To evaluate the effects of uterine artery embolization on preventing the pregnancy with complete placenta previa hemorrhage during induced labor in second trimester and its adverse effects.

We retrospectively analyzed 79 cases of labor induction on pregnancy with complete placenta previa during second trimester, who were admitted to the third affiliated hospital of Guangzhou medical university during January 2011 to December 2014. There were divided into embolization group and control group. In embolization group, 29 patients were induced labored by using rivanol and mifepristone. On the same time, they were performed uterine artery embolization (UAE). 18 cases were 20-27^{+ 6} gestational weeks and 11 cases were less than 20 gestational weeks. In control group, 50 patients were induced labored by using rivanol and mifepristone. 20 cases were 20-27^{+ 6} gestational weeks and 30 cases were less than 20 gestational weeks. The timing of labor induction, the number of loss bleeding, the rate of fever, the pain degree and the recovery phase of menstruation were compared between embolization group and control group.

(1) Excepted one performed cesarean section due to fail of induced labor, the timing of induced labor in 20-27^{+ 6} gestational weeks was (49.36±7.80) hour in embolization group and was(41.23±7.59)hour in control group. Under 20 gestational weeks, the timing of induced labors was (49.36±7.80) h and (41.23±13.85) h in embolization group and control group, respectively. Compared in the timing of induced labored between two groups, there was significant difference.(2)Compared in the number of loss bleeding in 20-27^{+ 6} gestational weeks between two groups, 294±60 ml and 356±81 ml were respectively in embolization group and control group, which was significant difference. There war not significant difference in less than 20 gestational weeks. (3)Compared in the pain degree in 20-27^{+ 6} gestational weeks between two groups, the score was respectively 8.70±0.90 and 2.11±0.50 in embolization group and control group, which was significant difference. Compared in the pain degree in less than 20 gestational weeks, the score was 7.27±1.80 and 1.65±0.48 respectively in embolization group and control group, which was significant difference.(4) The rate of fever was 61.11% in 20~27^{+ 6} gestational weeks of embolization group and 5% in control group, which was significant difference. Compared in less than 20 gestational weeks between two groups, there was respectively 63.63% and 6.67%, which also were significantly difference.

(1) UAE played a positive role on preventing hemorrhage due to central placenta previa in more than 20 gestational weeks. But there was not on less than 20 gestational weeks. (2) UAE could prolong the time of labor induction, increase the pain degree and the rate of fever. So we used UAE cautiously. (3) In induced labor with central placenta previa during second trimester, adept skill played a positive role on preventing and decreasing hemorrhage.