Running during pregnancy is safe, new research suggests.
Women who jog while expecting are not more likely to have babies born prematurely or of a low birth weight, according to the largest study of its kind.
Infant wellbeing is unaffected regardless of how far their mothers ran or if they did so throughout all three trimesters, the research adds.
Lead author Professor Andrew Shennan, from King’s College London, said: ‘Women can continue accustomed exercise during pregnancy, and we would encourage this to ensure a healthy outcome for both her and her baby.’
A previous study suggests high-intensity running affects the cervix and therefore foetal wellbeing, however, the scientists of the current research argue this trial assessed just six pregnant athletes, not average runners.
Around one-third of pregnant women are unsure whether it is safe to continue running when expecting, according to a poll by the charity Tommy’s.
Guidelines recommend 30 minutes of moderate daily exercise for most pregnant women to reduce their risk of weight gain, pre-eclampsia and gestational diabetes.
‘It is safe for both mother and baby if a woman runs during pregnancy’
Professor Janice Rymer, vice president for education at the Royal College of Obstetricians and Gynaecologists, said: ‘We recommend that all women take part in regular exercise during pregnancy as it can help to reduce fatigue, lower back pain, varicose veins, swelling of the ankles, and feelings of stress, anxiety and depression.
‘This new study shows that, in the majority of cases, it is safe for both the mother and the baby if a woman who runs regularly continues to do so during her pregnancy.’
Results further suggest pregnant runners are more likely to require forceps or a vaccum device during labour, which may be due to their greater pelvic floor muscle tone.
In addition, those who never run during their pregnancies are on average 2.3kg (5lbs) heavier than those who continue to do so.
The findings were published in the journal BMJ Open Sport & Exercise Medicine.
‘If you’re used to doing it why stop?’
Abi Gooch, 40, from Milton Keynes, who has been running for more than 20 years and completed triathlons, said: ‘I ran through both of my pregnancies and was fit and healthy throughout.
‘With my second daughter I did parkrun on Saturday, a spin class on the Monday and gave birth to my daughter with a four-hour labour on the Wednesday.’
Speaking of the results of the study, Ms Gooch, who has to pass an annual fitness test as part of her police firearms officer job, added: ‘It doesn’t surprise me that running has been deemed safe during pregnancy.
‘If you’re used to doing it and you still feel comfortable then why stop?
‘It’s great for mental health, keeping the body strong for labour and I also found I got back to fitness quickly afterwards.
‘I also found it helped me keep my identity and not just “a pregnant lady” or “mum”, I was still “me”.’
How the research was carried out
The researchers analysed 1,293 women who took part in weekly park run events across the UK.
Online questionnaires determined if the women continued to run during previous pregnancies.
Those who did were asked how many kilometres they generally ran a week and if they were active throughout all three trimesters.
Pregnancy outcomes, such as length of gestation and birth weight, were also collected.