What Causes Low Potassium During Pregnancy?
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Causes of Low Potassium During Pregnancy

Causes of Low Potassium During Pregnancy
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Updated on August 28, 2025
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Low potassium levels in the blood, known as hypokalemia, is a potentially dangerous condition that can affect anyone. During pregnancy, it is common for a woman’s potassium levels to drop due to normal changes in the body or to specific pregnancy-related health problems. While a slight decrease in potassium levels is normal, significant drops can potentially lead to life-threatening complications like cardiac arrhythmias (a change in heart function), respiratory failure, and kidney problems if left untreated or undiagnosed.

Symptoms of Low Potassium

Potassium is an essential mineral that helps maintain the body’s fluid and electrolyte balance. It also plays a significant role in the transmission of nerve impulses, muscle contractions, and releasing energy from carbohydrates, fat, and protein.

According to StatPearls, low potassium levels can cause symptoms that include:

  • Muscle cramps
  • Abnormal heart rhythms (palpitations)
  • Constipation
  • Fatigue

The American Pregnancy Association says that low potassium during pregnancy can indirectly cause swelling (edema) by disrupting the chemical balance, resulting in fluid buildup in the body’s tissues. Swelling is most common in the third trimester.

Causes of Low Potassium

The normal increase in a woman’s blood volume during pregnancy can dilute the concentration of potassium in the blood, leading to a slight drop in levels. According to a 2023 study, the other most common causes of potassium deficiency during pregnancy include:

  • Vomiting (especially a severe form of morning sickness called hyperemesis gravidarum)
  • Hypertensive disorders, such as preeclampsia and gestational hypertension
  • Certain medications, including corticosteroids and diuretics (which eliminate extra fluids from the body)

A 2020 study found that urinary tract infections (UTI), which can affect pregnant women, are another potential cause of hypokalemia in pregnancy because UTIs can potentially interfere with the kidneys’ ability to retain potassium.

Treatment of Low Potassium

According to StatPearls, mild cases of hypokalemia can be easily treated with oral potassium supplements. In extreme cases, hospitalization may be necessary. If you have any symptoms of hypokalemia, call your doctor right away.

Daily Requirements of Potassium

Getting the recommended amount of potassium can help keep problems associated with low potassium levels at bay. According to the National Institutes of Health Office of Dietary Supplements, pregnant women should consume about 2,900 milligrams (mg) of potassium a day. The Mayo Clinic says that during pregnancy your blood volume expands by 30 to 50 percent; therefore, you need more electrolytes, including potassium, to maintain a normal balance with the extra fluid in your body.

Potassium-rich foods include bananas, broccoli, potatoes, and spinach, among others.

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