Electrolytes in pregnancy

Electrolytes play a key role in the human body, as they are involved in nearly all cellular processes. Since pregnant women have an increased need for electrolytes, it is important to understand how to prevent excessive loss. What are considered normal values, and when should electrolytes be taken during pregnancy?

Electrolytes in pregnancy – what functions do they serve?

The role of electrolytes in the human body is difficult to define precisely, as they are involved in almost all biochemical and metabolic processes within body cells. The most important electrolytes include sodium, potassium, chloride, magnesium, and calcium. They regulate the function of the nervous and hormonal systems, heart activity, glucose transport, and influence the osmolarity of the blood. A deficiency or excess can therefore lead to serious dysfunctions throughout the body.

Electrolytes in pregnancy – reference values

Because electrolytes influence nearly every process in the human body, their blood levels are tightly regulated. The generally accepted normal blood values are as follows:

• Sodium: 136–145 mmol/l
• Chloride: 95–105 mmol/l
• Potassium: 3.5–5.1 mmol/l
• Magnesium: 0.7–1.1 mmol/l
• Calcium: 2.1–2.6 mmol/l

These reference values may vary slightly depending on the laboratory, so any lab result assessing electrolyte levels in a pregnant woman should be interpreted by the attending gynecologist. The examination of electrolyte balance in the blood is referred to as an ionogram. To obtain the most reliable results, the blood sample should be taken in the morning while fasting.

Electrolytes in pregnancy – when should they be taken?

Pregnant women are considered a risk group for electrolyte imbalances. The most common issue is low potassium levels (hypokalemia), which may cause painful muscle cramps and, in extreme cases, cardiac arrhythmias. Another frequently occurring deficiency is magnesium. Affected pregnant women may feel weak and excessively tired and may also suffer from cramps—similar to those seen in potassium deficiency.

To prevent electrolyte imbalances during pregnancy, a balanced diet and adequate fluid intake are essential. Potassium is abundant in tomatoes and bananas, calcium in dairy products, and magnesium in cocoa and legumes.
The daily water requirement for a pregnant woman is around 2.5 liters. Experts recommend drinking water with a low mineral content during this time. In cases of increased fluid and electrolyte loss—such as from severe nausea and vomiting during the first trimester—oral rehydration solutions may be necessary to compensate for the loss. However, a doctor should be consulted beforehand, especially in cases of so-called intractable pregnancy vomiting, to initiate appropriate examinations and treatment.

Electrolytes in pregnancy – are they really safe?

Oral rehydration solutions, commonly referred to as electrolytes, provide effective hydration in cases of increased fluid loss during pregnancy. They contain no substances harmful to pregnant women and are therefore considered safe to use throughout pregnancy. However, it is important that they are not taken without medical advice, but only after consulting with a gynecologist.