St. Luke’s Maternal Fetal Medicine

Genetic Counseling

What Are Genetic Counselors?
Genetic counselors are Master’s level, certified professionals who help you understand scientific, medical and genetic information relating to your family history, medical history and/or pregnancy. They help clarify the risks for occurrence or recurrence of a genetic or inherited disorder or condition in specified family members. They help patients and families make sense of complex options for testing and interventions and explain the results of diagnostic tests. Based on a genetic counselor’s risk assessment, individuals and families are able to make informed medical decisions in a supportive environment that affirms their personal cultural, religious and ethical beliefs.

In addition to providing education and support services to families with genetic concerns, genetic counselors are also involved in coordinating testing and connecting patients and families with national and community-based informational resources, including support groups and funding agencies.

Genetic Counseling Services at St. Luke’s
Genetic counseling services at St. Luke’s Maternal Fetal Medicine are provided by Heidi Nagel, MS, CGC and Jennifer Eichmeyer, MS. Both have extensive experience in addressing the complex educational and emotional needs of families in the face of a diagnosis or risk of occurrence of a genetic disorder or birth defect. Based on the nature of our practice, the majority of the patients seen for genetic counseling at St. Luke’s Maternal Fetal Medicine are contemplating or undergoing pregnancy and have been referred by their primary care provider for discussion of risks to their unborn baby and diagnostic testing or screening options.

Is Genetic Counseling for You?
Your doctor may refer you to see a genetic counselor at St. Luke’s Maternal Fetal Medicine if:

• You are 35 years of age or older and considering a pregnancy or currently pregnant.
• You have had a previous child with mental retardation, an inherited disorder or a birth defect.
• You or your partner have, or are concerned that you may have, an inherited disorder or birth defect.
• You have had two or more miscarriages or babies who died in infancy and are pregnant or considering pregnancy.
• You are concerned that your job, lifestyle or medical history may pose a risk to a pregnancy (i.e. due to chemical, radiation, drug or medication exposure).
• You and your partner are related (i.e. first cousins).
• You would like information or testing regarding genetic defects occurring more frequently in your ethnic group.
• You have been told that your pregnancy may be at increased risk for complications or birth defects based on results of tests such as the multiple marker blood test (“triple” or “quad” screen) or an ultrasound test.

If You Are Pregnant: Testing for Genetic Abnormalities
During your pregnancy, your health care professional may offer you prenatal tests to gain information and reassurance regarding the health of your baby. Certain screening tests, such as the maternal serum multiple marker screen are routinely offered to all pregnant women between their 15th and 18th week of pregnancy. This test can determine the level of risk in a given pregnancy for a variety of adverse outcomes, such as Down syndrome, spina bifida, and a severe chromosome abnormality called trisomy 18. Based on results of this test, further diagnostic testing, such as amniocentesis, may be recommended.

Most doctors will also perform an ultrasound evaluation to measure the baby’s growth and check amniotic fluid levels, as well as to screen for visible birth defects. At St. Luke’s Maternal Fetal Medicine, we offer high- resolution (level II) ultrasound, a detailed type of ultrasound evaluation which combines the imaging capabilities of our highly specialized equipment with evaluation and interpretation by our board-certified specialists in Maternal Fetal Medicine: Clarence Blea, MD; Stacy Seyb, MD and Michael Koszalka, MD. Ultrasounds may also be performed by a certified sonographer, in which case a physician reviews and interprets the results. Depending on the results of ultrasound tests, further testing may be recommended.

In certain cases, invasive diagnostic testing is offered during pregnancy, if the pregnancy is determined to be at reasonably elevated risk for an abnormality detectable through this type of testing. Examples of this kind of test include chorionic villus sampling (or “CVS”) and amniocentesis. Using specialized techniques, a small fetal tissue sample is collected, which can then be tested for chromosomal or other specific abnormalities. With CVS, a small piece of placenta is obtained for testing using a catheter inserted through the cervix (the lower part of the uterus). The cells of the placenta have the same chromosomal content as the baby's cells, so analysis of placental tissue can determine the chromosomal status of the fetus. Amniocentesis involves using a thin needle to collect a small amount of fluid from around the baby. This fluid contains skin cells of the baby, which can be tested for their chromosomal content. Analysis of amniotic fluid obtained through amniocentesis can also diagnose spina bifida in a fetus. In some cases, tissue samples obtained through CVS or amniocetesis may undergo other specialized tests.

Both CVS and amniocentesis offer highly accurate (greater than 99.9%) analysis of fetal chromosome makeup. Thus, conditions such as Down syndrome can be virtually ruled out. Amniocentesis will additionally detect up to 98% of cases of spina bifida. Due to the invasive nature of these tests, however, there is a small risk involved. If your doctor determines that CVS or amniocentesis may be appropriate for you, one of our genetic counselors can discuss the risks and benefits of these procedures with you in greater detail and assist you in locating an appropriately qualified practitioner to perform the procedure of your choice.

Even with normal prenatal testing results, there is a small chance that a baby will be born with problems. There are many birth defects, genetic conditions and other abnormalities that no prenatal testing method can detect. The background risk for fetal abnormalities not detectable through prenatal diagnosis is 3-5%.

Fetal Chromosome Abnormalities and Increased Maternal Age
It is now widely recognized that as a woman increases in age, her risk for a child with a chromosome abnormality, such as Down syndrome, increases. Down syndrome results when a fetus has an extra chromosome number 21. This results in three copies of chromosome 21 instead of the usual two. Another name for Down syndrome is “trisomy 21”. Down syndrome consists of a pattern of abnormalities including mental retardation, a characteristic physical appearance and medical problems (often including heart defects).

The risk for a child with Down syndrome increases with maternal age.

• A 20-year-old woman has about a one in 2000 chance of having a child with Down syndrome.
• At age 30, it is one in 952.
• By age 35, the chances increase to one in 385.
• At age 40, the risk is one in every 106 children.
• At 45, the chances are one in 30.

Prenatal tests such as amniocentesis can help rule out the presence of a chromosomal error, such as Down syndrome, early in pregnancy.

For information about genetic counseling, call:
Heidi L. Nagel, MS, CGC
Jennifer N. Eichmeyer, MS, CGC
(208) 381-3088

St. Luke’s Maternal Fetal Medicine
333 N. 1st Street, Suite 150
Boise, ID 83702
(208) 381-3088