Photoacoustic and ultrasound Imaging of placental functions in gestational diabetes: From diagnosis to precision interventions

The prevalence of gestational diabetes mellitus (GDM) is rising, with adverse maternal–fetal outcomes. Exercise is first-line therapy, but current evaluations rely on glycemic and anthropometric metrics, missing dynamic maternal–placental–fetal adaptations. This review synthesizes imaging evidence on high-intensity interval training (HIIT) and resistance training (RT) in GDM. Multimodal imaging—photoacoustic imaging, Doppler ultrasound, and power Doppler—provides quantitative information on placental hemodynamics, vascularization, and fetal adaptation. HIIT may improve vascular function, while RT may induce structural remodeling, though GDM-specific evidence is limited. Photoacoustic imaging provides spatially resolved tissue oxygenation estimates, complementing ultrasound-based placental assessment. We propose imaging endpoints as key secondary outcomes in GDM trials. Hybrid photoacoustic and ultrasound (PA/US) imaging may integrate hemodynamic and oxygenation information. Coupled with continuous glucose monitoring, this framework may support comprehensive efficacy evaluation and individualized exercise prescription, highlighting that improved glycemic control does not necessarily reflect enhanced placental function.