Intraoperative Blood Loss in Female Patients with Adolescent Idiopathic Scoliosis during Different Phases of the Menstrual Cycle

Background The vast majority of AIS patients who require surgical intervention are women. Blood loss is a major concern during the operation. Methods The medical records of all female AIS patients who underwent posterior correction and fusion operations using the all-pedicle screw system from January 2012 to January 2014 were reviewed. Patients with irregular menstruation; underwent osteotomy; use coagulants were excluded from the study. The remaining patients were divided into 4 groups according to the operation date in the menstrual cycle (A: premenstrual group, 24–30 d; B: follicle group, 6–11 d; C: ovulatory group, 12–17 d; D: luteal group, 18–23 d). The information of patients from the 4 groups was reviewed. The data was analyzed using analysis of variance, the Student-Newman-Keels test and Kruskal-Wallis Test. Results A total of 161 patients were included in this study. There were 40 patients included in group A, 38 patients in group B, 41 patients in group C and 42 patients in group D. The 4 groups were matched in age (P = 0.238), body height (P = 0.291), body weight (P = 0.756), Risser sign (P = 0.576), mean curve Cobb angle (P = 0.520), and bending flexibility index (P = 0.547), the number of levels fused (P = 0.397). The activated partial thromboplastin time (P = 0.235) and prothrombin time (P = 0.074) tended to be higher in group A, but the difference was not statistically significant. The fibrinogen level was lower in group B than the other 3 groups (P = 0.039). Blood loss and normalized intraoperative blood loss (NBL) was significantly higher in group A than the other 3 groups (P<0.01). Conclusions The hemostatic function tended to be lower in the premenstrual phase. The fibrinogen level was lowest in the mid-follicle phase. Female AIS patients tended to endure more intraoperative blood loss when the operation was performed in the premenstrual phase during the menstrual cycle.