Vaginal Ultrasonography

In vaginal ultrasonography, a probe inserted into the vagina reflects highfrequency sound waves to a transducer, forming an image of the pelvic structures. This study allows better evaluation of pelvic anatomy and earlier diagnosis of pregnancy. It also circumvents the poor visualization encountered with obese patients.

Purpose

• To establish pregnancy with fetal heart motion as early as the 5th to 6th week of gestation
• To determine ectopic pregnancy
• To evaluate abnormal pregnancy
• To diagnose fetal abnormalities and placental location
• To visualize retained products of conception
• To evaluate adnexal pathology, such as tubo-ovarian abscess, hydrosalpinx, and ovarian masses
• To evaluate the uterine lining (in cases of dysfunctional uterine bleeding and postmenopausal bleeding)
• To monitor follicular growth during infertility treatment

Patient preparation

• Describe the procedure to the patient, and explain the reason for the test.
• Assure her that the procedure is safe.

Procedure and posttest care

• The patient is placed in the lithotomy position. If the sonographer is a male, a female assistant should be present during the examination.
• Water-soluble conductive gel is placed on the transducer tip to allow better sound transmission, and a protective sheath is placed over the transducer.
• Place more lubricant on the sheathed transducer tip to allow for its gentle insertion into the vagina by the patient or the sonographer. Allowing the patient to introduce the probe may decrease her anxiety.
• To observe the pelvic structures, rotate the probe 90 degrees to one side and then the other.

Normal Findings

If the patient is not pregnant, the uterus and ovaries are normal in size and shape. If the patient is pregnant, the gestational sac and fetus are of normal size for the gestational dates.

Abnormal findings

Vaginal ultrasonography may reveal an empty uterus, if the patient was pregnant. Free peritoneal fluid may be visible in the pelvic cavity, indicating possible peritonitis. Ectopic pregnancies may also be visible in the pelvic cavity.

Interfering factors

• Mistaking the bowel for the ovaries
• Small tubal mass (possible difficulty in detecting ectopic pregnancies)
• Patient positioning (decreased visibility of structures)