Central nervous system congenital malformations, especially neural tube defects in 29 provinces, metropolitan cities and autonomous regions of China: Chinese Birth Defects Monitoring Program.

Data from the Chinese Birth Defects Monitoring Program (CBDMP) over the period of October 1986 to September 1987 were analysed to study the descriptive epidemiology of congenital malformations of the central nervous system (CNS), especially neural tube defects (NTDs) in China. A total of 4628 CNS congenital malformations were recorded within seven days of delivery among 1,243,284 live and stillbirths of 28 or more weeks gestation in 945 hospitals from all 29 provinces, metropolitan cities and autonomous regions of China. Neural tube defects account for 73.55% of these cases, hydrocephaly for 24.63% and microcephaly for 1.82%. The prevalence rates at birth of NTDs and congenital malformations of the CNS in China were 27.37 and 37.22 per 10,000 respectively. More NTDs were observed in females (35.68 per 10,000 female births) as compared to males (19.23 per 10,000 male births). The prevalence of NTDs in rural areas (51.69 per 10,000 births) was higher than that in urban areas (15.45 per 10,000 births).