What are the causes of birth defects?  What causes birth defects to occur?  These are common questions asked by parents who are expecting a baby with a congenital birth defect.  There can be many reasons why birth defects happen, but the actual causes of birth defects generally are unknown.

Parents seeking the cause of their infant’s birth defect are often left with many questions unanswered.  This can lead to frustration, because it can leave them questioning many of their actions and events during pregnancy.  Other times, however, the resulting birth defect can be pin-pointed, and the common culprits are environmental and genetic causes.

Environmental Causes of Birth Defects

Environmental causes are considered exposures during pregnancy.  The mother may be exposed to a certain chemical or medication, which can lead to a congenital defect, or birth defect.  Alcohol and drug abuse can also lead to birth abnormalities.  Certain maternal diseases during pregnancy may also cause a defect.

Genetic Causes of Birth Defects

Genetic causes consist of the genetic contributions from both the mother and father.  Genetic causes can include:

• Family History of Birth Defects – If a family has had other children with birth defects, or if there is a past family history of birth anomalies, then the risk of having an infant with the same birth defect may rise.
• Genes – Genes determine everything in a person, from hair color to the way a body makes certain hormones.  A defect in a single gene can lead to birth defects.
• Chromosomes – Humans normally have 23 pairs of chromosomes.  When a chromosome has a defect, this, too can result in birth defects.

Photo by D Sharon Pruitt under Creative Commons CC BY 2.0