Confusion surrounds physical activity prescription for pregnant women

There is strong evidence indicating that physical activity during pregnancy has significant health and quality of life benefits for both pregnant women and their unborn children.¹ With pregnancy seen as a ‘teachable moment’,² it presents as an opportune time to bring about positive behavioural changes, including increases in weekly physical activity. Unfortunately, few pregnant women are sufficiently active to obtain health benefits.¹ Previous research suggests that this is at least in part because they are confused and unsure as to what physical activity they can and cannot do during their pregnancy.³

As the majority of Australian pregnant women access the public healthcare system for their prenatal care,⁴ general practitioners are ideally placed to provide physical activity information and advice to pregnant women during the course of their pregnancy.⁵ Brief physical activity interventions involving general practitioners are known to be an effective strategy in helping pregnant women to become more active.⁶ General practitioners are also well situated to refer patients to local and accessible health promotion services when further support is needed to effect behaviour change.⁶ However, a major barrier to general practitioners and other health professionals, such as exercise and fitness professionals, providing exercise advice to pregnant women is the confusion surrounding what physical activity is recommended for pregnant women regardless of age.

The availability of detailed and evidence-based national ‘exercise during pregnancy’ guidelines is central to reducing this confusion. To date, several national guidelines regarding exercise and pregnancy have been developed in Australia, including in the past 18 months new guidelines for general practitioners,⁷ exercise and fitness professionals^8,9 and pregnant women.¹⁰ However, these guidelines present inconsistent recommendations, do not reflect current empirical evidence or do not prescribe the basic principles of physical activity prescription including frequency, intensity, time and type (FITT).

Current evidence suggests that for optimal health outcomes, healthy pregnant women (in the absence of medical or obstetric complications) should aim to be active on most, and preferably all, days of the week and accumulate at least 150 min of moderate-intensity aerobic activity per week, as well as two sessions of submaximal strength training targeting all major muscle groups.¹⁰ In contrast, guidelines developed to assist exercise and fitness professionals recommend that pregnant clients engage in at least 30 min of moderate intensity exercise on most days⁹ or simply suggest low–moderate intensity exercise on most days, without advising an overall target of exercise in min per week.⁸ Moreover, general practitioner clinical practice guidelines suggest that three to four days of physical activity is safe (without stipulating a duration of exercise),⁷ while guidelines for healthy pregnant women recommend participating in moderate–vigorous intensity exercise on most if not all days of the week.¹⁰

In addition to aerobic exercise, guidelines developed for healthy pregnant women and for exercise and fitness professionals encourage strength training during pregnancy.^8–10 However, no specific time or intensity recommendations are provided in these guidelines.^8–10 Moreover, the clinical practice guidelines developed for general practitioners do not provide a recommendation on time or even mention strength.⁷

Given these guideline inconsistencies, it is not surprising that there is confusion regarding physical activity prescription for pregnant women. To reduce this confusion and more effectively promote appropriate physical activity among pregnant women, a unified message offering the most up-to-date evidence-based physical activity advice that covers, at a minimum, the basic principles of physical activity prescription (i.e. frequency, intensity, time and type) and safety advice is needed. To achieve this, the development and endorsement of a singular set of appropriate ‘exercise during pregnancy guidelines’ by key national medical and exercise governing bodies is recommended.