An ultrasound is a technique used to create images and monitor information about a growing fetus inside a woman's womb. Traditional two-dimensional, or 2-D ultrasound can provide a variety of information about a baby, including age, heart rate, and potential birth defects. While these 2-D ultrasound images are informative to doctors, the grainy black-and-white images don't offer much of a view of the baby inside the mother's womb.
Technological advances have allowed for the creation of three- and four-dimensional, or 3-D and 4-D, ultrasound so expecting parents can get a detailed first look at their baby. Strictly elective, a 3-D or 4-D ultrasound does not replace a diagnostic ultrasound to evaluate the gestational age and anatomy of the fetus. This recent technology, however, may enhance the fetal-maternal bonding experience.
Benefits of 3-D Ultrasound
Parents may be able to watch the baby turn, yawn or suck on a tiny finger. With its real-time capabilities, 3-D and 4-D ultrasound helps to get a view of every one of the baby's movements.
Ultrasound in 3-D is just as safe as traditional 2-D ultrasound. In fact, it employs exactly the same sound waves to obtain images. The more advanced devices process the data in a more sophisticated way so each image contains more layers and provides a much fuller, more complete view of the baby.
Types of Ultrasound
There are distinct differences in the types of ultrasound used during pregnancy. In traditional 2-D ultrasound, the sound waves being sent straight down and reflected back. This will produce an outline and flat two-dimensional image of the fetus and internal organs. These are used in diagnostic settings, to examine the position and health of the fetus and mother.
In the 3-D ultrasound, however, sound waves are used to produce dimensional, external images of the fetus. In 4-D ultrasound, these images create a live video effect, which allows the parents to see the baby's body movements and facial expressions. This experience can be a valuable bonding experience between the expectant mother and baby.
In 3-D ultrasound, however, instead of the sound waves being sent straight down, they are sent at different angles. The returning echoes are received by a computer program and reconstructed into a 3-D image, in a similar way that a CT scan machine constructs a CT scan image from multiple X-rays.
The 3-D Ultrasound Procedure
A 3-D and 4-D ultrasound procedure may be performed in a physician's office or in a diagnostic imaging center by a radiologist. Typically, it is performed any time after 25 weeks of pregnancy. By that point, the baby's features are distinct. Ideally, it should be done before the final few weeks of pregnancy so the baby has room to turn, which provides a better variety of images. This is especially important if the baby is facing away from the ultrasound device. The patient is recommended to drink adequate water for one to two weeks before the procedure, in order to ensure the amniotic fluid is adequate and clear.
During the procedure, the technician will ask the patient to lay down and a special gel will be applied to her belly. This will aid the movement of the ultrasound waves. The technician will then hold the ultrasound probe against the belly in various positions and move it around to get an image. During the procedure, the patient and technician will see a two-dimensional image. The computer will produce the 3-D images or 4-D video for viewing and taking home. The procedure will last no more than 30 minutes.
Considerations and Risks of 3-D Ultrasound
The 3-D and 4-D ultrasound is an elective procedure. They are not widely available, and may not be covered by insurance. Three-dimensional ultrasound is not used to diagnose potential problems or issues with the baby.
There is a risk that the technician will not be able to produce a satisfactory image of the baby's face during the procedure, due to movement or the position of the baby. A secondary attempt at imaging may or may not be included in the cost of the procedure. It is best to discuss this possibility with the doctor prior to the appointment.
Little is known to date about the effects of ultrasound upon the health of the fetus. However, some experts are worried about the potential health risks to exposure of the extra ultrasound waves used in 3-D or 4-D imaging. There is some concern about placement of the ultrasound probe near the ears of the fetus, which may produce excessively high sound levels inside the womb. Any concerns about the ultrasound procedure should be discussed with the doctor.