Introduction: Prepregnancy overweight and obesity is an increasing public health issue worldwide, including Iceland, and has been associated with higher risk of adverse maternal and birth outcomes. The aim of this study was to investigate trends in prepregnancy weight amongst women in North Iceland from 2004 to 2022, and the prevalence of overweight and obesity in this population.
Material and methods: This retrospective cross-sectional study included all women who gave birth at Akureyri Hospital in North Iceland between 2004 and 2022 (N = 7410). Information on age, parity, height, and prepregnancy weight was obtained from an electronic labour audit database. Body mass index (BMI) was calculated from self-reported height and weight, and the median BMI and proportions in each of the six BMI categories were calculated for four time periods.
Results: Median BMI increased significantly from 24.5 kg/m2 in 2004-2008 to 26.2 kg/m2 in 2019-2022. On average, BMI increased by 0.15 kg/m2 with each passing year (p<0.001). The prevalence of normal weight decreased from 53% to 40% and the entire BMI distribution shifted towards a higher BMI. The proportion of women in obesity class I (BMI 30.0 - 34.9) increased from 12.8% to 17.3%, the proportion of women in obesity class II (BMI 35.0 - 39.9) doubled (3.7% to 8.1%) and tripled in obesity class III (BMI ≥ 40.0; 1.6% to 4.8%).
Conclusion: Prepregnancy weight of women in Northern Iceland has gradually increased over the last 19 years and 30% of pregnant women are now classified as obese. Further studies on the subsequent effects on maternal and birth outcomes are needed, with a focus on strategies to decrease adverse effects and reverse this trend.
Keywords: Iceland/epidemiology; obesity; overweight; pregnancy; prepregnancy body mass index.