Full length article Maternal obesity trends in a large Irish university hospital Ciara M.E. Reynolds a, *, Brendan Egan b , Léan McMahon a , Eimer G. O’Malley a , Sharon R. Sheehan a , Michael J. Turner a a UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Ireland b School of Health and Human Performance, Dublin City University, Ireland A R T I C L E I N F O Article history: Received 6 December 2018 Received in revised form 3 May 2019 Accepted 4 May 2019 Available online xxx Keywords: Maternal obesity prevalence Obesity trends Pregnancy complications Obstetric interventions Maternity costs A B S T R A C T Objective(s): This study aimed to examine recent trends in maternal obesity. Study design: This retrospective observational study used routinely computerised clinical and sociodemographic data of women who presented for antenatal care in a large maternity hospital in Ireland during the eight years 2010-17. Women with complete body mass index (BMI) data who delivered a baby weighing 500 g were included in the study. BMI was based on the measurement of weight and height and was categorised into the World Health Organizations (WHO) classifications. Results: The number of women delivered was 67,949 and 99.1% had complete data. The overall obesity rate increased from 16.0% (95% CI 15.3–16.8%) in 2010 to 18.9% (95% CI 18.0–19.7%) in 2017 (+18.1%, p < 0.001). This increase occurred in the mild, moderate and severe obesity subcategories (all p < 0.01). Overall, obesity was associated with multiparity, maternal age, maternal birth in Ireland or the United Kingdom (UK), depression, unemployment and unplanned pregnancy. The increase in obesity was more pronounced in nulliparas than in multiparas, particularly nulliparas <30 years. The increased obesity levels were accompanied by major sociodemographic changes in the hospital population from 2010 to 2017 with an increase in the average maternal age from 30.5 years to 32.2 years (p < 0.001) and a decrease in the proportion of nulliparas aged <30 years (from 40.6% to 28.8%, p < 0.001). Conclusion(s): It is likely that the escalating maternal obesity levels will lead to further increases in obstetric complications and interventions. The escalation was accompanied by major sociodemographic changes which have implications for healthcare planning and public health interventions. © 2019 Elsevier B.V. All rights reserved. Introduction Based on a Body Mass Index (BMI) >30.0 kg/m 2 , maternal obesity has emerged as one of the greatest challenges in contemporary maternity care, especially in high-income settings [1,2]. It is associated with an increase in pregnancy complications, such as Gestational Diabetes Mellitus (GDM) and preeclampsia, and an increase in interventions, such as Caesarean Section (CS) [2,3]. Severe obesity (BMI  40.0 kg/m 2 ), in particular, is associated not only with increased clinical risks but also technical challenges, for example, with diagnostic ultrasound, anaesthesia, surgical access, blood pressure measurements and appropriate equipment [4,5]. Maternal obesity may also potentially pose lifelong cardiovascular and metabolic problems for the woman and her offspring. Meeting all these challenges increases financial demands on the health services. There is considerable evidence that adult obesity levels are continuing to escalate globally [6,7]. There is a dearth of high quality data on obesity trends in pregnant women, including obesity subcategory trends, and evidence is often inferred from obesity trends in women of reproductive age [8,9]. The lack of quality data is also because BMI, if recorded, is usually based on self-reported weight and height which has underestimates BMI and miscategorises women using the WHO BMI classification [10, 11]. Furthermore, others are based on prepregnancy weight which is poorly standardised and open to recall bias [12]. The purpose of this study, therefore, was to report maternal obesity trends using prospectively measured height and weight at the first antenatal appointment from 2010 to 2017. Methods Data were prospectively collected and routinely computerised by trained midwives using a standardised questionnaire as part of the medical records at the first antenatal visit. The hospital is one of the largest maternity hospitals in Europe. It receives women from * Corresponding author: UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital, Cork Street, Dublin 8, Ireland. E-mail address: ciara.reynolds@ucdconnect.ie (C.M.E. Reynolds). https://doi.org/10.1016/j.ejogrb.2019.05.003 0301-2115/© 2019 Elsevier B.V. All rights reserved. European Journal of Obstetrics & Gynecology and Reproductive Biology 238 (2019) 95–99 Contents lists available at ScienceDirect European Journal of Obstetrics & Gynecology and Reproductive Biology journal homepage: www.elsevier.com/locate/ejogrb