Birth Defects and Congenital Anomalies

Birth Defects and Congenital Anomalies: "What is a birth defect?
A 'birth defect' is a health problem or physical change, present in a baby at the time he/she is born. Birth defects may be very mild where the baby looks and acts like any other baby, or birth defects may be very severe(you can immediately tell there is a health problem present). Some of the severe birth defects can be life threatening, in which case a baby may only live a few months or may die at a young age (in their teens, for example).

Birth defects are also called 'congenital anomalies' or 'congenital abnormalities.' The word 'congenital' means 'present at birth.' The words 'anomalies' and 'abnormalities' mean that there is a problem present in a baby.
How frequently do birth defects occur?
Most babies are born healthy. In fact, 96 to 97 out of every 100 babies born are born healthy. About three or four out of every 100 babies born, however, have some type of birth defect.
What causes birth defects to occur?
There are many reasons why birth defects happen. Most occur due to environmental and genetic factors, but often the cause is unknown.
Who is affected by birth defects?
Birth defects have been present in babies from all over the world, in families of all nationalities and backgrounds. Any time a couple become pregnant, there is a chance that their baby will have a birth defect. As mentioned above, this chance is three to four out of 100, or 3 to 4 percent. This means that there is a 96 to 97 percent chance, with each pregnancy, for a baby to be born normal and healthy. The 3 to 4 percent number is sometimes called the background rate for birth defects or the population risk for birth defects.
In a family where birth defects are already present, the chance for a couple to have a child with a birth defect may be higher than the background rate of 3 to 4 percent.
What are the genetic and environmental causes of birth defects
When a baby is born with a birth defect, the first question usually asked by the parents is 'how did this happen?' Sometimes, this question cannot be answered. This can be very upsetting for parents because it is normal to seek an answer as to why your baby has a health problem. For some birth defects, there is a known cause, which may have to do with either genetic or environmental factors, or a combination of the two. Here is some general information and terms related to the different causes of birth defects:
* Inheritance — Inheritance is a word used to describe a trait given to you or 'passed on' to you from one of your parents. Examples of inherited traits are eye color or blood type.
* Chromosome Abnormalities — Chromosomes are stick-like structures in the center of each cell (called the nucleus) that contain your genes.
* Single Gene Defects — Genes are what determine traits. A child can inherit not only those genes responsible for their normal traits, such as the color of their eyes, but also disease-causing genes that result in a birth defect.
* Multifactorial Inheritance — Multifactorial inheritance means that 'many factors' (multifactorial) are involved in causing a birth defect. The factors are usually both genetic and environmental.
* Teratogens — A teratogen is an agent, that can cause a birth defect. It is usually something in the environment that the mother is exposed to during her pregnancy. It could be a prescribed medication, a street drug, alcohol use or a disease that the mother has, which can increase the chance for the baby to be born with a birth defect.