Short Communication Impact of morbid obesity on the mode of delivery and obstetric outcome in nulliparous singleton pregnancy and the implications for rural maternity services Clive GREEN and David SHAKER Department of Obstetrics and Gynaecology, Rockhampton base hospital, Rockhampton, Queensland, Australia Obesity represents a rapidly emerging epidemic amongst pregnant women. Our study looks at the impact of morbid obesity on pregnant singleton nulliparous women in comparison with normal body mass index women. We conclude that morbid obesity is associated with a significantly higher risk of pre-existing medical conditions, developing antenatal complications, induction of labour, caesarean section and greater birth weight. However, there was no significant difference in caesarean section rates when adjusted for induction of labour. We also found no significant difference in length of hospital stay, postnatal complications and neonatal morbidity. Key words: morbid obesity, pregnancy, pregnancy outcome. Introduction Obesity represents a rapidly emerging epidemic amongst pregnant women. The World Health Organisation (WHO) characterises obesity as a pandemic issue. In 2005, the WHO reported 1.6 billion adults were overweight with a body mass index (BMI) >25 kg ⁄ m 2 and 400 million obese with a BMI >30 kg ⁄ m 2 . 1 Rockhampton, in central Queensland, is noted for its overweight and obese population. A 2009 central Queensland adult health survey found 34.7% of the population were overweight and 26.2% were obese. 2 In 2008, the Australian Institute of Health and Welfare (AIHW) reported that ‘people living in regional areas are significantly more likely to be overweight and obese than those in major cities’ and that ‘rural women who are obese are often required to deliver their babies in major centres rather than closer to home’. 3 In central Queensland, obstetricians from Gladstone, Biloela and Emerald refer their obese patients to Rockhampton hospital for continuing obstetric care from 38-week gestation because of perceived concerns about the risk of delivery. Research has shown that obese pregnant patients are at a greater risk of hypertension, gestational diabetes, thromboembolism, fetal complications, induction of labour, caesarean sections, postdelivery complications, neonatal complications and longer hospital admissions. 4–13 Our study was designed primarily to look at the impact of morbid obesity on the mode of delivery of pregnant singleton nulliparous patients in a rural setting. We hypothesise that morbid obesity (BMI > 35) increases antepartum complications, induction of labour, caesarean section rate, postpartum and neonatal complications. Materials and methods Our design was a retrospective cohort study of nulliparous women delivered in Rockhampton hospital between July 2008 and June 2009. Cases were identified from the labour ward register; data were collected from the Queensland perinatal data form; and women were categorised into two groups based on their antenatal booking BMI. Group I included women with a normal BMI (18.5–25), and Group II included morbidly obese women (BMI > 35). Hospital charts for these women were reviewed. Exclusion criteria included no BMI recorded, elective caesarean section, multiple pregnancy and terminations for fetal abnormality. The primary outcome measure was mode of delivery, and secondary outcome measures included pregnancy-related medical problems, induction of labour, intrapartum and postpartum complication rates, neonatal birth weight, neonatal morbidity and length of hospital stay. Student’s t-test (unpaired) was used for the analysis of continuous variables and Fisher’s exact test for the nominal variables. We also used Cochran–Mantel–Haenszel test to compare the caesarean section rate in each group adjusting for induction of labour. The study was approved by the Rockhampton hospital management and was exempted by Ethics committee from full Ethics committee approval as it is a part of a departmental audit. Correspondence: Dr C. Green, Department of Obstetrics and Gynaecology, Nambour hospital, Nambour, Qld 4560, Australia. Email: clive_green@health.qld.gov.au Received 7 November 2010; accepted 6 December 2010. 172 Ó 2011 The Authors Australian and New Zealand Journal of Obstetrics and Gynaecology Ó 2011 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists Australian and New Zealand Journal of Obstetrics and Gynaecology 2011; 51: 172–174 DOI: 10.1111/j.1479-828X.2010.01271.x Te Australian and New Zealand Journal of Obstetrics and Gynaecology