usually available within 10 to 14 days after CVS. The timing of results of DNA or other testing performed in cooperating laboratories may be different. The risk for complications that could lead to pregnancy loss (miscarriage) after CVS is considered to be about 1 in 370 (0.27%).

Amniocentesis: A procedure in which a needle is inserted through your abdomen and uterus to obtain a sample of amniotic fluid. Various tests can be performed through amniocentesis. Amniocentesis for genetic testing is most commonly performed between 15 and 20 weeks after the last menstrual period. The cells in the amniotic fluid are used for chromosome testing and/or other genetic testing you choose to have based on your particular needs. Chromosome results are usually available within 10 to 14 days after the amniocentesis. The timing of results of DNA or other testing performed in cooperating laboratories may be different. The risk for complications that could lead to pregnancy loss (miscarriage) after amniocentesis is considered to be about 1 in 370 (0.27%).

Cordocentesis/In Utero Transfusion: A therapeutic or diagnostic procedure where blood is obtained from the umbilical cord (cordocentesis). Using ultrasound for guidance, a thin needle is inserted by the MFM doctor through your uterus and into the baby’s umbilical cord. This procedure is most often performed when fetal anemia is suspected and if anemia is confirmed, a blood transfusion for the baby can be performed (in utero transfusion).

Amnioreduction: A therapeutic procedure to remove extra amniotic fluid in cases of polyhydramnios (when too much amniotic fluid has accumulated around the baby). Polyhydramnios can develop for a variety of reasons. When it does develop, it increases the risk for premature labor and delivery. Using ultrasound for guidance, a thin needle is inserted by the MFM doctor through your uterus and into the amniotic fluid to remove some of the fluid.

SIS (Saline Infused Sonohysterography): A procedure performed when you are not pregnant. Fluid is put into the uterus through the cervix during a transvaginal sonogram. This allows the endometrium (lining of the uterus) and uterine cavity to be better visualized. This technique can aid in the detection of abnormalities in how the uterus formed (such as bicornuate or septated uterus) or abnormalities within the uterus (such as fibroids, polyps or adhesions).

Dilation & Curettage (D&C) or Dilation & Evacuation (D&E): A therapeutic procedure to remove a pregnancy from the uterus or the remnants of a completed pregnancy. In the first trimester or after delivery, the procedure is called a D&C. In the 2nd trimester, the procedure is called a D&E. The procedure is usually done with the guidance of ultrasound. It is offered for fetal and/or maternal medical indications.

Selective Reduction: A procedure to improve the chances of delivering a healthy baby in certain types of multiple gestations (twins, triplets, or higher order multiples).

Antepartum Testing

BPP (Biophysical Profile): A biophysical profile or BPP is a well-being assessment of your baby using sonography performed in the third trimester. It involves an assessment of certain types of fetal body movements and behaviors as well as the amount of amniotic fluid around the baby.

Doppler: A specialized study using sonography to evaluate the flow of blood through certain blood vessels. During pregnancy, Doppler assessment is commonly performed on the umbilical cord, but assessments are also performed on blood vessels inside the baby’s body. Sometimes, Doppler assessments are done in conjunction with a biophysical profile.

NST (Non-Stress Test): A test to assess the well-being of the fetus. Fetal heart rate and uterine contractions are monitored for at least 20 minutes. The goal of the test is to identify fetuses at risk for intrauterine death or neonatal complications and intervene to prevent these adverse outcomes.

CST (Contraction Stress Test): A test to assess the well-being of the fetus. While the fetal heart rate and uterine contractions are monitored, contractions are induced to determine the response of the fetal heart rate.

Fetal Lung Maturity Testing: Performed on a sample of amniotic fluid obtained through amniocentesis to determine if a baby’s lungs are ready to support the baby outside of the womb. This test is used to help decide about timing of delivery when early delivery is being considered.