What is a potential fetal effect of cocaine use during pregnancy?

Cocaine use during pregnancy is associated with various negative effects on fetal development, one of which includes microcephaly. Microcephaly is characterized by an abnormally small head size, which can lead to a variety of developmental issues and neurological impairments. This occurs because cocaine can disrupt normal blood flow to the fetus, leading to impaired fetal growth and development. The drug can also interfere with the development of the fetal brain, contributing to the risk of microcephaly.

The other options do not accurately reflect the potential effects of cocaine use during pregnancy. For instance, increased birth weight and improved fetal development are unlikely outcomes, as cocaine use typically leads to growth restrictions and other complications. Additionally, cocaine is associated with an increased risk of prematurity rather than a decreased risk, as the drug can precipitate preterm labor and other adverse pregnancy outcomes.