From 1 August, 1981 to 31 July, 1984, the authors used epidemiological method to carry out a field retrospective investigation of 806 women who had had the Stainless Steel Ring (SSR) inserted for the first time. By th...From 1 August, 1981 to 31 July, 1984, the authors used epidemiological method to carry out a field retrospective investigation of 806 women who had had the Stainless Steel Ring (SSR) inserted for the first time. By the life table method, the one year continuation展开更多
文摘From 1 August, 1981 to 31 July, 1984, the authors used epidemiological method to carry out a field retrospective investigation of 806 women who had had the Stainless Steel Ring (SSR) inserted for the first time. By the life table method, the one year continuation
