The report by Cheney and colleagues in this issue of the MJA clearly shows the increasing contribution by the effects of overweight and obesity during pregnancy to adverse perinatal outcomes.1 The authors analysed pregnancy outcomes at a large teaching hospital in central Sydney, and found that the population attributable fractions (PAFs) of pre‐eclampsia, gestational diabetes, and fetal macrosomia associated with overweight and obesity (defined by maternal body mass index [BMI] categories) have risen significantly during the past 25 years. As troubling as these findings are, it is worth noting that nearly 80% of the study population had BMIs in the low or normal ranges. However, in the parts of Australia where overweight and obesity are more prevalent, intertwined with socio‐economic disadvantage, the PAF associated with overweight and obesity will be higher. Cheney and her co‐authors also report interesting trends in their nulliparous population with respect to other risk factors for adverse pregnancy outcomes, such as increasing age and falling smoking rates, and changes in the ethnic profile and dramatic improvements in socio‐economic status of the hospital catchment area. The authors modelled the impact of reducing the overall BMI category distribution of first‐time mothers, and the prospective improvements in outcomes are remarkable, suggesting that pre‐pregnancy weight loss interventions need to be a priority for improving perinatal health.