Your digestive system in pregnancy

Pregnancy puts extra demands on your digestive system. Nausea and vomiting tend to be issues for digestion in early pregnancy. As your baby grows and your uterus expands, it presses on your digestive tract and can contribute to constipation. You may also experience changes in your appetite. Both an increase and a decrease are typical at various times along with cravings or aversions to specific foods. 

What you eat, your baby eats

You are your baby’s food supply. As soon as three to five days after conception the fertilized egg starts absorbing nutrients secreted from your endometrium, the lining of your uterus. At around eight to nine days, the embryo implants and forms a yolk sac which continues to provide a nutritional exchange throughout most of the first trimester. After about ten weeks, the placenta continues the nutritional exchange, feeding your baby through the rest of your pregnancy. Your digestive system has a lot of work to do while eating for two since your baby’s digestive system won’t be operating until after birth. 

Good nutrition not only helps supply what you need during pregnancy but feeds your baby as well. A healthy diet along with a daily prenatal multivitamin can make an essential difference. 

Digestive system changes during pregnancy 

Pregnancy hormones affect your digestive system. Many of the common digestive complaints during pregnancy such as nausea, constipation, and heartburn are related to a slow down in your digestive tract action. Progesterone causes smooth muscle relaxation which can slow digestion throughout your system from the stomach through the small and large intestines. The gallbladder may delay emptying which can increase the possibility of gallstones (1).

Digestive issues during pregnancy

“Morning sickness” — if you experience nausea and vomiting, you are not alone. Morning sickness affects nearly 80% of pregnant women. Researchers are still working to understand the cause.

It can be the unfortunate side effects of high levels of estrogen and human chorionic gonadotropin, two hormones that help maintain pregnancy. Recent studies point to Helicobacter pylori as one possibility. Nausea and vomiting tends to be mild or temporary and many women find they can manage it by adjusting their diet and eating schedule (2).
A small percentage of pregnant women experience a severe form known as hyperemesis gravidarum. If you are concerned with the severity of your symptoms, discuss it with your health-care provider (2).
Helpful tips for morning sickness:
  • Eat small meals every couple hours and don’t skip meals
  • Have a piece of bread or a cracker first thing in the morning
  • Try a small snack before bedtime 
  • Try fruit, breads, cereals and other carbohydrate-rich foods
  • Try adding ginger to your diet 
  • Avoid fried, high-fat and processed foods
  • Avoid strong food smells
  • Avoid highly seasoned foods

Another common digestive issue during pregnancy is heartburn. This is caused by food digesting more slowly, remaining in the stomach longer. Hormones cause a more relaxed sphincter at the lower end of the esophagus which can allow stomach contents to back up into the esophagus, resulting in heartburn and belching. One plus is that the stomach produces less acid. 
Help with heartburn:
  • Try eating smaller, more frequent meals
  • Avoid bending or lying down right after eating
  • Avoiding caffeine, tobacco, alcohol, aspirin and other salicylates
  • Take liquid antacids, but avoid antacids that contain sodium bicarbonate due to high sodium
  • Avoid eating more than a small snack for several hours before bed
  • At night, try elevating the head of your bed or use pillows to prop your head and shoulders

Several things contribute to occasional constipation during pregnancy, another normal consequence of changes in your body. Your enlarging uterus puts pressure on the rectum and the lower intestine. High levels of progesterone slow muscular contractions, meaning food doesn’t move through the intestines as well (4).
Help with occasional constipation:
  • Eat small amounts of lower-fat foods frequently
  • Slow down and chew well
  • Avoid spicy foods
  • Avoid bending or lying down right after eating
  • Increase your fluids
  • Exercise regularly
  • Increase fiber in your diet

Constipation can create other problems such as hemorrhoids. Hemorrhoids can also result from the pressure of your growing uterus on the rectum. Hemorrhoids are varicose veins of the rectum covered by mucosa at or near the anal canal and are normally asymptomatic, although uncomfortable. You can ease the pain of hemorrhoids with stool softeners, anesthetic gels, or a warm soak (5).

Pica is the compulsive eating of non-nutritive substances (such as starch, clay, and ice cubes). Although pica’s pathophysiology is unknown, the symptom has been known for centuries. Pregnant women and preadolescents are at the highest risk of pica, often associated with iron deficiency. Iron absorption is reduced in the presence of non-nutritive substances. Iron therapy usually cures the pica behavior (6). Try adding an iron supplement such as Liquid Iron which is made with Albion® Taste-Free™ Iron. It absorbs quickly and helps to eliminate uncomfortable side effects.

Excess saliva
Along with morning sickness, many women experience an excessive secretion of saliva known as ptyalism gravidarum. Although annoying and sometimes distressing, it is harmless. It’s common for pregnant women with nausea and vomiting who might have difficulty in swallowing their saliva (7).

Gallbladder problems
Due to pregnancy hormones, women are twice as likely to have gallstones as men. Elevated hormones cause the gallbladder to function more slowly and less efficiently which can lead to gallbladder stone issues. In studies, gallstones were found in 6.5% to 8.4% of nulliparous women (women who haven’t given birth), and in 18.4% to 19.3% of women with two to three or more pregnancies. Some 20% to 30% of these gallstones redissolve postpartum. If you develop gallbladder issues, your healthcare provider can discuss treatment options which are generally concervative for pregnant women (8,9).

Tips for a better digestion:

  • Increase fiber intake — Foods like whole grains, beans, fruits and vegetables not only provide essential vitamins and minerals for you and your growing baby, they also contain fiber, which helps to aid digestion and prevent constipation. Be sure to drink plenty of fluids when increasing fiber intake or you may make your constipation worse. 

  • Identify which foods are culprits — You’ll discover some foods cause gas and discomfort for you more than others and can eliminate those from your diet. Common troublemakers include onions, cabbage, broccoli, spinach and cauliflower, as well as spicy, fried and fatty foods. Keeping a food diary can help you zero in on the culprits.

  • Snack — It seems counterintuitive, but eating something can help relieve nausea. When taking your prenatal vitamin, try taking it with a snack and look for supplements designed for better absorption that are easier on your system.

  • Hydrate — It’s important to drink plenty of water during your pregnancy which can also help with constipation. Water keeps things moving through your system and bowel movements soft. Aim for about 10 cups of fluids a day, mostly from water and avoid drinks that are high in sugar, and carbonated drinks which may cause more bloating and gas.

  • Move — In addition to contributing to your overall well-being, exercise stimulates digestion and will help prevent constipation and keep you regular.

  • Add more probiotics — Probiotics can help balance intestinal flora to aid digestive health and nutrient absorption. Probiotics can encourage the growth of more beneficial bacteria in our gut, which can help our intestines move food through (10). Probiotics also aid in improving the breakdown of protein, carbohydrates, fats, and converting fiber into healthy fatty acids. Better digestion means better absorption of nutrients from food and supplements. If mama is getting more nourishment, baby is too. 

The gut-brain connection

There are reasons to include probiotics beyond a happier digestive system. Inside your gut is what scientists call your enteric nervous system—your second brain. Your intestinal microbiome is a collection of bacteria and yeasts that live in your gut and do an enormous amount of work to keep you healthy. A growing body of evidence has shown two-way signaling between the gut and the brain. This includes multiple neuro and endocrine signal mechanisms. Changes to the gut microbiome affect brain health.

Although digestive issues are common during pregnancy, helpful tips like the ones here can help ease the discomfort and keep you feeling better.


(1)Pregnancy: How Your Digestion Changes. University of Rochester Medical Center.

(2) Nausea and vomiting of pregnancy. Am Fam Physician. 2003 Jul 1;68(1):121-8.

(3) Review article: the management of heartburn in pregnancy. Aliment Pharmacol Ther. 2005 Nov 1;22(9):749-57.

(4) Bowel Disorders in Pregnant Women: Constipation During Pregnancy. Eksp Klin Gastroenterol. 2016;(8):88-92.

(5) Haemorrhoids during pregnancy. J Obstet Gynaecol. 2010 Apr;30(3):231-7.

(6) Pica as a manifestation of iron deficiency. Expert Rev Hematol. 2016 Nov;9(11):1075-1080.

(7) Ptyalism gravidarum. N Am J Med Sci. 2009 Nov;1(6):303-4.

(8) Pregnancy and the biliary tract. Can J Gastroenterol. 2000 Nov;14 Suppl D:55D-59D.

(9) Gastrointestinal Body Changes During Pregnancy. BabyMed.


(10) Probiotic Bacillus coagulans GBI-30, 6086 Improves Protein Absorption and Utilization, National Library of Medicine, National Center for Biotechnology Information, Probiotics Antimicrob Proteins, 2018 Dec;10(4):611-615.