Trends in percentages of gestational diabetes mellitus attributable to overweight, obesity, and morbid obesity in regional Victoria: an eight-year population-based panel study

Abstract

Background Gestational diabetes mellitus (GDM) is the fastest growing type of diabetes in Australia with rates trebling over the past decades partially explained by rising obesity rates and maternal age among childbearing women. Percentage of GDM attributable to obesity has been documented, mostly focusing on metropolitan populations. In parts of regional (areas outside capital cities) and rural Australia where overweight, obesity and morbid obesity are more prevalent, intertwined with socioeconomic disadvantage and higher migrant communities, trends over time in adjusted percentages of GDM attributed to obesity are unknown. Methods In this population-based retrospective panel study, women, without pre-existing diabetes, delivering singletons between 2010 and 2017 in a tertiary regional hospital that serves 26% of Victoria’s 6.5 million Australian population were eligible for inclusion. Secular trends in GDM by body mass index (BMI) and age were evaluated. The percentage of GDM that would have been prevented each year with the elimination of overweight or obesity was estimated using risk-adjusted regression-based population attributable fractions (AFp). Trends in the AFp over time were tested using the augmented Dickey-Fuller test. Results Overall 7348 women, contributing to 10,028 births were included. The age of expecting mothers, their BMI, proportion of women born overseas, and GDM incidence significantly rose over time with GDM rising from 3.5% in 2010 to 13.7% in 2017, p < 0.001, increasing in all BMI categories. The incidence was consistently highest among women with obesity (13.8%) and morbid obesity (21.6%). However, the highest relative increase was among women with BMI < 25 kg/m2, rising from 1.4% in 2010 to 7.0% in 2017. Adjusting for age, country of birth, socioeconomic status, comorbidities, antenatal and intrapartum factors, an estimated 8.6% (confidence interval (CI) 6.1–11.0%), 15.6% (95% CI 12.2–19.0%), and 19.5% (95% CI 15.3–23.6%) of GDM would have been prevented by eliminating maternal overweight, obesity, and morbid obesity, respectively. However, despite the rise in obesity over time, percentages of GDM attributable to overweight, obesity, and morbid obesity significantly dropped over time. Scenario analyses supported these findings. Conclusions Besides increasing prevalence of obesity over time, this study suggests that GDM risk factors, other than obesity, are also increasing over time.

Incidence of gestational diabetes mellitus in the United Arab Emirates; comparison of six diagnostic criteria: The Mutaba’ah Study

“…Unlike in some settings ( 43 – 45 ), our study had shown a general reduction in the GDM incidence in the UAE using different criteria. The IADPSG criteria showed a GDM incidence of 21.3%, which was lower than the previous 37.7% ( 4 ) and 45.3% ( 29 ) shown in other studies in the country using the same criteria in previous years.…”

Third trimester re‐screening for gestational diabetes in morbidly obese women despite earlier negative test can reveal risks for obstetrical complications

“…According to previous studies, the rate of obesity in pregnancy is about 30%. [5][6][7]20 With alpha = 0.05, power of 90%, the sample size calculated was 216 (at least 50 women with obesity and 166 without obesity). A two-tailed p-value of <0.05 was considered statistically significant.…”

“…3,4 The worldwide increase in the prevalence of GDM has been shown to be partially explained by the increase in the incidence of obesity. 5 The risk of GDM correlates with body mass index (BMI). Women with pregestational obesity (BMI > 30 kg/m 2 ) have been found to have a threefold increase in GDM.…”

“…Women with pregestational obesity (BMI > 30 kg/m 2 ) have been found to have a threefold increase in GDM. [5][6][7] Excessive weight gain during pregnancy is associated with a greater risk of developing GDM, macrosomia, and a large-for-gestational-age (LGA) fetus. 8 Individualized guidelines are recommended for appropriate weight gain during pregnancy, based on pre-pregnancy BMI, to avoid excessive weight gain and to improve pregnancy outcomes.…”

“…Maternal obesity and gestational diabetes mellitus (GDM) are both associated with pregnancy complications, such as fetal macrosomia, shoulder dystocia, hypertension, and delivery by cesarean section (CS) 3,4 . The worldwide increase in the prevalence of GDM has been shown to be partially explained by the increase in the incidence of obesity 5 . The risk of GDM correlates with body mass index (BMI).…”