![]() Donald, the physician who helped develop the technology, was a devout High Anglican, and knew the images carried moral significance for women contemplating having an abortion. Seeing a developing fetus has a humanizing effect, too. In fact, Nicolson said, some women report not feeling pregnant until they've seen the ultrasound image. "Overwhelmingly, pregnant women expect to be scanned, and are moved and excited by seeing the fetus," Nicolson said - especially if the baby moves. ![]() In addition to revealing the baby's health, the images themselves provide a keepsake. Ultrasound has enjoyed an enthusiastic reception by pregnant women. For example, so-called "bonding scans," images taken purely for commemorative purposes, unnecessarily expose a fetus to the high-energy sound waves, Nicolson said. He said that ultrasound scans should only be done for clinically justified reasons. Researchers don't know exactly at what level this occurs, Nicolson said, adding that testing the threshold at which it becomes dangerous in humans would be unethical. However, at high power, ultrasound waves are able to damage human tissue. No pattern of damage has been found," Nicolson said. "We can be confident that at the levels currently used for clinical investigation, ultrasound is safe. ![]() Concerns about its safety have periodically surfaced, but Nicolson said he thinks these stem more from anxiety over the role of technology in pregnancy than from evidence of harm. The procedure has been safely performed on millions of pregnant women. One of the main advantages of ultrasound is that it's noninvasive. "But gradually, with developing expertise, they could discern fine structures in the fetus," he said. Based on the angle of the beam, and the time it takes for echoes to return, an image of body structures inside the fetus can be generated.Įarly in the use of fetal ultrasound, clinicians could only detect the baby's head, Nicolson said. It's used to confirm a pregnancy, to identify the sex and number of fetuses and to detect fetal abnormalities such as microcephaly (an abnormally small head), absence of kidneys, and spinal problems.ĭuring a scan, ultrasound waves are aimed at a pregnant women's abdomen. Obstetric ultrasonography is used to image a human fetus inside its mother's womb. Ultrasound imaging involves bouncing "ultrasonic" sound waves - above the audible range of human hearing - at body structures or tissues, and detecting the echoes that bounce back. The technology has undergone extensive development over the past 20 years, Nicolson told LiveScience, but "has probably reached more or less the pinnacle of its acuity." By the end of the 20th century, ultrasound imaging had become routine in maternity clinics throughout the developed world.
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