Population Physiologically Based Pharmacokinetic Modeling for the Human Lactational Transfer of PCB-153 with Consideration of Worldwide Human Biomonitoring Results

[[abstract]]Background: One of the most serious human health concerns related to environmental contamination with polychlorinated biphenyls (PCBs) is the presence of these chemicals in breast milk. Objectives: We developed a physiologically based pharmacokinetic model of PCB-153 in women, and predict its transfer via lactation to infants. The model is the first human, population-scale lactational model for PCB-153. Data in the literature provided estimates for model development and for performance assessment. Methods: We used physiologic parameters from a cohort in Taiwan and reference values given in the literature to estimate partition coefficients based on chemical structure and the lipid content in various body tissues. Using exposure data from Japan, we predicted acquired body burden of PCB-153 at an average childbearing age of 25 years and compared predictions to measurements from studies in multiple countries. We attempted one example of reverse dosimetry modeling using our PBPK model for possible exposure scenarios in Canadian Inuits, the population with the highest breast milk PCB-153 level in the world. Results: Forward-model predictions agree well with human biomonitoring measurements, as represented by summary statistics and uncertainty estimates. Conclusion: The model successfully describes the range of possible PCB-153 dispositions in maternal milk, suggesting a promising option for back-estimating doses for various populations

Prevalence and predictors of 6-month exclusive breastfeeding among Canadian women: a national survey

<p>Abstract</p> <p>Background</p> <p>In spite of the evidence supporting the importance of breastfeeding during the first year of life, data on breastfeeding practices remain limited in Canada. The study aimed to examine the prevalence and predictors of 6-month exclusive breastfeeding among Canadian women.</p> <p>Methods</p> <p>The analysis was based on the Maternity Experience Survey targeting women aged ≥ 15 years who had singleton live births between February 2006 - May 2006 in the Canadian provinces and November 2005 - February 2006 in the territories. The main outcome was exclusive breastfeeding based on the World Health Organization definition. Socioeconomic, demographic, maternal, pregnancy and delivery related variables were considered for a multivariate logistic regression using stepwise modeling. Bootstrapping was performed to account for the complex sampling design.</p> <p>Results</p> <p>The sample size in this study was 5,615 weighted to represent 66,810 Canadian women. While ever breastfeeding was 90.3%, the 6-month exclusive breastfeeding rate was 13.8%. Based on the regression model, having higher years of education, residing in the Northern territories and Western provinces, living with a partner, having had previous pregnancies, having lower pre-pregnancy body mass index and giving birth at older age were associated with increased likelihood of 6-month exclusive breastfeeding. Moreover, smoking during pregnancy, Caesarean birth, infant's admission to the intensive care unit and maternal employment status before 6 months of infant's age were negatively associated with exclusive breastfeeding. Mothers choosing to deliver at home were more likely to remain exclusively breastfeeding for 6 months (Odds Ratio: 5.29, 95% Confidence Interval: 2.95-9.46).</p> <p>Conclusions</p> <p>The 6-month exclusive breastfeeding rate is low in Canada. The study results constitute the basis for designing interventions that aim to bridge the gap between the current practices of breastfeeding and the World Health Organization recommendation.</p

Compliance with the "Baby-friendly Hospital Initiative for Neonatal Wards" in 36 countries.

In 2012, the Baby-friendly Hospital Initiative for Neonatal Wards (Neo-BFHI) began providing recommendations to improve breastfeeding support for preterm and ill infants. This cross-sectional survey aimed to measure compliance on a global level with the Neo-BFHI's expanded Ten Steps to successful breastfeeding and three Guiding Principles in neonatal wards. In 2017, the Neo-BFHI Self-Assessment questionnaire was used in 15 languages to collect data from neonatal wards of all levels of care. Answers were summarized into compliance scores ranging from 0 to 100 at the ward, country, and international levels. A total of 917 neonatal wards from 36 low-, middle-, and high-income countries from all continents participated. The median international overall score was 77, and median country overall scores ranged from 52 to 91. Guiding Principle 1 (respect for mothers), Step 5 (breastfeeding initiation and support), and Step 6 (human milk use) had the highest scores, 100, 88, and 88, respectively. Step 3 (antenatal information) and Step 7 (rooming-in) had the lowest scores, 63 and 67, respectively. High-income countries had significantly higher scores for Guiding Principles 2 (family-centered care), Step 4 (skin-to-skin contact), and Step 5. Neonatal wards in hospitals ever-designated Baby-friendly had significantly higher scores than those never designated. Sixty percent of managers stated they would like to obtain Neo-BFHI designation. Currently, Neo-BFHI recommendations are partly implemented in many countries. The high number of participating wards indicates international readiness to expand Baby-friendly standards to neonatal settings. Hospitals and governments should increase their efforts to better support breastfeeding in neonatal wards.info:eu-repo/semantics/publishe

Fatores associados com a retenção e o ganho de peso pós-parto: uma revisão sistemática Risk factors associated with postpartum weight gain and retention: a systematic review

INTRODUÇÃO: A retenção de peso após o parto é um dos determinantes da obesidade em mulheres. Seu desenvolvimento está relacionado com o ganho de peso gestacional, paridade, idade, situação marital, consumo energético, atividade física e lactação, mas as associações encontradas têm se mostrado inconclusivas e contraditórias. Objetivos: Avaliar estudos que identificaram fatores preditores da retenção e ganho de peso após o parto. MATERIAL E MÉTODOS: Foi realizada uma revisão de literatura na Base de Dados LILACS e MEDLINE, referente aos anos de 1993 a 2003. RESULTADOS: Vinte e oito artigos foram identificados, sendo 23 estudos de coorte, quatro estudos transversais e um estudo caso-controle. A maioria dos estudos foi realizada nos EUA e o tempo de acompanhamento após o parto ocorreu principalmente entre seis semanas e 24 meses. Cerca de 25% dos estudos apresentaram perdas superiores a 30%, 61% incluíram adolescentes na amostra e 75% não aferiram o peso pré-gestacional. Sete estudos foram considerados de melhor qualidade, pois utilizaram o peso pré-gestacional medido, incluíram grupo de comparação, excluíram adolescentes, apresentaram perdas de seguimento inferiores a 30% e controlaram para variáveis de confundimento. CONCLUSÃO: Ganho de peso gestacional, raça negra e paridade estão associados positivamente com a retenção de peso pós-parto. As evidências são contraditórias para a variável lactação e insuficientes para as variáveis consumo alimentar e atividade física. São necessários estudos cuidadosamente desenhados para esclarecer estas questões.<br>BACKGROUND: Postpartum weight retention is a trigger for developing obesity in women. It is often associated with weight gain during pregnancy, parity, age, marital status, food intake, physical activity and lactation. However, the associations found have proven to be inconclusive or contradictory. OBJECTIVES: The purpose of this review was to study risk factors associated with postpartum weight gain and retention. METHODS: A systematic review of the literature between January 1993 and June 2003 was performed through Medline and LILACS databases. RESULTS: Twenty-eight studies were found: 23 cohort studies, four cross-sectional studies and one case-control study. Most studies were performed in the US and the postpartum follow-up time was mainly between six weeks and 24 months. Twenty five percent of the studies had loss to follow-up above 30%, 61% included adolescents and 75% used self-reported pregravid body weights. The most reliable results came from seven studies, whose strengths were: use of measured pregravid body weight and comparison groups, exclusion of adolescents, loss to follow-up rates below 30% and adequate control for confounders. CONCLUSION: Gestational weight gain, black women and parity are positively associated with postpartum weight retention. The effect of lactation on weight retention is still controversial and there is lack of evidence on physical activity and food intake. Improved longitudinal studies are needed to clarify theses issues