Changing trends in the prevalence of anencephaly in Liaoning province of Northeast China from 2006-2015: data from a population-based birth defects registry.

The goal of this study was to assess the prevalence and trends of anencephaly on the basis of a large population-based cases identified by the Liaoning Birth Defects Registry, which included 14 cities over a 10-year period. Anencephaly prevalence, percent change, average changeand the contribution rates of each city were calculated. Statistical analysis was undertaken on the basis of a Poisson regression model. A total of 1600 anencephaly cases were collected during the observational period (4.92/10,000 live births). On average, the prevalence decreased 10.15% each year; this overall time trend was statistically significant (P<0.01). The top three leading cities were Huludao (10.33 per 10,000 live births), Chaoyang (8.56 per 10,000 live births) and Fuxin (6.36 per 10,000 live births). In contrast, Anshan (2.64 per 10,000 live births), Dalian (2.79 per 10,000 live births) and Yingkou (3.46 per 10,000 live births) were the cities with the lowest prevalence. Of note, significantly decreasing trends were observed in half of these cities (n=7). Additionally, Benxi, Yingkou and Dalian were the major cities contributing to over one third of the decreasing trend in Liaoning province. In conclusion, this study provided evidence of the decreasing prevalence of anencephaly from 2006 to 2015 in Liaoning province. In the future, prevention efforts should be strengthened to further reduce the risk of anencephaly in areas with high rates.