When you’re pregnant, the same hormones that help your body get accustomed to carrying a baby for nine months can also cause constipation. Some of the biggest hormonal changes occur in those early months of pregnancy.2 Since constipation occurs mostly during earlier stages of pregnancy, hormones likely play a role in constipation at this stage.
Hormones that can cause constipation during pregnancy include progesterone, relaxin, and aldosterone.
Progesterone levels rise around the second to the third month in the first trimester. The job of progesterone is to stimulate the thickening of the uterine lining to make it possible for a fertilized egg to get implanted.4 However, it can also make your gut muscles move slower than usual .2 When your gut muscles move slowly, it takes a longer time for food to pass through your gut; more water gets reabsorbed from your poop resulting in harder stool.
Another hormone released during pregnancy, known as relaxin, works by preventing muscle contractions and relaxing smooth muscles of the gut.2 The relaxation of smooth muscles can also increase the time it takes for food to pass through your gut, leading to constipation.
Aldosterone, is another hormone relevant in pregnancy, can increase water absorption.2 This can cause ‘colonic dehydration’ and the formation of hard poop that are difficult to pass.2