Symptoms of Down Syndrome in Fetus
- Down Syndrome Markers
- Cortex Area Change Measurements
- Measurements of Fetal Pelvis and Brain Structure
- Congenital Abnormality is Diagnosed – What to do
Down Syndrome Markers
Ultrasonic markers are the visual changes in the fetus associated with certain syndrome or congenital abnormality. The Down Syndrome has the typical set of signs.
Currently, the large informational base has been compiled in the field of ultrasonic researches as images and video-materials that show more and more apparent and collateral signs. It is the base that can be relied on to differentiate common signs for a certain disease. When comparing images, the diagnosis may be confirmed or rejected that allows reducing the risk of unviable child delivery.
If signs are available that tell on the high likelihood of the Down Syndrome in the fetus, the doctors hold the case conference. There is not a specific sign to be apparent to confirm 100 % diagnosis of the Down syndrome. A totality of signs allow suspecting and confirming this syndrome only.
The major marker that can cause suspicions in the doctor on that syndrome is the cortex volume thickness (about 75 % sensitivity). Absence of the nasal bone is ranked second (58 %). The signs like cardiac failure, quite short femoral tubular bones and humerus, high bowel echogenicity, vast cysts of blood vessel plexus, focal spots with cardiac hyper-echogenicity, signs of duodenum atresia refer to signs to confirm the Down syndrome in the fetus.
Cortex Area Change Measurements
The fetal cortex is the transparent region between the tissue folds on the embryo body visualized by ultrasonography. It is otherwise called nuchal fold. It is found in the area to form the neck and below the back of the head. If it changes, it is the case to suspect syndrome-related signs.
The period within the weeks 11 to 14 is the best to take measurements. This is compulsory procedure for the first pregnancy screening. The data collected at this stage are rather informative. They help to define the risk of chromosome abnormalities in the fetus. Signs of immaturity are apparent at this period.
The thickness of the neck fold is over 3 mm which is the sign of potential Down syndrome fetus, or the child will be born with other abnormalities.
Nevertheless, a greater volume of cortex is not the obvious sign of abnormality. In totality with further investigation results (biochemistry analysis, the fetal gestational age, maternal age), the doctor may suspect any abnormalities in the fetus. And even despite such signs, the likelihood of the true diagnosis is up to 80 %.
The term of data precision also refers to ultrasonography. Even if the doctor assumes that this test is the major tool to reveal chromosomal abnormalities, errors are possible. It occurs where the measurement technique is wrongly applied. The factor of human error should be also considered when reviewing cortex volume measurements and nasal bone study. The proper technique and experience of the doctor may be helpful to precisely identify abnormalities.
Measurements of Fetal Pelvis and Brain Structure
Abnormal development of the cerebellum structure may prove the Down syndrome. In particular, hyperplasia indicates on apparent development anomalies. A decrease in the frontal lobe evidences on the high risk of Down syndrome in the child-to-be.
The embryo tubular bones lesser in size refer to serious development anomaly. Reduction in the volume of upper hip bones and enlargement of the angle between them are well visualized in the case.
Congenital Abnormality is Diagnosed – What to do
It is up to parents to decide on the child they would like to have. Even if the fetus is diagnosed with the serious congenital abnormalities and the parent will be happy to have such a child, no one is eligible to force them to interrupt the pregnancy. The doctors will try their best to help this special child to socialize and adapt.
However, where the parents are not willing to bear such responsibility, they are entitled to appeal to the board of doctors to decide on the pregnancy termination. This is feasible up to week 21 of pregnancy. At later stages, the pregnancy termination is not allowed as per the laws of the Russian Federation.
Video: Diagnosis of Down Syndrome.