Patient characteristics
A total of 682 patients were enrolled in this study. One hundred sixty patients (138 with hypertensive disorders, eight with caesarean deliveries, seven with anaemia, six with preterm deliveries, and one with pyrexia) were excluded (Figure S1). A total of 522 patients were included in the final analysis: 228 (43.7%) with NLA and 294 (56.3%) without NLA. Patients with NLA had a median age of 25.5 years [IQR, 20-28], while patients without NLA had a median age of 23 years (IQR, 21-30); p<0.001). Table 1 displays the clinical characteristics, interventions, and outcomes of each group. Patients with NLA had a significantly greater median age, greater frequency of nulliparity, higher haemoglobin, and less cervical dilation. Most NLA procedures were performed as an epidural technique (96.1%). There were no other differences in the other variables between the groups. InTable S1 , we describe the missing data for each variable.
In the NLA group, 31 (13.6%) patients required the administration of one or more uterotonics. Eighty-seven percent (n =27) required methylergonovine, 22.6% (n =7) required carbetocin, and 26.2% (n =5) required misoprostol. A total of 183 patients (80.6%) in the NLA group received more than two boluses of analgesia. The presence of PPH was similar between patients with and without NLA.