Trends in maternal obesity in a large university hospital 2009-2013

INTRODUCTION: Maternal obesity has been identified as an important clinical priority in contemporary obstetrics. This study aimed to determine the incidence of maternal obesity in early pregnancy and track recent trends in body mass index (BMI) categories over 5 years 2009-2013. MATERIAL AND METHODS: This prospective observational study included all women who delivered an infant weighing ≥500 g during the 5 years 2009-2013 in a large university teaching hospital in Ireland. Body mass index was calculated using early pregnancy weight and height measured at first antenatal visits. Sociodemographic and clinical data were gathered prospectively. Trends in maternal obesity were tracked over 5 years and epidemiological associations with obesity were examined using logistic regression, adjusted for confounding variables. RESULTS: Of 42 362 women, 99.0% (n = 41 927) were eligible for analysis with a mean BMI of 25.5 kg/m(2) , mean age of 30.7 years and 40.7% (n = 17054) primigravidas. The absolute number of cases of severe obesity (BMI ≥40.0 kg/m(2) ) increased by 48.5% from 2009 to 2013 (p < 0.001). After multivariate logistic regression analyses, obesity incidence increased with increasing parity, advancing age and socioeconomic disadvantage. The maternal obesity rate among women born in the 13 European Union Accession countries was 8.6%, nearly half that of those born in existing European Union countries (p < 0.001). CONCLUSION: It is concerning that while the overall obesity rate remained stable, the number of cases of severe obesity increased over 5 years. We recommend renewed public health efforts addressing obesity rates before pregnancy and reinforcing attempts to optimize a woman's weight after delivery.