Fig. 2

Expressing frequency and changes and predictive value of expressed milk volume. A. Expressing frequency on day 7 postpartum and discharge of infants. B. The proportions of mothers with increased, same, or decreased expressed milk volume compared with the previous time point. Expressed milk volume was measured on day 7 postpartum, at infant discharge, 2 weeks post-discharge, and 3 months corrected age. C. The predictive values of expressed milk volume on day 7 postpartum. ROC curve showed that expressed milk volume on day 7 postpartum reaching 190 mL/d was the optimal threshold for predicting expressed milk volume more than 300 mL/d at discharge (sensitivity, 72.5%; specificity, 73.7%; area under the curve [AUC], 0.77, 95% confidence interval, 0.65, 0.90; p = 0.001)