Indirect Effects of Neighbourhood Socioeconomic Status on Preterm Birth Risk in an Argentine Population.

BACKGROUND: Preterm birth (PTB) is the main condition related to perinatal morbimortality worldwide. The aim of this study was to determine the indirect effects of neighbourhood socioeconomic status (NSES) on the risk of spontaneous PTB. METHODS: We carried out a retrospective case-control study including sociodemographic and obstetric data of multigravid women who gave birth at a maternity hospital in Tucumán, Argentina, between 2005 and 2010: 949 women without previous PTB nor pregnancy loss who delivered at term and 552 who had spontaneous PTB. NSES was estimated from the Unsatisfied Basic Needs index of census data. Variables selected through penalised regressions were used to create a data-driven Bayesian network; then, pathways were identified and mediation analyses performed. RESULTS: Maternal age less than 20 years mediated part of the protective effect of high NSES on spontaneous PTB [natural indirect effect (NIE) -0.0125, 95% confidence interval (CI) (-0.0208, -0.0041)] and on few prenatal visits (< 5) [NIE - 0.0095, 95% CI (-0.0166, -0.0025)]. These pathways showed greater sensitivity to unobserved confounders that affect the variables mediator-outcome in the same direction, and exposure-mediator in the opposite direction. They did not show sensitivity to observed potential confounders, nor to the parameterization used to define NSES. Meanwhile, urinary tract infections showed a trend in mediating the effect of low NSES on spontaneous PTB [NIE 0.0044, 95% CI (-0.0006, 0.0093), P 0.0834]. CONCLUSIONS: High NSES has protective indirect effects on spontaneous PTB risk, mainly associated with a lower frequency of teenage pregnancy.

Genetic susceptibility for retinopathy of prematurity and its associated comorbidities.

BACKGROUND: Retinopathy of prematurity (ROP) is one of the leading cause of child blindness. Preterm newborns of very low gestational age (GA) and very low birth weight are at the greatest risk. Our objective was to evaluate the role of genetic variants associated with ROP risk and its comorbidities in an Argentinian sample of premature infants. METHODS: A sample of 437 preterm infants <33 weeks GA, born at a maternity hospital in Tucumán, Argentina, 2005-2010, was analyzed. Environmental factors, perinatal outcomes, and fourteen single nucleotide polymorphisms associated with ROP were evaluated, comparing ROP with non-ROP newborns. A lasso logistic regression was performed to select variables; then, a conditional logistic regression was used to identify ROP maternal and perinatal risk factors adjusting by maternal and gestational ages, respectively. RESULTS: ROP maternal risk factors were alcohol intake, periodontal infections, and severe stress. Respiratory distress, sepsis, and intracranial hemorrhage were the ROP perinatal risk factors. Markers rs186085 of EPAS1 and rs427832 of AGTR1 were significantly associated with ROP newborns. CONCLUSION: We identified three maternal and three perinatal risk factors associated with ROP. Genes EPAS1 and AGTR1, involved in angiogenesis and vascularization, were identified to be of risk for ROP. IMPACT: Genetic and environmental risk factors associated with ROP and its comorbidities are evaluated in a Latin American population. Genes EPAS1 and AGTR1, involved in angiogenesis and vascularization, were identified to be of risk for ROP. Three maternal and three perinatal risk factors associated with ROP were also identified. A matrix of significant relationships among genetic markers and comorbidities is presented. Reported data may help develop more effective preventive measures for ROP in the Latin American region.

Gene-environment interactions and preterm birth predictors: A Bayesian network approach.

Preterm birth (PTB) is the main condition related to perinatal morbimortality worldwide. The aim of this study was to identify gene-environment interactions associated with spontaneous PTB or its predictors. We carried out a retrospective case-control study including parental sociodemographic and obstetric data as well as newborn genetic variants of 69 preterm and 61 at term newborns born at a maternity hospital from Tucumán, Argentina, between 2005 and 2010. A data-driven Bayesian network including the main PTB predictors was created where we identified gene-environment interactions. We used logistic regressions to calculate the odds ratios and confidence intervals of the interactions. From the main PTB predictors (nine exposures and six genetic variants) we identified an interaction between low neighbourhood socioeconomic status and rs2074351 (PON1, genotype GG) variant that was associated with an increased risk of toxoplasmosis (odds ratio 12.51, confidence interval 95%: 1.71 - 91.36). The results of this exploratory study suggest that structural social disparities could influence the PTB risk by increasing the frequency of exposures that potentiate the risk associated with individual characteristics such as genetic traits. Future studies with larger sample sizes are necessary to confirm these findings.

Lethality of Birth Defects in Live Born Infants Categorized by Gestational Age and Birth Weight.

OBJECTIVE: This study aimed to describe lethality of birth defects (BDs) in newborns categorized by gestational age and birth weight and to identify BDs associated with prematurity. STUDY DESIGN: Live born infants (n = 16,452) with isolated BDs classified by severity, and 42,511 healthy controls were assigned to categories: adequate growth, preterm, or small for gestational age (SGA). Proportion of cases and BDs' lethality rates were obtained by category and compared with controls. RESULTS: Overall fewer malformed than nonmalformed infants were of adequate growth, while the opposite occurred in the preterm and SGA categories where gastroschisis and esophageal atresia were among the most outstanding defects. For most severe BDs, the early neonatal death rate was higher than control values in all categories; for mild defects, except cleft lip in the preterm category, they did not differ. Diaphragmatic hernia showed the highest lethality values, while those of spina bifida were among the lowest. Talipes, hypospadias, and septal heart defects were mild defects significantly associated with prematurity. CONCLUSION: Although reasons, such as induced preterm delivery of fetuses with certain anomalies, could partially account for their high prematurity rates, susceptibility to preterm birth might exist through underlying mechanisms related with the defects. The identification of BDs associated with prematurity should serve to improve measures that prevent preterm birth especially of fetuses at risk. KEY POINTS: · Some BDs predispose to prematurity.. · Prematurity is an additional risk factor for mortality in infants with mild defects.. · Lethality values should be adjusted by gestational age and birth weight..

Diseases during pregnancy in a large unselected South American sample.

OBJECTIVE: Our aim was to describe the prevalence of diseases during pregnancy and the association between fetal exposure to the most frequent maternal diseases and the risk of preterm (PTB) and/or small for gestational age (SGA) newborns in an unselected sample of women who gave birth in South American countries. METHODS: We conducted a descriptive, cross-sectional study including 56,232 mothers of non-malformed infants born between 2002 and 2016, using data from the Latin American Collaborative Study of Congenital Malformations (ECLAMC). Diseases with higher- than-expected PTB/SGA frequencies were identified. Odds ratios of confounding variables for diseases and birth outcomes were calculated with a multivariable logistic regression. RESULTS: Of the 14 most reported diseases, hypertension, genitourinary infection, epilepsy, hypothyroidism, diabetes, and HIV/AIDS showed higher PTB and/or SGA frequencies. Advanced and low maternal age, previous fetal loss, low socioeconomic level, and African-American ancestry were associated with PTB, while advanced maternal age, primigravidity, previous fetal loss, low socioeconomic level, and African-American ancestry were associated with SGA. After adjusting for the associated variables, the identified illnesses maintained their association with PTB and all, except epilepsy, with SGA. CONCLUSION: The description of an unselected population of mothers allowed identifying the most frequent diseases occurring during gestation and their impact on pregnancy outcomes. Six diseases were associated with PTB and two with SGA newborns. To the best of our knowledge, there are no similar reports about women not intentionally selected by specific diseases during pregnancy in South American populations.

Genes, exposures, and interactions on preterm birth risk: an exploratory study in an Argentine population.

Preterm birth (PTB) is the main condition related to perinatal morbimortality worldwide. The aim of this study was to identify associations of spontaneous PTB with genetic variants, exposures, and interactions between and within them. We carried out a retrospective case-control study including parental sociodemographic and obstetric data, and fetal genetic variants. We sequenced the coding and flanking regions of five candidate genes from the placental blood cord of 69 preterm newborns and 61 at term newborns. We identify the characteristics with the greatest predictive power of PTB using penalized regressions, in which we include exposures (E), genetic variants (G), and two-way interactions. Few prenatal visits (< 5) was the main predictor of PTB from 26 G, 35 E, 299 G × G, 564 E × E, and 875 G × E evaluated terms. Within the fetal genetic characteristics, we observed associations of rs4845397 (KCNN3, allele T) variant; G × G interaction between rs12621551 (COL4A3, allele T) and rs73993878 (COL4A3, allele A), which showed sensitivity to anemia; and G × G interaction between rs11680670 (COL4A3, allele T) and rs2074351 (PON1, allele A), which showed sensitivity to vaginal discharge. The results of this exploratory study suggest that social disparities and metabolic pathways linked to uterine relaxation, inflammation/infections, and collagen metabolism would be involved in PTB etiology. Future studies with a larger sample size are necessary to confirm these findings and to analyze a greater number of exposures.

Preterm birth etiological pathways: a Bayesian networks and mediation analysis approach.

BACKGROUND: The aim of this study was to determine the mediating effect of spontaneous preterm birth (PTB) main predictors that would allow to suggest etiological pathways. METHODS: We carried out a case-control study, including sociodemographic characteristics, habits, health care, and obstetric data of multiparous women who gave birth at a maternity hospital from Tucumán, Argentina, between 2005 and 2010: 998 women without previous PTB who delivered at term and 562 who delivered preterm. We selected factors with the greatest predictive power using a penalized logistic regression model. A data-driven Bayesian network including the selected factors was created where we identified pathways and performed mediation analyses. RESULTS: We identified three PTB pathways whose natural indirect effect was greater than zero with a 95% confidence interval: maternal age less than 20 years mediated by few prenatal visits, vaginal bleeding in the first trimester mediated by vaginal bleeding in the second trimester, and urinary tract infection mediated by vaginal bleeding in the second trimester. The effect mediated in these pathways showed greater sensitivity to confounders affecting the variables mediator-outcome and exposure-mediator in the same direction. CONCLUSION: The identified pathways suggest PTB etiological lines related to social disparities and exposure to genitourinary tract infections. IMPACT: Few prenatal visits (<5) and vaginal bleeding are two of the main predictors for spontaneous preterm birth in the studied population. Few prenatal visits mediates part of the risk associated with maternal age less than 20 years and vaginal bleeding in the second trimester mediates part of the risk associated with vaginal bleeding in the first trimester and with urinary tract infection. Social disparities and exposure to genitourinary tract infections would be etiological lines of spontaneous preterm birth.

Diseases during pregnancy in a large unselected South American sample / Prevalência de doenças durante a gravidez em uma grande amostra sul-americana não selecionada

ABSTRACT Objective: Our aim was to describe the prevalence of diseases during pregnancy and the association between fetal exposure to the most frequent maternal diseases and the risk of preterm (PTB) and/or small for gestational age (SGA) newborns in an unselected sample of women who gave birth in South American countries. Methods: We conducted a descriptive, cross-sectional study including 56,232 mothers of non-malformed infants born between 2002 and 2016, using data from the Latin American Collaborative Study of Congenital Malformations (ECLAMC). Diseases with higher- than-expected PTB/SGA frequencies were identified. Odds ratios of confounding variables for diseases and birth outcomes were calculated with a multivariable logistic regression. Results: Of the 14 most reported diseases, hypertension, genitourinary infection, epilepsy, hypothyroidism, diabetes, and HIV/AIDS showed higher PTB and/or SGA frequencies. Advanced and low maternal age, previous fetal loss, low socioeconomic level, and African-American ancestry were associated with PTB, while advanced maternal age, primigravidity, previous fetal loss, low socioeconomic level, and African-American ancestry were associated with SGA. After adjusting for the associated variables, the identified illnesses maintained their association with PTB and all, except epilepsy, with SGA. Conclusion: The description of an unselected population of mothers allowed identifying the most frequent diseases occurring during gestation and their impact on pregnancy outcomes. Six diseases were associated with PTB and two with SGA newborns. To the best of our knowledge, there are no similar reports about women not intentionally selected by specific diseases during pregnancy in South American populations.

RESUMO Objetivo: Descrever a prevalência de doenças durante a gravidez e a associação entre a exposição fetal às doenças maternas mais prevalentes e o risco de recém-nascidos prematuros (PP) e/ou pequenos para a idade gestacional (PIG) em uma amostra não selecionada de mulheres que deram à luz em países da América do Sul. Métodos: Estudo descritivo transversal que incluiu 56.232 mães de crianças não malformadas nascidas entre 2002 e 2016, utilizando dados do Estudo Colaborativo Latino-americano de Malformações Congênitas (ECLAMC). Foram identificadas as doenças com maior número de casos observado/esperado de PP/PIG. O esperado foi obtido dos controles sem doenças. Odds ratios para variáveis de confusão de doença e eventos ao nascimento foram calculadas usando regressão logística multivariada. Resultados: Das 14 doenças mais referidas, hipertensão, infecção geniturinária, epilepsia, hipotireoidismo, diabetes e HIV/AIDS apresentaram maiores frequências de PP e/ou PIG. Idade materna nos dois extremos, perda fetal prévia, baixo nível socioeconômico e ascendência afro-americana foram associados a PP, enquanto idade materna avançada, primigravidez, perda fetal prévia, baixo nível socioeconômico e ascendência afro-americana foram associados a PIG. Após ajuste para as variáveis associadas, as doenças identificadas mantiveram associação com PP e todas, exceto epilepsia, com PIG. Conclusão: A descrição de uma população não selecionada de gestantes possibilitou identificar as doenças mais frequentes e seu impacto nos resultados adversos na gravidez. Seis doenças foram associadas a PP e duas a recém-nascidos PIG. Até onde sabemos, não há relatos semelhantes sobre mulheres não selecionadas intencionalmente por doenças específicas durante a gravidez em populações sul-americanas.

[Social inequities in teenage mothers and the relationship to adverse perinatal outcomes in South American populations]. / Inequidades sociales en madres adolescentes y la relación con resultados perinatales adversos en poblaciones sudamericanas.

The aim was to explain differences in the rates of adverse perinatal events in teenage mothers with low and high schooling. The sample was collected from the Latin American Colaborative Study of Congenital Malformations (ECLAMC) database. From a total of 2,443,747 births in 93 hospitals, 66,755 live newborns without congenital malformations were recruited from 2000 to 2017. Teenage mothers were classified according to low, medium, and high schooling. A multivariate model was used that included reproductive history, access to health services, demographic and socioeconomic variables, and ethnic group. The Fairlie decomposition model was applied to quantify the contribution of explanatory variables to the adverse perinatal event rates. Of the 66,755 newborns analyzed, 21.1% (n = 14,078) were born to teenage mothers. Distribution of maternal schooling was 24.2%, 59.8%, and 16% for low, medium, and high schooling, respectively. The highest rates of adverse perinatal events were seen in teenage mothers with low schooling. The variable "access to health services" explained 35%, 37%, and 23% of the disparities in low birthweight, prematurity, and intrauterine growth restriction, respectively, among teenage mother with low and high schooling. Low number of prenatal visits was the only risk factor for the two levels of schooling and the variable that best explained the differences between the rates of adverse perinatal events. From the public health perspective, prenatal care represents a low-cost intervention with the possibility of increased implementation through adequate information for the population and systematic measures in primary care.

El objetivo fue explicar las diferencias en la frecuencia de eventos perinatales adversos entre madres adolescentes con baja y alta escolaridad. La muestra poblacional se recogió en la base de datos del Estudio Colaborativo Latinoamericano de Malformaciones Congénitas (ECLAMC). Entre 2.443.747 nacimientos ocurridos en 93 hospitales, se reclutaron 66.755 recién nacidos vivos, sin defectos congénitos, durante el período 2000-2017. Las madres adolescentes se clasificaron según su escolaridad en: baja, media y alta. Se utilizó un modelo multivariado, que incluyó efectos reproductivos, acceso a servicios de salud, variables demográficas-socioeconómicas, así como de grupo étnico. El modelo de descomposición de Fairlie se aplicó para cuantificar la contribución de variables explicativas en las frecuencias de eventos perinatales adversos. De los 66.755 recién nacidos investigados, el 21,1% (n = 14.078) fue primigrávida de madres adolescentes. La distribución por escolaridad materna fue de 24,2%, 59,8% y 16% para baja, media y alta escolaridad, respectivamente. Las mayores frecuencias de eventos perinatales adversos se observaron en madres adolescentes con baja escolaridad. La variable "acceso a servicios de salud" explicó un 35%, 37% y 23% de las disparidades en el bajo peso al nacimiento, prematuridad y retardo de crecimiento intrauterino, respectivamente, entre madres adolescentes con baja y alta escolaridad. El bajo número de consultas prenatales fue el único factor de riesgo para los dos niveles de escolaridad y la variable que mejor explica las diferencias entre las frecuencias de eventos perinatales adversos. Desde el punto de vista de la salud pública, ellos representan una intervención de bajo coste, con posibilidad de que se incrementen mediante información adecuada para la población y medidas sistemáticas en los niveles de atención primaria.

O objetivo foi explicar as diferenças na frequência de eventos perinatais adversos entre mães adolescentes com baixa e alta escolaridade. A amostra populacional foi coletada na base de dados do Estudo Colaborativo Latino-Americano de Malformações Congênitas (ECLAMC). Entre 2.443.747 nascimentos ocorridos em 93 hospitais, 66.755 recém-nascidos vivos sem defeitos congênitos foram recrutados no período 2000-2017. As mães adolescentes foram classificadas segundo sua escolaridade em: baixa, média e alta. Foi utilizado um modelo multivariado que incluiu efeitos reprodutivos, acesso a serviços de saúde, variáveis demográficas-socioeconômicas e de grupo étnico. O modelo de decomposição de Fairlie foi aplicado para quantificar a contribuição de variáveis explicativas nas frequências de eventos perinatais adversos. Dos 66.755 recém-nascidos pesquisados, o 21,1% (n = 14.078) foi a mãe adolescente. A distribuição por escolaridade materna foi de 24,2%, 59,8% e 16% para baixa escolaridade, média escolaridade e alta escolaridade, respectivamente. As maiores frequências de eventos perinatais adversos foram observadas em mães adolescentes com baixa escolaridade. A variável "acesso a serviços de saúde"; explicou 35%, 37% e 23% das disparidades no baixo peso ao nascer, prematuridade e retardo de crescimento intrauterino, respectivamente, entre mães adolescentes com baixa e alta escolaridades. O baixo número de consultas pré-natais foi o único fator de risco para os dois níveis de escolaridade e a variável que melhor explica as diferenças entre as frequências de eventos perinatais adversos. Do ponto de vista da saúde pública, eles representam uma intervenção de baixo custo, com possibilidade de ser incrementadas por meio de informações adequadas à população e medidas sistemáticas nos níveis de atenção primária.

Preterm birth and genitourinary tract infections: assessing gene-environment interaction.

BACKGROUND: Preterm birth (PTB) is the leading cause of perinatal morbimortality worldwide. Genetic and environmental factors could raise PTB risk. The aim of this study was to analyze the contribution of the statistical interaction between genes and vaginal-urinary tract infections (VI-UTI) to the risk of PTB by clinical subtype. METHODS: Twenty-four SNPs were genotyped in 18 candidate genes from 352 fetal triads and 106 maternal triads. Statistical interactions were evaluated with conditional logistic regression models based on genotypic transmission/disequilibrium test. RESULTS: In PTB-idiopathic subtype mothers exposed to UTI, fetal SNPs rs11686474 (FSHR), rs4458044 (CRHR1, allele G), rs883319 (KCNN3), and maternal SNP rs1882435 (COL4A3) showed a nominal significant increment in prematurity risk. In preterm premature rupture of membranes (PPROM), fetal SNP rs2277698 (TIMP2) showed a nominal significant risk increment. In mothers exposed to VI, fetal SNP rs5742612 (IGF1) in PTB-PPROM and maternal SNP rs4458044 (CRHR1, allele C) in spontaneous PTB showed nominal significant increment in prematurity risk. CONCLUSIONS: Certain maternal and fetal genes linked to infectious/inflammatory and hormonal regulation processes increase prematurity risk according to clinical subtype when mothers are exposed to UTI or VI. These findings may help in the understanding of PTB etiology and PTB prevention. IMPACT: Preterm birth is a major cause of perinatal morbimortality worldwide and its etiology remains unknown. This work provides evidence on the statistical interaction of six genes with gestational vaginal or urinary infections leading to the occurrence of preterm births. Statistical interactions vary according to infection type, genotype (maternal and fetal), and clinical subtype of prematurity. Certain maternal and fetal genetic variants of genes linked to infectious/inflammatory and hormonal regulation processes would increase the risk of prematurity according to clinical subtype and infection type. Our findings may help in the study of etiology of preterm birth and its prevention.

A graph theory approach to analyze birth defect associations.

Birth defects are prenatal morphological or functional anomalies. Associations among them are studied to identify their etiopathogenesis. The graph theory methods allow analyzing relationships among a complete set of anomalies. A graph consists of nodes which represent the entities (birth defects in the present work), and edges that join nodes indicating the relationships among them. The aim of the present study was to validate the graph theory methods to study birth defect associations. All birth defects monitoring records from the Estudio Colaborativo Latino Americano de Malformaciones Congénitas gathered between 1967 and 2017 were used. From around 5 million live and stillborn infants, 170,430 had one or more birth defects. Volume-adjusted Chi-Square was used to determine the association strength between two birth defects and to weight the graph edges. The complete birth defect graph showed a Log-Normal degree distribution and its characteristics differed from random, scale-free and small-world graphs. The graph comprised 118 nodes and 550 edges. Birth defects with the highest centrality values were nonspecific codes such as Other upper limb anomalies. After partition, the graph yielded 12 groups; most of them were recognizable and included conditions such as VATER and OEIS associations, and Patau syndrome. Our findings validate the graph theory methods to study birth defect associations. This method may contribute to identify underlying etiopathogeneses as well as to improve coding systems.

Inequidades sociales en madres adolescentes y la relación con resultados perinatales adversos en poblaciones sudamericanas / Social inequities in teenage mothers and the relationship to adverse perinatal outcomes in South American populations / Iniquidades sociais em mães adolescentes e sua relação com resultados perinatais adversos em populações sul-americanas

Resumen: El objetivo fue explicar las diferencias en la frecuencia de eventos perinatales adversos entre madres adolescentes con baja y alta escolaridad. La muestra poblacional se recogió en la base de datos del Estudio Colaborativo Latinoamericano de Malformaciones Congénitas (ECLAMC). Entre 2.443.747 nacimientos ocurridos en 93 hospitales, se reclutaron 66.755 recién nacidos vivos, sin defectos congénitos, durante el período 2000-2017. Las madres adolescentes se clasificaron según su escolaridad en: baja, media y alta. Se utilizó un modelo multivariado, que incluyó efectos reproductivos, acceso a servicios de salud, variables demográficas-socioeconómicas, así como de grupo étnico. El modelo de descomposición de Fairlie se aplicó para cuantificar la contribución de variables explicativas en las frecuencias de eventos perinatales adversos. De los 66.755 recién nacidos investigados, el 21,1% (n = 14.078) fue primigrávida de madres adolescentes. La distribución por escolaridad materna fue de 24,2%, 59,8% y 16% para baja, media y alta escolaridad, respectivamente. Las mayores frecuencias de eventos perinatales adversos se observaron en madres adolescentes con baja escolaridad. La variable "acceso a servicios de salud" explicó un 35%, 37% y 23% de las disparidades en el bajo peso al nacimiento, prematuridad y retardo de crecimiento intrauterino, respectivamente, entre madres adolescentes con baja y alta escolaridad. El bajo número de consultas prenatales fue el único factor de riesgo para los dos niveles de escolaridad y la variable que mejor explica las diferencias entre las frecuencias de eventos perinatales adversos. Desde el punto de vista de la salud pública, ellos representan una intervención de bajo coste, con posibilidad de que se incrementen mediante información adecuada para la población y medidas sistemáticas en los niveles de atención primaria.

Abstract: The aim was to explain differences in the rates of adverse perinatal events in teenage mothers with low and high schooling. The sample was collected from the Latin American Colaborative Study of Congenital Malformations (ECLAMC) database. From a total of 2,443,747 births in 93 hospitals, 66,755 live newborns without congenital malformations were recruited from 2000 to 2017. Teenage mothers were classified according to low, medium, and high schooling. A multivariate model was used that included reproductive history, access to health services, demographic and socioeconomic variables, and ethnic group. The Fairlie decomposition model was applied to quantify the contribution of explanatory variables to the adverse perinatal event rates. Of the 66,755 newborns analyzed, 21.1% (n = 14,078) were born to teenage mothers. Distribution of maternal schooling was 24.2%, 59.8%, and 16% for low, medium, and high schooling, respectively. The highest rates of adverse perinatal events were seen in teenage mothers with low schooling. The variable "access to health services" explained 35%, 37%, and 23% of the disparities in low birthweight, prematurity, and intrauterine growth restriction, respectively, among teenage mother with low and high schooling. Low number of prenatal visits was the only risk factor for the two levels of schooling and the variable that best explained the differences between the rates of adverse perinatal events. From the public health perspective, prenatal care represents a low-cost intervention with the possibility of increased implementation through adequate information for the population and systematic measures in primary care.

Resumo: O objetivo foi explicar as diferenças na frequência de eventos perinatais adversos entre mães adolescentes com baixa e alta escolaridade. A amostra populacional foi coletada na base de dados do Estudo Colaborativo Latino-Americano de Malformações Congênitas (ECLAMC). Entre 2.443.747 nascimentos ocorridos em 93 hospitais, 66.755 recém-nascidos vivos sem defeitos congênitos foram recrutados no período 2000-2017. As mães adolescentes foram classificadas segundo sua escolaridade em: baixa, média e alta. Foi utilizado um modelo multivariado que incluiu efeitos reprodutivos, acesso a serviços de saúde, variáveis demográficas-socioeconômicas e de grupo étnico. O modelo de decomposição de Fairlie foi aplicado para quantificar a contribuição de variáveis explicativas nas frequências de eventos perinatais adversos. Dos 66.755 recém-nascidos pesquisados, o 21,1% (n = 14.078) foi a mãe adolescente. A distribuição por escolaridade materna foi de 24,2%, 59,8% e 16% para baixa escolaridade, média escolaridade e alta escolaridade, respectivamente. As maiores frequências de eventos perinatais adversos foram observadas em mães adolescentes com baixa escolaridade. A variável "acesso a serviços de saúde"; explicou 35%, 37% e 23% das disparidades no baixo peso ao nascer, prematuridade e retardo de crescimento intrauterino, respectivamente, entre mães adolescentes com baixa e alta escolaridades. O baixo número de consultas pré-natais foi o único fator de risco para os dois níveis de escolaridade e a variável que melhor explica as diferenças entre as frequências de eventos perinatais adversos. Do ponto de vista da saúde pública, eles representam uma intervenção de baixo custo, com possibilidade de ser incrementadas por meio de informações adequadas à população e medidas sistemáticas nos níveis de atenção primária.