1 If you are pregnant and have never had chickenpox, and you get chickenpox during the:  First half (about 20 weeks) of your pregnancy, there is a very slight risk (0.4% to 2%) for birth defects or miscarriage.
Certain medications can also cause leg cramps. These include: 1  High blood pressure drugs. 2  Statins to treat high cholesterol. 3  Medications for chronic obstructive pulmonary disease (COPD).
Causes of leg cramps. The cause of leg cramps is sometimes unknown (idiopathic). In other cases, there may be an underlying condition or another identifiable cause.auses of leg cramps. The cause of leg cramps is sometimes unknown (idiopathic). In other cases, there may be an underlying condition or another identifiable cause.