Grasp the legs above the fetlocks and pull slowly. That pressure often will restart productive contractions. If the foal is delivered to the point where the shoulders are clearing and progress stops, more serious traction should be applied, preferably by two people. Don't use ropes or chains unless you are very experienced. If results are not evident very quickly, call your veterinarian.
Labor stops after it is well under way.
Exhaustion of the mare, including obvious weakness or unsteadiness, is observed. The foal appears weak, not attempting to get up after 20 minutes, not breathing well. After Delivery Is Completed Routine post-delivery treatment of the mare is not indicated, assuming her tetanus prophylaxis is up to date and her behavior is normal. Delivery of the placenta is important. Find out when your veterinarian would like to intervene if delivery is not accomplished.