Hello, Thanks for your query. Normally, a valve between the esophagus and the stomach keeps stomach contents where they belong. Until this valve has time to mature, spitting up may be an issue especially if your baby eats too much or too quickly. Minimal spitting up doesn t hurt. It isn t likely to cause coughing, choking or discomfort even during sleep. Chances are your baby won t even notice the fluid dripping out of his or her mouth. Spitting up tends to peak at age 4 months, and most babies stop spitting up by age 12 months. I do hope that you have found something helpful and I will be glad to answer any further query. Take care