RESUMO
What is already known about this topic?: The Shanxi Province, located in northern China, holds the highest prevalence of birth defects (BDs) across the country. Following the implementation of a nationwide folic acid supplementation program in 2009, a significant reduction of 53.89% in the prevalence of neural tube defects (NTDs) was observed in Shanxi from 2012 to 2017. However, despite this decrease, the prevalence rate for congenital heart defects (CHDs) in 2017 was over four times that of the 2012 rate. Since 2014, CHDs have emerged as the most predominant BD in Shanxi. What is added by this report?: The present study has identified a marked reduction in the prevalence of both total BDs and NTDs in five counties within Shanxi over the past two decades. As of 2017-2022, NTDs continue to be the most prevalent BDs recorded in this region. Contrarily, there has been a noteworthy increase in the prevalence of CHDs, ranking them among the top five most common BDs in the region between 2017 and 2022, though their rate remains below the national average. Additionally, the proportion of external anomalies remains high. Nevertheless, due to constrained access to primary healthcare services and diagnostic facilities, the early detection rate for internal anomalies, particularly CHDs, may be underestimated in the region. What are the implications for public health practice?: The results of this study underscore the necessity for augmented efforts in promoting folic acid supplementation as a preventive measure for NTDs. Moreover, improvements in the distribution of medical resources within this region are recommended, particularly the introduction and enforcement of local training programs aimed at enhancing CHD screening and diagnostic processes in these respective counties.
RESUMO
Folate insufficiency during the periconceptional period increases the risk of neural tube defects (NTDs) in offspring, and folic acid supplementation substantially reduces the risk. Widespread large-scale folic acid supplementation (0.4-mg folic acid tablet) has been adopted as a main strategy to prevent NTDs in China since 2009. We examined folate concentrations in plasma and red blood cells (RBCs) of pregnant women and the factors associated with blood folate concentrations in a population with a high prevalence of NTDs in northern China. A cross-sectional survey was conducted in 2014, and 1,107 pregnant women were recruited from 11 county or city maternal and child health centres across Shanxi province. Microbiological assays were used to determine folate concentrations. Factors associated with blood folate insufficiency were identified. The median (25th and 75th percentiles) folate concentrations were 28.4 (17.6, 45.2) nmol L-1 and 1,001.2 (658.7, 1,402.5) nmol L-1 in plasma and RBCs, respectively. According to the proposed RBC (906 nmol L-1 ) concentrations for optimal NTD prevention, 42.4% participants had RBC folate insufficiency. Rural women had a higher proportion of folate insufficiency than urban women. Folic acid supplementation was the only factor associated with RBC folate insufficiency. A large proportion of women had RBC folate concentrations that are not optimal for the prevention of NTDs despite free access to folic acid supplements. Actions that aim to improve folic acid supplementation compliance are needed to reach the full potential of the nationwide folic acid supplementation programme in terms of NTD prevention.