This is a trial of treatment with tablets containing magnesium for leg cramps in pregnancy.

Healthy pregnant women between 18 and 36 weeks of pregnancy suffering from leg cramps at least twice a week were treated with magnesium tablets or placebo for two weeks, 120 mg x 3 daily.

Inclusion Criteria:

• Pregnant women with recurrent leg cramps (at least twice a week).
• No disease according to helath certificate. Written participation consent must be signed.
• Linguistic ability demanded: Norwegian as the first language. Gestation length more than 17 weeks, less than 36 weeks.

Exclusion Criteria:

• Twin pregnancy.
• Oedema.
• Pre-eclampsia.
• Magnesium supplementation beyond the trial treatment.