Renaissance Women's Group – Austin OBGYN


Dr. Byron Darby specializes in prenatal diagnosis, including CVS and amniocentesis, and obstetrical/gynecological ultrasounds.

Dr. Darby is accredited by the American Institute of Ultrasound in Medicine and certified for the First Trimester Down’s syndrome Screen.
One of the most common procedures done during pregnancy is an ultrasound exam. Ultrasound scanning involves the use of a hand held probe (called a transducer) that sends out sound waves of a very high frequency, but of very low power. These sound waves bounce off of structures and are reflected back to provide a picture of pelvic structures or of the baby. Pelvic structures must be imaged by filling the bladder, pushing the intestines out of the pelvis, thereby providing a clear “sonic window.” The weight of the patient and/or the position of the fetus can affect the quality of the image.

Obstetrical Ultrasounds

There are many reasons an ultrasound might be ordered by your doctor during the pregnancy. Before 20 weeks a patient may choose to have a First trimester screen to evaluate the risk for fetal Down syndrome. Amniocentesis and CVS are prenatal diagnostic tests that are also offered before 20 weeks. In our practice, an ultrasound is frequently ordered at about 20 weeks. The primary focus of the 20 week ultrasound is to evaluate fetal anatomy, such as the heart, the brain, and the spine. Other information such as placental location, amount of amniotic fluid, and fetal activity can also be assessed. Many, although not all, birth defects can be seen. At present there are no known risks to the baby or the mother with an ultrasound exam. Please remember that this is a medical diagnostic test, so ultrasounds are not ordered without indications.

Gynecological Ultrasounds

During a gynecologic ultrasound, the uterus and ovaries can be seen and measured. Pelvic masses can usually be seen. Ultrasound is only a tool to help make more educated decisions about a problem. It sometimes cannot provide a definite diagnosis. Further testing may be required to make a definitive diagnosis. We may also need to employ the use of a transvaginal transducer in order to obtain the best possible image. This is usually no more uncomfortable than a routine pelvic exam.