A: Spitting up causes a bit of extra work and worry for moms, but in most cases, it doesn't cause babies any problems. As long as your son isn't showing signs of discomfort, such as frequent crying and writhing after eating, and as long as he's eating well and gaining weight, spitting up isn't an indication that something is wrong.
Believe it or not, about half of all babies spit up frequently due to infant acid reflux, especially during the first three months of life. That's because the valve between the stomach and the esophagus, called the lower esophageal sphincter (LES), isn't mature, and doesn't close tightly enough to keep stomach contents where they belong—in the stomach. So until this valve has had a chance to mature, your son may continue to spit up, especially if he eats too quickly. Although spitting up peaks in babies at around four months of age, every baby is different, so your son may take a little longer to overcome it. Almost all babies have stopped spitting up by the time they're a year old.
In the meantime, there are a few things you can do to help your baby spit up less.
Put gravity to work for you. Hold your son in a relatively upright position as you feed him, and keep him upright for about 15 to 30 minutes after he's finished. It might also help to keep the head of your son's crib elevated so that the contents of his stomach will be more likely to stay put. You can buy specially designed reflux baby pillows or other devices that safely elevate one end of the mattress or crib by 30 degrees.
Burp often. Burping your baby several times during and after feedings will help prevent air from accumulating in his stomach and reduce the spitting up problem.
Feed less, more often. Because a very fully stomach can stretch out the valve that normally keeps stomach contents in the stomach, it might help to feed your baby less milk at each feeding. To make sure he's still getting enough to eat, you can feed him a little more frequently.
Try a different bottle. Some bottles are especially designed to minimize the amount of air that gets into a baby's stomach while he's feeding, and these might be helpful. Regardless of the bottle type that you use, make sure the nipples that you're using have just the right size hole. If it's too big, the milk flows too fast, which causes your baby to eat too fast. If the hole is too small, it can cause your baby to swallow a lot of air as he's working to pull the milk out. A nipple that's just the right size will allow a few drops of milk to escape when you hold the bottle upside down.
There's a good chance that these steps will reduce the amount and frequency of your son's spitting up. But if they don't, it's time to head back to the doctor's office.