Prenatal Ambient Air Pollution, Placental Mitochondrial DNA Content, and Birth Weight in the INMA (Spain) and ENVIRONAGE (Belgium) Birth Cohorts.

BACKGROUND: Mitochondria are sensitive to environmental toxicants due to their lack of repair capacity. Changes in mitochondrial DNA (mtDNA) content may represent a biologically relevant intermediate outcome in mechanisms linking air pollution and fetal growth restriction. OBJECTIVE: We investigated whether placental mtDNA content is a possible mediator of the association between prenatal nitrogen dioxide (NO2) exposure and birth weight. METHODS: We used data from two independent European cohorts: INMA (n = 376; Spain) and ENVIRONAGE (n = 550; Belgium). Relative placental mtDNA content was determined as the ratio of two mitochondrial genes (MT-ND1 and MTF3212/R3319) to two control genes (RPLP0 and ACTB). Effect estimates for individual cohorts and the pooled data set were calculated using multiple linear regression and mixed models. We also performed a mediation analysis. RESULTS: Pooled estimates indicated that a 10-µg/m3 increment in average NO2 exposure during pregnancy was associated with a 4.9% decrease in placental mtDNA content (95% CI: -9.3, -0.3%) and a 48-g decrease (95% CI: -87, -9 g) in birth weight. However, the association with birth weight was significant for INMA (-66 g; 95% CI: -111, -23 g) but not for ENVIRONAGE (-20 g; 95% CI: -101, 62 g). Placental mtDNA content was associated with significantly higher mean birth weight (pooled analysis, interquartile range increase: 140 g; 95% CI: 43, 237 g). Mediation analysis estimates, which were derived for the INMA cohort only, suggested that 10% (95% CI: 6.6, 13.0 g) of the association between prenatal NO2 and birth weight was mediated by changes in placental mtDNA content. CONCLUSION: Our results suggest that mtDNA content can be one of the potential mediators of the association between prenatal air pollution exposure and birth weight. CITATION: Clemente DB, Casas M, Vilahur N, Begiristain H, Bustamante M, Carsin AE, Fernández MF, Fierens F, Gyselaers W, Iñiguez C, Janssen BG, Lefebvre W, Llop S, Olea N, Pedersen M, Pieters N, Santa Marina L, Souto A, Tardón A, Vanpoucke C, Vrijheid M, Sunyer J, Nawrot TS. 2016. Prenatal ambient air pollution, placental mitochondrial DNA content, and birth weight in the INMA (Spain) and ENVIRONAGE (Belgium) birth cohorts. Environ Health Perspect 124:659-665; http://dx.doi.org/10.1289/ehp.1408981.

Prevalencia y factores asociados con la duración de la lactancia materna exclusiva durante los 6 primeros meses en la cohorte INMA de Guipúzcoa / Prevalence of factors associated with the duration of exclusive breastfeeding during the first 6 months of life in the INMA birth cohort in Gipuzkoa

Objetivos Estimar la prevalencia de la lactancia materna exclusiva en la cohorte INMA (Infancia y Medio Ambiente) de Guipúzcoa durante los primeros 6 meses de vida del bebé. Identificar las razones de su abandono y determinar los factores asociados. Método La población de estudio está formada por 638 mujeres embarazadas (www.proyectoinma.org) seguidas desde el primer trimestre de embarazo hasta los 14 meses de edad de sus hijos. Para determinar los factores asociados con el abandono de la lactancia materna exclusiva se utilizan modelos de regresión logística en dos etapas diferentes (4 meses/fase temprana y 6 meses/fase tardía).Resultados La prevalencia de lactancia materna exclusiva fue del 84,8% al alta hospitalaria, el 53,7% a los 4 meses y el 15,4% a los 6 meses de vida. Las razones descritas por las madres sobre el abandono de la lactancia materna exclusiva asociadas a la fase temprana son problemas de lactancia, escasa ganancia de peso e hipogalactia. Otros factores que influyen en la etapa temprana son la intención previa durante el embarazo de dar lactancia materna exclusiva, la paridad, la comarca de residencia y la clase social. En la etapa tardía influye el tiempo de baja por maternidad. Conclusiones Los resultados de este estudio pueden ser de utilidad para los profesionales sanitarios y desde una perspectiva de salud pública, ya que permiten diseñar estrategias para apoyar a las madres lactantes, teniendo en cuenta las razones principales de abandono temprano y tras la reincorporación a la vida laboral (AU)

Objective To estimate the prevalence of exclusive breastfeeding (EB) during the first 6 months of life in the Gipuzkoa birth cohort, identify the reasons for abandonment of EB, and establish the associated factors.Methods The study population consisted of 638 pregnant women from the INMA-Gipuzkoa (Infancia y Medio Ambiente, www.proyectoinma.org) birth cohort, who were followed up from the third trimester of pregnancy until the child was aged 14 months. To determine the factors related to abandonment of EB, logistic regression models were used in two different stages (4 months or early stage and 6 months or late stage).Results The prevalence of EB within the Gipuzkoa cohort was 84.8% after hospital discharge, 53.7% at 4 months of life and 15.4% at 6 months of life. The reasons given by the mothers for early EB cessation were: breastfeeding problems, low weight gain and hypogalactia. Other factors influencing the early phase were the intention to provide EB, parity, area of residence and social class. Abandonment in the late stage was influenced by the length of maternity leave. Conclusions From a public health perspective, the results of this study could help health professionals to develop strategies to support breastfeeding mothers, taking into account the main reasons for early and late abandonment (AU)

[Prevalence of factors associated with the duration of exclusive breastfeeding during the first 6 months of life in the INMA birth cohort in Gipuzkoa]. / Prevalencia y factores asociados con la duración de la lactancia materna exclusiva durante los 6 primeros meses en la cohorte INMA de Guipúzcoa.

OBJECTIVE: To estimate the prevalence of exclusive breastfeeding (EB) during the first 6 months of life in the Gipuzkoa birth cohort, identify the reasons for abandonment of EB, and establish the associated factors. METHODS: The study population consisted of 638 pregnant women from the INMA-Gipuzkoa (Infancia y Medio Ambiente, www.proyectoinma.org) birth cohort, who were followed up from the third trimester of pregnancy until the child was aged 14 months. To determine the factors related to abandonment of EB, logistic regression models were used in two different stages (4 months or early stage and 6 months or late stage). RESULTS: The prevalence of EB within the Gipuzkoa cohort was 84.8% after hospital discharge, 53.7% at 4 months of life and 15.4% at 6 months of life. The reasons given by the mothers for early EB cessation were: breastfeeding problems, low weight gain and hypogalactia. Other factors influencing the early phase were the intention to provide EB, parity, area of residence and social class. Abandonment in the late stage was influenced by the length of maternity leave. CONCLUSIONS: From a public health perspective, the results of this study could help health professionals to develop strategies to support breastfeeding mothers, taking into account the main reasons for early and late abandonment.

Mediterranean diet adherence during pregnancy and risk of wheeze and eczema in the first year of life: INMA (Spain) and RHEA (Greece) mother-child cohort studies.

Maternal diet during pregnancy might influence the development of childhood allergic disorders. The aim of the present study was to evaluate the impact of Mediterranean diet (MD) adherence during pregnancy on wheeze and eczema in the first year of life in two population-based mother-child cohorts in Spain and Greece. We studied 1771 mother-newborn pairs from the Spanish multi-centre 'INMA' (INfancia y Medio Ambiente) study (Gipuzkoa, Sabadell and Valencia) and 745 pairs from the 'RHEA' study in Crete, Greece. The symptoms of wheeze and eczema were based on the criteria of the International Study of Asthma and Allergies in Childhood. Maternal diet during pregnancy was assessed by FFQ and MD adherence was evaluated through an a priori score. Multivariate log-binomial regression models were used to adjust for several confounders in each cohort and summary estimates were obtained by a meta-analysis. MD adherence was not associated with the risk of wheeze and eczema in any cohort, and similar results were identified in the meta-analysis approach. High meat intake (relative risk (RR) 1·22, 95 % CI 1·00, 1·49) and 'processed' meat intake (RR 1·18, 95 % CI 1·02, 1·37) during pregnancy were associated with an increased risk of wheeze in the first year of life, while a high intake of dairy products was significantly associated with a decreased risk of infantile wheeze (RR 0·83, 95 % CI 0·72, 0·96). The results of the present study show that high meat intake during pregnancy may increase the risk of wheeze in the first year of life, while a high intake of dairy products may decrease it.

Socio-economic inequalities in health, habits and self-care during pregnancy in Spain.

Socioeconomic disadvantage can be harmful for mother's health and can influence child's health long term. The aim of this study is to analyse social inequalities between pregnant women from four INMA (INfancia y Medio Ambiente) cohorts. The analysis included 2,607 pregnant women recruited between 2004 and 2008 from four INMA cohorts. Data on maternal characteristics were collected through two questionnaires completed in the first and third trimester of pregnancy. The relationship between socioeconomic status (SES) and maternal health, dietary intake, lifestyle habits and self-care related variables was modelled using logistic regression analysis. 33.5 % of women had a university level of education and 47 % had high occupational class. Women with higher SES reported healthier habits, fewer complications during pregnancy, better weight gain control and attended more prenatal appointments than women with lower SES. The risk of sedentary behaviour and passive smoking was higher among women with a lower level of education (OR = 1.7, 95 % CI 1.3-2.2 and OR = 1.6, 95 % CI 1.2-2.3, respectively) and with less skilled occupations (OR = 1.7, 95 % CI 1.4-2.0 and OR = 1.2, 95 % CI 1.0-1.5, respectively). Although both SES indicators-occupation and education-act as social determinants of diet, occupation was a more powerful determinant than education. For other lifestyle and self-caring variables, education was a more powerful predictor than occupation. Social inequalities were observed in health, habits and self-care during pregnancy. Proper care during pregnancy requires the control of common clinical variables and the knowledge of socioeconomic conditions of the pregnant women.