Maternal and Perinatal Outcomes in Nulliparous Women With a Booking Body Mass Index Exceeding 50 kg/m2

( Aust N Z J Obstet Gynaecol . 2024;64(6):603-607. doi: 10.1111/ajo.13839) Obesity increases risks of many general adverse health outcomes, as well as maternal morbidity in the obstetric population. Obesity is increasingly common across the world, and the incidence of class IV obesity [a body mass index (BMI) of 50 kg/m 2 or above] is also rising. In Australia, the incidence of class IV obesity in women giving birth is 1 in 500. Previous literature has been clear about the potential complications associated with class IV obesity and above in the obstetric population. Information on outcomes in nulliparous women with class IV obesity and above is scarce. This study aimed to describe maternal and perinatal outcomes in nulliparous women with BMI >50 kg/m 2 and assess factors that influence mode of delivery. In addition, this study was designed to describe medical and obstetric risk factors for this population.