As part of prenatal diagnostics, an examination of the child in the womb, further diagnostics may become necessary. This is done by means of fine ultrasound, a special sonographic examination that enables the physician to follow up on indications of a possible developmental disorder of the child or physical abnormalities.
What is fine ultrasound?
As part of prenatal diagnostics, an examination of the child in the womb, further diagnostics may be necessary. This is done using fine ultrasound. Regular ultrasound examinations now have a permanent place in pregnancy diagnostics and are also written down in the maternity guidelines. The situation is different with fine ultrasound, also known as organ ultrasound, organ screening, sonographic fine diagnostics or malformation ultrasound. The different names already give the best indication of the objective: organs and organ structures of the unborn child are imaged with the help of this procedure and checked for irregularities or malformations. A fine ultrasound is much more detailed in its results and is performed with a particularly high-resolution device. The examination, for which a pregnant woman must allow about two hours, is performed through the abdominal wall of the expectant mother, as in normal sonography. However, only physicians specially trained on this equipment are allowed to perform this diagnostic procedure, such as gynecologists and radiologists. Because this is a special examination, health insurance companies do not easily cover the cost. Most require a gynecological opinion that shows a clear indication why such an examination is necessary. A heart defect, for example, that makes immediate surgery unavoidable immediately after birth and for which appropriate precautions must be taken.
Function, effect, and goals
A fine ultrasound is performed, if necessary, between the 19th and 22nd week of pregnancy, in the second trimester, should, for example, the regular ultrasound examination reveal an abnormality. The examination proceeds in the same way as a regular ultrasound: contact gel is applied to the expectant mother’s abdomen, after which the doctor moves the transducer over the abdominal wall. The transducer sends ultrasound waves into the uterus. The returning echo allows visualization of the fetal organs and organ structures. This special examination allows the experienced physician to see whether the child’s organs are present and developed appropriately for the time. Developmental disorders and physical peculiarities can be detected or excluded in this way. This organ screening is recommended by gynecologists for certain indications. These include couples who already have a sick child. In the case of previous illnesses of the parents, which may possibly influence the development of a child, such as diabetes. In case of hereditary diseases and congenital heart defects in the family. In case of known drug use by the expectant mother and in case of smokers. Or in women who have been exposed to strong radiation. Older pregnant women (from the age of 34) and women who have become pregnant by means of artificial insemination are also often advised to undergo fine ultrasound diagnostics as a precaution. The main focus of such an examination is on the development of the internal organs, limbs, brain, face and spine. Thus, defects and malformations can be detected at an early stage by means of this diagnostic method. Spina bifida, an open spinal canal, becomes visible in this way. This is important because, depending on the severity of the obstruction, surgery may be required within 24 to 48 hours after birth. It is also easier to detect heart defects, such as white spots, also called golf ball phenomenon. These are dot-like compressions that occur particularly in the left ventricle. Further attention is paid to the gastrointestinal tract, so that a possible intestinal obstruction is not overlooked. This also applies to the kidney and urinary tract in order to detect malformations or cysts in time. The limbs of the unborn child are examined for shortening, special positions and multifingeredness. During the head examination, the size is taken into account and attention is paid to the development of the cerebral ventricle.It is also possible to detect a cleft lip and palate at an early stage during such an examination. The aim of organ screening is a general clarification of the developmental state of the unborn child in the second trimester of pregnancy. The ultrasound images are evaluated after the examination and discussed with the expectant parents. Chromosomal abnormalities cannot be detected on fine ultrasound. So-called sonographic soft markers do give an indication that a chromosomal abnormality may be present. To be sure, the attending physician will recommend further diagnostic measures, such as an amniocentesis or a chorionic villus sampling. This is a test to detect chromosomal abnormalities, such as those that occur in Down syndrome, beyond a doubt.
Risks, side effects, and dangers
For both the mother and the unborn child, the fine ultrasound examination is as harmless as the normal ultrasound examination. There are also no known side effects. However, the significance of an organ ultrasound depends on many factors. The quality of the device plays a central role. So does the experience of the doctor performing the examination. Also, the amount of amniotic fluid is not insignificant. The lower the fluid, the worse the sound waves are conducted. The result is influenced by the thickness of the abdominal wall of the expectant mother, scars, the position of the fetus and the week of pregnancy. Making the right diagnosis here requires a great deal of experience and tact. Therefore, the education of the parents by the physician before such a screening is carried out is of great importance. Because honestly, every doctor must make it clear to the parents that no examination can predict a healthy child beyond doubt. Fine ultrasound is no more than an auxiliary tool that can help detect organic maldevelopment.
