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.
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
Some embryos develop in the fallopian tube instead of in the uterus. A fetal ultrasound can help your health care provider detect and treat a tubal (ectopic) pregnancy.
Determine your baby’s gestational age
Knowing the baby’s age can help your health care provider determine your due date and track various milestones throughout your pregnancy.
Confirm the number of babies
If your health care provider suspects a multiple pregnancy, an ultrasound may be done.
Assess fetal anatomy
An ultrasound can help your health care provider assess the anatomy of your baby and identify various congenital abnormalities. Early diagnosis may lead to early interventions that help to save or improve a baby’s life. However, it cannot detect all birth defects.
Evaluate your baby’s growth
Your health care provider can use ultrasound to determine whether your baby is growing at a normal rate.
To study the placenta
Placental location and the maturity of the placenta can be evaluated.
Investigate new signs or symptoms
If you’re bleeding or having other complications, an ultrasound may help your health care provider determine the cause.
Determine fetal position before delivery
What To Expect At Your Appointment
During a standard fetal ultrasound, your sonographer will apply an ultrasound gel to your abdomen as you recline on an exam table. The sonographer will move the transducer over your abdomen in order to obtain all required information.
Don’t worry if you can't ‘see’ your baby! Ultrasound images are difficult to understand for an untrained observer.
Medically indicated fetal ultrasounds are safe for both the mother and baby. There are no adverse effects from fetal ultrasound on children.
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.