Abstract
Gestational Diabetes Mellitus (GDM) is a growing concern in Nigeria, driven by multiple risk factors. This study investigates socio-demographic, obstetric, and lifestyle-related risk factors for GDM among 161,839 pregnancies in Osun State tertiary hospitals (2011–2022), identifying 109 GDM cases (0.07% prevalence). Key risk factors included advanced maternal age (median 34.01 years, 67% aged 25–39), obesity (mean BMI 33.6 kg/m², 62.4% ≥35 kg/m²), urban residence (77.1%), tertiary education (85.3%), trading occupation (41.3%), nulliparity (32.1%), and alcohol use (38.5%). High diet compliance (82.6%) was noted but did not mitigate risk. These findings align with regional trends and underscore the need for targeted interventions, including weight management and urban-focused lifestyle programs, to reduce GDM incidence in Osun State.