[Impacts of birth defects on perinatal deaths in Chinese population]

To examine the time trends of perinatal mortality and the frequency of birth defects occurring in perinatal deaths, and to provide a national perspective on the impacts of congenital anomalies on perinatal mortality from 1990 through 2001.

Data were from Chinese Birth Defects Monitoring network-a hospital-based congenital anomalies registry system. During 1990 - 2001, all live or still births with 28 weeks of gestation or more, born in monitoring units, were studied within 7 days after delivery. The proportion of perinatal deaths due to birth defects, which was defined as the number of perinatal deaths associated with congenital anomalies per 100 perinatal deaths, was calculated by birth area (urban versus rural), geographic-economic status (coast areas, inner land areas and remote areas), to evaluate the impacts of birth defects on perinatal mortality.

Perinatal mortality declined from 22.85 per 1000 in 1990 to 13.26 per 1000 in 2001, which showed a significant downward trend. Similar trend was also observed in the rate of stillbirth and the ratio of early neonatal death. However, the proportion of perinatal deaths due to birth defects had an increasing trend although the perinatal birth defects-specific death rate was declining, especially during 1996 - 2001. This result was also seen in urban and rural area, in coast regions, in inner land regions and in remote regions of China. Higher rate of birth defects occurring in perinatal deaths was observed in urban area than in rural area. Significant difference of this rate was also found among different geographic-economic regions, with the highest one in inland regions.

Birth defects were accounted for an increasing proportion of perinatal deaths in China, and had become one of the major causes of perinatal deaths.