Ultrasound is commonly used during pregnancy to provide information about the developing baby. During an ultrasound, reflected sound waves are used to form a visual image of the baby in the womb. While several types of ultrasounds are available, a transvaginal ultrasound is more common during the early stages of the baby’s development.
What It Is
A transvaginal ultrasound machine has a long, thin probe with a small transducer at the end. The probe looks a bit like a wand. The transducer at the end of the wand sends sound waves through the vagina, creating a visual image the ovaries, fallopian tubes and uterus. A transvaginal ultrasound can also allow the technician to see inside the uterus, offering a view of the baby as well as the embryonic sac.
When It's Used
A transvaginal ultrasound is more commonly used in the first trimester, during the earliest stages of pregnancy. The Mayo Clinic reports that early on in gestation, the uterus and fallopian tubes are closer to the vagina than to the abdominal wall. During the first several weeks of pregnancy, a transvaginal ultrasound offers the best view of the baby. At this stage, it can be used to confirm the baby’s heartbeat and to take measurements of the embryo and embryonic sac. In some cases, transvaginal ultrasound results can help the doctor confirm the estimated gestational age. Medline Plus reports that early in the first trimester, ultrasounds can also help the doctor assess potential problems with pregnancy. These include an ectopic pregnancy, as well as any structural problems in the reproductive organs or the placenta. A transvaginal ultrasound can also provide clear evidence of multiple babies in the womb.
What to Expect
Having a transvaginal ultrasound is similar to having a pelvic exam. The probe is inserted into the vagina without the use of a speculum. There may be a little pressure or discomfort, but in general a transvaginal ultrasound is not painful. It usually takes only a few minutes to complete. As with a traditional pregnancy ultrasound, the mother will likely receive a picture or two of the baby as a souvenir once the test is complete.
How to Prepare
Unlike for an abdominal ultrasound, a patient may be asked to empty her bladder before a transvaginal ultrasound. Like with a pelvic exam, she will remove her bottom garments or change into a hospital gown. Next, she will lie on an examination table with a sheet over her knees and her feet in stirrups. The rest is done by the technician.
After the Ultrasound
Unless there are any problems detected with the pregnancy, chances are the mother will only have one transvaginal ultrasound. The next ultrasound usually takes place around 18 to 20 weeks gestation, when an abdominal ultrasound scan is more appropriate.
