A 24 year old primigravida at 30 weeks gestation presents to the clinic with persistent headaches and visual spots. Blood pressure is 162 over 104 mm Hg on repeat measurements. Urinalysis shows 2 plus protein, and platelet count is 150,000 per microliter with normal liver enzymes and creatinine. She has no epigastric pain or shortness of breath, and fetal testing is reassuring. What is the best initial management?