中国部分地区出生人口性别比影响因素分析

Sex ratio at birth in parts of China and its influencing factors

目的了解中国部分地区出生人口性别比状况及其影响因素。方法采用分层、随机整群抽样方法,在内蒙古、江苏、甘肃,贵州及黑龙江省5个省份各抽取1个城市,于2009年3—6月以2006—2008年出生的17 093名婴幼儿及其父母为调查对象进行调查。结果 5个城市2006—2008年平均出生人口性别比为119.48。男、女婴在不同地区、不同胎次及不同民族间分布有差异(P<0.05);性别比在织金县最高(163.4),常州市最低(108.65);在不同胎次间≥3胎最高(199.6),第1胎最低(112.63);在不同民族中穿青族最高(176.41),蒙古族最低(106.01)。多因素logistic回归分析结果表明,影响性别比升高的因素有引产史(OR=1.579)、高胎次(2胎OR=1.261,≥3胎OR=1.395)、父母偏爱男孩(父亲OR=1.580,母亲OR=1.772)、父亲低文化程度(<9年OR=1.244,9~12年OR=1.336)、父母偏好女孩(父亲OR=0.504、母亲OR=0.544)。结论有引产史、高胎次、父母偏爱男孩、父亲低文化程度会使生育男孩的可能性增大,使出生人口性别比升高;父母偏好女孩会使生育女孩的可能性增大,从而降低出生人口性别比。

Objective To access the sex ratio at birth and its related factors in parts of China.Methods Using stratified random cluster sampling,we sampled one of cities from Inner Mongolia,Jiangsu,Gansu,Guizhou and Heilongjiang province,respectively,and investigated 17 093 infants born between 2006 and 2008 and their parents in the five cities from March through June 2009.Results From 2006 to 2008,the average sex ratio at birth was 119.48 （male to female） for the newborns during the 3-year period in the five cities and the ratio was different among the newborns of various regions,different live birth order,and different nationality （P〈0.05 for all）.The sex ratio at birth was the highest in Zhijin county （163.4） of Guizhou province and the lowest in Changzhou municipality （108.65） of Jiangsu province.For the newborns of different live birth order,the sex ratio was the lowest for the first-borns （112.63） and the highest for the third-borns （199.6）;for the newborns of various ethnic groups,the sex ratio was the lowest for the newborns of Mongolian （106.01） and the highest for the newborns of Chuanqing nationality （176.41）.The results of multivariate logistic regression showed that history of induced abortion （odds ratio[OR]=1.579）,high live birth order （second born：OR=1.261,third born or above OR=1.395）,boy preference of parents （father：OR=1.580,mother：OR=1.772）,and low educational level of the father （〈9 years：OR=1.244,9-12 years：OR=1.336） were associated with high sex ratio at birth and parental girl preference （father：OR=0.504,mother：OR=0.544） was related to low sex ratio.Conclusion The factors associated with high male to female ratio at birth are history of induced abortion,high parity,boy preference in parents,and low education of father;the factor related to low sex ratio is parental girl preference in parts of China.