Keeping fit when pregnant has always been thought to be beneficial, but every so often headlines appear in the newspapers urging caution.

One report from Denmark warned that high impact exercise during early pregnancy could triple the risk of miscarriage. It also indicated that women exercising more than seven hours a week were also more at risk.

Our expert Claire Friars, midwife for Tommy's the baby charity, says, 'The risk of exercise is of overdoing it and overheating, particularly in the first 12 weeks, but you just need to be sensible.

'Avoid racquet sports, martial arts and ball games because of the risk of knocks and falls. It's OK to jog if you're used to it, but don't start if you're new to it.

'Listen to your body and stop when you're working too hard. You should be able to do the 'talk test' - if you're so out of breath you can't talk, ease off. 

'Be realistic - you shouldn't be trying to peak your fitness at this time, just aim to stay fit and healthy. It's important to remember there are so many benefits of exercising for yourself and your baby.

'In the second trimester, women often get a burst of energy and want to be more active, which can be hard if you haven't kept it up in those early months.'