Creatine Kinase as a Potential Diagnostic Biomarker for Distinguishing Placenta Accreta Spectrum and Placenta Previa: A Prospective Pilot Study.

BACKGROUND

Placenta previa (PP) and placenta accreta spectrum (PAS) are major causes of severe obstetric hemorrhage, yet in some scenarios, antenatal discrimination and risk stratification remain challenging with imaging alone. An inexpensive, widely available adjunct biomarker such as maternal serum creatine kinase (CK) may help differentiate PP from PAS, reflect imaging-based placental severity, and identify women at increased risk of intraoperative massive hemorrhage.

METHODS

This pilot prospective cohort study enrolled women with singleton pregnancies managed at a tertiary center between January 2025 and January 2026 with suspected PP or PAS. PP and PAS were confirmed by intraoperative inspection and postoperative histopathology. Serum CK was measured using third-trimester blood samples. Ultrasound and MRI placental scores were calculated using predefined scoring systems. Spearman correlation assessed associations between CK and imaging scores. Multivariable logistic regression explored risk factors for intraoperative massive hemorrhage.

RESULTS

Thirty-one participants were included (PP, n = 22; PAS, n = 9). Late-gestation CK levels were significantly higher in PAS than PP (78.28 ± 30.01 vs. 38.07 ± 17.86 U/L; p = 0.041). PAS had higher ultrasound and MRI placental scores than PP (both p < 0.001). CK was moderately positively correlated with the ultrasound score (ρ = 0.484, p = 0.003) and MRI score (ρ = 0.401, p = 0.026). In multivariable analyses, higher CK, more prior cesarean deliveries, and higher ultrasound and MRI scores were associated with increased odds of intraoperative massive hemorrhage.

CONCLUSION

Late-gestation maternal serum CK was elevated in PAS versus PP, correlated with ultrasound- and MRI-based placental scores, and was associated with massive hemorrhage risk, suggesting CK as a potential adjunct biomarker for PAS.

TRIAL REGISTRATION: ChiCTR2100054068, December 8, 2021.