Stillbirth risk by fetal size among 126.5 million births in 15 countries from 2000 to 2020: A fetuses-at-risk approach.

OBJECTIVE: To compare stillbirth rates and risks for small for gestational age (SGA), large for gestational age (LGA) and appropriate for gestational age (AGA) pregnancies at 24-44 completed weeks of gestation using a birth-based and fetuses-at-risk approachs. DESIGN: Population-based, multi-country study. SETTING: National data systems in 15 high- and middle-income countries. POPULATION: Live births and stillbirths. METHODS: A total of 151 country-years of data, including 126 543 070 births across 15 countries from 2000 to 2020, were compiled. Births were categorised into SGA, AGA and LGA using INTERGROWTH-21st standards. Gestation-specific stillbirth rates, with total births as the denominator, and gestation-specific stillbirth risks, with fetuses still in utero as the denominator, were calculated from 24 to 44 weeks of gestation. MAIN OUTCOME MEASURES: Gestation-specific stillbirth rates and risks according to size at birth. RESULTS: The overall stillbirth rate was 4.22 per 1000 total births (95% CI 4.22-4.23) across all gestations. Applying the birth-based approach, the stillbirth rates were highest at 24 weeks of gestation, with 621.6 per 1000 total births (95% CI 620.9-622.2) for SGA pregnancies, 298.4 per 1000 total births (95% CI 298.1-298.7) for AGA pregnancies and 338.5 per 1000 total births (95% CI 337.9-339.0) for LGA pregnancies. Applying the fetuses-at-risk approach, the gestation-specific stillbirth risk was highest for SGA pregnancies (1.3-1.4 per 1000 fetuses at risk) prior to 29 weeks of gestation. The risk remained stable between 30 and 34 weeks of gestation, and then increased gradually from 35 weeks of gestation to the highest rate of 8.4 per 1000 fetuses at risk (95% CI 8.3-8.4) at ≥42 weeks of gestation. The stillbirth risk ratio (RR) was consistently high for SGA compared with AGA pregnancies, with the highest RR observed at ≥42 weeks of gestation (RR 9.2, 95% CI 15.2-13.2), and with the lowest RR observed at 24 weeks of gestation (RR 3.1, 95% CI 1.9-4.3). The stillbirth RR was also consistently high for SGA compared with AGA pregnancies across all countries, with national variability ranging from RR 0.70 (95% CI 0.43-0.97) in Mexico to RR 8.6 (95% CI 8.1-9.1) in Uruguay. No increased risk for LGA pregnancies was observed. CONCLUSIONS: Small for gestational age (SGA) was strongly associated with stillbirth risk in this study based on high-quality data from high- and middle-income countries. The highest RRs were seen in preterm gestations, with two-thirds of the stillbirths born as preterm births. To advance our understanding of stillbirth, further analyses should be conducted using high-quality data sets from low-income settings, particularly those with relatively high rates of SGA.

[Intentional search and reclassification of maternal deaths: quality information and its analysis to reduce maternal mortalityBusca intencional e reclassificação de mortes maternas: informação de qualidade e sua análise para reduzir a mortalidade materna]. / Búsqueda intencionada y reclasificación de muertes maternas: información de calidad y su análisis para reducir la mortalidad materna.

Objective: To describe the methodology of the intentional search and reclassification of maternal deaths (BIRMM, acronym in Spanish), which allows the identification and correction of misclassification and underreporting of maternal deaths. Methods: The BIRMM methodology, initially developed in Mexico in 2003 and disseminated in other Latin American countries since 2012, was used. BIRMM consists of four key components: i) reclassification of confirmed maternal deaths; ii) identification and investigation of suspected cases of maternal death; iii) cross-referencing with other information sources; and iv) publication of results and statistical analysis. Results: The application of BIRMM makes it possible to identify and analyze maternal deaths in maternal mortality committees, which has facilitated the implementation of effective response plans, contributing to a sustained reduction in maternal mortality in the countries. Conclusions: The BIRMM methodology is an effective tool for correcting underreporting and misclassification of maternal deaths, allowing better surveillance and response to this problem. Its adoption and routine implementation are essential to improve the quality of maternal mortality information and reduce maternal deaths in the Region of the Americas. The sustainability of this methodology depends on institutional commitment and political will in the countries.

Objetivo: Descrever a metodologia da busca intencional e reclassificação de mortes maternas (BIRMM), que permite identificar e corrigir erros de classificação e subnotificação de mortes maternas. Método: Foi utilizada a metodologia BIRMM, desenvolvida inicialmente no México em 2003 e disseminada em outros países da América Latina a partir 2012. A BIRMM consiste em quatro componentes principais: i) reclassificação de mortes maternas confirmadas ii) identificação e investigação de mortes maternas suspeitas; iii) confrontação com outras fontes de informação e iv) publicação de resultados e análise estatística. Resultados: A aplicação da BIRMM permite identificar e analisar as mortes maternas nos comitês de mortalidade materna, o que facilitou a implementação de planos de resposta eficazes, contribuindo para uma redução sustentada da mortalidade materna nos países. Conclusões: A metodologia BIRMM é uma ferramenta eficaz para corrigir a subnotificação e a classificação incorreta de mortes maternas, permitindo uma melhor vigilância e resposta a este problema. Sua adoção e implementação rotineira são essenciais para melhorar a qualidade da informação sobre mortalidade materna e reduzir as mortes maternas na Região das Américas. A sustentabilidade desta metodologia depende do compromisso institucional e da vontade política dos países.

National data linkage assessment of live births and deaths in Mexico: Estimating under-five mortality rate ratios for vulnerable newborns and trends from 2008 to 2019.

BACKGROUND: Linked datasets that enable longitudinal assessments are scarce in low and middle-income countries. OBJECTIVES: We aimed to assess the linkage of administrative databases of live births and under-five child deaths to explore mortality and trends for preterm, small (SGA) and large for gestational age (LGA) in Mexico. METHODS: We linked individual-level datasets collected by National statistics from 2008 to 2019. Linkage was performed based on agreement on birthday, sex, residential address. We used the Centre for Data and Knowledge Integration for Health software to identify the best candidate pairs based on similarity. Accuracy was assessed by calculating the area under the receiver operating characteristic curve. We evaluated completeness by comparing the number of linked records with reported deaths. We described the percentage of linked records by baseline characteristics to identify potential bias. Using the linked dataset, we calculated mortality rate ratios (RR) in neonatal, infants, and children under-five according to gestational age, birthweight, and size. RESULTS: For the period 2008-2019, a total of 24,955,172 live births and 321,165 under-five deaths were available for linkage. We excluded 1,539,046 records (6.2%) with missing or implausible values. We succesfully linked 231,765 deaths (72.2%: range 57.1% in 2009 and 84.3% in 2011). The rate of neonatal mortality was higher for preterm compared with term (RR 3.83, 95% confidence interval, [CI] 3.78, 3.88) and for SGA compared with appropriate for gestational age (AGA) (RR 1.22 95% CI, 1.19, 1.24). Births at <28 weeks had the highest mortality (RR 35.92, 95% CI, 34.97, 36.88). LGA had no additional risk vs AGA among children under five (RR 0.92, 95% CI, 0.90, 0.93). CONCLUSIONS: We demonstrated the utility of linked data to understand neonatal vulnerability and child mortality. We created a linked dataset that would be a valuable resource for future population-based research.

Stillbirths: Contribution of preterm birth and size-for-gestational age for 125.4 million total births from nationwide records in 13 countries, 2000-2020.

OBJECTIVE: To examine the contribution of preterm birth and size-for-gestational age in stillbirths using six 'newborn types'. DESIGN: Population-based multi-country analyses. SETTING: Births collected through routine data systems in 13 countries. SAMPLE: 125 419 255 total births from 22+0 to 44+6 weeks' gestation identified from 2000 to 2020. METHODS: We included 635 107 stillbirths from 22+0 weeks' gestation from 13 countries. We classified all births, including stillbirths, into six 'newborn types' based on gestational age information (preterm, PT, <37+0 weeks versus term, T, ≥37+0 weeks) and size-for-gestational age defined as small (SGA, <10th centile), appropriate (AGA, 10th-90th centiles) or large (LGA, >90th centile) for gestational age, according to the international newborn size for gestational age and sex INTERGROWTH-21st standards. MAIN OUTCOME MEASURES: Distribution of stillbirths, stillbirth rates and rate ratios according to six newborn types. RESULTS: 635 107 (0.5%) of the 125 419 255 total births resulted in stillbirth after 22+0 weeks. Most stillbirths (74.3%) were preterm. Around 21.2% were SGA types (PT + SGA [16.2%], PT + AGA [48.3%], T + SGA [5.0%]) and 14.1% were LGA types (PT + LGA [9.9%], T + LGA [4.2%]). The median rate ratio (RR) for stillbirth was highest in PT + SGA babies (RR 81.1, interquartile range [IQR], 68.8-118.8) followed by PT + AGA (RR 25.0, IQR, 20.0-34.3), PT + LGA (RR 25.9, IQR, 13.8-28.7) and T + SGA (RR 5.6, IQR, 5.1-6.0) compared with T + AGA. Stillbirth rate ratios were similar for T + LGA versus T + AGA (RR 0.7, IQR, 0.7-1.1). At the population level, 25% of stillbirths were attributable to small-for-gestational-age. CONCLUSIONS: In these high-quality data from high/middle income countries, almost three-quarters of stillbirths were born preterm and a fifth small-for-gestational age, with the highest stillbirth rates associated with the coexistence of preterm and SGA. Further analyses are needed to better understand patterns of gestation-specific risk in these populations, as well as patterns in lower-income contexts, especially those with higher rates of intrapartum stillbirth and SGA.

Neonatal mortality risk for vulnerable newborn types in 15 countries using 125.5 million nationwide birth outcome records, 2000-2020.

OBJECTIVE: To compare neonatal mortality associated with six novel vulnerable newborn types in 125.5 million live births across 15 countries, 2000-2020. DESIGN: Population-based, multi-country study. SETTING: National data systems in 15 middle- and high-income countries. METHODS: We used individual-level data sets identified for the Vulnerable Newborn Measurement Collaboration. We examined the contribution to neonatal mortality of six newborn types combining gestational age (preterm [PT] versus term [T]) and size-for-gestational age (small [SGA], <10th centile, appropriate [AGA], 10th-90th centile or large [LGA], >90th centile) according to INTERGROWTH-21st newborn standards. Newborn babies with PT or SGA were defined as small and T + LGA was considered as large. We calculated risk ratios (RRs) and population attributable risks (PAR%) for the six newborn types. MAIN OUTCOME MEASURES: Mortality of six newborn types. RESULTS: Of 125.5 million live births analysed, risk ratios were highest among PT + SGA (median 67.2, interquartile range [IQR] 45.6-73.9), PT + AGA (median 34.3, IQR 23.9-37.5) and PT + LGA (median 28.3, IQR 18.4-32.3). At the population level, PT + AGA was the greatest contributor to newborn mortality (median PAR% 53.7, IQR 44.5-54.9). Mortality risk was highest among newborns born before 28 weeks (median RR 279.5, IQR 234.2-388.5) compared with babies born between 37 and 42 completed weeks or with a birthweight less than 1000 g (median RR 282.8, IQR 194.7-342.8) compared with those between 2500 g and 4000 g as a reference group. CONCLUSION: Preterm newborn types were the most vulnerable, and associated with the highest mortality, particularly with co-existence of preterm and SGA. As PT + AGA is more prevalent, it is responsible for the greatest burden of neonatal deaths at population level.

Vulnerable newborn types: Analysis of population-based registries for 165 million births in 23 countries, 2000-2021.

OBJECTIVE: To examine the prevalence of novel newborn types among 165 million live births in 23 countries from 2000 to 2021. DESIGN: Population-based, multi-country analysis. SETTING: National data systems in 23 middle- and high-income countries. POPULATION: Liveborn infants. METHODS: Country teams with high-quality data were invited to be part of the Vulnerable Newborn Measurement Collaboration. We classified live births by six newborn types based on gestational age information (preterm <37 weeks versus term ≥37 weeks) and size for gestational age defined as small (SGA, <10th centile), appropriate (10th-90th centiles), or large (LGA, >90th centile) for gestational age, according to INTERGROWTH-21st standards. We considered small newborn types of any combination of preterm or SGA, and term + LGA was considered large. Time trends were analysed using 3-year moving averages for small and large types. MAIN OUTCOME MEASURES: Prevalence of six newborn types. RESULTS: We analysed 165 017 419 live births and the median prevalence of small types was 11.7% - highest in Malaysia (26%) and Qatar (15.7%). Overall, 18.1% of newborns were large (term + LGA) and was highest in Estonia 28.8% and Denmark 25.9%. Time trends of small and large infants were relatively stable in most countries. CONCLUSIONS: The distribution of newborn types varies across the 23 middle- and high-income countries. Small newborn types were highest in west Asian countries and large types were highest in Europe. To better understand the global patterns of these novel newborn types, more information is needed, especially from low- and middle-income countries.

Leading causes of excess mortality in Mexico during the COVID-19 pandemic 2020-2021: A death certificates study in a middle-income country.

Background: The death toll after SARS-CoV-2 emergence includes deaths directly or indirectly associated with COVID-19. Mexico reported 325,415 excess deaths, 34.4% of them not directly related to COVID-19 in 2020. In this work, we aimed to analyse temporal changes in the distribution of the leading causes of mortality produced by COVID-19 pandemic in Mexico to understand excess mortality not directly related to the virus infection. Methods: We did a longitudinal retrospective study of the leading causes of mortality and their variation with respect to cause-specific expected deaths in Mexico from January 2020 through December 2021 using death certificate information. We fitted a Poisson regression model to predict cause-specific mortality during the pandemic period, based on the 2015-2019 registered mortality. We estimated excess deaths as a weekly difference between expected and observed deaths and added up for the entire period. We expressed all-cause and cause-specific excess mortality as a percentage change with respect to predicted deaths by our model. Findings: COVID-19 was the leading cause of death in 2020-2021 (439,582 deaths). All-cause total excess mortality was 600,590 deaths (38⋅2% [95% CI: 36·0 to 40·4] over expected). The largest increases in cause-specific mortality, occurred in diabetes (36·8% over expected), respiratory infections (33·3%), ischaemic heart diseases (32·5%) and hypertensive diseases (25·0%). The cause-groups that experienced significant decreases with respect to the expected pre-pandemic mortality were infectious and parasitic diseases (-20·8%), skin diseases (-17·5%), non-traffic related accidents (-16·7%) and malignant neoplasm (-5·3%). Interpretation: Mortality from COVID-19 became the first cause of death in 2020-2021, the increase in other causes of death may be explained by changes in the health service utilization patterns caused by hospital conversion or fear of the population using them. Cause-misclassification cannot be ruled out. Funding: This study was funded by Conacyt.

Búsqueda intencionada y reclasificación de muertes maternas: información de calidad y su análisis para reducir la mortalidad materna / Intentional search and reclassification of maternal deaths: quality information and its analysis to reduce maternal mortality / Busca intencional e reclassificação de mortes maternas: informação de qualidade e sua análise para reduzir a mortalidade maternal

[RESUMEN]. Objetivo. Describir la metodología de la búsqueda intencionada y reclasificación de muertes maternas (BIRMM), que permite identificar y corregir la clasificación errónea y el subregistro de defunciones maternas. Métodos. Se utiliza la metodología BIRMM, desarrollada inicialmente en México en el 2003 y difundida en otros países de América Latina a partir del 2012. La BIRMM consta de cuatro componentes clave: i) reclasificación de muertes maternas confirmadas; ii) identificación e investigación de casos sospechosos de muerte materna; iii) confronta con otras fuentes de información; y iv) publicación de resultados y análisis estadístico de la mortalidad materna. Resultados. La aplicación de la BIRMM permie identificar y analizar las muertes maternas en comités de mortalidad materna, lo que ha facilitado la implementación de planes de respuesta efectivos, contribuyendo a una reducción sostenida de la mortalidad materna en los países. Conclusiones. La metodología BIRMM es una herramienta efectiva para corregir el subregistro y la mala clasificación de muertes maternas, lo que permite una mejor vigilancia y respuesta a este problema. Su adopción y ejecución rutinaria son esenciales para mejorar la calidad de la información sobre mortalidad materna reducir las muertes maternas en la Región de las Américas. La sostenibilidad de esta metodología depende del compromiso institucional y la voluntad política en los países.

[ABSTRACT]. Objective. To describe the methodology of the intentional search and reclassification of maternal deaths (BIRMM, acronym in Spanish), which allows the identification and correction of misclassification and underreporting of maternal deaths. Methods. The BIRMM methodology, initially developed in Mexico in 2003 and disseminated in other Latin American countries since 2012, was used. BIRMM consists of four key components: i) reclassification of confirmed maternal deaths; ii) identification and investigation of suspected cases of maternal death; iii) cross-referencing with other information sources; and iv) publication of results and statistical analysis. Results. The application of BIRMM made it possible to identify and analyze maternal deaths in maternal mortality committees, which has facilitated the implementation of effective response plans, contributing to a sustained reduction in maternal mortality in the countries. Conclusions. The BIRMM methodology is an effective tool for correcting underreporting and misclassification of maternal deaths, allowing better surveillance and response to this problem. Its adoption and routine implementation are essential to improve the quality of maternal mortality information and reduce maternal deaths in the Region of the Americas. The sustainability of this methodology depends on institutional commitment and political will in the countries.

[RESUMO]. Objetivo. Descrever a metodologia da busca intencional e reclassificação de mortes maternas (BIRMM), que permite identificar e corrigir erros de classificação e subnotificação de mortes maternas. Método. Foi utilizada a metodologia BIRMM, desenvolvida inicialmente no México em 2003 e disseminada em outros países da América Latina a partir 2012. A BIRMM consiste em quatro componentes principais: i) reclassificação de mortes maternas confirmadas; ii) identificação e investigação de mortes maternas suspeitas; iii) confrontação com outras fontes de informação; e iv) publicação de resultados e análise estatística. Resultados. A aplicação da BIRMM possibilitou a identificação e a análise das mortes maternas em comitês de mortalidade materna, o que facilitou a implementação de planos de resposta eficazes, contribuindo para uma redução sustentada da mortalidade materna nos países. Conclusões. A metodologia BIRMM é uma ferramenta eficaz para corrigir a subnotificação e a classificação incorreta de mortes maternas, permitindo uma melhor vigilância e resposta a este problema. Sua adoção e implementação rotineira são essenciais para melhorar a qualidade da informação sobre mortalidade materna e reduzir as mortes maternas na Região das Américas. A sustentabilidade desta metodologia depende do compromisso institucional e da vontade política dos países.