【摘要】 １９８９年，我国妇女双胞胎生育率是０．７９％，其中一卵双生占２６．８３％，二卵双生占７３．１７％。双胞胎出生率最高的是山东省，为１．４３％；最低的是西藏，只有０．４２％。一卵双生率最高的是上海，达５８．５４％；最低的是山东，为０。上海、北京同性别双生儿中，主要是一卵双生，而山西同性别双生儿中主要是二卵双生。我国妇女在１５～３９岁年龄段中，３３岁妇女双生率最大（１．３３％），１５岁双生率最小（０．３％）。一卵双生和二卵双生既与遗传有关，也与环境有关，因此，一卵双生和二卵双生可能属于数量性状。更多还原

【Abstract】 he rate of twins-bearing constituted 0.79 percent in china in 1989. The monozygotic(MZ)twins constituted 26.83 percent of all twins,and the dizygotic(DZ)twins 73.17 percent.Shan-dong Province had the highest rate of twins(1. 43%),and Tibet the lowest rate(0.42%).Thehighest rate of MZ twins was found in shanghai(58. 84%),and the lowest one was found inShandong Province(0).The MZ twins make up most part of the same-sex twins in Shanghai andBeijing,While DZ twins in Shanxi Province,The highest rate of twins-bearing was foud in womenof 33 vears old (1. 33%),and the lowest one in women of 15 years old (0.3%).It is thought thatthe rate of MZ and DZ twins relates not only to heredity, but also to natural environment.Theyare perhaps of a quantitative character.更多还原