Hold a dumbbell weight (3–5 pounds) in your left hand, arm hanging toward the floor, palm facing backward (A). Bend your left elbow up and back while pulling your shoulder blades together; bring the elbow back far enough to feel a stretch in your chest muscles without rotating your torso (B). Return to the starting position, complete 8–10 reps, switch sides and repeat. Do 2 sets on each side. Strengthens the upper-back and shoulder muscles, which will help you keep your chest open and make breathing easier during labor.