Changes in the Incidence of Congenital Anomalies in Henan Province, China, from 1997 to 2011

AIM To investigate changes in incidence and characteristics of congenital anomalies in infants in Henan Province of China over a period of 15 years. METHODS Population-based surveillance in Henan Province was conducted from 1997 to 2011 in 75 hospitals (40 urban districts and 35 rural counties, comprising about 20% of the total births). Basic population information was obtained from the healthcare network. All live births, intrauterine deaths after 28 weeks, and stillbirths were included. Congenital anomalies were diagnosed and reported to Henan Provincial Maternal and Pediatric Healthcare Hospital. RESULTS Of 1,815,920 births from 1997 to 2011, 15,660 cases of congenital anomalies were identified, resulting in an average incidence of 86.2 cases per 10,000 births. The incidence of congenital anomalies showed a significant downward trend (p < 0.0001) in rural areas and the whole province (p < 0.0001), but an increase in urban areas (p = 0.003). The incidence was much higher in rural than in urban areas in 1997, but this discrepancy decreased rapidly and no difference was seen between rural and urban areas in 2003. The incidence in females was higher than in males in 1997-1999 but decreased to a similar level as that in males in 2000. Maternal age exceeding 35 years was associated with a higher incidence of congenital anomalies. Among the 23 types of congenital anomalies recorded, neural tube defects were the most common; the incidence declined from 39.3 cases per 10,000 births in 1997 to 6.1 cases per 10,000 births in 2011. CONCLUSION The incidence of congenital anomalies has decreased in Henan Province over the past 15 years due to significant reductions in rural areas and among girls. This decrease was partly related to a reduction in neural tube defects that was likely the result of a folic acid intervention in the province.