What Are The Causes Of Low Potassium Levels In Pregnancy?

Potassium is an electrolyte, as are sodium and calcium. Maintaining potassium balance is essential for the normal function of many tissues, including your nerves, muscles and heart. Low dietary intakes of potassium do not cause low blood potassium, also known as hypokalemia. However, certain drugs and conditions, some of which are associated with pregnancy, can cause low potassium levels. Symptoms include weakness and constipation.

Mild Hyperventilation

Pregnancy is associated with a mild alkalosis, or increase in your blood's pH. This is due to an increase in breathing rate, common in pregnancy -- a condition known as mild hyperventilation. As carbon dioxide leaves your body, hydrogen ions exit your cells, which causes potassium levels to decline. The condition is usually mild and not associated with symptoms, but if you have a rapid heartbeat or feel dizzy or short of breath, contact your doctor, as this may indicate hyperventilation that is more severe.

Vomiting and Diarrhea

Potassium is present in many foods, and fruits and vegetables such as bananas and artichokes are the richest sources. If severe, symptoms such as vomiting and diarrhea, which are common in pregnancy, can cause dietary potassium to be lost and result in low potassium levels. Most women experience some degree of morning sickness, but a small percentage can suffer hyperemesis gravidarum, or severe vomiting, which can lead to excessive potassium loss, according to the American Pregnancy Association.

Swelling

Swelling of your feet and legs may become more common as your pregnancy progresses. This condition, known as dependent edema, is associated with elevated levels of the hormone aldosterone, which stimulates potassium loss and may result in low levels. However, the swelling is usually not severe enough to clinically impact potassium levels. If you notice swelling of the hands or eyes or symptoms such as dizziness, talk to your doctor.

SIADH

Another condition that can lead to low levels of potassium and that may occur during pregnancy is the syndrome of inappropriate anti-diuretic hormone, or SIADH. In this condition, your body secretes a hormone that causes you to retain water. The water dilutes the potassium in your blood, causing relatively low levels, although the actual quantity may be normal. This condition is not associated with symptoms of low blood potassium.