Th1 type immunity to trophoblast is associated with URSA. Over expression of Th1 cytokine and the imbalance of Th1/Th2 might be the reason of URSA.

• 结论 正常妊娠以Th2型细胞因子反应为主 ,而在反复自然流产患者中 ,Th1型细胞因子过度表达 ,Th1 /Th2失去平衡 ,可能是原因不明反复自然流产发生的原因