A vaginal (or transvaginal) ultrasound is used to examine the structures in a woman’s pelvis in great detail. The ultrasound probe, which is about the size of a finger, is introduced into the vagina and generates the sound wave that is detected by the receiving equipment.
There is no pain, heat or discomfort other than the sensation of the probe in the vagina when conducting a vaginal ultrasound. Much more detailed pictures of the uterus and ovaries can be obtained by a vaginal ultrasound than one performed on the abdomen only. Abnormalities of the uterus (eg. fibroids) and ovaries (eg. cysts) can be readily detected.
More importantly, the thickness of the endometrium lining the uterus can be determined to see if it is thick enough to nurture an inseminated egg. A thickness of over 5 mm at the time of ovulation is considered normal. On the other hand, if there is a strong echo from the ultrasound, despite an adequate thickness, the endometrium may be too dense to allow implantation.
It is not unknown for a scan to reveal a forgotten intrauterine device (IUD) – a fairly definite cause of infertility.