A 32-year-old primigravida at 30 weeks gestation presents to the emergency department with regular uterine contractions (4 per 10 minutes) and vaginal spotting. Cervical examination reveals 3 cm dilation, 80% effacement, and intact membranes. Fetal heart rate is 145 bpm with normal variability. She has no prior medical illness. What is the most appropriate next step in management?