An inadequate or excessive amount of some nutrients may cause malformations or medical problems in the fetus, and neurological disorders and handicaps are a risk that is run by mothers who are malnourished. An estimated 24% of babies worldwide are born with lower than optimal weights at birth due to lack of proper nutrition. Personal habits such as consumption of alcohol or large amounts of caffeine can negatively and irreversibly affect the development of the baby, which happens in the early stages of pregnancy.