It doesn’t matter if it is day or night. When leg muscles contract suddenly—squeezing your calf with an excruciatingly strong grip—it’s alarming. As the pain subsides, you wonder why you would be so afflicted during pregnancy. Leg cramps, or Charley horses, occur commonly in pregnancy. How often do these muscle spasms occur? What causes cramps? Are there treatments for leg cramps during pregnancy? Learn about this common affliction and what can be done about it.
The Frequency and Causes of Leg Cramps in Pregnancy
Unfortunately, leg cramps can be quite common during pregnancy. In fact, they increase in frequency as pregnancy progresses. These cramps can be disruptive to sleep. Approximately 10% of women will experience leg cramps before becoming pregnant. During the first trimester, nearly 21% are afflicted. This steadily increases to 57% in the second trimester and up to 75% in the third trimester.
The causes of leg cramps among pregnant women is unknown. There may be changes in how the body uses and metabolizes important elements, including calcium, magnesium, and phosphate. The return of blood to the heart through the venous system may also be disrupted. As the size of the abdomen increases during pregnancy, there may be increased pressure that slows the return of the blood from the legs. In addition, progesterone may relax the veins. This may lead to pooling of blood that is exhausted of nutrients and increased cramping.
It is also important not to mistake leg cramp symptoms for restless legs syndrome (RLS). RLS commonly presents or worsens during pregnancy. The symptoms include an uncomfortable feeling with an urge to move that occurs when lying down at night and is relieved by movement. The treatments for RLS are different.
Treatment of Pregnancy-Related Leg Cramps
There is a limited amount of research supporting the effectiveness of various treatments for pregnancy-related leg cramps. Many people advocate the use of multivitamins or mineral tablets. Herbal supplements may be touted, but these have questionable quality and unknown safety profiles. In fact, only supplements with magnesium (containing a mixture of lactate and citrate) have a clear benefit.
Many pregnant women wish to avoid taking medications that may be harmful to their developing child. There are a handful of lifestyle changes and exercises that may be helpful instead. Some women enjoy and find relief with leg massage. Stretching before bedtime can be useful. The application of warm heating pads or cold compresses may cause the spasms to relent. In addition, some women can reduce the frequency of the leg cramps by reducing the consumption of foods that contain phosphorus (such as milk and meat).
If leg cramps are keeping you up at night, you might start by making some of these lifestyle changes. For those who are still struggling with uncomfortable spasms, you may wish to speak to your doctor. It can be especially important to rule out RLS as a cause.
Kryger, MH et al. "Principles and Practice of Sleep Medicine." ExpertConsult, 5th edition, 2011, pp. 1576-1579.