Association Between Intensity of Physical Activity in Pregnancy and Gestational Diabetes in a Multi-Ethnic Population: Results from the PROMOTE Cohort Study

<b>Introduction</b>: The demographic shift amongst pregnant women, including older age and increasing obesity, has resulted in an increased risk of cardiometabolic complications during pregnancy, particularly gestational diabetes. This paper presents physical activity and gestational diabetes data in a multi-ethnic urban Australian population. <b>Methods and analysis</b>: The PROMOTE cohort study is an ongoing prospective pregnancy cohort study recruiting pregnant participants < 16 weeks gestation at a large urban public teaching hospital with high social and cultural diversity in Sydney, Australia. Participants are surveyed about their physical activity levels, dietary quality, emotional wellbeing and socio-demographic status using validated tools. Participants are consented for use of routinely collected clinical and social data, including medical conditions, body mass index (BMI), blood pressure (BP) and glycaemia. Follow-up is from routinely collected data. <b>Results</b>: A total of 459 participants were recruited between February 2022 and February 2024. Physical activity levels at recruitment were sufficiently active, low active and inactive in 39%, 45% and 16% of participants. Participation in moderate or vigorous physical activity was reported in 19% and 16% of participants, respectively. Participation in vigorous physical activity occurred in 10% of those with GDM vs. 17% of those without GDM (<i>p</i> = 0.11). Participation in any moderate/vigorous physical activity was reported in 20% of those with GDM vs. 30% of those without GDM (<i>p</i> = 0.058). Compared to inactive behaviour, the unadjusted odds ratio of developing GDM amongst those participating in any moderate/vigorous physical activity was 0.58 (95% CI 0.33-0.97), <i>p</i> = 0.045. Participation in any moderate/vigorous physical activity showed an association with lower oral glucose tolerance test levels at 1 h (7.49 vs. 8.17 mmol/L, <i>p</i> = 0.002). Participation in any vigorous activity was associated with lower oral glucose tolerance test levels at 1 h (7.25 vs. 8.11, <i>p</i> = <0.001). <b>Conclusions</b>: Uptake of existing physical activity recommendations is low. Gestational diabetes risk showed a trend toward variation by intensity of physical activity, with a trend toward greater intensity being associated with a possible lower rate of gestational diabetes.