Obstetrical ultrasound is a safe, noninvasive procedure that uses sound waves to create images of the fetus, placenta and amniotic fluid. These images can be viewed in real time on a computer monitor by patient and doctor.
This procedure can be performed transabdominally, which involves moving a transducer across the skin of the lower abdomen, or transvaginally, which involves inserting a transducer into the vagina and rotating it for a comprehensive view of the fetus and surrounding organs.
An obstetrical ultrasound is performed several times throughout pregnancy to monitor the growth and development of the fetus. During the first trimester, ultrasound can determine the age of the fetus or detect any potential birth defects, such as Down syndrome. Later in the pregnancy, regular ultrasound exams measure the size and position of the fetus, placenta and amniotic fluid to help ensure that delivery will not have any major complications.
The results of this procedure are visible immediately on a computer screen for the doctor and patient to view together. More detailed results are usually available within one to two days, which your doctor will analyze for any additional information. Normal results will show a healthy fetus that has a normal size, heart and breathing rate and no visible birth defects.
An abnormal ultrasound may indicate a fetus that is too small or underdeveloped for its age, in a breech position or has a birth defect such as absent kidneys or anencephaly. It can also indicate serious problems such as an ectopic pregnancy or lack of a fetal heartbeat. If abnormal results occur, your doctor may perform additional testing.
Ultrasounds are one of the most commonly performed diagnostic procedures and have been safely used for years in fetal monitoring and for many other purposes. It is painless, and no needles or ionizing radiation are used during this procedure, eliminating the common risks of other diagnostic procedures.