Final answer:
Infants born to women who take methadone during their pregnancies do not typically develop spina bifida before they enter school.
Step-by-step explanation:
Infants born to women who take methadone during their pregnancies typically do not develop spina bifida before they enter school. Spina bifida is a type of birth defect affecting the spinal cord. However, it has been shown that the intake of a B vitamin called folate during pregnancy can greatly reduce the incidence of these birth defects. Other teratogens, such as heroin, cocaine, methamphetamine, and certain medications, can pose risks to the developing fetus. However, methadone is not known to cause spina bifida in infants.