A pregnant belly can feel hard during all phases of pregnancy and this is a normal sensation that can happen for many reasons. You can often identify what causes you belly to be hard by identifying and monitoring for other symptoms.

The most common causes include mild muscle stretching (which is common at the beginning of pregnancy), labor-related contractions or a possible miscarriage.

However, if you feel any abnormality at any point of your pregnancy, you should inform your OBGYN. He or she will assess you and determine whether this is a normal finding or if you require further evaluation.

Causes for a hard belly during pregnancy (sorted by trimester) are as follows:

During the first trimester

The first trimester covers the first week of pregnancy up until the thirteenth week. Causes of belly hardening during this time include:

1. Stretching abdominal muscles

With the growth of the uterus and development of the baby, the belly can start to feel firmer, even early on in pregnancy. Hardening is mostly due to excessive stretching of abdominal muscles. This generally happens around weeks 7 and 8.

It is normal for the lower abdomen to appear more swollen and harder than when you were not pregnant.

What to do: Because this is a normal finding, no specific treatment is required. If the hard belly sensation becomes very uncomfortable, you should report it to your OBGYN. Read more about reasons why you may feel abdominal pain during pregnancy.

2. Constipation

Constipation is another very common problem that can affect women throughout the entire pregnancy. It happens due to the rapid hormonal changes that occur, particularly in the first trimester, which slow down intestinal flow. Slower intestinal flow can result in increased gas formation, which can make the belly bloated and harder. Learn more about symptoms of constipation during pregnancy.

In addition, some women use iron supplements during pregnancy, which can also make stool much harder.

What to do: To reduce discomfort associated with constipation, you should ensure adequate hydration throughout the day. Your diet should be rich in fiber, and you should incorporate foods like vegetables, fruit with the peel on and whole grains into your meals. Check out safe ways you can relieve gas during pregnancy.

3. Miscarriage

A hard belly in the first trimester can also be a sign of a miscarriage, which most commonly occurs before week 12. However, you will also notice other symptoms, like intense lower back pain and vaginal bleeding with clots. Get an understanding of the classic symptoms of a miscarriage and when to seek medical attention.

What to do: If you suspect you are having a miscarriage, proceed immediately to the hospital. The doctor will order an ultrasound to assess the baby and your placenta. Get a better understanding about what can cause a miscarriage and how it is treated.

During the second trimester

The second semester covers weeks 14 to 27. The most common causes for a hard belly during this period are:

1. Round ligament inflammation

At this point of pregnancy, abdominal muscles and ligaments are continuing to stretch, causing the belly to feel even harder. As a result of belly growth, many women experience inflammation of the round ligament, which causes constant pain on the inside of the belly. The pain can also radiate to the groin.

What to do: To relieve round ligament pain, you should rest and avoid being in the same position for prolonged periods. Lying on your side with your belly supported by a pillow may also help with the pain.

2. Braxton Hicks contractions

Braxton Hicks contractions, also known as prodromal labor contractions, can emerge after week 20. These contractions help to train the muscles and prepare for actual labor. When these contractions occur, they will make the entire belly feel hard. They generally last for about 2 minutes.

What to do: Braxton Hicks contractions are completely normal, and therefore, no specific treatment is needed. If they are very uncomfortable, inform your OBGYN.

During the third trimester

The third trimester represents the last 3 months of pregnancy. In addition to continuing to experience Braxton Hicks contractions, round ligament pain and constipation during this time, there is another very important reason why your belly may become hard: labor contractions.

Generally, labor contractions are very similar to Braxton Hicks, but as time goes on, labor contractions will become more intense with less rest periods in between each one. It is normal for the woman’s water to rupture if she is having contractions.

What to do: If you think you are in labor, proceed immediately to the hospital for your contractions to be assessed. Your cervix will also be inspected for dilation, which will confirm if it is time for the baby to be born. The integrity of your mucus plug will also be assessed if it is still in place.

When to go to the doctor

You should see your doctor or OBGYN if you also have:

Intense pain when your belly hardens
A suspicion that you are in labor - read more about signs of labor
A fever
Vaginal bleeding
Felt less movement from your baby

In any case, if you suspect that something is wrong, you should bring your concerns to your OBGYN. If you are unable to reach them, you should go to the emergency room or labor and delivery unit immediately.