Trisomy-18
March is Trisomy awareness month
What is trisomy?
Most people have 23 pairs of chromosomes, for a total of 46 chromosomes total. A baby gets 23 chromosomes from the mother’s egg and 23 from the father’s sperm.
Trisomy is a genetic disorder in which an individual has an extra chromosome (partial or whole). Early identification is important in order to best evaluate, treat, and monitor for any possible developmental deficits or possible medical complications.
Most common Trisomy disorders are Trisomy 21, more commonly known as Down syndrome, Trisomy 18, also called Edwards syndrome, and Trisomy 13 or Patau syndrome.
What is Trisomy-18?
Trisomy-18 is the disruption of the normal pattern of development for an unborn baby that can be life threatening. This is usually caused by an error in the division of cells, resulting in an extra chromosome 18 in the developing baby.
A baby’s organs develop abnormally when a trisomy-18 baby has 3 copies of chromosome 18.
How is Trisomy-18 diagnosed?
During the first trimester of pregnancy, a series of non-invasive tests are done, and this includes an ultrasound scan of the developing baby and blood tests (PAPP-A and free βhCG) from the mother. A chromosomal abnormality called Trisomy-18 is one of the things that are screened for.
From this, the risk factor for having a Trisomy-18 baby is then determined. Further tests will need to be done if the mother is at high risk. This doesn’t mean that the baby will have abnormalities, all that will be needed is further tests to determine a diagnosis.
What are the symptoms of a Trisomy-18 baby?
Babies who are born with this condition are often very small, frail and have serious health and physical defects. This naturally can be very stressful especially for first time mothers who not only have to deal with a new born baby but one who needs additional care.
Some of these symptoms include:
- Cleft palate
- Deformed feet
- Defective lungs, kidneys, intestines
- Low seat ears
- Small head
There is no cure or prevention for Trisomy-18, but by having screenings done for abnormalities could assist parents in making an informed decision in their pregnancy journey. Results of any screening and tests should be thoroughly discussed with your health care provider, as it is important to remember that the initial tests are screening tests and not definitive diagnosis. Please contact your healthcare provider should any concerns arise during your pregnancy.
