Accuracy of Blood Loss Estimation and Identification of Factors Contributing to Early Postpartum Hemorrhage Following Vaginal Delivery.

Objective

The study aimed to assess the accuracy of two distinct methods for estimating blood loss (EBL) and to identify potential factors contributing to early-onset postpartum hemorrhage (PPH) following a vaginal delivery (VD).

Methods

Women in singleton pregnancies undergoing spontaneous/induced VD were recruited for this prospective observational cohort study. Methods of EBL included: (1) visual assessment by an attending obstetrician (sEBL) and (2) implementation of a mathematical formula (fEBL). Early PPH was defined as a cumulative blood loss exceeding 500 mL within the first 24 h after delivery as reflected by clinical assessment.

Results

During the study period, 485 women delivered vaginally, and early PPH was diagnosed in 29 cases (5.97%). Among patients with PPH, a significant increase in the duration of the 2nd (61 min. vs. 33.5 min., p < 0.05) and 3rd (13 min. vs. 7 min., p < 0.001) stages of labor, as well as in the application of a dinoprostone insert (31% vs. 10.5%, p < 0.01) was noted. Additionally, in the same cohort, uterine atony (41.4% vs. 1.5%, p < 0.001), 3rd/4th degree perineal rupture (6.9% vs. 0%, p < 0.01), fetal macrosomia (17.2% vs. 4.8%, p < 0.05) and stillbirth (6.9% vs. 0.2%, p < 0.05) occurred significantly more frequently. In both groups visual estimation of blood loss was significantly lower compared to fEBL: (PPH sEBL: 800 mL vs. fEBL 1439.6 mL, p < 0.001; control sEBL: 250 mL vs. fEBL 621.8 mL, p < 0.001). In the multivariate analysis, factors such as third stage of delivery time ≥ 30 min. (OR 11.6; 95% CI: 4.18-32.33), FBW ≥ 4000 g (OR 6.37; 95% CI: 1.54-26.3), and dinoprostone insert application (OR 4.33; 95%CI: 1.63-11.48) were selected as independent predictors of the PPH.

Conclusions

Compared to mathematical formula, visual estimation of blood loss by an attending obstetrician is significantly decreased. Prolonged third stage of delivery, fetal macrosomia, and application of a dinoprostone insert are the strongest contributors to early PPH following a VD.