流产在日常的临床工作中经常遇到,占妊娠总数之10～15%。流产发病原因很多,可是在发病时很少能明确其因果关系。本文结合最新文献,按内外因加以叙述。一、与卵细胞发生异常有关的内因:由卵异常引起的流产率较高,如Hertig等通过1,000例自然流产分析,61.7%为卵或附属物的异常。可能和以下因素有关:(1)母体年龄:自30岁随着年龄增长自然流产率逐渐上升,至40岁其流产率急剧增加。原因虽尚不能确切解答,与年龄同时增长的卵变性、卵巢机能变化、卵受精适应性缺乏以及因诱发排卵而排出未成熟卵有关。(2)孕次:早期流产在第一次妊娠时和第三次妊娠以后为多。随着妊娠次数 Abortion is often encountered in routine clinical work, accounting for 10 to 15% of the total number of pregnancies. Many causes of miscarriage, but very few causation in the pathogenesis. This article combines the latest literature, according to internal and external reasons to be described. First, the internal factors associated with abnormal egg cells: abortion caused by abnormal egg rates higher, such as Hertig through 1,000 cases of spontaneous abortion analysis, 61.7% of eggs or ancillary abnormalities. It may be related to the following factors: (1) Maternal age: The spontaneous abortion rate increases gradually with age since the age of 30, and the abortion rate dramatically increases to 40 years of age. Although the reasons are not yet the exact answer, with age at the same time the growth of ovarian degeneration, changes in ovarian function, lack of adaptive fertilization of eggs and induced ovulation evoked immature eggs. (2) Pregnancy: early abortion in the first pregnancy and after the third pregnancy as much. With the number of pregnancies