Efficacy of oral glucose tolerance testing of pregnant women post bariatric surgery

Globally, an estimated one in five women aged 20 years or older is obese, defined as a body mass index (BMI) ≥30 kg/m² (Ng et al, 2014). It is becoming increasingly common for pregnant women to have undergone bariatric surgery before conceiving. Bariatric surgery has been associated with a decreased risk of gestational diabetes and excessive fetal growth; shorter gestation, and an increased risk of small-for-gestationalage fetuses (Johansson et al, 2015). Gestational diabetes mellitus (GDM) is defined as the onset of glucose intolerance in pregnancy and is increasing in prevalence due to a number of factors, including the rising incidence of obesity (Catalano and Shankar, 2017). In the UK, GDM affects between 3% and 5% of all pregnancies (Ryan et al, 2018). GDM is now recognised as one of the most common complications of pregnancy, and has increased by more than 30% worldwide within the past 20 years (Zhu and Zhang, 2016). Gestational diabetes can lead to adverse maternal and fetal outcomes and it is therefore important that GDM is diagnosed and managed appropriately in pregnancy (Monteiro et al, 2016). The World Health Organization (WHO) (2016) recommends diagnosing GDM if any of the following criteria are met: