A stomach ache during pregnancy is a common symptom during the first trimester due to normal hormonal changes associated with pregnancy. It is usually related to morning sickness that can begin as early as 2 to 4 weeks after conception and usually gets better or disappears completely by the second trimester.

However, a stomach ache during pregnancy can also be a symptom of food poisoning, gastritis, or gastroesophageal reflux, and may be accompanied by other symptoms like heartburn, diarrhea, or excess gas.

It is important to consult your OBGYN or midwife for a stomach ache that is not getting better on its own. This is so a cause can be identified and treatment started, if necessary.

pregnant person with a hand on their belly preparing vegetables

Common causes

The main causes of a stomach ache during pregnancy include:

1. Morning sickness

Morning sickness (or pregnancy nausea) is very common during the first trimester of pregnancy, starting as early as 2 to 4 weeks after conception. It can happen at any time of day, not just in the mornings.

Morning sickness is most common during the first trimester, however it may continue through the whole pregnancy. It may involve both nausea and vomiting and make it difficult to eat and drink.

What to do: tips for managing morning sickness include avoiding strong smells, staying well-hydrated, resting, and eating small, frequent meals throughout the day. Try to stick to foods that are bland and easy to digest, such as chicken, fish, fruit, toast, and crackers.

You can also try drinking ginger tea once per day for a maximum of three days in a row.

2. Hyperemesis gravidarum

Hyperemesis gravidarum is an extreme form of nausea and vomiting during pregnancy, defined by multiple episodes of vomiting throughout the day lasting for weeks.

This condition can cause persistent nausea that does not improve, stomach ache, fatigue, and loss of appetite. It can also lead to dehydration and nutritional deficiencies.

Hyperemesis gravidarum more often affects twin pregnancies and is more common in pregnant people with a family history of this condition.

What to do: hyperemesis gravidarum requires treatment by an OBGYN and typically involves medications to help reduce vomiting, such as metoclopramide (Reglan), for example.

Severe cases of hyperemesis gravidarum may require admission to the hospital for treatment with IV fluids and antiemetics.

3. Gastritis

A stomach ache during pregnancy can also be caused by gastritis, which is usually accompanied by other symptoms like heartburn or a burning sensation in the stomach, as well as nausea and vomiting.

Gastritis during pregnancy can develop due to hormonal changes of pregnancy as well as increased levels of stress and anxiety.

What to do: eat small meals and avoid lying down immediately after eating to help alleviate discomfort. Another important tip is to avoid drinking liquids during meals, as well as fried foods and spicy foods.

4. Gastroesophageal reflux

Gastroesophageal reflux, or acid reflux, can cause a stomach ache as well as other symptoms such as heartburn, a burning sensation in the stomach, a bad taste in the mouth, excess gas, and, in some gases, a scratchy throat.

Acid reflux is more common after week 24 of pregnancy, as the growing uterus can put pressure on the stomach from below, causing stomach acids to back up into the esophagus.

Digestion also slows down during pregnancy, with food remaining in the stomach for longer. This can contribute to the backflow of food up into the esophagus and the mouth, leading to symptoms like heartburn.

What to do: eating small, frequent meals every 2 to 3 hours and avoiding fried foods, spicy foods, and saucy foods can help alleviate discomfort from acid reflux.

In some cases, your OBGYN or midwife may recommend taking antacids, such as milk of magnesia. It is important to only take medications for acid reflux as directed by your obstetrics provider.

Check out home remedies for heartburn during pregnancy.

5. Food poisoning

Food poisoning can happen at any time during pregnancy after consuming foods contaminated by toxins produced by fungi or bacteria.

The most common symptoms of food poisoning are stomach ache, nausea, vomiting, headache, diarrhea, extreme fatigue, weakness, fever, and dehydration.

Food poisoning happens more commonly from eating foods that have not been properly stored, that are past their expiration date, or have been prepared without following proper food safety guidelines.

What to do: increase fluid intake and stick to foods that are light and easy to digest. Drinking lots of fluids will help to prevent dehydration and flush out the toxins.

Your doctor or midwife may also prescribe antibiotics if there is concern that the food poisoning was caused by bacteria. People who are dehydrated or very sick may need to be admitted to the hospital for treatment with IV fluids and other medications.

Read more about causes and treatment of food poisoning, including an online symptoms quiz.

6. Excess gas

Excess gas, caused by an increase in progesterone that slows down digestion, can also cause a stomach ache during pregnancy. This is because slower digestion means more time for food to ferment in the stomach.

What to do: it is recommended to avoid gas-producing foods like beans, cabbage, broccoli, and cauliflower, for example.

In addition, it is important to keep the body well hydrated and to consume fiber-rich foods like fresh fruit and whole grains.

7. Growing uterus

The growing uterus can compress the stomach during pregnancy, causing stomach ache and acid reflux.

What to do: it is important to avoid lying down right after meals and to eat small, frequent meals every 2 to 3 hours. You can also try raising the head of the bed higher to avoid lying flat.

8. Gastric ulcer

In the majority of cases, a gastric ulcer is the result of chronic gastritis or an H. pylori infection. Conditions that damage or weaken the lining of the stomach can contribute to the formation of gastric ulcers due to the constant irritation from stomach acids.

The most common symptoms of a gastric ulcer in pregnancy are a stomach ache, bloating, nausea, vomiting, excess gas, and frequent burping.

What to do: treatment of a gastric ulcer may be done by your obstetrics provider in consultation with a gastroenterologist (GI doctor). Treatment typically involves the use of pregnancy-safe medications to reduce stomach acid, allowing the ulcer to heal.

9. Preeclampsia

Symptoms of preeclampsia include sudden shortness of breath, severe headache, stomach pain or burning, dizziness, rapidly worsening swelling, decreased urination, and vision changes (blurry vision, flashing lights, spots in your vision).

Preeclampsia happens during the second half of pregnancy and can lead to eclampsia, a serious complication of pregnancy that can put the lives of the pregnant person and fetus at risk.

What to do: it is important to seek urgent medical attention for any signs or symptoms of preeclampsia. Management of preeclampsia usually involves admission to the hospital for continuous monitoring as well as treatment with antihypertensive medications to lower blood pressure and anticonvulsants like magnesium sulfate to prevent seizures.

Will a stomach ache harm the baby?

A stomach ache during pregnancy is a very common symptom of pregnancy and will not harm the fetus.

That being said, if a stomach ache is frequent or accompanied by other symptoms, it may lead to nutritional deficiencies in the pregnant person that could interfere with fetal development.

For this reason, it is important to keep all routine prenatal appointments and to contact your OBGYN or midwife if you are experiencing stomach ache or stomach pain, especially if it is accompanied by other symptoms.

When to see a doctor

It is important to talk to your doctor or midwife right away if you are experiencing a stomach ache, especially if it is accompanied by the following symptoms:

Persistent or severe nausea and vomiting;
Dehydration;
Diarrhea;
Extreme fatigue;
Loss of appetite or weight loss;
Fever;
Headache or muscle aches;
Black stools or blood in the stool;
Vaginal bleeding;
Leaking of amniotic fluid;
Decreased fetal movement.

In addition, make sure to keep all of your regularly scheduled prenatal appointments and complete all tests and exams ordered by your OBGYN or midwife. This can help ensure a healthy pregnancy and optimal fetal development.