The incorporation of PA orientated motivational interview into routine clinical care for women with GDM has demonstrated encouraging results. Self-reported PA levels increased significantly at two-week follow-up. It appears women with GDM are receptive to this approach, with a mean increase of 75 minutes/week in PA levels, with more than half of the women increasing their activity to meet the PA guidelines(8, 9).
At baseline visit only 27% of women attending our GDM service reported meeting the aerobic portion of the PA recommendations, in contrast to approximately 58% of all women aged 16 and over in England meeting this part of the guideline(18). Whilst it is acknowledged activity levels decline during pregnancy(19), post motivational interview intervention figures were comparable to those of the general population (56% vs 58%).
Comparing studies examining activity levels in pregnancy, particularly in the third trimester, is difficult due to variations in recording methods and definitions. In most studies, PA is treated as a categorical variable, reported as a summary measure for the entire pregnancy or only reported in a single trimester(20). Therefore, it is challenging to established typical/expected PA levels. Amongst those using a validated assessment in the third trimester, Harrod et al using the Pregnancy Physical Activity Questionnaire (PPAQ) found 38% of the 823 pregnant women met the previous ACOG guidelines (30 minutes of moderate activity on most days of the week) in late pregnancy(21) whilst Watson et al using hip accelerometery found a median MVPA in 16.6 min/day amongst 85 women in the third trimester(22).
Relatively few studies have assessed PA levels specifically in women with GDM. An early report in 2006, found in a postal survey of 28 women with GDM that only 39% of women were meeting exercise recommendations(23). A more recently published report found comparable findings in 2706 women with GDM (measured with the International Physical Activity Questionnaire, IPAQ). It reported that 26% were classified as inactive (0–10 min PA/week), 39.7% insufficiently active (11–149 min PA/week) and 34.3% active (more than 150 min PA/week) during pregnancy(10). This is similar to our cohort, of whom 27% reported more than 150 min/week of moderate intensity physical activity, and 31% reported less than 30 min/week. Nevertheless, no studies using objective measures have been reported.
Whilst the limited evidence suggests that PA levels are low amongst women with GDM(10, 23), in contrast, there is growing high quality evidence surrounding the benefits of PA. Specifically; meta-analyses have shown that PA interventions can improve glycaemic control(6, 7). A recent systematic review of twelve trials including both aerobic and resistance exercise found that requirements of insulin therapy, dosage, and latency to administration were improved in the exercise groups(6). This is supported by high quality evidence that PA is a beneficial adjunctive therapy in the management of type 2 diabetes mellitus through its ability to increase glucose uptake and improve insulin sensitivity(24).
There is currently insufficient high-quality evidence to determine the effect of exercise on longer term maternal and infant outcomes(25). Programs of either aerobic or resistance exercise appear to be effective at improving postprandial glycaemic control and lowered fasting blood glucose. The characteristics exercise programs are those that are performed at a moderate intensity and for a minimum of three times a week(5). Greater supervision, either face-to-face or via phone follow-up, appeared to be associated with higher levels of adherence to exercise interventions(5). The challenge remains to translate these established research findings into practical everyday use in health care system where PA interventions in secondary care are notably underutilized.
This evaluation highlights the promising opportunity for motivational interviewing to be used to increase PA levels in this setting. The diagnosis of GDM can have a profound effect on women and appears to be a moment of change that encourages them to reprioritise their health and lifestyle(12). Positive use of this emotive response is important due to the short window of opportunity for maximising blood glucose control and minimising risk to the fetus.
Whilst motivational interviewing has been shown to increase physical activity in individuals with long-term health conditions(14), there is an absence of specific evidence regarding PA motivational interviewing interventions in women with GDM. There are successful examples of motivational interviewing being used in other lifestyle interventions amongst pregnant women. A small pilot study demonstrated significant reduction in alcohol consumption at 2-month follow-up after a 1-hour motivational interview(26). It has been shown to be effective in improving healthy eating behaviours in pregnant women with T2DM(27). The multi-centre randomised controlled DALI trial(28) used motivational interviewing principles in women at risk for GDM to address healthy eating and physical activity behaviour changes, reporting increased task self-efficacy for PA.
The intervention in this evaluation encompasses some of the key elements highlighted in the literature and may explain its effectiveness to increase PA levels through addressing key barriers and enablers. Harrison et al highlights that women with GDM require clear, simple, specific PA messages directly related to pregnancy outcomes that are delivered by a credible source with flexible options tailored to fit in with lifestyles(12). The importance of the clinician’s role to increase self confidence in women’s ability to be physically active, as well as provide guidance to overcome barriers to PA, is emphasised(29). A systematic review of 14 studies of behaviour change interventions in pregnancy found that a range of BCTs can be implemented to reduce the decline of PA during pregnancy. Face-to-face interventions, with goal setting and feedback are more likely to be associated with positive change(13) and combined face-to-face and telephone interventions have been shown to be effective(30).
This service evaluation is a successful example of how a motivational interviewing PA intervention can be incorporated into routine care and women with GDM appear willing to engage. Whilst the findings are positive, they must be interpreted with caution. The sample size was small, non-randomised and lacked a control group. Participation was not mandatory, which may have resulted in a selection bias toward those more likely to respond to motivational interviewing. There was a high loss to follow up rate, with many women not answering the follow up telephone call. This is likely to be explained by many women not willing answer a call from an unknown number (caller identification is withheld from the hospital phoneline).
A validated self-reported outcome measure was used, however this relied on patient recall and has not been specifically validated for pregnant women. No objective measurement of PA was taken. Self-reported measures for PA are shown to over-estimate activity when compared to objective measurement. This may have affected the follow-up result in our study. The fidelity of the motivational interviewing session was not tested and the duration of the follow up was limited to two weeks.
Further work is now required to evaluate this intervention in a randomised controlled trial with objective measurement of PA. Longer term follow-up data including postpartum data would be valuable to understand whether this intervention can influence longer term outcomes, such as the development of type 2 diabetes. Understanding other clinical outcomes such as blood glucose control, insulin use, maternal and fetal outcomes is required. Finally, cost effectiveness of this intervention needs to be evaluated to help consider the scalability of this intervention and measure to reduce the number of women lost to follow up.