Medio ambiente y embarazo: un análisis espacial en Temuco / Environment and pregnancy: a spatial analysis in Temuco

INTRODUCCIÓN: El embarazo constituye una ventana que determina la carga de enfermedad que sufrirán los individuos a lo largo de su vida. Una exposición a variables ambientales adecuada permite una evolución intrauterina balanceada que resulta primordial para el crecimiento del feto; la ruptura de dicho balance genera consecuencias en el binomio madre-hijo. Una complicación común que afecta del 2 al 10% de las embarazadas es la preeclampsia, siendo una de las principales causas de mortalidad materna, fetal y neonatal, especialmente en países de ingresos medios y bajos. En Latinoamérica y Chile no existen estudios disponibles que cuantifiquen o dimensionen esta patología en términos de incidencia, factores protectores o predisponentes; asimismo, se desconoce el rol que ejercen las variables ambientales sobre ella. Recientemente, se ha descrito que el medio ambiente tendría influencia en el embarazo, específicamente, el espacio verde actuaría de forma beneficiosa probablemente a través de la actividad física en el tiempo de ocio y bienestar. Así también, el efecto que la combustión residencial de leña posee sobre la gestación no ha sido clarificado. Esta tesis doctoral se inserta en la tendencia actual de investigación mundial que busca conocer el efecto de la exposición crónica a variables ambientales, tanto positivas como negativas, específicamente durante el embarazo, dada su importancia en la salud materna como en el desarrollo del niño. OBJETIVO: Determinar el impacto de exposición crónica a variables ambientales espaciales (espacio verde y contaminación atmosférica) en el riesgo de preeclampsia, utilizando Temuco/Padre Las Casas como área de estudio. MÉTODOS: Estudio de cohorte histórica de mujeres embarazadas de las comunas de Temuco y Padre Las Casas (Región de La Araucanía), cuyos partos fueron asistidos en el Hospital Regional de Temuco Dr. Hernán Henríquez Aravena durante los años 2009 a 2015. De la ficha clínica de las embarazadas se obtuvieron datos sociodemográficos, de morbilidad y obstétricos. La variable resultado fue la preeclampsia, mientras que las de exposición fueron espacio verde y MP2,5 atribuido a emisiones de combustión por leña residencial. El espacio verde fue medido a través del Índice de Vegetación de Diferencia Normalizada (IVDN), mediante escaneo multiespectral del mapeador temático de Landsat 5-8 con una resolución de 30 x 30 m, el cual fue obtenido desde la NASA. Para estimar la exposición a MP2,5, se utilizó un modelo de regresión por uso de suelo, el cual fue construido mediante una campaña de medición de MP2,5 en todo Temuco durante un año, de modo de incluir variabilidad espacial y temporal. Las variables predictoras del modelo fueron obtenidas a partir de bases de datos del Sistema Información Geográfica en Temuco, las que incluyeron uso de suelo, topografía de elevación de modelos digitales, densidad de población y hogares, y vías, incluyendo tipo de camino, longitud y distancia a los caminos, características del tráfico. El análisis estadístico consideró validación de datos, análisis univariado, análisis bivariado, cálculos para incidencia, análisis de datos perdidos y modelamiento. Para estimar el efecto de la exposición a espacio verde se construyeron modelos de regresión logística y para MP2,5 atribuido a leña modelos aditivos generalizados. RESULTADOS: La muestra quedó conformada por 15.516 nacimientos. La media de edad de las embarazadas fue de 25,7 años, siendo predominante el nivel de escolaridad secundario (47%). La prevalencia de desórdenes hipertensivos del embarazo fue de 10% y de preeclampsia de 3%. Ambas ciudades se caracterizaron por contar con escasa vegetación urbana, con valores bajos de verdor (mediana IVDN=0,30; Rango Intercuartílico (RIC)=0,30). La cohorte residía en lugares con menor verdor (mediana IVDN=0,25; RIC=0,11) que la ciudad, encontrándose los mayores valores del IVDN en residencias periurbanas. Con respecto a áreas verdes, se encontró un aumento en el riesgo de desarrollar preeclampsia asociado a un aumento de NVDI en 300m (OR=1,20; IC 95% 1,05-1,37 para un aumento equivalente al RIC) y 500m (OR=1,23; IC 95% 1,07-1,41 para un RIC) alrededor del hogar de las participantes. Respecto a exposiciones a MP2,5, se observaron asociaciones en modelos lineales y modelos de umbral, teniendo este último un mejor desempeño. El modelo de umbral, encontró aumento del riesgo para preeclampsia de 17% (CI95% 1,01-1,36) y 11% (CI95%1,03-1,21) por cada 10 µg/m3 de aumento del contaminante por sobre un umbral de 100 µg/m3 para todo el embarazo y el segundo trimestre, respectivamente. CONCLUSIÓN. La presente tesis doctoral ha evidenciado asociaciones entre la exposición a factores ambientales y preeclampsia permitiendo contar con 14 evidencia para apoyar la toma de decisiones a nivel público, tanto a nivel internacional como nacional, ya que ha cuantificado el efecto que las variables ambientales ejercen sobre la salud de la embarazada y el feto. Los resultados constituyen un llamado a la acción en primer lugar para evaluar la presencia de riesgo para la salud en las áreas periurbanas de Temuco y Padre Las Casas y en caso de existir por ejemplo microbasurales, eliminarlos para contribuir a la mejora en la seguridad y calidad de vida de la población. Luego, como un punto de inicio para re-pensar intervenciones específicas basadas en los efectos en salud de la leña como combustible durante el embarazo, dado el impacto que las exposiciones en la vida intrauterina tienen en todo el curso de vida de la población

INTRODUCTION: Pregnancy constitutes a window that determines the burden of disease that individuals will suffer throughout their lives. An exposure to adequate environmental variables allows a balanced intrauterine evolution that is essential for the growth of the fetus; the breakdown of this balance generates consequences in the mother and his child. A common complication that affects 2 to 10% of pregnant women is preeclampsia, being one of the main causes of maternal, fetal and neonatal mortality, especially in middle and low income countries. In Latin America and Chile there are no studies available that quantify this syndrome in terms of his incidence, protective or predisposing factors; Likewise, the role of environmental variables on it is unknown. Recently, it has been described that the environment would have an influence on pregnancy, specifically, the green space would act beneficially probably through physical activity at leisure and well-being. Also, the effect that residential combustion of firewood has on pregnancy has not been clarified. This doctoral thesis is inserted in the current global research trend that seeks to know the effect of chronic exposure to environmental variables, both positive and negative, specifically during pregnancy, given its importance in maternal health and in the development of the child. OBJECTIVE: To determine the impact of chronic exposure to spatial environmental variables (green space and air pollution) on the risk of preeclampsia, using Temuco/Padre Las Casas as a study area. METHODS: Retrospective cohort study of pregnant women from Temuco and Padre Las Casas (La Araucanía Region), whose deliveries were assisted at the Temuco Regional Hospital Dr. Hernán Henríquez Aravena during 2009 to 2015. From the clinical record of the pregnant women were obtained sociodemographic, morbidity and obstetric data. The outcome variable was preeclampsia, while the exposure variables were green space and PM2.5 attributed to emissions from residential wood-burning. The green space was measured through the Normalized Difference Vegetation Index (NDVI), through multispectral scanning of the Landsat 5-8 thematic mapper with a resolution of 30 x 30 m, which was obtained from NASA. To estimate the exposure to PM2.5, a land use regression model was built with data from PM2.5 campaign measuring throughout Temuco for one year, to include spatial and temporal variability. The predictive variables of the model were obtained from databases of the Geographic Information System in Temuco, which included land use, elevation topography of digital models, population and household density, and roads, including road type, length and distance to roads, traffic characteristics. The statistical analysis considered data validation, univariate analysis, bivariate analysis, calculations for incidence, missing data analysis and modeling. To estimate the effect of exposure to green space, logistic regression models were developt and for PM2.5 attributed to wood burning generalized additive models. RESULTS: The sample was conformed of 15,516 births. The average age of the pregnant women was 25.7 years-old, the secondary level of education was predominant (47%). The prevalence of hypertensive disorders of pregnancy was 10% and preeclampsia was 3%. Both cities were characterized by low urban vegetation, with low green values (median NDVI=0.30; Interquartile Range (IQR)=0.30). The cohort used to live in places with less greenness (median NDVI=0.25; IQR=0.11) in the city; the women with the highest values of the NDVI lived in peri-urban areas. Regarding green spaces, there was an increased risk of preeclampsia associated with an increase in NVDI by 300m (OR=1.20; 95% CI 1.05-1.37 for an increase equivalent to IQR) and 500m (OR=1.23; CI 95% 1.07-1.41 for a IQR) around the participants' residence. Regarding exposures to PM2.5, associations were observed in linear models and threshold models, the latter having a better performance. The threshold model found an increased risk for preeclampsia of 17% (CI95% 1.01-1.36) and 11% (CI95% 1.03-1.21) for every 10 µg/m3 increase of the pollutant over a threshold of 100 µg/m3 for the entire pregnancy and the second trimester, respectively. CONCLUSION: This doctoral thesis has shown associations between exposure to environmental factors and preeclampsia allowing evidence to support decision making at the public level, both internationally and nationally, since it has quantified the effect that environmental variables have on health of the pregnant woman and the fetus. The results constitute a call to action to evaluate the presence of health risk in the peri-urban areas of Temuco and Padre Las Casas and if any, for example, eliminate dumps to contribute to the improvement in safety and quality of population life. Then, as a starting point to rethink specific interventions based on the health effects of wood as a fuel during pregnancy, given the impact that exposures in intrauterine life have on the entire life course of the population

Are there differences in birth weight according to sex and associations with maternal exposure to air pollutants? A cohort study / Existem diferenças no peso ao nascer de acordo com sexo e associações com exposição materna a poluentes do ar? Estudo de coorte

ABSTRACT CONTEXT AND OBJECTIVE: Several effects of exposure to air pollutants on human health are known. The aim of this study was to identify whether exposure of pregnant women to air pollutants contributes towards low birth weight and which sex is more affected. DESIGN AND SETTING: Longitudinal study using data on newborns from mothers living in São José do Rio Preto (SP) who were exposed to air pollutants in 2012-2013. METHODS: A hierarchical model on three levels was built using maternal and newborn variables and environmental concentrations of particulate matter, ozone and nitrogen dioxide in quartiles. Preterm new-borns, twins and newborns with birth defects were excluded and exposure windows of 30, 60 and 90 days before delivery were considered. RESULTS: 8,948 newborns were included: 4,491 males (50.2%) and 4,457 females (49.8%); 301 newborns presented low birth weight (3.4%). The mean weight differed between males (3281.0 g) and females (3146.4 g) (P < 0.001). Exposure to ozone was significantly associated with low birth weight in both sexes in the 30-day window (odds ratio, OR = 1.38) and 90-day window (OR = 1.48); and among females, in the 30-day window (OR = 1.58) and 90-day window (OR = 1.59). Exposure to particulate matter had a paradoxical protective effect. No association was found among male newborns. CONCLUSIONS: Female newborns showed greater susceptibility to maternal exposure to air pollutants. Studies on low birth weight in relation to maternal exposure to air pollutants should deal with males and females separately.

RESUMO CONTEXTO E OBJETIVO: São vários os efeitos da exposição a poluentes do ar na saúde humana. O objetivo deste estudo foi identificar se a exposição da gestante contribui para o baixo peso ao nascer e qual o sexo mais acometido. TIPO DE ESTUDO: Estudo longitudinal com dados de recém-nascidos de mães residentes em São José do Rio Preto (SP) com exposição a poluentes do ar em 2012 e 2013. MÉTODOS: Foi construído modelo hierarquizado em três níveis com variáveis maternas, do recém-nascido e concentrações de material particulado, ozônio e dióxido de nitrogênio, em quartis. Foram excluídos recém-nascidos prematuros, gemelares ou com malformações e consideradas janelas de exposição de 30, 60 e 90 dias anteriores ao parto. RESULTADOS: Foram incluídos 8.948 recém-nascidos, 4.491 do sexo masculino (50,2%) e 4.457 do feminino (49,8%), e identificados 301 recém-nascidos com baixo peso (3,4%). Os pesos médios foram diferentes entre o sexo masculino (3.281,0 g) e o feminino (3.146,4 g) (P < 0,001). Exposição ao ozônio esteve associada significativamente ao baixo peso ao nascer em ambos os sexos nas janelas de 30 dias (odds ratio, OR = 1,38) e 90 dias (OR = 1,48) e, no sexo feminino, nas janelas de 30 dias (OR = 1,58) e 90 dias (OR =1,59). Exposição ao material particulado teve efeito protetor paradoxal. Não houve associação no sexo masculino. CONCLUSÕES: Houve maior susceptibilidade do sexo feminino aos poluentes a partir da exposição materna. Estudos sobre baixo peso ao nascer segundo exposição materna a poluentes do ar devem separar sexo masculino e feminino.

Environmental risk factors associated with biliary atresia in Rio Grande do Sul, Brazil

Biliary atresia (BA) seems to be a multifactorial disorder in which environmental factors interact with the patient's genetic constitution. This study aimed to analyze information concerning environmental risk factors associated with BA in southern Brazil. A case-control study with mothers of patients with BA and mothers of patients with cystic fibrosis (CF) was conducted. Inquiry included questions related to exposition to environmental risk factors during the periconceptional and gestational (second and third trimesters) periods. Mothers of BA patients had smoked during pregnancy more frequently in comparison with the mothers of CF patients, but no significant difference was found in a multivariate analysis. There was no between group difference in terms of seasonality, but the multivariate analysis showed a significant difference within the BA group between date of conception in winter compared to other seasons. In conclusion, smoking during pregnancy seemed to increase the risk of BA while date of conception in winter decreased it (AU)

Exposición a plaguicidas y prácticas de uso y protección en embarazadas de zona rurales en control de atención primaria en la región de Valparaíso, Chile / Exposure to pesticides and use and protection practices in pregnant women from rural areas in primary care control in the Valparaíso region, Chile

ANTECEDENTES: Los trabajadores agrícolas y habitantes rurales están expuestos a productos plaguicidas. Aun cuando las políticas sanitarias se preocupan de normarlos, diversos estudios demuestran exposición en trabajadores y residentes cercanos a las zonas productivas. Entre ellos se encuentran mujeres gestantes, consideradas población particularmente vulnerable frente a plaguicidas. OBJETIVO: Identificar el contacto con plaguicidas, así como conductas asociadas a su uso, en mujeres gestantes de dos comunas agrícolas de la V Región en control prenatal en Centros de Salud Familiar. MÉTODO: Estudio observacional transversal, realizado en una muestra de ochenta gestantes que ingresaron a control entre mayo 2013 y abril 2014. El instrumento de recolección de datos fue una encuesta, aplicada por el equipo de salud al ingreso. RESULTADOS: Las gestantes, en su gran mayoría, alguna vez han tenido contacto con plaguicidas, y cerca de la mitad lo tuvo en el mismo año en que se aplicó la encuesta. La exposición a plaguicidas se da tanto en los espacios productivos, como residenciales. Se observó que las medidas preventivas asociadas al contacto con agrotóxicos son insuficientes. A la vez, destaca la exposición a fumigaciones aéreas, frente a las cuales la posibilidad de prevención es aún menor. CONCLUSIÓN: En comunas rurales puede existir un contacto permanente de la población femenina gestante con plaguicidas, lo cual sucede sin las medidas de protección adecuadas, incrementando el riesgo de exposición a estas sustancias. Es pertinente entonces, desarrollar una labor educativa activa para mejorar las prácticas de uso de plaguicidas.

BACKGROUND: Agriculture workers and rural dwellers are exposed to pesticide products. Sanitation policies attempt to regulate their use, but studies demonstrate that a significant percentage of workers and residents who are close to the productive zones are exposed to these chemicals. Pregnant women are particularly vulnerable to pesticides. AIM: To identify the risk of exposure to pesticides and practices of pesticide handling in women under pregnancy control programs in Family Health Care Centers in two rural districts of the 5th Region. METHOD: Cross-sectional study, conducted during May 2013 and April 2014 on eighty women, who entered pregnancy control programs in either rural district. The health professionals of the Centers collected the data in a survey. RESULTS: Most of the pregnant women declared having been in contact with pesticides at some point. Almost half of them had this contact in the same year of their interview, that is previous or during their pregnancy. The exposure to pesticides takes place in productive locations as well as residential areas. The preventive measures associated to the contact with pesticides are not sufficient. Rural populations are also exposed to aerial fumigations, which further limits preventive measures. CONCLUSION: Pregnant women living in a rural district may be permanently exposed to pesticides. Exposure to agrochemicals is not associated to safe prevention practices which increase the risk of exposure. Educational programs may aid to enhance safe pesticide use.

Prenatal tobacco exposure is related to neurobehavioral modifications in infants of adolescent mothers

INTRODUCTION: Prenatal tobacco exposure interferes with neonatal outcomes. OBJECTIVE: To determine the neonatal neurobehavioral effects of in utero tobacco exposure. METHODS: This prospective cross-sectional study included healthy, term, with birth weight appropriate for gestacional age neonates without exposure to alcohol, drugs, or infections, born to adolescent mothers without psychiatric disorders or post-traumatic stress. Infants were classified according to in utero tobacco exposure, as identified by the Composite International Diagnostic Interview administered to mothers. Neurobehavior was assessed by the Neonatal Intensive Care Unit Network Neurobehavioral Scale. Both tools were administered between 24 and 72 hours after birth. Neurobehavioral outcomes were compared between exposed and nonexposed infants by ANOVA. The associations between neurobehavioral scores and number of cigarettes smoked were studied by linear correlation. RESULTS: During the study, 928 newborns of adolescent mothers were born, and 388 were included in the study. Of these, 23 were exposed to tobacco, and 365 neonates were not exposed. There were no differences between the groups in gestational age, birth weight, post-natal age at the exam, or time between last feeding and exam. Exposed neonates showed higher scores on arousal (p = 0.004), excitability (p = 0.003), and stress/abstinence signals (p = 0.019) and a lower score on regulation (p = 0.025). After adjusting for the type of anesthesia, mode of delivery, gender, age at neurologic exam, exam duration and time between last feeding and exam, differences in arousal and excitability remained significant. The mean number of cigarettes consumed daily was positively correlated with lethargy (p = 0.013) and inversely with attention (p = 0.043). CONCLUSIONS: Neonates exposed in utero to tobacco showed worse neurobehavioral performance between 24 and 48 hours of life.

Are environmental pollutants risk factors for low birth weight? / Os poluentes ambientais são fatores de risco para o baixo peso ao nascer?

The aim of this study was to assess the association between prenatal exposure to air pollutants and low birth weight in a medium-sized city. An ecological study was performed, using live birth data from São José dos Campos, São Paulo State, Brazil. The environmental data were obtained from the São Paul State Environmental Agency. The study included full-term newborns whose mothers were 20 to 34 years of age and had at least a complete high school education, seven or more prenatal visits, singleton pregnancy, and vaginal delivery, in order to minimize potential confounding from these variables. Logistic regression was used to estimate the effect of each pollutant. Low birth weight was defined as less than 2,500g. The sample included a total of 2,529 data from 2001 that met the inclusion criteria (25.6 percent of the total). We identified 99 newborns (3.95 percent of the sample) with low birth weight, and the pollutants sulfur dioxide and ozone were associated with low birth weight. The final model was À(x) = -1.79 + 1.30 (SO2) + 1.26 (O3). Thus, sulfur dioxide and ozone were identified as risk factors for low birth weight in a medium-sized city in Southeast Brazil.

O objetivo foi estimar o papel de poluentes no baixo peso ao nascer numa cidade de porte médio. Foi um estudo ecológico com dados obtidos da Declaração de Nascido Vivo relativos a São José dos Campos, São Paulo, Brasil. Os dados ambientais foram fornecidos pela Companhia de Tecnologia de Saneamento Ambiental (CETESB). Foram incluídos no estudo recém-nascidos a termo, com mães entre 20 e 34 anos de idade, segundo grau completo, sete ou mais consultas realizadas no pré-natal, gravidez única e parto normal, para minimizar o efeito de confusão destas variáveis. Utilizou-se regressão logística para estimar o efeito de cada poluente. Baixo peso ao nascer foi considerado aquele inferior a 2.500g. Foram incluídos 2.529 dados de 2001 que atenderam aos critérios de inclusão (25,6 por cento do total). Identificamos 99 recém-nascidos (3,95 por cento dessa amostra) com baixo peso e os poluentes dióxido de enxofre e ozônio como associados ao baixo peso ao nascer. O modelo final foi À(x) = -1,79 + 1,30 (SO2) + 1,26 (O3). Assim, identificou-se o dióxido de enxofre e ozônio como responsáveis pelo baixo peso ao nascer numa cidade de porte médio do Sudeste brasileiro.

A importância do Serviço de Informações sobre Agentes Teratogênicos, Bahia, Brasil, na prevenção de malformações congênitas: análise dos quatro primeiros anos de funcionamento / Importance of the Teratogen Information Service in Bahia, Brazil, for prevention of congenital malformations: an initial four-year review

Agente teratogênico é definido como o agente físico, químico, biológico ou estado de deficiência que, durante a vida embrionária, leva a alteração na estrutura ou função do concepto. Informações sobre a conduta a ser tomada no caso de exposições a teratogênicos durante a gestação são imprescindíveis. Com essa finalidade, em 2001, foi implantado o Serviço de Informações sobre Agentes Teratogênicos da Bahia (SIAT-BA), localizado no Serviço de Genética Médica do Hospital Universitário Professor Edgard Santos da Universidade Federal da Bahia. O objetivo é descrever as características do atendimento do SIAT-BA nos seus primeiros quatro anos de funcionamento. As consultas foram realizadas através do contato via telefone, fax ou e-mail, entre março de 2001 e maio de 2005. Nesse período, o SIAT-BA recebeu 408 consultas, totalizando 1.091 motivos. A maioria das consultas foi realizada por gestantes e profissionais de saúde. Produtos para cabelo, chás e misoprostol foram os agentes mais investigados. O pequeno número de consultas (1/dia) indica a necessidade de maior divulgação do serviço e da conscientização da população sobre os riscos oferecidos pelos diversos agentes.

Teratogenic agents are defined as physical, chemical, or biological agents or nutrient deficiencies that lead to fetal structural or functional alterations. Information on the effects of exposure to teratogens during pregnancy is of the utmost importance. In order to achieve this goal, in 2001, the Bahia State Teratogen Information Service was created in the Medical Genetics Department at the University Hospital of the Federal University in Bahia. The current paper aimed to describe the first four years of operation in the service. From March 2001 to May 2005, the service was consulted by telephone, fax, and e-mail. During this period, 408 queries were made, for a total of 1,091 different reasons. Most queries were made by pregnant women and health care professionals. Hair products, herbal teas, and misoprostol were the most widely investigated agents. The low number of queries (average 1/day) shows the need for more awareness-raising on the risks posed by the various agents.

Factores de riesgo para el desarrollo de tumor de Wilms en la edad pediátrica / Risk factors for Wilms' tumor development in children

INTRODUCTION: Wilms' tumor (WT) is the most frequent embryonic renal neoplasia in children. OBJECTIVE: This study was carried out to investigate risk factors in the development of WT. MATERIAL AND METHODS: A design of cases and controls, proactive, of incident cases, with four controls per case. The study population of cases were children of two oncologic reference Center of the Mexican Institute of Social Security (IMSS) in the Mexican Federal District during 5-year period. For the control group, children were frequency matched by age and sex at with cases from the same clinic. A questionnaire, previously validated, was applied to determine risk factors in both groups. RESULTS: During the period of study, 34 cases and 136 controls were revised. Significant risk factors were: antecedent of a relative with Down syndrome (OR = 7.6, 95CI 1.4-51.1, p = 0.008), eczema (OR = 3.7, 95Cl 1.1-12, p = 0.01); having been conceived in autumn (OR = 5.4, 95CI 1.3-31.6, p = 0.007) or winter (OR = 4.9, 95Cl 1.1-29.9, p = 0.01), and beet ingestion (OR = S. 7, 95Cl 1.7-19.4, p = 0.0007). CONCLUSIONS: In this study, influence of prenatal factors are shown and we attempt to explain the etiology of WT, the important of beet ingestion, and conclusions suggest that that more epidemiologic studies are necessary to determine the chain of events that causes Wilms' tumor.

In utero exposure to cadmium pollution in Cairo and Giza governorates of Egypt

Serum cadmium levels at delivery were measured in a consecutive sample of 100 mother-infant pairs in Egypt using venous blood from mothers and umbilical cord blood from neonates. The serum cadmium levels of mothers ranged from 0.4 to 2.2 microg/L [mean 0.73 microg/L] and of infants from 0.2 to 1.5 microg/L [mean 0.66 microg/L]. Infant cadmium levels were about 70% of maternal levels in most pairs. Serum cadmium was significantly higher in mothers and babies passively exposed to tobacco smoke. Five-minute Apgar scores were negatively correlated with cord blood cadmium levels. The cadmium levels did not differ between subjects from Cairo and Giza or according to urban, suburban or rural areas. Thus, in utero exposure to cadmium was evident and wider-scale studies on its long-term effects are recommended

Deficiencia de folatos y su asociación con defectos de cierre del tubo neural en el norte de México / Folic acid deficiency and its relationship with neural tube defects in northern Mexico

Objetivo. Valora la asociación de la deficiencia de folatos y otros factores de riesgo con la ocurrencia de defectos de cierre del tubo neural (DCTN), en la población rural del norte de México (Chihuahua, Durango y Zacatecas). Material y métodos. Se hizo un estudio multicéntrico de casos y controles. Se consideraron como casos a los recién nacidos vivos (RNV) y a los muertos con DCTN, y como controles, a los RNV sanos, no malformados. Se determinó la exposición a factores de riesgo conocidos, estableciendo su asociación con los DCTN, con un modelo de análisis múltiple de regresión logística. Resultados. Los factores de riesgo asociados a DCTN fueron: la deficiencia de folatos (RM 11.1; IC95 por ciento 1.2-106.2, p= 0.04); el antecedente, en embarazos previos, de productos con DCTN (RM 3.3; IC95 por ciento 1.1-18.8, p= 0.05), y óbitos (RM 7.1; IC95 por ciento 1.1-46.3, p= 0.04). Conclusiones. La deficiencia de folatos constituye uno de los principales factores de riesgo asociado a los DCTN en la población rural del norte de México. Es necesario llevar a cabo más investigaciones para determinar la contribución de otros factores de riesgo y establecer las medidas preventivas adecuadas