9 Types of Lower Stomach Pain During Pregnancy Third Trimester.

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Common causes of lower stomach pain during pregnancy (third trimester) include:

  • Pregnancy growth with subsequent fetal movements and certain fetal positions.
  • False labor pain (Braxton Hicks contractions).
  • True labor pain (pre-term labor).
  • Gastrointestinal conditions such as IBS and infections.
  • Placental abruption (premature separation of the placenta from the uterus).
  • Intra-amniotic infections.
  • Lower abdominal muscle strain.
  • Urinary conditions such as cystitis.
  • Other pelvic diseases include ovarian cysts, Pelvic adhesions, pelvic inflammatory diseases, etc.

1. Pregnancy growth, Fetal position, and movement.

Fetal growth and movement is the most common and benign cause of lower stomach pain during the third trimester of pregnancy (reference).

When you reach the trimester of pregnancy, your baby’s growth and development are nearly complete. His movements and head size also become more prevalent.

Mild lower abdominal pain or discomfort is very common among women in their third trimester because of pregnancy growth. In addition, the cephalic position of the baby (head in the pelvis) often causes mild pelvic pain or discomfort.

Baby kicking in the third trimester may induce abdominal pain. The pain from kicking and fetal movement can be anywhere in the abdomen, including the lower abdominal area.

The pain from kicking is often momentary and soon goes away as the fetus stops.

No need to worry about lower abdominal pain or discomfort as long as:

  • The pain is very mild and transient.
  • The pain is related to fetal kicking or movement.
  • The pain is not progressively worsening over time.
  • The pain is not severe or not associated with severe lower abdominal tenderness.
  • There is no severe diarrhea, constipation, or vomiting.
  • There is no fever.
  • There are no urine color changes or severe burning micturition (frequent urination is expected during the third pregnancy trimester).

2. True labor pain (preterm birth).

About 10.1% of pregnancies end in preterm labor (reference). In addition, lower abdominal pain in the third trimester of pregnancy can be due to preterm labor. So, it is important to be fully aware of the signs and symptoms of true labor.


Labor pain starts as a lower abdominal pain that:

  • Increase in intensity over time.
  • Becomes more frequent over time.
  • The pain is often associated with lower back pain and pelvic pressure.
  • The duration of pain becomes more prolonged over time.
  • Finally, the pain becomes severe and intense within hours or a day.
  • Passage of bloody show (bloody mucus).
  • A sense of continuous pelvic pressure.
  • Loose stools or diarrhea.

3. False labor pain (Braxton Hicks contractions).

False labor pains or Braxton Hicks contractions are milder, irregular lower abdominal tightness or pain that may start as early as the fourth month of pregnancy.

They are not real labor pain and may be mistaken for impending labor, especially in the third trimester of pregnancy.

Some people may continue to feel Braxton Hicks throughout pregnancy.

What causes false labor pain?

Scientists think Braxton Hicks contractions are how your body prepares itself for the true delivery.

Some conditions that may predispose to Braxton Hicks contractions:

  • Not drinking enough water (dehydration).
  • Intense physical activity.
  • Ignoring the urge to pee.
  • Intercourse.
  • Lifting heavy objects.


  • Women who experience Braxton Hicks contractions often describe mild to moderate menstrual contracting.
  • They occur as lower abdominal pain or tightness in the lower abdomen (often during the last weeks of the third trimester of pregnancy.
  • They are irregular and don’t get closer together over time.
  • Unlike true labor pain, they DO NOT increase in intensity or frequency over time.
  • They may be aggravated by changing positions.
  • Rest may improve them.
  • They are generally mild and don’t interfere with your daily activities.

True V.S. False labor pain

 True labor painFalse labor pain
FrequencyIncrease in their frequency over time.Irregular, come and go.
Relation to movementNOMay increase by movement and may decrease by rest.
The durationBetween 30 seconds to 1.5 minutes.Variable.
IntensityContractions get stronger over time.Variable. Often start strong, then get weak.
Pain locationLower abdomen, pelvis (cervix), and lower backIn the lower abdomen.
Associated symptoms

–  Bloody show.

– loss of mucus plug.
– water break


3. Placental abruption

The placental is an organ that develops in the uterus during pregnancy. They are essential for pregnancy growth.

The placental is often attached to the inner wall of the uterus. In 0.4-1% of pregnant women, the placenta may prematurely separate from the uterine wall (abruption).

This is a serious pregnancy complication that may cause preterm labor, fetal death, or even serious complications to the mother.

Symptoms of acute placental abruption:

  • Vaginal bleeding.
  • Severe lower abdominal pain (placental abruption commonly occurs in the second half of pregnancy, especially in the third trimester).
  • The pain may spread to the lower back.
  • Severe tenderness and rigidity over the uterus (lower abdomen).
  • True labor pain may occur as a result.

Learn more about placental abruption.

4. Intestinal/colonic pain.

Your digestive tract is the most common source of abdominal pain. Lower abdominal pain in the third trimester of pregnancy is not necessarily pregnancy-related.

Always consider disease affecting your digestive tract as a cause of the pain, such as:

  • Gas pain: It causes colics that come and goes. Gas pain is often associated with bloating, farting, etc. Learn More.
  • Irritable bowel syndrome (IBS): Chronic or recurrent abdominal colics associated with bowel habit changes (constipation or diarrhea). Learn More.
  • Acute gastroenteritis: sudden onset lower abdominal cramps, severe yellow watery diarrhea, and may be nausea and/or vomiting. Learn More.
  • Acute appendicitis: Sudden onset of severe lower abdominal pain around the umbilicus or in the lower right quadrant with severe tenderness. Learn More.
  • Diverticular disease or acute diverticulitis: Learn More.
  • Constipation: chronic or occasional constipation is common with pregnancy. Females with constipation in their third trimester may experience lower abdominal pain or discomfort (particularly in the lower left quadrant). Learn More.

6. Urinary bladder pain.

The growing fetus in the third trimester may compress the urinary bladder and cause urinary symptoms.

Also, Urinary tract infections are common among pregnant women and may cause lower abdominal pain during the third trimester of pregnancy.

Symptoms include:

  • Dysuria (pain or burning sensation when you pee).
  • Frequent urination.
  • Persistent urge to pass urine even immediately after peeing.
  • Bloody or turbid urine.
  • Fever and muscle aches.
  • Lower abdominal pain (increases when you cough, bend or move).
  • Urine incontinence.

7. Other pelvic diseases.

The female pelvic organs are a common source of abdominal pain. Consider these pelvic organs if you are female and have lower abdominal pain when coughing.

Common causes include:

  • Ovarian cysts.
  • Pelvic inflammatory disease.
  • Pelvic adhesions.
  • Pelvic congestion.
  • Uterine fibroids.
  • Pelvic tumors (such as ovarian cancer).

8. Intra-amniotic infection.

Infection of the amniotic fluid surrounding the fetus can occur in the third trimester of pregnancy. Also, the inflammation may involve the placenta.

It occurs due to patients’ bacterial (multiple strains) infection secondary to ruptured membranes.

It is one of the most common pregnancy and delivery-related infections.


  • Fever.
  • Fast heartbeats.
  • Lower abdominal pain.
  • Tenderness over the lower abdomen (uterus).
  • Purulent or foul-smelling discharge.
  • Sweating.

9. . Abdominal muscle strain.

Abdominal muscle strain is a minor muscle injury or partial tear of the microfibers of the lower abdominal muscles (reference).

When you cough, the injured muscle in the lower abdomen cause pain.

Common causes include:

  • Intense workouts (especially Ab workouts, but they can occur with other types of body workouts).
  • Lifting heavy objects.
  • Sudden twisting or fast movements.
  • Not getting enough rest after stressful workouts.
  • Prolonged stress on the abdominal muscles (running a marathon, biking, hiking, swimming for long periods, etc.).


  • You have a history of stressful workouts, sudden twisting, or lifting a heavy object a few hours or days before the onset of pain.
  • A cough that is severe or prolonged may cause lower abdominal strain. In such a case, the onset of lower abdominal pain is after the onset of the cough.
  • The pain also increases when you sneeze, bend, move, or lift an object.
  • The pain is very mild or absent when your stay still or sleep.
  • The pain is stabbing or stretching in nature.
  • A feeling of continuous spasm or tension in the lower abdomen.