Final answer:
Cocaine use during pregnancy can cause vasoconstriction leading to fetal hypoxia and increase the risk of abruptio placentae. Among the drugs listed, cocaine is specifically associated with these adverse effects during pregnancy.
Step-by-step explanation:
If a mother is abusing a certain illicit drug, and the nurse suspects vasoconstriction related to abruptio placentae, the drug in question is Cocaine. Cocaine use during pregnancy can lead to a number of adverse effects including peripheral vasoconstriction which can reduce the blood supply to the fetus, resulting in fetal hypoxia. Additionally, cocaine is known to cause growth restriction, preterm delivery, spontaneous abortion, and central nervous system abnormalities. Unlike other drugs, such as heroin or methamphetamine, cocaine's stimulant properties specifically contribute to vasoconstriction, making it the substance of concern in cases of suspected abruptio placentae due to this effect.