Investigating Placenta Accreta Spectrum Disorder Incidence, Risk Stratification, and Surgical Outcomes in the Context of Rising Caesarean Rates in Nigerian Tertiary Hospitals

Placenta accreta spectrum (PAS) disorder incidence is rising globally in parallel with increasing caesarean delivery rates, and Nigeria's climbing caesarean rate creates an emerging PAS burden whose magnitude, risk profile, and surgical management outcomes in tertiary hospitals have not been characterised. This dissertation investigates PAS incidence, risk stratification, and surgical outcomes at six Nigerian tertiary hospitals spanning all geopolitical zones. A prospective multi-site cohort enrolled all suspected and confirmed PAS cases managed over a four-year period at University College Hospital (South West), University of Maiduguri Teaching Hospital (North East), Aminu Kano Teaching Hospital (North West), NAUTH Awka (South East), UPTH (South South), and UATH Abuja (North Central). PAS diagnosis was confirmed by intraoperative findings and histopathology. Magnetic resonance imaging and colour Doppler ultrasound were evaluated as preoperative diagnostic tools. A total of 84 PAS cases were identified, yielding an incidence of 1 in 420 deliveries. Incidence was highest at sites with the longest established high caesarean rates. Prior caesarean count was the dominant risk factor (OR 6.8 per additional caesarean). Multidisciplinary team management was associated with significantly lower blood transfusion requirements and hysterectomy rates. MRI showed 88 percent sensitivity for PAS depth classification. Maternal mortality was 4.8 percent, highest in cases without preoperative diagnosis. The dissertation provides Nigeria's first prospective multi-site PAS database and recommends mandatory multidisciplinary team protocols and preoperative imaging in all prior-caesarean pregnancies with placenta praevia. Keywords: placenta accreta spectrum, caesarean section, surgical outcomes, Nigeria, multidisciplinary team