What is Trisomy 18 Syndrome?

Trisomy 18 syndrome (also known as Edwards syndrome) is a condition that is caused from a chromosomal defect. This syndrome usually occurs in about 1 of every 3,000 live births. This number is increases significantly when the early pregnancy loss has been factored and they occur to the 3rd and 2nd trimesters of pregnancy. If you are new to all these, you might ask yourself what really causes trisomy 18 syndrome.

The cause of the trisomy 18 syndrome can be explained at conception. At conception, the 23 chromosomes coming from the mother and 23 chromosomes coming from the father all combine so that a baby can be created using a set of about 46 chromosomes in each of the cell. The trisomy is going to occur when your baby has up to three chromosome #18 instead of having the normal two. All these usually happen when conception is taking place. Many parents usually worry so much about this, but it better that parents know it is not their doing.

what is trisomy 18 syndrome edwards syndrome

If your baby happens to suffer from trisomy 18 syndrome, then it is your duty as a parent to notify your doctor and know the type of syndrome your baby is suffering from. Trisomy 18 manifests in three types including Mosaic trisomy 18, partial trisomy 18 and full trisomy 18. The full trisomy syndrome is one of the most commonly known types of trisomy.


With the full trisomy, you are going to have the extra #18 chromosomes occur in all the cells of your child’s body. Partial trisomy is another type of trisomy that is usually very rare. This chromosome is rare because it occurs when a part of the extra chromosome is available. The other type of trisomy is mosaic trisomy 18 syndrome. This type is said to be rare and appears when the other chromosomes are present in some of your body’s cells.

What Is the Survival Rate for Trisomy 18?

Trisomy 18 causes developmental issues that can cause medical complications. The highest risk for life-threatening situations is during the first months and years of life. For example, over half of the babies carried to full term will be stillborn (this rate is slightly higher for males than females born with Trisomy 18 syndrome).

Of those that live through birth, the survival rate for children past one year is less than 10 percent.

A small percent of these children do live into their thirties, although typically with assisted caregiving as the developmental challenges faced by those afflicted make it difficult to live independently.

Trisomy 18 Signs and Testing

The primary biological characteristic of Trisomy 18 is an extra copy on the 18th chromosome of genetic material. In the majority of cases, this chromosome is present prior to the fusion of the sperm and ovum where the child is initially conceived; and there is nothing that can be done to prevent this occurrence. There are however a number of telltale signs and symptoms that can be noticed which will help future parents of chromosomally defective children plan for the future.


Signs of Trisomy 18

Among the most prevalent signs of Trisomy 18 is the presence of an abnormally enlarged uterus and an excess amount of amniotic fluid, both of which can be realized through either an Ultrasound or maternal serum screening. These tests are preliminary and are meant to be estimates similar to a weather forecast. If the tests show a high risk of an extra 18th chromosome, the doctor will then speak with the family and suggest a more comprehensive testing regimen. These tests are more diagnostic in nature, typically either Amniocentesis or Chorionic Villi Sampling depending on how early the doctor wishes to move forward with the testing. CVS testing is used when a problem is absolutely suspected, and is able to give a diagnosis in advance relative to Amniocentesis. If necessary, a CVS test will normally be performed sometime in between the 10th and 12th week after conception.


How is a CVS Test done?

There are two types of CVS tests that can occur, depending on one’s individual needs and preferences. The first type is through the belly, where the doctor will use an extremely thin needle and puncture the stomach to extract the sample of placenta for testing. An alternative method sometimes used is directly through the cervix, where a thin tube is inserted up the vagina and a small sample of placenta is sucked in. At this point, the testing sample will normally be sent out to a third-party lab; although many providers increasingly have on-site staff to perform this type of testing. Typically the turnaround time for results is approximately seven days.

Following a successful Chorionic villus sampling, the doctor will have a vast array of data to look for any genetic abnormalities in a child. A good provider will consult with you and go over the findings in detail, as well as give you treatment options should any test results show positive. In many cases the child can be treated prior to birth via medicines or surgery, although this will depend heavily on the specific scenario.


Are there any risks involved with CVS testing?

As with the majority of  medical procedures, there is a small risk involved with this type of test. In over 99% of cases the test is completed without any issues, however in a fraction of cases the woman will have a miscarriage following testing. It is best to consult with your physician and even perhaps seeking a second opinion prior to moving forward with testing to make sure one understands all of the risks involved.


Trisomy 18 Treatment Options

Edwards syndrome is a genetic disorder where a person has a third copy of chromosome 18 instead of the usual two. The syndrome is a common type of disorder that occurs more frequently in girls than boys. The baby having extra material from chromosome 18 is the main cause. What happens is the extra materials interfere with the normal two interfering in the development of the child.

For one to know whether the child has been affected by this disorder, he/she will show various symptoms. Some of these symptoms include clenched hands, crossed legs, having feet with rounded bottom, the baby being born with a low birth weight, and low set ears. There are also signs and tests done to pregnant women that show whether your baby will be born with Edwards syndrome or not.

In pregnant women, the tests normally showed an unusually large uterus and extra amniotic fluid. Another sign is the diminutively small placenta seen when the baby is born. Many mothers panic whenever told that they have given birth to a baby with physical disorders. However, what these parents cannot wait to hear is whether there is treatment for Edwards syndrome or not.

Treatment for children with Edwards syndrome is planned. This means that the child may have different treatment options according to the case or the condition of the patient. This disorder has no permanent cure, but it is treated to a certain extent. For children suffering from weight loss, they are to see a nutritionist for treatment. Another may have difficulty in swallowing food; he/she should see a feeding specialist.

Stool softener medication is helpful for reducing the irritation during bowel movements in children. Other conditions like spina bifida are surgically treated. When giving medical care to patients suffering from Edwards syndrome, the medication should focus on certain things – some of which include treating infections, heart defects, and proper nutrition.