To compare the accuracy of visual observation method and hemoglobin assay method in estimation of volume of postpartum hemorrhage (PPH).

A total of 332 cases of pregnant women delivered in Department of Obstetrics, Chengdu Women and Children′s Hospital, from January 2012 to January 2013 were included in the study. They were divided into two groups according to the modes of delivery: cesarean section group (n=186) and vaginal delivery group (n=146). ①General clinical data between 2 groups were analyzed by stastical methods. ②Volumes of PPH within 24 h after delivery between 2 groups were evaluated by visual observation method and hemoglobin assay method, respectively. ③Incidence rates of PPH between 2 groups were evaluated by visual observation method and hemoglobin assay method, respectively. ④The volume of PPH were calculated when per 10 g/L of hemoglobin (Hb) level decreased. The study protocol was approved by the Ethical Review Board of Investigation in Human Beings of Chengdu Women and Children′s Central Hospital. Informed consent was obtained from each participating patient.

①There were no significant differences between 2 groups of pregnant women in the aspects of maternal age, gravidity and parity, gestational age, weight before birth, and birth weight and length of the neonates (P>0.05). ②The volumes of PPH within 24 h after delivery in cesarean section group and vaginal delivery group evaluated by visual observation method were 380.0 mL (348.8-406.3 mL) and 274.5 mL(220.0-331.1 mL), respectively. The median volume of PPH within 24 h after delivery of cesarean section group evaluated by visual observation method was significantly higher than that of vaginal delivery group, and the difference was statistically significant (H=84.4, P<0.001). The volumes of PPH within 24 h after delivery of 142 and 121 cases with Hb level decreased in cesarean section group and vaginal delivery group evaluated by the hemoglobin assay method were 340.2 mL (170.1-539.5 mL) and 377.1 mL (103.1-652.8 mL), respectively. The volumes of PPH within 24 h after delivery in vaginal delivery group evaluated by hemoglobin assay method was significantly higher than that of cesarean section group, and the difference was statistically significant (H=6.6, P<0.001). ③The incidence rates of PPH estimated by visual observation method in cesarean section group and vaginal delivery group, and in the 263 cases of pregnant women with Hb levels decrease, were significantly lower than those of hemoglobin assay method, and the differences were statistically significant (χ²=21.4, 45.6, 64.0; P<0.001). ④When per 10 g/L of Hb level decrease, the median volume of PPH within 24 h after delivery was 374.9 mL (330.0-419.6 mL).

The hemoglobin assay method provides more accurate estimates of volume of PPH within 24 h after delivery than that of the visual observation method, but it has limitations to estimate the volume of PPH by hemoglobin assay method alone.