Leg cramps affect up to half of all pregnancy women, probably because the leg muscles are tired from carrying around extra weight. Typically the cramps begin during the second trimester, get worse as the pregnancy progresses and are worse at night. They may be aggravated by the pressure that the expanding uterus puts on the returning blood vessels from the legs to the heart and the nerves leading from the trunk to the legs.
Whilst there is some conjecture that insufficient dietary calcium or potassium or too much phosphorus from processed meat and snack foods can cause leg cramps, there are no good research studies that support these hypotheses.
Clearly it is a good idea to make sure that you have sufficient calcium in your diet when pregnant otherwise the developing baby may leach the calcium he needs from your bones, putting you at a higher risk of osteoporosis later. However it is unlikely to impact on your prevalence for cramping (nb please discuss any dietary supplementation with your healthcare provider before taking or changing your intake of supplements).
Some studies have indicated that magnesium supplementation may provide some benefits for some pregnant women. eg Young and Jewell (1) showed that magnesium ingested as magnesium lactate or citrate as 5mmol in the morning and 10 mmol in the evening had some benefits. Magnesium taken as dolomite may not be a suitable source of magnesium if it contains high lead levels (again please discuss any supplementation with you healthcare professional).
What can you do to reduce the incidence of leg cramps
Stretch calf muscles regularly during the day and before you go to bed
Avoid standing for long periods of time
Avoid sitting with your legs crossed
Exercise - gentle exercise can be beneficial (unless your midwife or healthcare professional has advised otherwise.
Stay hydrated by drinking water
Lie on your left side at night may improve circulation.
Gentle massage to your legs can help reduce swelling in the legs/feet to reduce pressure on the nerves
If you do get a cramp then immediately stretch your calf muscles: straighten your legs and gently pull the toes back towards the shins. Whilst it might hurt at first it will ease the spasm and the pain should go away. Massaging the calf or walking around may also help.
Please note: if there is pain in your legs which is associated with swelling and/or tenderness that does not go away then contact your doctor. In rare cases, a blood clot may have developed that requires immediate attention.
(1) Young GL, Jewell D. Interventions for leg cramps in pregnancy. The Cochrane Database of Systemic Reviews 2002, Issue 1. Art No.:CD000121. DOI: 10/1002/14651858.CD000121
Any information, advice, recommendations, statements or otherwise contained herein, or in any other communication made by or attributed to Inner West Massage and its representatives, whether oral or in writing, is not intended to replace or to be a substitute for medical advice trained by a trained physician or healthcare practitioner.
