Birth defects and pregnancy

Are birth defects common? This is my first pregnancy and I am worried? 

Birth defects continue to occur despite good prenatal care. It is estimated that one in every 33 infants born in North America has some type of birth defect. Birth defects can affect almost any part of the body. Birth defects also vary in severity. Some infants may have a simple cleft lip but others may have serious heart and limb defects. Birth defects of the heart can often be life threatening but most of these can be corrected with surgery within the first year of life. Unfortunately, in other parts of the world the majority of babies born with even the most simplest of heart defects die because of lack of surgeons. If you eat right, do not smoke, do not drink, and do not ingest medications during pregnancy, i would not worry about it. Most things in medicine happen because of bad luck rather than any specific factor.