Everyone, pregnant or not, has some gas. You may be surprised to learn that the average person produces between 1 and 4 pints of gas each day and passes gas about 14 to 23 times a day. Once you're pregnant, you may find yourself belching or passing gas a lot more than usual or having to unbutton your pants to relieve bloating weeks before you begin to show.
Why do you make more gas during pregnancy? The primary reason is that you have much higher levels of progesterone, a hormone that relaxes smooth muscle tissue throughout your body, including your gastrointestinal tract. This relaxation slows down your digestion, which can lead to gas, bloating, burping, and flatulence and generally create miserable sensations in your gut, especially after a big meal.
In later pregnancy, your growing uterus crowds your abdominal cavity, further slowing digestion, and pushes on your stomach, making you feel even more bloated after eating.
Gas gets caught in the digestive tract in two ways: when you swallow air and when bacteria in your colon (large intestine) break down undigested food. Most stomach gas results from swallowing air and is typically released by burping, though a small amount can continue down to the large intestine to be released as flatulence.
Most of the gas that causes flatulence is produced when bacteria in the large intestine break down food that was incompletely digested by enzymes in the stomach and small intestine. Certain carbohydrates are the main culprits. (Protein and fat produce little gas directly, although fats, because they slow down digestion, can contribute to a sense of bloating and gassiness.)
Some people get a lot of gas from foods that don't bother others at all. For example, lactose intolerant folks get bloated and gassy if they have dairy products like milk or ice cream. That's because they don't make enough lactase – the enzyme that breaks down lactose (the sugar in dairy products). Individual variation in the balance of bacteria in the colon may also affect how much gas you make.
The most effective way to reduce gas may be to cut back on the foods that are most likely to cause it. But if you eliminated everything that might cause gas, it would be hard to eat a balanced diet.
So start by cutting out the most likely culprits, and if that gives you relief, begin adding those foods back into your diet one by one to try to pinpoint what's causing the problem for you. Keeping a food diary can help you see the relationship between eating certain foods and having more gas.
Beans, whole grains, and certain vegetables – such as cabbage, cauliflower, Brussels sprouts, broccoli, and asparagus – are common offenders. They contain the sugar raffinose, which makes a lot of people gassy.
Some people have trouble if they have too much fructose, a sugar present in various foods. A relatively high amount of naturally occurring fructose is present in leeks, onions and scallions, artichokes, dried fruit, pears, apples, honey, and wheat.
Many sodas and fruit drinks are sweetened with a form of fructose called high fructose corn syrup. (It's a good idea to avoid sodas and fruit drinks anyway because they're empty calories and the carbonation in sodas can contribute to bloating.) Many processed foods are also made with high fructose corn syrup.
Certain starches (such as wheat, corn, and potatoes, but not rice) can cause gas for some people. And certain fiber-rich foods (such as oat bran, beans, peas, and many kinds of fruit) cause gas because they're normally broken down in the large intestine.
Wheat bran, on the other hand, basically passes through your digestive system without getting broken down. This makes wheat bran a good choice if you have constipation and need more fiber but also suffer from flatulence.
People who are lactose intolerant will find that dairy products give them gas. If you're highly lactose intolerant, you probably knew this before you got pregnant, since dairy may give you diarrhea and abdominal pain.
If you're only somewhat lactose intolerant and haven't been aware of dairy having any effect on you, a dramatic boost in your consumption of dairy products during pregnancy may cause you some distress. To avoid this problem, look for lactose-free milk or calcium-fortified soy milk in your supermarket. (If you aren't drinking any kind of milk, you'll probably need to take a calcium supplement.)
Finally, try to steer clear of high-fat and fried foods.
These suggestions may lessen the frequency and severity of your symptoms:
Call your practitioner if your intestinal discomfort ever feels more like abdominal pain or cramping or is accompanied by blood in your stool, severe diarrhea, constipation, or an increase in (or a new bout of) nausea and vomiting.