You're probably already having a hard enough time catching Zzzs these days, with your belly getting bigger by the day and your mind on overdrive — and leg cramps aren't helping.

When do leg cramps start during pregnancy?

Also sometimes called "charley horses," leg cramps during pregnancy usually start in the second or third trimester.

These painful spasms that radiate through the calves and up the legs are very common among the expectant set. Although they can be felt during the day, they're usually more noticeable at night, when fatigue and fluid accumulation are at their peak (and when you have all that quiet and stillness to ponder them).[1]

What causes leg cramps during pregnancy?

Short answer: Nobody's quite sure. Various theories point to the following causes of leg cramps during pregnancy:[2]

  • Pregnancy fatigue from carrying the extra baby weight
  • Compression of the blood vessels in the legs
  • Diet (an excess of phosphorus and a shortage of calcium or magnesium) 
  • Pregnancy hormones since they seem to cause so many pregnancy aches and pains

How can I get rid of leg cramps when I’m pregnant?

When you get a leg cramp, try the following:

  • Flex your feet. Straighten your leg and gently flex your ankle and toes back toward your shins several times. You can do this in bed, but you may find you get faster relief if you get up and do it on your feet.
  • Cool it. Try standing on a cold surface, which can sometimes stop a spasm. An ice pack or cool compress may also help.
  • Warm up. If stretching and cold help subside the pain, try a heating pad for added relief. (Don’t use heat if pain persists.)
  • Get a massage. Another option: treat yourself to a prenatal massage, or ask your partner to give you a rub-down. (Don't massage if pain persists.)

Can I prevent leg cramps during pregnancy?

While leg cramps during pregnancy aren't exactly preventable, there are a few steps you can take to minimize the frequency and duration:

  • Try stretching exercises. Stop cramps before they strike with a few pregnancy-safe stretching exercises. Before you head to bed, stand about two feet away from a wall and put your palms flat against it. Lean forward, keeping your heels on the floor. Hold the stretch for 10 seconds, then relax for five. Try this three times.[3]
  • Switch it up. Alternate periods of activity with periods of rest throughout the day.
  • Put your feet up. Kick back with your feet raised as often as you can when you're seated.
  • Update your wardrobe. Try sporting a pair of support hose (aka compression socks) during the day, which may help reduce swelling in the ankles and feet by improving circulation in your lower extremities. If possible, try to wear shoes with a firm heel counter (the part that cups the heel) to properly position your foot in the shoe.[4]
  • Stay hydrated. Make sure you're drinking plenty of water (most pregnant women need about eight to 10 glasses of fluids a day from all sources, but ask your practitioner if you need more). A good sign you’re hydrated: Your pee is light yellow, not straw-colored.
  • Eat a well-balanced diet. It should include lots of calcium (try yogurt, which may also help with pregnancy constipation) and magnesium (bananas are full of it).
  • Take your prenatal vitamin every day. This can help ensure you're getting all the vitamins and minerals you and baby need while you're pregnant.
  • Talk to your practitioner. Ask if you should be taking a magnesium supplement before going to bed.
  • Try a glass of milk with a banana before bed. Some patients report that this magnesium-rich combo aids relaxation, which in turn may help yo fall asleep.

When can I expect leg cramps to end while I'm pregnant?

Really bad cramps (like a charley horse) can cause pain for a few days, and that's nothing to worry about.

Leg cramps are especially common in the second half of pregnancy, when pregnancy weight gain, increased swelling and overall fatigue are at their high points — and interruptions to your sleep are most frustrating. 

Unfortunately for most women, leg cramps last through the third trimester of pregnancy. Taking steps to reduce leg cramps (drinking lots of water, eating a well-balanced diet, stretching) can help keep them at bay.

When to see your doctor about leg cramps

If the pain is severe and persistent (and if you notice swelling, warmth or redness in the area), talk to your practitioner. In very rare cases you could have a blood clot in a vein known as deep vein thrombosis (DVT) that requires medical attention.