The correct answer highlights the significant risk of intrauterine growth retardation (IUGR) in infants whose mothers smoked during pregnancy. Maternal smoking is known to restrict blood flow and oxygen delivery to the developing fetus. The harmful substances in cigarettes, such as nicotine and carbon monoxide, can lead to placental insufficiency, which in turn impairs the fetus's ability to grow normally within the uterus.
IUGR is characterized by reduced fetal growth and can result in lower birth weight, increased susceptibility to infections, and developmental delays later in life. Research consistently supports that infants born to mothers who smoke experience a higher incidence of IUGR, making this condition particularly relevant in assessing the impact of prenatal smoking on infant health.
Addressing the other options, while central nervous system dysfunction, teratogenic effects, and lower intellectual levels can also be concerns in infants exposed to smoking in utero, the direct and well-documented link between smoking and IUGR makes it the most significant risk factor in this context. Each of these other conditions may arise as secondary effects of the consequences of IUGR, but the primary risk associated with maternal smoking during pregnancy is more directly aligned with intrauterine growth restrictions.