My wife was ‘discussing’ her condition with me the other day. She is 30 weeks pregnant and wanted to start running more often. These days it is important that doctors have their own GP so I suggested she see our general practitioner. But it did strike me that I get asked about the safety of exercise while pregnant quite regularly and so there may not be a lot of up to date information out there.
Pregnant women in the past have been discouraged from performing physical activity due to their new physiological condition. Historically this has been due to cultural and societal concerns rather than being based on firm scientific evidence. It was not until 2002 when the American College of Obstetricians and Gynaecologists (ACOG) reviewed the restriction on exercise during pregnancy and subsequently issued a different set of guidelines. Now attitude towards pregnancy and exercise is very different. ACOG in their 2015 update noted that now “pregnancy is an ideal time for maintaining or adopting a healthy lifestyle”. However patients are still often advised to take it easy when pregnant and to avoid exercise, with recent studies showing that women will follow doctors advice at this time in their lives and will decrease their activity out of concerns for their developing baby.
Exercising impacts blood sugar level – in a good way! This is particularly important in pregnant women due to their risk of developing a condition called gestational diabetes mellitus (GDM). Gestational diabetes is when a non diabetic patient will develop high blood sugar during pregnancy. It is thought to be due the body tissues becoming resistant to insulin making them less able to take up sugar from the bloodstream. While studies show significantly lower blood sugar levels in exercising pregnant women than non exercising women at the 24-28 week mark, it has not been shown definitively to have an effect on decreasing the risk of developing GDM. This is quite possibly only due to the fact that studying pregnant women is difficult so we are still waiting for the evidence to come in. If a woman does GDM then physical activity can help significantly and has been shown to reduce the requirement for injection of insulin.
Exercise can also help with pregnant women manage high blood pressure. A recent large analysis of a number of important papers has shown that exercise has been linked to a reduction in high blood pressure during pregnancy.
In regards to safety of the baby and exercising, birthweight is no different in exercising pregnant women when compared to non exercising women. On the contrary, physical activity can actually reduce the risk of a large-for-gestational age (LGA) newborns. LGA babies have more serious outcomes when it comes to birth trauma and need to elective c-sections, so reducing this risk is definitely a positive thing.
Some doctors may still be concerned regarding certain perceived poor outcomes that they associate with exercising these historically include miscarriage, injury, poor foetal growth, and early delivery. The Australian College of Obstetricians and Gynaecologists (RANZCOG) say that “there is no evidence to suggest that regular exercise during an uncomplicated pregnancy is detrimental to the women or foetus and accordingly all women with an uncomplicated pregnancy should be encouraged to participate in aerobic and strength conditioning exercise”. When it comes to giving birth there is even evidence to support the fact that exercise can shorten the time of labour and reduce the risk of caesarean section. This makes sense as exercise is thought to improve muscle tone, particularly of the pelvic musculature, necessary for an efficient labour. There is also evidence that exercise has been shown to reduce lower back pain symptoms and disability in function and improve mobility in pregnant women. With lower back pain being a major cause of pain in pregnant women, the simple treatment of regular exercise seems like a good prescription.
So how should a woman who has not exercised regularly before but is pregnant commence a physical activity program? First of all the program should have structure and be supervised. A transition needs to be planned to transition throughout the pregnancy as the baby grows and the woman’s centre of gravity shifts. This includes moving from a weight bearing exercise routine, such as running in the first and second trimester, to a non weight bearing exercise for example swimming in the third trimester. Athletes need to avoid exercising in the hottest part of the day and need to stretch thoroughly both before and after exercise. Cessation of activity must take place if the woman is experiencing nausea, lightheadedness or overheating. If a patient is experiencing a moderate or high risk pregnancy any commencement of physical activity must be done following consultation with their obstetrician.
The current recommendations are for 150-300 minutes per week of moderate intensity exercise which is similar to brisk walking. This is easily gaged – if a woman can comfortably hold a conversation while exercising she is undertaking moderate activity. Activity should be completed on most or all days. Ideally this equates to 30 minutes of activity per day. There is no maximal upper limit on time exercising although RANZCOG suggests that it would be unwise to exercise longer than 60 minutes per session due to concerns regarding regulation of body heat. A woman must have adequate caloric intake to avoid hypoglycaemia when exercising and monitoring for dehydration is important. No physical activity with a high risk of trauma to the abdominal region should be pursued. And scuba diving is definitely out! If a woman is engaged in very vigorous exercise prior to the pregnancy she can continue with this activity although it is not the time for aiming for personal bests or competing at a high level. Avoid lying on your back after your first trimester during physical activity and avoid lunging type activity to avoid pelvic connective tissue injury.
When should exercise be stopped during pregnancy? A woman needs to think about her exercise regime if she notices bleeding, shortness of breath prior to exercise, lightheadedness or headache, calf pain or muscle weakness, pain in the chest, any contractions or suspected amniotic fluid leakage. These symptoms are contraindications to exercise in pregnancy and if they occur the woman should see her GP or obstetrician for further assessment and advice.
For further reading on this topic you can find the Australian guidelines for exercise in pregnancy at the Australian and New Zealand College of Obstetricians and Gynaecologists website here.
I suggested to my wife she might like to try some swimming and that I’d even look after the older kids while she went to the pool! So what has your experience been, do you feel that doctors have the right end of the stick when it comes to exercise and pregnancy or is it still being advised against?
GPearls on the GC
- Exercise has a lot of benefits during pregnancy especially when giving birth
- 30 minutes per day of moderate intensity exercise or continue exercise you are used to
- NO scuba diving!