A 27-year-old woman (gravida 3, para 2) comes to the delivery floor at 37 weeks gestation. She has had no prenatal care. She complains that, on bending down to pick up her 2-year-old child, she experienced sudden, severe back pain that now has persisted for 2 h. Approximately 30 min ago she noted bright red blood coming from her vagina. By the time she arrives at the delivery floor, she is contracting strongly every 3 min; the uterus is quite firm even between contractions. By abdominal palpation, the fetus is vertex with the head deeply engaged. Fetal heart rate is 130/min. The fundus is 38 cm above the symphysis. Blood for clotting is drawn, and a clot forms in 4 min. Clotting studies are sent to the laboratory. Which of the following actions can wait until the patient is stabilized?