Can MRI measurements help identify patients at risk of heavy bleeding during childbirth?

Details

Placenta accreta spectrum (PAS) disorders encompass conditions ranging from placenta accreta to placenta percreta and are usually associated with postpartum hemorrhage (PPH).

This cross-sectional study enrolled 109 patients at Sichuan Provincial People's Hospital from November 2018 to March 2022. PAS was suspected based on previous ultrasound results or clinical risk factors. Of the 109 patients, 34 had PPH and 75 did not.

Every patient underwent magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI). Researchers measured and compared the apparent diffusion coefficient (ADC) from DWI; perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) from IVIM; and mean diffusion kurtosis (MK) and mean diffusion coefficient (MD) from DKI.

Correlation analysis assessed the relationship between DWI parameters and estimated blood loss (EBL) during surgery. The study also compared the diagnostic performance of the two methods for predicting PPH.

Blood loss during delivery was positively correlated with D (r=0.331, P<0.001, 95% confidence interval [CI]: 0.170 to 0.477), D* (r=0.389, P<0.001, 95% CI: 0.207 to 0.527), f (r=0.222, P=0.02, 95% CI: 0.036 to 0.398), and MD (r=0.277, P=0.003, 95% CI: 0.108 to 0.439). It was negatively correlated with MK (r=-0.280, P=0.003, 95% CI: -0.431 to -0.098).

Multivariate analyses identified placenta previa and D as independent risk factors for PPH. Combining these two factors produced an area under the curve (AUC) of 0.795 (95% CI: 0.711 to 0.878).

The researchers concluded that IVIM and DKI parameters correlate with estimated blood loss. Using placenta previa and D together can help predict PPH in patients at high risk of PAS disorders.