Fetoscopy is a relatively new procedure, available only in a select number of specialized obstetrical-care centers. The instrument used to perform the test, called a fetoscope, is a telescope or narrow tube about the diameter of a large needle, with a light at the end of it. The fetoscope is inserted through the abdomen in order to view the fetus. The physician is also able to obtain fetal skin or fetal blood samplings through this very fine instrument.
Some physicians claim that although fetoscopy is a well-established procedure, it has limited usage for prenatal diagnosis. It has been used for intrauterine fetal therapy, such as giving blood transfusions, and in identifying defects that are difficult to detect through amniocentesis.
The blood samples are used to detect inherited abnormalities, such as sickle-cell anemia, hemophilia, and beta-thalassemia. The results from tests done on samples of blood by fetoscopy are obtained within five days, a quarter of the time it takes for the results of amniocentesis to be processed.
After a possible birth defect is noted via fetoscopy, a physician may choose to do surgery on the fetus using the fetoscope. In some instances, photographs of the fetus may be taken with a special camera located at the end of the fetoscope.
A fetoscopy is often done in the hospital without an overnight stay. Like in amniocentesis, an ultrasound is done before the test to determine fetal age and position. You will have an intravenous drip that may contain a medication to relax you. Prior to the test you will be given a local anesthetic near the site of your incision, which will be very small, about one-eighth of an inch. A tiny tube is inserted alongside the fetoscope to obtain the blood sample.
The procedure is usually done between the seventeenth and twentieth weeks, when the blood vessels are mature enough to ensure a sufficient sampling. Fetal skin sampling may also be done on the fetal scalp to detect hereditary skin disorders, although ultrasound directed biopsy has proven to be a safer procedure.