Low Potassium (Hypokalemia) In Pregnancy: Causes, Risks, And Treatment

check_icon Research-backed

Image: iStock


Low potassium or hypokalemia in pregnancy can be due to its loss from the body through diarrhea or vomiting. Low potassium levels in the blood can be associated with certain symptoms such as muscle cramps, constipation, weakness, and abnormal heart rates since they play vital roles in muscle and nerve functioning and blood pressure regulation (1).

You may seek a doctor if you are concerned about the lower potassium levels. Read on to understand the consequences of low potassium levels in pregnancy, how to manage this and when to seek medical care.

What Is The Normal Level Of Potassium In Blood During Pregnancy?

As per a study conducted on healthy pregnant women, the mean serum potassium concentration was found to be 5.65 millimoles per liter (mmol/l). The serum potassium level was 4.25 mmol/l in the first trimester, 5.83 mmol/l in the second trimester, and 5.95 mmol/l in the third trimester, which were considered normal (2).

If your serum potassium level falls below the normal level in any phase of your pregnancy, you may develop hypokalemia.

How Does Hypokalemia Affect Your Pregnancy?

Low potassium levels may lead to the following conditions in pregnant women.

  • Weakness, fatigue, muscle cramps, and constipation (3)
  • Hypokalemic periodic paralysis, which causes occasional bouts of muscle weakness in the legs, arms, and eyes (4).
  • Cardiac dysrhythmia, an abnormal rhythm of the heartbeat that may cause cardiac arrest (5).

Causes Of Low Potassium In Pregnancy

Low potassium in pregnancy might occur due to the following factors:

  • Excessive nausea and vomiting: These can cause an imbalance of fluids and electrolytes, resulting in potassium loss (6).
  • Use of diuretics to treat high blood pressure: This could result in loss of fluids and urine, resulting in low potassium levels (7).
  • Use of certain antibiotics: Antibiotics such as gentamicin and carbenicillin could deplete the potassium levels from the body (8).
  • Increased production of aldosterone: Aldosterone plays a key role in regulating blood pressure during pregnancy. An increase in the level of aldosterone due to the hormonal changes during pregnancy could result in potassium excretion (9).

Symptoms Of Hypokalemia In Pregnancy

When the potassium level falls below the average level, you may experience the following signs and symptoms (10).

  • Edema, mostly in legs and ankles
  • Numbness
  • Dizziness
  • Low blood pressure
  • Muscle weakness
  • Leg cramps
  • Depression
  • Constipation

Most of these are similar to pregnancy symptoms and can be diagnosed by testing the potassium level in your blood.

Diagnosis Of Hypokalemia In Pregnancy

Your doctor identifies the cause behind the loss of potassium. You may be asked if you recently had diarrhea, vomitings, and heart problems and if you were on antibiotics or diuretics. If the doctor suspects you are hypokalemic, they may recommend the following tests:

  • Blood tests to check the potassium level
  • Blood pressure test as it is affected by hypokalemia
  • Electrocardiogram (ECG) to check the heartbeat (11)

Treatment For Hypokalemia In Pregnancy

  • The treatment is usually directed towards replenishing potassium in the body and minimizing further loss.
  • The treatment depends on the underlying cause. For instance, if the condition is a result of morning sickness, addressing that issue helps. If hypokalemia is caused due to a specific medication, you may be given an alternative medicine.
  • The doctor may also prescribe potassium supplements, either oral or intravenous (in severe cases).
  • Your doctor may recommend you to add potassium-rich foods to your diet. Although including potassium foods in your diet could be beneficial, it may be less effective than taking supplements (12).

Food Sources Of Potassium

According to the US National Academy of Medicine, the adequate intake (AI) for potassium in pregnant women ranges between 2,500 and 2,900mg depending on their age (13).

You can meet this requirement by eating foods such as beet, greens, baked sweet potatoes, spinach, tomato juice, plain yogurt, orange juice, kidney beans, lentils, winter squash, dried peaches, coconut water, chicken, and salmon. You may check with your doctor or a nutritionist about the servings in the diet.

Can You Prevent Hypokalemia During Pregnancy?

The following measures may help in reducing the risk of hypokalemia.

  • Include a diet rich in potassium foods.
  • Increase electrolyte intake.
  •  Manage conditions such as diabetes and blood pressure.

Can Low Potassium Levels Cause Miscarriage?

Low potassium levels are not known to cause miscarriage.

Frequently Asked Questions

1. Does low potassium cause preeclampsia?

No. In fact, according to a study, consuming low potassium may reduce the risk of hypertension in women with a history of pregnancy hypertensive disorders (14). Moreover, high potassium levels seem to be associated with the development of preeclampsia (15).

2. Is hypokalemia common in pregnancy?

Hypokalemia or low potassium levels in pregnancy is rare, occurring in about 1% of the healthy pregnancy population (16).

Potassium is an essential nutrient that helps run several psychological functions in your body. Persistent or excessive diarrhea and vomiting are some conditions when you can have a fluid loss, causing potassium deficiency. Low potassium or hypokalemia in pregnancy may lead to issues such as weakness, muscle cramps, and abnormal heartbeat. These issues can affect the baby as well. Thus, prompt diagnosis and treatment of hypokalemia are vital. Eating a well-balanced diet and maintaining optimum electrolyte balance can help prevent potassium insufficiency or deficiency during pregnancy.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1.Potassium; Linus Pauling Institute | Oregon State University
2. Tomala J, Jendryczko A, and Kossowski; Serum potassium levels during pregnancy; Zentralbl Gynakol (1994).
3. Potassium; healthdirect.gov.au
4. Hypokalemic periodic paralysis; U.S. Department of Health and Human Services National Institutes of Health
5. Cardiac Dysrhythmia; Tufts Medical Center Community Care
6. Howard Ernest Herrell; Nausea and Vomiting of Pregnancy; American Academy of Family Physicians (2014).
7. Low potassium levels from diuretics; Harvard Health Publishing
8. Understanding hypokalemia; Nursing 2020 – The Peer-Reviewed Journal Of Clinical Excellence (2002).
9. Genevie`ve Escher;Hyperaldosteronism in pregnancy; Therapeutic Advances in Cardiovascular Disease; SAGE Journals (2009).
10. Potassium; University of Rochester Medical Center
11. Efstratios Kardalas et al.; Hypokalemia: a clinical update; Endocr Connect (2018).
12. Anthony J. Viera and Noah Wouk; Potassium Disorders: Hypokalemia and Hyperkalemia; American Academy of Family Physicians (2015)
13. The Nutrition Source – Potassium; Harvard T.H. Chan School of Public Health
14. Helmut K. Lackner et al. (2018); History of Preeclampsia Adds to the Deleterious Effect of Chronic Stress on the Cardiac Ability to Flexibly Adapt to Challenge.
Was this article helpful?
The following two tabs change content below.

Rebecca Malachi

Rebecca is a pregnancy writer and editor with a passion for delivering research-based and engaging content in areas of fertility, pregnancy, birth, and post-pregnancy. She did her graduation in Biotechnology and Genetics from Loyola Academy, Osmania University and obtained a certification in ‘Nutrition and Lifestyle in Pregnancy’ from Ludwig Maximilian University of Munich (LMU). She has been into health and... more

Dr. Shashwat Jani

Dr. Shashwat Jani is a consultant obstetrician & gynecologist in Smt. N.H.L. Municipal Medical College, Ahmedabad. His field of interests are High Risk Pregnancy, Infertility and Endoscopy. He has written 12 chapters in reference books of Ob/Gyn and published 18 articles in Index journals. Dr. Jani has been invited as faculty in more than 200 national and international conferences. He... more