The document discusses various prenatal factors that can affect motor development and increase the risk of birth defects. It notes that 1 in 28 babies born in the US have some type of birth defect, including heart defects, skeletal deformities, and chemical imbalances. Conditions in the mother like asthma, cancer, diabetes, and STDs can increase risk. Prenatal malnutrition, drugs/alcohol/smoking, stress, teenage pregnancy, and hereditary/chromosome/genetic disorders can also negatively impact prenatal development. Environmental factors and maternal stress during pregnancy are associated with various infant and childhood health issues. Regular prenatal care is important for monitoring these potential risks.