Prenatal Imaging and Diagnosis
At the Center for Prenatal Pediatrics, we use state-of-the-art imaging machines with 2D and 3D capabilities in order to provide a complete spectrum of diagnostic imaging services required for all pregnancies.
- 2D ultrasound: A prenatal ultrasound uses high frequency sound waves to create an image of the uterus, placenta and fetus. An ultrasound can be performed throughout the entire pregnancy, however it is usually performed at specific times, such as in the first trimester (between 11 and 14 weeks) to obtain the nuchal translucency and accurate dating and in the second trimester (between 18 and 22 weeks) to survey the fetal anatomy. Depending on the purpose and timing in pregnancy of the ultrasound, it can take anywhere between 20 minutes to two hours. Ultrasound can be performed either abdominally or transvaginally and is safe during pregnancy.
- 3D and 4D ultrasound: Using similar technique and technology as with the 2D ultrasound, a 3D ultrasound can produce detailed images of the fetus similar to a photograph. This is particularly useful if certain/specific abnormalities are suspected. 4D ultrasound enables real-time 3D imagery of the fetus.
- Fetal echocardiography: Fetal echocardiography is a specialized ultrasound to evaluate the fetal heart. The images are interpreted by a specialist in congenital heart disease. As with prenatal ultrasound, imaging gel and the probe are applied to the mother’s abdomen. It is not painful and causes no harm to the baby. A fetal echocardiogram may require anywhere from 30 minutes to over two hours, depending on the complexity of the baby’s heart. Fetal echocardiograms can reliably be performed any time after 17 weeks; however, as technology progresses and with the use of transvaginal ultrasound, the ability to obtain images of the fetal heart as early as 13 weeks may be possible.
- MRI: A fetal MRI (magnetic resonance imaging) is a diagnostic technique. It manipulates magnetic fields to obtain views of the baby, its placenta, and the maternal uterus and body from many different angles. It can be especially useful for obtaining images of the fetal brain, chest, and abdomen. During an MRI, the mother must lay as still as possible on either her back or side. The study usually takes approximately 30-45 minutes. MRI during pregnancy is believed to be safe with no adverse risks on unborn babies. As the machine is a giant magnet, no metal objects are allowed inside of it.
Diagnosis and Screening
- Chorionic villus sampling (CVS): CVS is a prenatal test typically performed between 10 and 14 weeks of pregnancy. It is the withdrawal of a small amount of chorionic tissue (part of the placenta), by either a catheter through the cervix or a needle inserted into the abdomen. The procedure is performed under ultrasound guidance. CVS can detect chromosome abnormalities, such as aneuploidy, rearrangements, and major duplications/deletions, with 99.6 to 99.8 percent accuracy.
- Amniocentesis: Amniocentesis is typically performed between 15 and 23 weeks of pregnancy. In this procedure, a small amount of amniotic fluid (fluid surrounding the unborn baby) is withdrawn from the uterus by a thin needle through the abdomen. Like the CVS, the procedure is done under ultrasound guidance and can detect chromosome abnormalities, such as aneuploidy, large duplications or deletions, and large rearrangements, with 99.6 to 99.8 percent accuracy. The procedure can also detect open neural tube defects (spina bifida and anencephaly) and abdominal wall defects with approximately 95 percent accuracy.
To learn more about genetic testing at Columbia, visit the Women's Genetics division.