A nurse is caring for a client who is in labor at 40 weeks of gestation and reports that she has saturated two perineal pads with blood in the past 30 min. The nurse caring for her suspects placenta previa. Which of the following is an appropriate nursing action?

Choice A reason: Blunt force trauma is a possible risk factor for placental abruption, which is a condition where the placenta detaches from the uterine wall and causes bleeding, pain, and fetal distress. However, blunt force trauma is not the most common risk factor, as it accounts for only a small percentage of cases. The most common causes of blunt force trauma are motor vehicle accidents, falls, or domestic violence.

Choice B reason: Hypertension is the most common risk factor for placental abruption, as it affects about 50% of cases. Hypertension can cause vasospasm and reduced blood flow to the placenta, which can weaken the attachment and lead to separation. Hypertension can be chronic, gestational, or related to preeclampsia.

Choice C reason: Gestational diabetes mellitus is not a risk factor for placental abruption, but rather a condition where the client develops high blood sugar levels during pregnancy and can cause complications, such as macrosomia, polyhydramnios, or neonatal hypoglycemia. Gestational diabetes mellitus does not affect the placental attachment or function.

Choice D reason: Cigarette smoking is a risk factor for placental abruption, as it can cause vasoconstriction and reduced oxygen delivery to the placenta, which can impair its growth and development. However, cigarette smoking is not the most common risk factor, as it affects about 25% of cases.

Choice A reason: To call for an immediate magnesium sulfate level is not the immediate action that the nurse should take, as it is a diagnostic test that requires a blood sample and a laboratory analysis, which can take time and delay the treatment. The nurse should first stop the infusion and notify the provider, as the client is showing signs of magnesium sulfate toxicity, which is a life-threatening condition that can cause respiratory depression, cardiac arrest, or coma.

Choice B reason: To prepare to administer hydralazine is not the immediate action that the nurse should take, as it is a pharmacological intervention that requires a prescription and an assessment of the blood pressure and the fetal status. Hydralazine is an antihypertensive drug that lowers the blood pressure and prevents the complications of severe preeclampsia, such as eclampsia, stroke, or organ damage. However, the client's blood pressure is not very high and is not the main problem at the moment.

Choice C reason: To discontinue the magnesium sulfate infusion is the immediate action that the nurse should take, as it is the first and most important intervention that can reverse the effects of magnesium sulfate and restore the neuromuscular function and the respiratory rate. Magnesium sulfate is a drug that prevents seizures and lowers the blood pressure in clients with severe preeclampsia, but it can also cause toxicity if the dose is too high or the infusion is too fast.

Choice D reason: To administer oxygen is not the immediate action that the nurse should take, as it is a supportive intervention that improves the oxygen delivery to the tissues and organs, but does not address the underlying cause of the respiratory depression, which is the magnesium sulfate toxicity. The nurse should administer oxygen only after stopping the infusion and assessing the oxygen saturation and the respiratory status.