Repetitive arrays of ultrasound beams scan the fetus in thin slices and are reflected back onto the same transducer.The information obtained from different reflections are recomposed back into a picture on the monitor screen (a sonogram, or ultrasonogram).Your midwife may recommend an early scan at between six weeks and 10 weeks if you have experienced bleeding.You may also be offered an early scan if you've had a previous miscarriage.The ultrasound date is usually later than the period date, so accurate dating has been found to reduce the number of women having labour induced because their babies are overdue The ultrasound can check that your baby has a heartbeat and is developing normally.Your baby's head, limbs, hands and feet, and some organs can be seen, and - though looking for abnormalities isn't the purpose of the ultrasound - some major problems can be seen at this early stage.In normal state, each body tissue type, such as liver, spleen or kidney, has a unique echogenicity.

Ultrasounds are more accurate than using the LMP and, if the ultrasound date differs from your period dates, the ultrasound date will be used.

Currently used equipments are known as real-time scanners, with which a continous picture of the moving fetus can be depicted on a monitor screen.

Very high frequency sound waves of between 3.5 to 7.0 megahertz (i.e.

Obstetric Ultrasound is the use of ultrasound scans in pregnancy.

Since its introduction in the late 1950s ultrasonography has become a very useful diagnostic tool in Obstetrics.