What are Ultrasound Scans?
Ultrasound scans were introduced in the late 1950′s and are used for diagnosing in obstetrics and examining body organs such as the heart, liver and kidneys. Ultrasound scans are images of the internal organs made from sound waves. The information gathered from the reflections are brought back into a picture on the monitor. Movements are detected and measurements can be made from the images on the screen. Gestational age, fetal heart beat, and growth size can all be determined from an ultrasound scan.
Why and when is Ultrasound used in A Pregnancy?
An ultrasound is used to diagnose an early pregnancy. A gestational sac can be seen as early as four and a half weeks of gestation and the yolk sac can be seen around five weeks. Around five and a half weeks, measurements can be taken of the embryo. If vaginal bleeding is present in an early pregnancy, an ultrasound can be used to detect a fetal heart beat around 6 weeks. A blighted ovum can also be detected by an ultrasound, which is an empty sac with no fetal pole or heart. Ultrasounds can determine fetal age, especially early in a pregnancy. Ultrasounds help predict the gestational age of the fetus for women who are unsure of when their last menstrual cycle was. An ultrasound locates where the placenta is in the womb. This is important because there are many abnormalities that can occur with the placenta. For example, placenta previa and intrauterine growth retardation. An ultrasound can detect the amount of amniotic fluid inside the uterus. Excessive or decreased amounts of fluid can both cause a problem to the pregnancy.
What are 3-D and 4-D Ultrasounds?
A 3-D ultrasound gives 3 dimensional images of what is being scanned. Images are taken and sliced, then the computer interprets the images given as 3 dimensional. With computer controls, the operator can obtain views that might not be as clear as a 2-D ultrasound scan. Measurements are more correct and there is more of a psychological bond formed with the parents and baby. 3-D ultrasounds have been used to detect cleft lips, fetal cardiac problems, and chromosomal abnormalities. Recently, 4-D scanners have become the new attraction in the market. It can capture the facial movement of a baby. Experts agree that 3-D and 4-D ultrasounds are not necessary and that a 2-D scan is still suitable for diagnosing.
Are Ultrasounds Safe?
Different from x-rays, ultrasounds do not give off any ionizing irradiation or embryo toxic effects. High intensity ultrasounds coincide with the effects of cavitation and heating. Studies done in a laboratory setting show no abnormalities in embryos from the use of diagnostic ultrasounds. Smaller studies in Europe have shown some ill-effects such as speech and hearing problems as well as low birth weight.