Prevalence of Clinical and Pre-Clinical Obesity at Six Months Postpartum Following Gestational Diabetes Mellitus

<b>Background/Objectives</b>: A number of initiatives have refocused attention from obesity to adiposity-related organ dysfunction. In this prospective observational study, we examined this paradigm postpartum. <b>Methods</b>: At King's College Hospital, London, UK, we invited for review by six months postpartum, consecutive women with GDM (N = 1442, September 2023-August 2025) and without GDM (N = 646, January 2025-August 2025). Those with excess adiposity (BMI ≥ 30 kg/m² and waist-to-height ratio > 0.5) were assessed for organ dysfunction, using criteria from a recent Commission: anovulation, metabolism or renal clusters, raised blood pressure, or elevated end-diastolic left ventricular filling pressure. Multiple regression determined predictors of adiposity-related organ dysfunction, the prevalence of which was calculated as a range (highest estimate: absolute organ dysfunction prevalence; lowest estimate: adiposity-adjusted, as highest estimate minus prevalence of organ dysfunction in women without excess adiposity). <b>Results</b>: Of those invited for review, 1086/1442 (75.3%) GDM and 562/646 (87.0%) non-GDM women attended, at median 5.8 months after birth (interquartile range 4.8-6.7). Excess adiposity was observed in 385/1086 (35.5%) GDM and 117/562 (20.8%) non-GDM women, among whom organ dysfunction was seen in 61.0% GDM (235/385), 51.3% non-GDM (60/117). 35.9% (408/1137) of women without excess adiposity. Organ dysfunction attributable to excess adiposity was estimated to be 22.9% (58.8% minus 35.9%), and was poorly predicted by the multivariable model (AUC 0.64, 95%CI 0.60-0.69). <b>Conclusions</b>: Among women with prior GDM, organ dysfunction attributable to excess adiposity affects at least 20% of those with excess adiposity postpartum, and is not currently predictable.