An ultrasound is a procedure that uses sound waves to create images of your baby while it’s in the uterus (womb). During the scan, gel is placed on your abdomen (tummy) and a probe called a transducer is placed against your skin. Pulses of sound waves are then sent from the probe to your baby, creating echoes that are turned into images by computer. You can see these images on a monitor.
Dating and Viability Scan
The dating scan is an ultrasound done in early pregnancy to establish the gestational age of the pregnancy. The dating scan also can reveal other important information such as the number of foetuses and gestational sacs, the presence of a heartbeat and also the size of the foetus which helps to establish the gestation of the pregnancy
The Fetal Growth Scans
The Foetal Growth Scans are usually done in the third trimester. The growth scan provides useful information such as the foetal presentation and position, foetal size and growth of the baby, the volume of amniotic fluid around the baby, the blood flow to the baby from the placenta via the umbilical cord, the activity and movement of the baby and the length of the cervix.
3D and 4D Ultrasound
A 3-dimensional ultrasound is an image created by processing multiple 2-dimensional images in order to get depth to the picture. It uses safe ultrasound waves, which are then processed by high power computer technology.
A 4D ultrasound takes multiple 2-dimensional ultrasound images, creates a 3-dimensional image and then does this repeated so that, over time, you can see movement of the fetus in 3-dimension. The 4th dimension is time.