A fetal ultrasound is an imaging technique that uses sound waves to produce images of a baby in the uterus. The information gathered by a fetal ultrasound can help your health care provider evaluate your baby’s growth and development and determine how your pregnancy is progressing.

There are two ways to obtain sonological information regarding pregnancy.

• Trans-abdominal (images taken from the surface of the abdomen)
  
  
• Trans-vaginal (images taken with an ultrasound probe inside of the vagina)

Both of these tests work well in combination and can be highly diagnostic

Why it’s done

A fetal ultrasound can be done at any point during pregnancy. Your health care provider may use a fetal ultrasound to:

• Confirm the pregnancy and its location.
  
  
• Determine your baby’s gestational age. 
  
  
• Confirm the number of babies. 
  
  
• Assess fetal anatomy.
  
  
• Evaluate your baby’s growth.
  
  
• Study the placenta.
  
  
• Investigate new signs or symptoms like bleeding or pain.
  
  
• Determine fetal position before delivery.

Safety

Medically indicated fetal ultrasounds are safe for both mother and baby. There are no adverse effects from fetal ultrasound on children followed for several years after birth.

Preparation:

A full bladder is required for obstetrical ultrasound examinations – one litre of fluid one hour prior to the ultrasound examination is required after 28 weeks of pregnancy – 500 ml of fluid one hour prior to the ultrasound examination is required do not void prior to your examination.

What you can expect:

During a standard fetal ultrasound, doctor will apply an ultrasound gel to your abdomen as you recline on an exam table. The doctor will move the transducer over your abdomen in order to obtain all required information. Transvaginal examination may be required in some cases.

Don’t worry if you cannot ‘see’ your baby, ultrasound images are difficult to understand for an untrained observer.