Ultrasound Obstetric (pregnancy)

The main use of obstetric ultrasound are in the following areas:

• Diagnosis and confirmation of early pregnancy,
• Vaginal bleeding in early pregnancy.- assessing viability of the fetus ,
• Determination of gestational age and assessment of fetal size - fetal body measurements,
• Diagnosis of fetal malformation - structural abnormalities,
• Placental localization - exclusion of placenta praevia,
• Multiple pregnancies - determining the number of fetuses,
• Polyhydramnios and Oligohydramnios,
• Cervix length and cervix stitch evaluation.

Detection of other obstetric conditions such as:

• Confirmation of intrauterine death,
• Confirmation of fetal presentation in uncertain cases,
• Evaluating fetal movements,
•  Tone and breathing in the Biophysical Profile,
• Diagnosis of uterine and pelvic abnormalities during pregnancy e.g. fibromyomata and ovarian cyst.

It is important to wear a two-piece set of clothing to be able to expose your abdomen.

You must:

1. Drink 1 litre of water 1 hour prior to your scan
2. DO NOT empty bladder until the sonographer asked you to

Please bring ALL previous scans with you. We cannot evaluate fetal growth if we do not have ALL the scans this baby has had. Your yellow Antenatal Record card may also be required.


It is extremely important to follow ALL instructions prior to your appointment. If these instructions are not followed then your appointment may be cancelled.

Once in the ultrasound room the sonographer will apply gel to your abdomen and move an instrument called a transducer over your abdomen to obtain images of your fetus/baby. The images that this takes will appear on a screen.
Once the sonographer is satisfied with the accuracy of the images the examination is usually over. Sometimes the specialist doctor who will do your results needs to see the live imaging.

It is possible to obtain 3-D ultrasound pictures of your baby at Liverpool hospital. NB: Perfect pictures cannot always be obtained eg: if baby is not co-operating, but we do try to get a nice picture for you. If we forget to print a baby photo for you, please ask before you leave. We do not charge for baby photos because babies do not always co-operate.

The specialised doctor will carefully analyse your images and make a report to your referring doctor. If the referring doctor is in the hospital they will be able to access the results on the computer. If they are not then the clerks will be able to burn the results on a disc.