Leg cramps (pregnancy sleep)

What’s causing my painful leg cramps?

About a third of pregnant women suffer from leg cramps, particularly in the third trimester (NHS 2017, Simon et al 2014). It's likely that a combination of factors contribute to cramps:

• Your muscles are bearing the increasing weight of your baby, and are probably feeling the strain (Murray and Hassall 2014, Zhou et al 2015).
• Your growing baby will be putting pressure on the main vein from your legs, particularly if you lie on your back (Murray and Hassall 2014).
• The pregnancy hormone progesterone can affect the muscle tone in your legs (Murray and Hassall 2014).

Some small studies suggest that a lack of certain nutrients might cause cramps or make them worse, but more research is needed (Harding 2017, Sebo et al 2014, Supakatisant and Phupong 2015, Zhou et al 2015).

The good news is that your cramps are likely to go away once your baby's born (NCT 2018).

Is there anything I can do to prevent leg cramps?

Try some of these simple and practical measures during the day. They may help you have a cramp-free sleep:

• Calf stretches. Stand about a metre from a wall. With your feet flat on the floor, lean forwards with your arms outstretched to touch the wall. Hold this position for five seconds, then release. Repeat for five minutes, three times a day, especially before going to bed (NICE 2018).
• Drink plenty of liquid (Johnson 2018). If you're worried about having to get up in the night for trips to the loo, try drinking almost nothing for an hour or two before bedtime. Just make sure you drink at least eight to 10 glasses of water during the day.
• Other lower leg and foot stretches, such as flexing your foot or walking on your heels (Johnson 2018, NICE 2018). Do these three times a day, focusing on the areas that cramp at night (NICE 2018).

If you find these exercises help to ease your leg cramps during the night, continue doing them until your baby is born.

Some women also find it helpful to avoid sitting or standing in the same position for too long, and not to cross their legs when sitting. You may also find a warm bath before bed helps to relax your muscles (Johnson 2018).

You could also try taking a pregnancy supplement that contains magnesium or vitamin B. There's limited evidence that they may help prevent cramps, but the research isn’t conclusive (Harding 2017, Sebo et al 2014, Supakatisant and Phupong 2015, Zhou et al 2015). Always ask your pharmacist, doctor or midwife for advice before taking any supplements during pregnancy.

Once you’re in bed, allow your feet space to move around. If you sleep with your bedding tucked in, keeping your toes pointing downwards, it can make cramps worse (NICE 2018, Tidy 2019).

Try raising your feet too, by propping them on a pillow (Tidy 2019). Or, if you're still lying on your front in early pregnancy, hang your feet off the end of the bed (Tidy 2019).

Read our article on natural remedies for cramp.

What can I do to ease a leg cramp?

If you're woken by a cramp, stretch the muscle straight away. Straighten your leg, heel first, and gently flex your ankles and toes (NICE 2018). It might hurt at first, but the pain should gradually go away. You can ask your partner to help with this.

You can also relax the cramp by massaging the muscle (Harding 2017, NICE 2018). If this doesn't work, try getting out of bed and walking around on your heels for a few minutes (Schaefer 2018).

If your muscle pain is constant and not just an occasional cramp, or if you notice swelling or tenderness in your leg, contact your doctor. In rare cases (one or two in 1,000 pregnancies) a blood clot can develop and lodge in the leg vein (venous thromboembolism). This needs immediate treatment (RCOG 2015).

Cramp not the only thing keeping you up? Learn how to manage these other sleep disturbances:

• nausea
• restless legs
• needing the loo
• heartburn and indigestion