Obstetric ultrasound (including comprehensive ultrasound evaluations of fetal anatomy and prenatal genetic diagnosis) and gynecologic evaluations at Barnes-Jewish Hospital are provided by the Division of Genetics, Maternal-Fetal Medicine and Ultrasound at Washington University School of Medicine. State-of-the-art ultrasound equipment and the latest diagnostic techniques are employed to provide both. Patient care is provided in the Ultrasound/Genetics Unit by a team of board-certified physicians, sonographers and genetic counselors.
Because the quality of ultrasound examination is highly dependent upon operator experience, patients may be assured that all physicians and sonographers working in the Ultrasound/Genetics Unit are highly experienced in providing obstetric and gynecologic ultrasound services.
Approximately 75 percent of patients are referred to the Ultrasound/Genetics Unit at Washington University for obstetric evaluations; the remaining 25 percent of patients are referred for gynecological ultrasound scans.
The Ultrasound/Genetics Unit provides both ultrasound evaluation of fetal anatomy and prenatal genetic diagnosis.
Women with uncomplicated pregnancies may be referred to Ultrasound/Genetics between the 16th and 20th week of pregnancy for routine evaluation of fetal anatomy. Many structural birth defects can be identified using ultrasound examination during the mid-trimester of pregnancy. Women who exhibit symptoms (such as bleeding) that suggest a possible complication with their pregnancy also are referred to Washington University for ultrasound evaluation. A sonographer will perform a complete ultrasound evaluation; a physician will then review these films and perform complex studies as medically indicated.
PRENATAL GENETIC DIAGNOSIS
Prenatal genetic diagnosis is generally offered to the following groups of patients:
- Women who will be 35 or older at delivery.
- Couples who previously have had a child with a chromosomal abnormality.
- Couples who are known carriers of a chromosome translocation.
- Women who are carriers for sex-linked disease such as hemophilia or muscular dystrophy.
- Couples who are known carriers or who are members of at-risk populations to be carriers of certain hereditary disorders (such as Sickle Cell Anemia in the African-American community or Tay-Sachs disease in the Jewish population).
- Couples with a family history of neural tube defects such as spina bifida, anencephaly or encephalocele (birth defects involving the brain or spinal cord).
- Couples who previously had or are at risk to have children with certain structural birth defects that may be detected by diagnostic ultrasound.
- Women who have had an abnormal maternal serum screen (alpha-fetoprotein +/- additional biochemical markers)
- Women with prenatal exposure to certain medications, drugs or certain viruses.
Patients will be asked to complete a medical questionnaire, including a family history, in order to evaluate their risk of genetic abnormalities in pregnancy. Genetic counselors are available to help families assess these risks.
If problems are identified through testing, we coordinate care for the patient and work closely with pediatric sub-specialists and neonatologists at St. Louis Children's Hospital. Patients are counseled prenatally and can tour the neonatal intensive care unit (NICU) so they know what to expect. Our goal is to keep the patient as informed as possible.
Barnes-Jewish Hospital obstetricians and sonographers are some of the most experienced teams in the region. Each year, we perform more than 15,000 obstetrical and gynecological ultrasounds. Our sonographers and obstetricians focus exclusively on obstetrical ultrasound. The quality from a prenatal ultrasound depends upon the expertise of the health-care professional. Expertise and experience matter the most to be able to detect the majority of malformations.
Washington University physicians are skilled in performing both genetic amniocentesis and chorionic villus sampling (CVS). We perform more than 1,000 genetic amniocentesis and first trimester chorionic villus (CVS) sampling procedures each year. These tests may detect certain birth defects and genetic disorders during early pregnancy. Such conditions include chromosome abnormalities such as Down Syndrome, neural tube defects such as spina bifida (open spine), and hereditary disorders such as Tay-Sachs disease and sickle cell disease.
A physician performs genetic amniocentesis by passing a thin needle through the mother's abdominal wall and into the amniotic sac under ultrasound guidance. A small amount of amniotic fluid then is withdrawn. This fluid contains cells that have been shed from the fetal skin surface, which may be used to detect certain genetic disorders. Amniocentesis and ultrasound studies are performed on an outpatient basis, usually between the 15th and 17th week of pregnancy.
Cells from the amniotic fluid sample are grown in a laboratory culture with cytogenetic results, usually available within 14 days.
CHORIONIC VILLUS SAMPLING
Chorionic villus sampling (CVS) allows prenatal diagnosis of certain genetic disorders during the first trimester of pregnancy. Chorionic villus (placental) tissue originates from the same cells that form the fetus, and usually reflects fetal genetic constitution. In CVS, a physician passes a very small catheter through the woman's cervix and beneath the placenta under ultrasound guidance. A small amount of villus tissue is then suctioned from the placenta.
Washington University physicians are highly skilled and experienced in performing CVS, which has been offered by the university for more than a decade.
CVS is performed on an outpatient basis 10 to 12 weeks following the start of the last normal menstrual period. The chorionic villus sample is delivered to the laboratory, where it undergoes microscopic analysis of cultured villus cells. Cytogenetic results usually are available within eight days.
NON-CHROMOSOMAL GENETIC DISORDERS
Diagnostic testing for certain non-chromosome disorders, such as Tay-Sachs disease or sickle cell anemia, must be performed in Washington University's highly specialized laboratories. Depending upon the test performed, results will be available one to six weeks following testing.
In most cases, prenatal diagnosis provides reassurance about fetal health. If, however, a serious abnormality is detected, this information will be conveyed to the patient and referring physician with an assessment of the severity of handicap involved. Reproductive options, including medical treatment or termination of pregnancy, are discussed fully, with no bias or persuasion.
Talk to your physician for a referral to the Washington University Maternal-Fetal Medicine and Ultrasound specialists at Barnes-Jewish Hospital.