PRL and hyperprolactinemia: However, high serum levels of prolactin can also be seen with pregnancy (range: 200–500 μg/L), medication-induced hyperprolactinemia (range: 25–200 μg/L), or the “stalk effect” (range: 25–250 μg/L), where the inhibitory dopamine secretion is blocked and causes a rise in prolactin [29,30,31].