Ultrasonographic estimation of postpartum postvoid residual bladder volume: a comparison between transabdominal and transvaginal ultrasonography.

Postvoid residual bladder volume (PVRBV) was estimated in 89 patients with postpartum urinary retention using two ultrasonographic volume estimation methods. The PVRBV estimated by transabdominal and transvaginal ultrasonography are compared using the plot of difference against mean and the paired t-test. Neither showed any significant difference between the two methods (paired sample t-test, P > 0.05). The two methods have high correlation coefficient of 0.903 (Spearman's correlation, P < 0.0001). Either ultrasonographic volume estimation method gives reasonable bladder volume assessment in postpartum patients and could be used interchangeably as the clinical situation requires.