Prevalence and trend of isolated and complicated congenital hydrocephalus and preventive effect of folic acid in northern China, 2005–2015

Abstract

Congenital hydrocephalus (CH) was a major birth defect of the central nervous system besides neural tube defects (NTDs). Few studies have focused on both the prevalence and trend of isolated and complicated CH in China. Data were drawn from a population-based birth defects surveillance program in five rural counties in northern China from 2005 to 2015. All livebirths and pregnancy terminations at any gestational age affected with CH were recorded. The prevalence and trend of isolated and complicated CH were examined. During the 11-year period, a total of 176,223 births and 357 CH cases were recorded, resulting in a prevalence rate of 20.3 CH cases per 10,000 births. Of the CH cases, 146 were isolated CH, resulting in a prevalence rate of 8.3 per 10,000 births. The pre-perinatal prevalence (<28 gestational weeks) was higher than the perinatal prevalence for both isolated and total CH. The prevalence rates of total and isolated CH showed a similar downward trend during the 11-year period. This downward trend was statistically significant after 2009 (p < 0.05), when a massive folic acid supplementation program was introduced. Although it decreased over time, the prevalence of CH remains high in this population which has a high prevalence of neural tube defects.

Assessment of the Prevalence and Associated Risk Factors of Pediatric Hydrocephalus in Diagnostic Centers in Addis Ababa, Ethiopia

“…This study is also similar to another study that suggested the consumption of adequate amounts of folic acid by women before pregnancy and during early pregnancy decreases their risk for having a pregnancy affected by NTDs (26). This study again goes following the study conducted in Northern China that found the supplementation of folic acid reduced the incidence of HCP and NTDs in their study population (12). This study supports the ndings above.…”

Folic acid supplementation and risk for congenital hydrocephalus in China

“…The main effect of FA supplementation (exposure) on CH was estimated. Because our previous study revealed that only 40 % of CH was non-NTD CH (3) , to comprehensively reflect CH status we included both CH and non-NTD CH in our study. As there were no reports in the literature on relative risk, we used the preventive effect of FA on NTD (i.e., the OR of the exposure group relative to the control group), 0•8 (8) , to estimate the incidence of CH in the control group at 0•81 per 1000 births (7) .…”

“…Our study provides new evidence that non-NTD CH is also preventable with periconceptional FA supplementation. As FA supplementation has a strong impact on plasma folate concentrations, massive FA supplementation in northern China has significantly improved folate concentrations and reduced CH over time (3) . The cause as well as the heterogeneity of its mechanisms needs to be explored further.…”

“…Diagnoses of birth defects were made according to the International Classification of Diseases, Ninth Revision, Clinical Modification. CH was diagnosed in accordance with code 742.3, while non-NTD CH refers to CH without anencephaly (740), spina bifida (741) or encephalocele (742•0) (3) .…”

“…In lowincome countries, an estimated 29 % of neonatal deaths related to visible congenital abnormalities are attributable to neural tube defects (NTD), which are also associated with lifelong disability (2) . Besides NTD, congenital hydrocephalus (CH) is another common major birth defect of the CNS, and 60 % of CH is complicated with NTD (3) . CH, which is characterised by an imbalance in cerebrospinal fluid secretion/absorption that results in the accumulation of fluid in the brain with consequential pathophysiology (4,5) , is an important cause of neurological morbidity and mortality in children (6) .…”