Center for Genetics & Maternal-Fetal Medicine

FAQs

What is genetic counseling?

Genetic counseling is a process by which a specialist works with women and their families who have a significant medical and/or pregnancy history for birth defects or genetic conditions. This process involves imparting information to you and facilitating your decisions about reproductive options and preventive strategies. The family, medical and pregnancy histories are reviewed. Then the tests that are appropriate are discussed in detail including: the benefits, the limitations, and the potential risks of all procedures. If it is helpful, we also recommend support groups, and assist in referring to other specialists.
Who should consider genetic counseling and/or prenatal diagnosis?

  • Women 35 years of age or older, since the risk of chromosome abnormalities increases with the mother's age.
  • Parents who have had a child with a chromosome abnormality such as Down Syndrome, or a neural tube defect (such as spina bifida or anencephaly).
  • Women who have had a positive maternal serum screening test (AFP or Triple Marker Test) result for a neural tube defect, Down syndrome, or Trisomy 18.
  • Parents who have a family history of a genetic condition such as some forms of mental retardation, cystic fibrosis, sickle cell anemia, muscular dystrophy, tay sachs or other conditions that are rare.
  • Families in which one parent has a chromosome rearrangement.
  • Couples with a history of multiple pregnancy losses.
  • In certain situations, women with exposures to medications, drugs, infections, or women with certain chronic illnesses.
What is Prenatal Diagnosis?

Prenatal diagnosis is the process of detecting certain types of birth defects and inherited disorders before a baby is born.
What tests are included in prenatal diagnosis?

Ultrasound: This test uses sound waves to create a picture of the unborn baby on a special screen. This picture is called a sonogram. It provides useful information about the pregnancy, such as: Size of the unborn baby (which correlates to age); position of the unborn baby; Presence of twins (or more); and presence of some physical defects.

Ultrasound testing has been done on millions of pregnant women without any known harm to the mother or the baby. No radiation is involved.

Screening Tests (first and second trimester): These tests are used to obtain an educated guess as to whether or not a baby has a specific condition. Some women will receive an increased risk and some women will receive a decreased risk. In other words, these tests do not determine exactly which babies do or do not have one of the following birth defects: Down syndrome, spina bifida, or Trisomy 18. In summary, a screening test narrows down the number of pregnancies that need more extensivetesting.

Amniocentesis: After locating a safe area by ultrasound, a thin needle can be inserted through the woman’s abdomen into the uterus while watching with ultrasound. A small amount of the fluid around the fetus is taken out. The fluid and the cells in the fluid are sent to a laboratory for analysis.

Chorionic Villi Sampling (CVS): After locating the placenta and the fetus with ultrasound, a catheter is inserted through the woman’s vagina and cervix or a thin needle is inserted through the woman’s abdomen to obtain a sample of the placenta so the fetal chromosomes can be examined.
When can the tests be done in the pregnancy?

Ultrasound: Anytime in pregnancy. The age of the pregnancy significantly determines the information that can be learned from the exam.

Screening Tests: Between 15 and 20 weeks.

Early Amniocentesis: Between 12 and 14 weeks.

Routine Amniocentesis: From 15 weeks on.

Chorionic Villi Sampling: Between 10 and 12 weeks.
What birth defects can be found by these tests?

Structural Defects: Ultrasound can find some physical birth defects depending on the size, age, and position of the baby.

Chromosomal Disorders: Chromosomes are packages of genes that pass certain characteristics from parents to their children. When there are too many chromosomes, too few chromosomes, or there is a defect in a chromosome, birth defects usually occur. Down syndrome is the most common disorder, causing mental retardation and other health problems, such as heart defects. Other less common chromosomal disorders can lead to serious handicaps and sometimes death.

Neural Tube Defects: These are defects in the spine or the skull of the fetus.
  • If the defect is an opening in the bones of the spine, it is called spina bifida. Most infants born with spina bifida will have some or all of the following lifelong problems: weak or paralyzed legs, problems with bladder and bowel control, bladder and kidney infections, and sometimes mental retardation.
  • If part of the skull is missing, the brain is not formed properly. This condition is called anencephaly. Babies with anencephaly die before or soon after birth.
Other Inherited Conditions: There are additional tests that can be performed with amniotic fluid for a variety of inherited medical conditions. An example is muscular dystrophy. These special tests are recommended only when there is a specific family history. The specialist in the center can help determine if there is an increased risk for a birth defect by reviewing the family and pregnancy histories.

What are birth defects?

Birth defects are abnormalities in a baby that may produce mental or physical problems after the baby is born. The problems can be mild, moderate, or severe. Babies with birth defects may have minimal problems or may be mentally retarded, physically handicapped, or otherwise disabled. The purpose of genetic screening is to provide the parents with information to prepare for and deal with the potential problems.
Are there any special instructions?

Before the genetic counseling appointment, it would be helpful for you to find out as much about your family history as possible.

On the day of the ultrasound, CVS and/or amniocentesis procedure, it would be best to wear a two piece outfit. You DO NOT need to have a full bladder and you can eat normally before your appointment.
Are there risks from CVS or Amniocentesis?

These are relatively safe procedures. Currently, the risks are believed to be low enough to warrant their use for the types of family situations listed above. There will be full counseling regarding specific risks and complications during your session with us.
How long does it take to obtain chromosomal results?

A report of the chromosomal analysis generally takes 12-16 days. We choose to work with the laboratory with the highest quality standards so that all possible chromosomal disorders can be ruled out, not just Down syndrome. A longer time is sometimes necessary if the cell growth is slow, if the diagnosis involves biochemical testing, or if the cell cultures must be sent to other laboratories for specialized examination.
What happens if an abnormality is found?

You will be notified and given a full report of all of the findings from the tests. Our goal is to aid you and your care provider (physician and/or midwife) by providing information. All information is confidential.

The philosophy and principles of our center are non-judgmental and non-directive counseling. This means that we do not tell you what to do. We will explain to you all the information about the situation and explain all of your options. We support you and the decisions that you make.
Does the test guarantee a normal baby?

No. Even though an ultrasound examination and amniocentesis are the most complete testing available, they cannot detect all abnormalities that affect children. Many other disorders such as deafness, blindness, some heart defects, and some mental retardation cannot be determined before birth. However, the risk for each of these problems is low in the general population.