Anesthesia and blood loss in preterm cesarean section: comparison between general and regional anesthesia

Changes in maternal hemoglobin concentrations after cesarean section performed before 35 weeks gestation were analyzed according to the type of anesthesia in a case-control retrospective study. There were 30 mothers who received general anesthesia (GA group) and 30 mothers who received regional anesthesia (RA group). The groups were matched for gestational age at delivery, type of uterine incision, and the use of tocolytic therapy (isoxuprine) before delivery. The indications for delivery were preterm labor or fetal/maternal complications following premature rupture of membranes without labor. There was no significant difference between the GA and RA groups in the pre-operative hemoglobin (11.9+/-1.4 vs 11.6+/-1.1 g/dl) or postoperative hemoglobin (11.1+/-1.7 vs 11.3+/-1.2 g/dl). The GA group, however, demonstrated a significant fall in the postoperative hemoglobin (P < 0.05). The GA group also had a higher incidence of a drop in hemoglobin of > 10% compared to the RA group (46.7% vs 20.0%, P < 0.05). Our results suggest that general anesthesia may be associated with more blood loss than regional anesthesia in cesarean sections performed before 35 weeks.