Methods: TC199 low level of folic acid cultivation method was performed to analyse both the frequency and the distribution of chromosome fragile sites in 31 habitual abortion couples.

• 方法采用低叶酸TC199培养诱导法,观察了31对染色体核型无异常的习惯性流产夫妇染色体脆性位点,并观察了脆性位点的分布。