Adding sources of fiber to the diet can have many benefits during pregnancy, to include the prevention and aid of constipation and hemorrhoids, and the regulation of blood sugar, hunger, and even weight.
Women should add more fibrous foods gradually to their diet, while increasing their fluid intake at the same time to ease gastrointestinal side effects that may occur. These effects – if they occur at all – are temporary as the body adjusts to the additional fiber.
Foods that contain fiber usually contain numerous other valuable nutrients during pregnancy and women should aim to increase fiber through food when possible. However, fiber supplements are considered safe during pregnancy when used appropriately.
Women should talk to their health care provider (HCP) first if they want to use fiber supplements, as some supplements can interfere with certain medications (such as insulin).
Background
Fiber is a type of carbohydrate and essential nutrient that passes through the body undigested. Fiber helps regulate hunger and blood sugar, increases good bacteria in the gut, prevents and aids constipation and hemorrhoids, and lowers blood cholesterol.
Fiber includes parts of plant foods the body cannot digest or absorb, which passes through the stomach and intestines well intact, taking harmful substances out with it.
The U.S. Food and Drug Administration (FDA) has approved two health claims for dietary fiber. A decreased consumption of fats and increased consumption of dietary fiber from fruits, vegetables and whole grains, may reduce the risk of some types of cancer and coronary heart disease.
Further, dietary fiber also helps regulate energy intake that can either enhance weight loss or weight maintenance and may lower the risk for type two diabetes.
Soluble fiber (dissolves in water) and insoluble fiber (does not dissolve in water) are terms used to distinguish the two types of fiber, mostly because they have different qualities and benefits.
Soluble fiber helps regulate blood sugar (slower absorption) and blood cholesterol, while insoluble fiber is known more for the aid and prevention of constipation and hemorrhoids.
Fiber increases the weight and size of stool, softens it, and makes it easier to pass, thereby decreasing the risk of constipation and hemorrhoids. Fiber can also help loose, watery stools become slightly firmer by absorbing water and adding bulk.
The Nutrition Facts Label on food and beverage packages shows the amount of fiber in grams per serving.
Adults need at least 20 to 30 grams of fiber per day, but generally fall short of this recommendation.
Pregnancy
Information on fiber intake during pregnancy and its potential benefits is limited beyond what is known for non-pregnant individuals, described above.
However, fiber has been theorized to aid in preeclampsia risk by potentially preventing pregnancy-associated high cholesterol, and to improve healthy gut bacteria during pregnancy.
Higher fiber intake is also associated with lower daily insulin requirements in pregnant women with type 1 diabetes.
Further, as stated above, fiber can greatly assist in the management and prevention of pregnancy-related symptoms such as constipation and hemorrhoids, and may help regulate weight gain.
Food Sources
Whole fruits provide more fiber than fruit juice, especially if the skin is eaten (apples, pears, plums).
However, the fiber in wheat and oat bran is even more effective than fiber from fruits and vegetables.
Additional good sources of fiber include whole grain versions of rice, breads, flours, crackers, and cereals, as well as oatmeal, nuts, cauliflower, potatoes (with skin), beans, lentils, apples, carrots, broccoli, cucumbers, tomatoes, peas, barley, low-fat popcorn, and blueberries.
White flours contain very little fiber because the grain-refining process removes the outer coat (bran) from the grain, which contains most of the fiber.
Whole foods rather than fiber supplements are generally better as they also provide additional nutrients that supplements (Metamucil®, Citrucel®) do not.
Fiber supplements, or too much dietary fiber, can cause abdominal bloating and gas, and may reduce the absorption of certain medications (such as insulin).
Action
Women should talk to their HCP before taking any fiber supplements, or making any dramatic changes to their diet.
Pregnant women should aim for dietary sources of fiber as described above, which can lead to a healthier gastrointestinal (GI) system through the avoidance of constipation and hemorrhoids, which are common during pregnancy.
Women should increase fiber intake gradually, and drink plenty of water so the GI tract can slowly adjust to the additional fiber.
Women should also see “whole grain” or “whole wheat” as a first ingredient on nutrition labels. Added fiber in foods such as muffins, cereals, and granola bars are usually labeled as "inulin" or "chicory root".
Resources
Dietary Fiber: Essential for a Healthy Diet (Mayo Clinic)
Fiber Fact Sheet (Oregon State University, Micronutrient Information Center)