Leg cramps are common, usually occurring in the third trimester of pregnancy. Cramps mainly affect the calves and are due to strong involuntary muscle contractions. The theory is that they are due to a build-up of lactic and pyruvic acids in muscles, but the exact cause is not known.
Studies have been performed to assess the best treatment and nothing has been found to be super useful. Treatments based on calcium supplements have shown no benefit, but treatments using magnesium supplements have shown some benefit.
Most pregnancy multivitamin preparations would have a good amount of both calcium and magnesium. If cramping is experienced, extra magnesium can be taken usually just before bedtime.
If cramping occurs despite adequate use of supplements it is best to try calf stretching exercises, leg jiggling or “walking it out”. Other things you can try include a warm shower or bath and/or ice massage.
Prevention measures may be of more benefit especially in those women who have had leg cramps in previous pregnancies.
These include regular exercise to condition and strengthen the muscles, calf stretching exercises, wearing flat comfortable shoes and ensuring an adequate fluid intake.