Pelvic Ultrasound Health Article

Definition

Pelvic ultrasound is a procedure in which high-frequency sound waves create images of the pelvic organs. The sound waves are projected into the pelvis, and measure how they reflect—or echo—back from the different tissues.

Purpose

Ultrasound is a preferred method of examining the pelvis, and functions as an extension of a physical examination, particularly for obese patients. It is a common initial step after physical examination when a patient complains of pelvic pain or abnormal vaginal bleeding. The procedure is performed routinely during pregnancy and examinations to determine the cause of infertility. Ultrasound has the ability to detect the size and shape of pelvic organs, such as the bladder, and is useful in evaluating the cause of bladder dysfunction. In women, pelvic ultrasound is used to examine the uterus, ovaries, cervix, and vagina. In general, ultrasound can detect inflammation, free fluid, cysts (abnormal fluid-filled spaces), and tumors in the pelvic region.

A primary use of pelvic ultrasound is during pregnancy. In early pregnancy (about five to seven weeks), ultrasound may determine the size of the fetus to confirm the suspected due date, detect multiple fetuses, or confirm that the fetus is alive (viable). Ultrasound is particularly useful in distinguishing between intrauterine (within the uterus) and ectopic (outside the uterus) pregnancies. Toward the middle of the pregnancy (about 16–20 weeks), the procedure can confirm fetal growth, reveal defects in the anatomy of the fetus, and check the placenta and amniotic fluid. Toward the end of pregnancy, it may be used to evaluate fetal size, position, growth, or to check the placenta.

Doctors may use ultrasound to guide the biopsy needle during amniocentesis and chorionic villus sampling. The imaging allows precise placement of the long needle that is inserted into the patient's uterus to collect cells from the placenta or amniotic fluid.