Leg Cramps in Pregnancy: Why They Happen & How to Stop Them

Leg cramps—sudden, painful muscle contractions in your calves or feet—affect about 50% of pregnant people, especially in the second and third trimesters. They typically occur at night and can wake you from sleep. The exact cause isn’t fully understood but may relate to changes in blood circulation, pressure on nerves and blood vessels, mineral imbalances, or muscle fatigue. Relief comes from stretching, staying hydrated, gentle exercise, and possibly magnesium supplementation.¹

Why Pregnancy Causes Leg Cramps

Circulatory changes: Increased blood volume and pressure on blood vessels may contribute.

Uterine pressure: Your growing uterus puts pressure on nerves and blood vessels in your pelvis and legs.

Mineral changes: Some research suggests calcium or magnesium imbalances may play a role, though evidence is mixed.²

Muscle fatigue: Carrying extra pregnancy weight strains leg muscles.

Slower circulation: Blood flow slows in your legs, especially when lying down.

Instant Relief When a Cramp Strikes

Stretch immediately: Straighten your leg and gently flex your foot toward your body (toes toward shin). Hold until the cramp releases.³

Massage the muscle: Use firm pressure to knead the cramped muscle.

Walk it out: If you can, stand up and walk around to improve circulation.

Apply heat: After the acute cramp passes, apply a warm compress or heating pad to the sore muscle.

Avoid pointing toes: This can worsen the cramp.

Prevention Strategies

Stretching

Calf stretches before bed: Stand arm’s length from a wall, place hands on wall, step one foot back, keep heel on floor, and lean forward. Hold 30 seconds each leg.⁴

Foot flexes: Throughout the day, flex and point feet, rotate ankles.

Hydration and Nutrition

Drink plenty of water: Aim for 8-10 glasses daily.

Eat magnesium-rich foods: Nuts, seeds, whole grains, leafy greens, bananas.

Calcium sources: Dairy, fortified plant milk, leafy greens.

Magnesium supplements: Some studies suggest magnesium supplements may reduce cramps. Ask your provider before starting.⁵

Lifestyle Modifications

Regular gentle exercise: Walking, swimming, or prenatal yoga improves circulation.⁶

Elevate legs: During the day, elevate feet to improve circulation.

Warm bath before bed: Helps relax muscles.

Supportive shoes: Good arch support reduces muscle strain.

Change positions frequently: Don’t sit or stand in one position too long.

Sleep Positioning

Don’t point toes: Avoid positions that point your toes while sleeping (like heavy blankets pushing feet down).

Loose blankets: Use lighter covers that don’t press on your feet.

Pillow under knees: When lying on your side, place a pillow between or under your knees.

When to Call Your Provider

Contact your healthcare provider if:⁷

• Cramps are severe, frequent, or persistent
• One leg is significantly swollen, red, warm, or tender (possible blood clot)
• Cramping is constant rather than intermittent
• You have other concerning symptoms

References

Footnotes

1. Young GL, Jewell D. (2002). “Interventions for leg cramps in pregnancy.” Cochrane Database of Systematic Reviews. ↩

2. Garrison SR, et al. (2012). “Magnesium for skeletal muscle cramps.” Cochrane Database of Systematic Reviews. ↩

3. Mayo Clinic. (2024). “Leg cramps during pregnancy.” https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/leg-cramps-during-pregnancy/faq-20057766 ↩

4. Mayo Clinic. (2024). “Leg cramps during pregnancy.” ↩

5. Garrison SR, et al. (2012). “Magnesium for skeletal muscle cramps.” ↩

6. ACOG. (2020). “Physical Activity During Pregnancy.” ↩

7. Mayo Clinic. (2024). “Leg cramps during pregnancy.” ↩