OBJECTIVE: To investigate the diagnostic efficacy and detection value of matrix metalloproteinase-9 (MMP-9) and VEGF in menacing pernicious placenta previa (PPP). METHOD: Among all the cases of PPP, a critical condition within the Placenta Accreta Spectrum (PAS) caused by aberrant implantation of the placenta in the uterine wall, which were analyzed between April 2021 and March 2023, there were sixty-three cases. The control group consisted of those sixty-three women who had a normal placenta. Serum levels of MMP-9 and VEGF were measured and compared in both groups. The expression levels of MMP-9 and VEGF were analyzed along with ultrasound scores related to different degrees of placental implantation. Comparisons between groups were performed using RESULTS: MMP-9, VEGF expression, and ultrasound scores of pregnant women in the PPP group were significantly higher than those in the control group ( CONCLUSION: MMP-9, VEGF, and ultrasound scores help predict placental implantation in PPP, which, in turn, provides significant support for clinical understanding.