Final answer:
The left-lateral recumbent position for a preeclampsia client helps to maximize uterine and kidney perfusion by relieving vessel compression, which is critical for both the mother's and the fetus's well-being.
Step-by-step explanation:
It is important for a nurse to encourage a client with preeclampsia to lie in the left-lateral recumbent position because this position is beneficial for maximizing uterine and kidney perfusion by relieving compression of major vessels such as the inferior vena cava and aorta. This optimal position helps in maintaining a better blood flow to both the mother's organs and the fetus, improving oxygenation and nutrient delivery, and reducing the risk of complications associated with preeclampsia.