Backed Up With a Bun in The Oven?

Whether you are at the start of your pregnancy dealing with fatigue and morning sickness or are towards the end of your pregnancy suffering from sore swollen feet, constipation is probably not going to be very welcome, right?

As all things go, constipation during pregnancy is actually a common problem that can affect women in each trimester of pregnancy and 6 to 12 weeks postpartum. It is most prevalent in the third trimester (6-9 months). However, it can start as early as 12 weeks!

Constipation During Pregnancy: Why Does it Happen?

While constipation is often blamed exclusively on “anatomical” reasons – the unborn baby pushing on your intestines – causes of constipation are multifactorial. Constipation yes, can be attributed to those anatomical changes; however, physiological, hormonal, behavioural factors and pregnancy-related supplements also contribute.

Let’s dig a little deeper.


During pregnancy, the release of hormones progesterone, oestrogen and relaxin are enhanced. Resulting in the relaxation of intestinal muscles, reducing contractility. Also, inhibition of the hormone motilin occurs. Motilin generally stimulates the gastrointestinal muscles and movement through the gastrointestinal tract. The result of this cascade of hormonal changes results in faecal matter moving slowly through the intestinal tract. The longer it takes, the more water your body absorbs from the stool – making them dryer and harder.


Some physiological shifts further compound those hormonal influences. From the 12th to the 20th week of pregnancy, the absorption of water and sodium from the colon increases. Resulting in hard, difficult to pass stools.


During pregnancy, it is typical to see an overall reduction in physical activity. Activities such as walking are great for helping to keep you regular as it reduces the time it takes for food to move through the large intestines. Faster transit means your body absorbs less water from the stools, reducing your risk of forming hard, dry stools.


Iron deficiency is a common issue faced by many pregnant women. First-line treatment for iron deficiency is iron tablets. Replenishing iron stores is essential for both mum and bubs health; unfortunately, for many iron tablets can cause constipation. Constipation resulting from iron tablets is often dose-dependent.

Constipation During Pregnancy: What to Do?

As you can see, there are a large number of factors that contribute to constipation outside of having bub squishing your intestines. These changes or changes in needs are a recipe for constipation and bowel trouble. Fortunately, there are several practical ways you can keep things moving to prevent constipation.

  1. Eat two pieces of fruit daily. Fruits such as pears, prunes, apples and kiwi fruits are excellent choices to get things moving.
  2. Eat five serves of vegetables/salad daily. Aim to include them with at least two meals.
    1. Single-serve is equal to:
      1. 1 cup of salad
      2. 1/2 cup of cooked vegetables.
  1. Choose whole grains such as brown rice, multigrain bread and crackers and oats.
  2. Eat legumes such as chickpeas, lentils, baked beans and kidney beans. Add them to salads, mince dishes or have them on toast.
  3. Aim to drink at least eight glasses of water daily
  4. If safe to do so, try walking for 10-15 minutes a few times a day.
  5. If iron supplements are giving you grief – talk to your doctor or dietitian.

There is a lot that can be done through diet to relieve constipation. If you are having trouble with your bowels, book an appointment with one of our dietitians to get a personalised plan.