(HealthDay News) -- No two babies seem exactly the same size when born. So what causes some babies to be born much larger than others?
The American Academy of Pediatrics says contributing factors include:
- Having a pregnancy that lasts longer or shorter than the normal 40 weeks.
- Overstimulated growth in the uterus during gestation.
- Genetic differences.
- The mother's weight during pregnancy.
- The ethnic background of the mother.
- The number of previous pregnancies.
- Alcohol use or substance abuse during pregnancy.
- Health conditions, such as diabetes, heart disease, kidney disease or high blood pressure.