Effect of pathoanatomic diagnosis on the quality of birth defects surveillance in China

Global prevalence of congenital anencephaly: a comprehensive systematic review and meta-analysis

Background

Anencephaly is a fatal congenital anomaly characterized by the absence of brain hemispheres and cranial arch. Timely preventive measures can be taken by knowing the exact prevalence of this common neural tube defect; thus, carried out through systematic review and meta-analysis, the present study was conducted to determine the worldwide prevalence, incidence and mortality of anencephaly.

Methods

Cochran’s seven-step instructions were used as the guideline. Having determined the research question and inclusion and exclusion criteria, we studied MagIran, SID, Science Direct, WoS, Web of Science, Medline (PubMed), Scopus, and Google Scholar databases. Moreover, the search strategy in each database included using all possible keyword combinations with the help of “AND” and “OR” operators with no time limit to 2021. The I² test was used to calculate study heterogeneity, and Begg and Mazumdar rank correlation tests were employed to assess the publication bias. Data were analyzed by Comprehensive Meta-Analysis software (Version 2).

Results

In this study, the statements of Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) were used. In the first stage, 1141 articles were found, of which 330 duplicate studies were omitted. 371 articles were deleted based on the inclusion and exclusion criteria by reviewing the title and abstract of the study. 58 articles were removed by reviewing the full text of the article because it was not relevant to the research. 360 studies with a sample size of 207,639,132 people were considered for the meta-analysis. Overall estimate of the prevalence, incidence and attenuation of anencephaly worldwide were 5.1 per ten thousand births (95% confidence interval 4.7–5.5 per ten thousand births), 8.3 per ten thousand births (95% confidence interval 5.5–9.9 per ten thousand births), 5.5 per ten thousand births (95% confidence interval 1.8–15 per ten thousand births) respectively the highest of which according to the subgroup analysis, belonged to the Australian continent with 8.6 per ten thousand births (95% confidence interval 7.7–9.5 per ten thousand births).

Conclusion

The overall prevalence of anencephaly in the world is significant, indicating the urgent need for preventive and treating measures.

Anencephaly is a fatal congenital anomaly characterized by the absence of brain hemispheres and cranial arch. Cochran’s seven-step instructions were used as the guideline. Having determined the research question and inclusion and exclusion criteria, we studied MagIran, SID, Science Direct, WoS, Web of Science, Medline (PubMed), Scopus, and Google Scholar databases. Moreover, the search strategy in each database included using all possible keyword combinations with the help of “AND” and “OR” operators with no time limit to 2021. Out of 1141 initial articles found, and after excluding repetitive ones in various databases and those irrelevant to inclusion criteria, 360 studies with a sample size of 207,639,132 people were considered for the meta-analysis. Overall estimate of the prevalence, incidence and attenuation of anencephaly worldwide were 5.1 per ten thousand births (95% confidence interval 4.7–5.5 per ten thousand births), 8.3 per ten thousand births (95% confidence interval 5.5–9.9 per ten thousand births), 5.5 per ten thousand births (95% confidence interval 1.8–15 per ten thousand births) respectively the highest of which according to the subgroup analysis, belonged to the Australian continent with 8.6 per ten thousand births (95% confidence interval 7.7–9.5 per ten thousand births). The overall prevalence of anencephaly in the world is significant, indicating the urgent need for preventive and treating measures.

Effect of periconceptional folic acid supplementation on the risk of neural tube defects associated with a previous spontaneous abortion or maternal first-trimester fever

STUDY QUESTION

Does maternal periconceptional no folic acid supplementation have an increased risk of neural tube defects (NTDs) associated with previous spontaneous abortion or first-trimester fever?

SUMMARY ANSWER

Maternal periconceptional no folic acid supplementation can increase the risk of NTDs associated with previous spontaneous abortion or first-trimester fever, independent of known confounding factors.

WHAT IS KNOWN ALREADY

Maternal periconceptional folic acid deficiency can increase the risk of NTDs. However, whether an interaction between periconceptional no folic acid supplementation and history of spontaneous abortion or first-trimester fever may have an increased risk of NTDs remains unknown.

STUDY DESIGN, SIZE, DURATION

A population-based case-control study was performed including 104 nuclear families with offspring with NTDs and 100 control families with normal offspring between 1993 and 2002.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We investigated the potential interaction between periconceptional no folic acid use and a maternal history of spontaneous abortion or first-trimester fever in the risk for NTDs. Information on exposure factors was obtained at the onset of pregnancy, and pregnancy outcomes were collected during the first week after delivery or at the time of termination of the pregnancy. A multivariate logistic regression analysis was performed.

MAIN RESULTS AND THE ROLE OF CHANCE

The interaction between periconceptional no folic acid use and a maternal history of spontaneous abortion markedly increased the risk of NTDs (adjusted odds ratio (aOR) 18.68, 95% CI, 4.43-78.76) after adjusting for potential confounding factors. The interaction coefficient was found to be 2.08, higher than 1, indicating that there is a significant interaction between two factors. Mothers who did not take periconceptional folic acid and had first-trimester fever had an increased risk of NTDs (aOR 21.81, 95% CI, 8.81-80.73). However, the interaction coefficient was found to be 0.62, less than 1, indicating that there is no significant interaction between two factors.

LIMITATIONS, REASONS FOR CAUTION

A potential limitation was that the interval between the previous spontaneous abortion and the beginning of the subsequent pregnancy could not be estimated accurately, but was at least 1 year or more.

WIDER IMPLICATIONS OF THE FINDINGS

We emphasize that a previous spontaneous abortion may represent a first occurrence of NTDs rather than be the cause of NTDs. Our findings indicate that mothers with a history of spontaneous abortion are ideal candidates for periconceptional folic acid supplementation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by National Natural Science Foundation of China (41871360) and Danone Nutrition Center for Dietary Nutrition Research and Education Foundation (DIC2015-05). There are no competing interests to declare.

Epidemiology characteristics of birth defects in Shenzhen city during 2003 to 2009, China

OBJECTIVES

To explore the epidemiology characteristics of birth defects (BDs) in perinatal infants in Longgang District, Shenzhen City.

METHODS

Data used in this study was obtained from birth defects surveillance network during 2003 to 2009. The prevalence with 95% confidence interval of BDs by year, gender, household registration and type were examined. Cochran-Armitage trend tests were conducted to evaluate the tendency by year.

RESULTS

The overall prevalence of BDs in Longgang District was 13.43 (12.92, 13.95) per 1000 live births and there was an increasing trend from 2003 to 2009 in migrant and permanent population. Furthermore, the migrant population and male infant had a higher prevalence, OR = 1.22(1.09, 1.37), 1.21(1.11, 1.31) respectively. Congenital heart disease was the most common birth defect.

CONCLUSIONS

Shenzhen city is confronted with severe challenges to prevent BDs. The preventive program of BDs, especially for the migrant population, should be better performed.