目的 了解重庆市渝东南和渝东北地区0～5岁儿童出生缺陷总体发生水平，描述其主要出生缺陷病种及发生情况，为开展有针对性的出生缺陷干预提供科学依据。方法 采用按比例多阶段整群随机抽样方法选择对象，统一制定严格的诊断标准和复核标准，由经过严格培训的调查员现场对调查对象进行病史询问和体格检查。结果 渝东南和渝东北地区的出生缺陷发生率分别为39.84‰(41/1 029)和49.48‰(114/2 190)，差异无统计学意义(χ²=1.49，P=0.22)；两地区前3位出生缺陷类型分别为疝、多指(趾)并指(趾)、隐睾以及疝、隐睾、先天性心脏病。渝东南地区男童、女童出生缺陷发生率分别为59.65‰和15.25‰，渝东北地区分别为71.37‰和21.67‰，两地区男童的出生缺陷发生率均显著高于女童（P<0.05）。渝东南地区各年龄组缺陷发生率比较差异无统计学意义(χ²=1.22，P=0.87)；渝东北地区1岁年龄组缺陷发生率最高，4～5岁组次之，两组相比差异有统计学意义(χ²=9.91，P<0.05)。渝东北地区农村儿童出生缺陷的发生率(56.72‰)高于城镇（32.02‰）(χ²=7.80，P<0.05)，并且高于渝东南地区农村儿童出生缺陷发生率（37.36‰）(χ²=4.50，P<0.05)。结论 基于人群的出生缺陷调查结果全面揭示了重庆市渝东南和渝东北地区0～5岁儿童出生缺陷的实际发生水平及其三间分布特征，应针对其中发生率高且危害严重的疾病寻找主要危险因素，进行相应预防和控制。

Objective To investigate the prevalence of birth defects among children aged 0 to 5 years in southeastern and northeastern Chongqing, to illustrate the main types and conditions of defects, and to provide scientific evidence for the prevention of birth defects. Methods Subjects were selected through multi-stage proportional cluster random sampling. The criteria for diagnosis and re-checking were standardized, and the data of medical history and physical examinations were obtained by investigators with strict training. Results The prevalence rates of birth defects in southeastern and northeastern Chongqing were 39.84‰ (41/1029) and 49.48‰ (114/2190) respectively, with no significant difference between them (χ²=1.49，P=0.22). Hernia, polydactylism and cryptorchidism took the first three places of birth defects in southeastern Chongqing, while hernia, cryptorchidism and congenital heart disease in northeastern Chongqing. The prevalence rates of birth defects among boys and girls in southeastern Chongqing were 59.65‰ and 15.25‰ respectively, and those in northeastern Chongqing were 71.37‰ and 21.67‰ respectively, with the prevalence rates of boys significantly higher than those of girls in both areas (P<0.05). There was no significant difference in the prevalence rates of birth defects among different age groups in southeastern Chongqing (χ²=1.22，P=0.87). The prevalence rate of birth defects of 1-year age group was the highest in northeastern Chongqing, with that of 4-5-year age group ranking second, and there were significant differences between these two age groups (χ²=9.91，P<0.05). The prevalence rate of birth defects in the rural area (56.72‰) was higher than that of the urban area (32.02‰) in northeastern Chongqing (χ²=7.80，P<0.05), and was higher than that of the rural area in southeastern Chongqing (37.36‰)(χ²=4.50，P<0.05). Conclusion The prevalence of birth defects among children aged 0 to 5 years has been vividly illustrated by the cross-sectional investigation, which helps to identify the birth defects with high prevalence rate and severe damage and find the risk factors for the disease control and prevention.