Sir,We read with interest the article on prevalence of gestational diabetes mellitus and associated risk factors at a tertiary care hospital in Haryana published recently1. As pointed out by the authors, as per an earlier study conducted at various centres across India the prevalence of gestational diabetes mellitus was found to be 16.55 per cent2. This makes gestational diabetes mellitus an important area for research. I have some reservations with the criteria used to define body mass index (BMI) in this study. The cut-offs used in this study are applicable to normal adult population and cannot be applied to pregnant women. It is expected that a pregnant women will gain weight due to pregnancy, which may affect her BMI. Therefore, BMI in pregnancy needs to be viewed in light of this weight gain. The following guidelines by Mayo Clinic can be considered before deciding on the status of obesity in pregnancy3.The situation is further complicated in case of a twin pregnancy. Another area of concern is the universal use of Kuppuswamy scale for assessment of socio-economic status in study population without reflecting on the residential status of the study participants.