Is high-dose misoprostol able to lower the incidence of cesarean section? A randomized controlled trial.
OBJECTIVE
To determine whether high-dose (100 microg) misoprostol was able to increase the rate of successful labor induction and lower the incidence of Cesarean section without adverse fetal effects.


METHODS
A total of 360 women were randomized to receive either oxytocin (n = 192) by intravenous infusion, or misoprostol (n = 168) 100 microg intravaginally every 4 h. The Cesarean section rate was the primary end-point. Incidences of uterine and fetal heart rate abnormalities during labor and adverse neonatal outcomes were assessed as secondary end-points.


RESULTS
Compared with those women receiving oxytocin, patients given misoprostol had a significantly shortened labor (10.7+/-6.0 vs. 15.4+/-10.4 h, p < 0.001). The Cesarean section rate did not differ between patients receiving misoprostol or oxytocin (36 (21.4%) vs. 38 (19.8%), p = 0.79) despite a sample size adequate to detect a 13 percentage point difference in this outcome. Patients receiving misoprostol had a higher incidence of the hyperstimulation syndrome (27 (16.1%) vs. 9 (4.7%), p < 0.001), and of fetal intolerance of labor as an indication for Cesarean delivery (23 (63.9%) vs. 15 (39.5%), p = 0.06), and had a greater number of umbilical artery cord blood pH findings of< 7.20 (20 (43.5%) vs. 6 (17.1%), p = 0.02). These worrisome trends on interim analysis resulted in our prematurely terminating the study.


CONCLUSIONS
High-dose intravaginal misoprostol did not reduce the Cesarean section rate and was associated with a greater hazard of fetal intolerance of labor.
de la Torre
S
S
Department of Obstetrics and Gynecology, University of New Mexico Health Sciences Center, Albuquerque 87131, USA.
Gilson
G J
GJ
Flores
S
S
Curet
L B
LB
Qualls
C E
CE
Rayburn
W F
WF
D000282:Administration, Intravaginal; D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007262:Infusions, Intravenous; D007751:Labor, Induced; D016595:Misoprostol / Q000008:administration & dosage / Q000627:therapeutic use*; D009516:New Mexico / Q000453:epidemiology; D010120:Oxytocics / Q000008:administration & dosage / Q000627:therapeutic use*; D010121:Oxytocin / Q000008:administration & dosage / Q000627:therapeutic use; D011247:Pregnancy; D011256:Pregnancy Outcome
D010120:Oxytocics; D016595:Misoprostol; D010121:Oxytocin