DEFINITION OF ULTRASOUND
Ultrasound is a screening device used to view the fetus during gravidity. It is also called sonogram, and it has been used for many purposes such as underwater navigation for submarines since World War I. Physical therapists have relied on ultrasound since the 1940s for its heating effects which can alleviate inflammation, incite local blood flow and breakdown scar tissue. Since the 1960s, ultrasound has substituted for X-rays as the first method of fetal imaging in pregnancy. We now know X-rays are considered fatal to the fetus and are seldom used during pregnancy. Primarily, ultrasound was a screening device to look for high risk conditions. However now it has become a routine and commonly done test during pregnancy.
Ultrasound is an ultra-high frequency sound wave which generates an image to view the fetus in uterus. The sound waves are above the range of human hearing. From a transducer or a probe put deep within the vagina (in early gravidity) or on the surface of the abdomen (second and third trimesters), sound waves are emitted at millions of cycles per second. A pattern of echo waves creates an image from a variety of oversides from fluid and soft tissues to a boney skeleton. Contemporary ultrasound energy degree of strength is higher than compared to earlier decades. The following ultrasound and energy exposures are used in obstetrics:
- Standard Scan: The standard scan is applied on the abdominal part after early pregnancy. Provides a brief pulse ultrasound of lower exposure.
- Trans Vaginal Ultrasound: Used in early pregnancy. In which the exposure levels is at its peak due to close proximity of probe to early developing fetus. .Uncomfortable procedure commonly known by some women as “diagnostic rape”.
- Doppler Ultrasound: Mostly used by many obstetricians and midwives because it provides relatively minimal exposure level.
- Fetal Monitors: Applied in late gestation and during labor to monitor baby and heart level. High level of exposure.
- 3-D Ultrasound: To generate 3-D images of the developing fetus.
- 4-D or Dynamic 3-D Ultrasound: Uses specially designed scanners to look at the face and movements of the baby.
- Fetal Echocardiography: Uses ultrasound waves to check the baby’s heart in suspected congenital heart defects (CHDs).
• Confirm early pregnancy using a vaginal ultrasound.
• Detect multiple births.
• Assess due date through measurements of fetus’ skull, femur, or crown-rump length (CRL) (done in second trimester).
• Inspect fetal organs for growth and development.
• Verify fetal position and breech presentation.
• Inspect the placenta and placement.
• Many expectant parents are happy to see the ultrasound including the 4D sonogram technology that makes it possible to clearly see a baby close up.
Risks of Ultrasound
• “The long term effects of concurrent ultrasound exposures on the fetus are not fully aware of. It is proposed that ultrasound only be used if medically indicated.” (American Pregnancy Association)
• Leads to worry and stress for parents who are given abnormal results or false positive findings.
• Ultrasound heats the tissue and researchers think that the waves lead to formation of small local gas pockets which vibrate and collapse known as cavitation.
• Studies done on animal (mice) have shown intestinal bleeding caused by changes in the cells. Scientists concur to that there would be similar effects in humans.
• The following abnormalities has been linked to ultrasound; – early labor, preterm birth, miscarriage, low birth weight, poorer health at birth, increased learning disabilities, epilepsy, delayed speech development, dyslexia and perinatal death.
However these associated risks are negligible.
NOTE: The use of ultrasound in monitoring stimulated cycles in fertility treatment and pregnancy is safe and highly important, as emphasized by a recent research finding.