Epidemiological trends of isolated and non-isolated central nervous system congenital malformations in live births in a middle-income setting

Abstract

Objectives

This study aimed to analyze, in the São Paulo state of Brazil, time trends in prevalence, neonatal mortality, and neonatal lethality of central nervous system congenital malformations (CNS-CM) between 2004 and 2015.

Methods

Population-based study of all live births with gestational age ≥22 weeks and/or birthweight ≥400 g from mothers living in São Paulo State, during 2004–2015. CNS-CM was defined by the presence of International Classification Disease 10th edition codes Q00–Q07 in the death and/or live birth certificates. CNS-CM was classified as isolated (only Q00–Q07 codes), and non-isolated (with congenital anomalies codes nonrelated to CNS-CM). CNS-CM associated neonatal death was defined as death between 0 and 27 days after birth in infants with CNS-CM. CNS-CM prevalence, neonatal mortality, and lethality rates were calculated, and their annual trends were analyzed by Prais-Winsten Model. The annual percent change (APC) with 95% confidence interval (95%CI) was obtained.

Results

7,237,628 live births were included in the study and CNS-CM were reported in 7526 (0.1%). CNS-CM associated neonatal deaths occurred in 2935 (39.0%). Isolated CNS-CM and non-isolated CNS-CM were found respectively in 5475 and 2051 livebirths, with 1525 (28%) and 1410 (69%) neonatal deaths. CNS-CM prevalence and neonatal lethality were stationary, however neonatal mortality decreased (APC −1.66; 95%CI −3.09 to −0.21) during the study. For isolated CNS-CM, prevalence, neonatal mortality, and lethality decreased over the period. For non-isolated CNS-CM, the prevalence increased, neonatal mortality was stationary, and lethality decreased during the period. The median time of CNS-CM associated neonatal deaths was 18 h after birth.

Conclusions

During a 12-year period in São Paulo State, Brazil, neonatal mortality of infants with CNS-CM in general and with isolated CNS-CM showed a decreasing pattern. Nevertheless CNS-CM mortality remained elevated, mostly in the first day after birth.

Keywords:

• Nervous system malformations
• neonatal mortality
• epidemiological studies
• survival analysis
• temporal distribution

Acknowledgements

We thank FAPESP for the funding, all technical staff of SEADE Foundation for their work with the database and Josiane Quintiliano Xavier de Castro, MD, for helping in the deterministic linkage between Live Birth Certificates and Death Certificates.

Disclosure statement

The authors report no conflict of interest. Database use was possible due to FAPESP (Project # 2017/03748-7) and due to agreements #23089.004297/2008-11 and #23089.000057/2014-95 between Fundação SEADE and Universidade Federal de São Paulo.

Data availability statement

Data are available upon reasonable request from the corresponding author, upon reasonable request.

Additional information

Funding

This research was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Project # 2017/03748-7, however with no role in any step of the study and report (including study design, analysis and interpretation of data, in the writing of the report or in the decision to submit the paper for publication), which was authors’ responsibility.