Mechanism
Ultrasound uses sound waves to get images of structures within the body. It is commonly used to visualize a fetus during pregnancy. Ultrasound creates the sound waves using a small electrical transducer that creates brief sound waves at specific frequencies. These sound waves then bounce back off the fetus and the way in which they are reflected back can reflect what the structures inside the uterus look like. In a very basic sense, medical ultrasound works by measuring and analyzing echoes, similar to the process that a bat uses.
Ultrasound and Pregnancy
Ultrasound is a commonly used way of imaging a developing fetus during pregnancy, particularly because of the extremely low health risks it poses to the fetus. There are many different types of ultrasound, including 2D, 3D, and 4D. 2D ultrasound is the most basic and produces black-and-white images. With 2D ultrasound, the probe/detector (the device that both transmits the sound waves and then analyzes the echoes) is held in one place. This device can be used to determine a baby's gender and observe the heartbeat. 3D ultrasound generates color pictures with more detail and is done by moving the probe/detector around to send ultrasound waves at different angles. These images are then combined by computers to give a 3D image. 4D ultrasound involves taking multiple 3D images over a short period of time so that movements and changes over time can be visualized.
3D Ultrasound and Gender
Although in many cases gender can be determined using 2D ultrasound, many parents also like to have gender determination done via 3D and 4D ultrasound for more detail. Gender determination can be done at any time after 14 weeks and until the baby comes to term. While gender determination is quite accurate at 14 weeks, the later in pregnancy that gender determination is performed, the lower the risk of a misdiagnosis.
