Objective To study the efficacy and possible mechanism of Bushen Huoxue Formula（ kidney-supplementing and blood-quickening formula） combined with dydrogestrone for recurrent spontaneous abortion（ RSA）.Methods Totally 62 cases of RSA were randomized into the Chinese medicine group of 21 cases

western medicine group of 20 cases and integrative medicine group of 21 cases. The Chinese medicine group was given self made Bushen Huoxue Formula one dose daily. The western medicine group was given dydrogestrone 10 mg each time and twice daily. The integrative medicine group was given both Chinese medicine and western medicine. The patients were treated from the 5th week to the 12 th week of pregnancy. Twenty healthy pregnant women were selected as the normal control group. The changes of beta human chorionic gonadotropin（ β-HCG） and progesterone（ P） were observed 18 days after basic body temperature（ BBT） rising and once weekly from the 6th week to the 10 th week of pregnancy.The levels of vascular endothelial growth factor（ VEGF） and soluble fms-like tyrosine kinase-1（ sFlt-1） were observed before and after treatment. The comprehensive efficacy was observed after treatment. Results The total comprehensive efficacy of the Chinese medicine group

western medicine group and integrative medicine group was76. 19%

70% and 85. 71% respectively

with significant differences among groups（ P < 0. 05）

but with no significant difference between groups（ P > 0. 017）. The levels of β-HCG and P in all treatment groups were significantly lower than those in the normal control group before treatment（ P < 0. 05）. The level of β-HCGP was gradually increased with gestational age in all groups. There was a significant difference between the level of β-HCGP in all groups as compared with the previous level（ P < 0. 01）. The level of β-HCGP in the integrative medicine group was significantly higher than that in the Chinese medicine group and western medicine group at the end of the 8th and 9th weeks of pregnancy（ P < 0. 05）. The level of P in the western medicine group and integrative medicine group was significantly increased after the 6th week of pregnancy（ P < 0. 05） and were significantly higher than that in the Chinese medicine group（ P < 0. 05）. The level of P in the integrative medicine group was significantly higher than that in the Chinese medicine group at the end of the 9th week of pregnancy（ P < 0. 05）. Comparing with 18 days after BBT rising

the levels of β-HCGP and P in all treatment groups were significantly increased at the end of the 9th week of pregnancy（ P < 0. 01）. Comparing between treatment groups

there were significant differences in the levels of β-HCGP and P at the end of the 9th week of pregnancy（ P < 0. 05）. The level of β-HCGP in the integrative medicine group was significantly higher than that in the Chinese medicine group and western medicine group（ P < 0. 05）. The level of P in the integrative medicine group was significantly higher than that in the Chinese medicine group（ P <0. 05）. The level of VEGF in all treatment groups was significantly lower than that in the normal control group before treatment（ P < 0. 01）. The level of sFlt-1 in all treatment groups were significantly higher than that in the normal control group before treatment（ P < 0. 01）. After treatment

the level of VEGF was significantly increased but the level of sFlt-1 was significantly decreased in all treatment groups（ P < 0. 01）. There were significant differences between treatment groups in the levels of VEGF and sFlt-1（ P < 0. 05）. The level of VEGF in the integrative medicine group was significantly higher than that in the Chinese medicine group and western medicine group（ P < 0. 05）. Conclusion The combo therapy of Bushen Huoxue Formula and dydrogestrone is effective for RSA. It can effectively regulate the endocrine level

promote placental angiogenesis and maintain pregnancy.