Factors Associated with Maternal Serum Levels of Perfluoroalkyl Substances and Organochlorines: A Descriptive Study of Parous Women in Norway and Sweden.

INTRODUCTION: Perfluoroalkyl substances (PFASs) and organochlorines (OCs) are ubiquitous and persistent in the environment and proposed endocrine disrupting chemicals (EDCs). They can be transferred across the placenta during pregnancy, and studies suggest that the prenatal period may be particularly sensitive for influences on fetal growth and development. Several studies have investigated socio-demographic and pregnancy related factors associated with maternal serum PFAS and OC levels, but few studies have been conducted in time periods with increasing emissions of PFASs and recent emissions of OCs. METHODS: Serum from 424 pregnant women participating in the NICHD Scandinavian Successive Small-for-gestational Age (SGA) births study was collected in 1986-1988, and analyses of two PFASs and six OCs were conducted. Associations between EDCs and geographic, time dependent, socio-demographic and pregnancy related variables were evaluated by using multivariable linear regression models. RESULTS: Previous breastfeeding duration, time since last breastfeeding period, sampling date and country of residence were important factors associated with serum levels of PFOS and PFOA. Smoking status and pre-pregnancy BMI were negatively associated with PFOS, and maternal height was borderline negatively associated with PFOS and PFOA. Glomerular filtration rate (GFR) was negatively associated with PFOS in a sub-sample. Maternal serum levels of OCs were positively associated with maternal age, and negatively associated with previous breastfeeding duration and sampling date. Smoking had a consistently negative association with PCB 118 in a dose-dependent manner. Education level, pre-pregnancy BMI and alcohol consumption varied in importance according to the compound under study. CONCLUSIONS: Several maternal factors, including potentially modifiable factors, markers of pregnancy physiology and factors also related to perinatal outcomes were associated with EDC levels. Results from this study are relevant to populations with still high PFAS and OC levels, i.e. developing countries. Moreover, we can use this knowledge about associated factors on emerging EDCs with similar properties.

The impact of pre- and postnatal exposures on allergy related diseases in childhood: a controlled multicentre intervention study in primary health care.

BACKGROUND: Environmental factors such as tobacco exposure, indoor climate and diet are known to be involved in the development of allergy related diseases. The aim was to determine the impact of altered exposure to these factors during pregnancy and infancy on the incidence of allergy related diseases at 2 years of age. METHODS: Children from a non-selected population of mothers were recruited to a controlled, multicenter intervention study in primary health care. The interventions were an increased maternal and infant intake of n-3 PUFAs and oily fish, reduced parental smoking, and reduced indoor dampness during pregnancy and the children's first 2 years of life. Questionnaires on baseline data and exposures, and health were collected at 2 years of age. RESULTS: The prevalence of smoking amongst the mothers and fathers was approximately halved at 2 years of age in the intervention cohort compared to the control cohort. The intake of n-3 PUFA supplement and oily fish among the children in the intervention cohort was increased. There was no significant change for indoor dampness. The odds ratio for the incidence of asthma was 0.72 (95% CI, 0.55-0.93; NNTb 53), and 0.75 for the use of asthma medication (95% CI, 0.58-0.96). The odds ratio for asthma among girls was 0.41 (95% CI 0.24-0.70; NNTb 32), and for boys 0.93 (95% CI 0.68-1.26). There were no significant change for wheeze and atopic dermatitis. CONCLUSION: Reduced tobacco exposure and increased intake of oily fish during pregnancy and early childhood may be effective in reducing the incidence of asthma at 2 years of age. The differential impact in boys and girls indicates that the pathophysiology of asthma may depend on the sex of the children. TRIAL REGISTRATION: Current Controlled Trials ISRCTN28090297.

Family eczema-history in 2-year-olds with eczema; a prospective, population-based study. The PACT-study, Norway.

BACKGROUND: A maternal line of inheritance regarding eczema has been described in several studies, whereas others find associations to both a maternal as well as a paternal line of inheritance. When studying family history of eczema symptoms, cohort studies including siblings are rare. Time point for assessing family eczema-history could be of importance when studying the associations between family eczema-history and children with eczema, as parents with unaffected children may not recall mild symptoms in other siblings or their own disease history. We therefore aimed to study the associations between reported eczema in mother, father and siblings and reported eczema in index child where information on family history was collected at two different ages of index child. METHODS: Parents/children participating in The Prevention of Allergy among Children in Trondheim (PACT) study were given questionnaires on reported eczema symptoms in mother, father and siblings at 6 weeks and 1 year. When index child was 2 years of age, a detailed questionnaire on different health issues with emphasize on different allergy related disorders were filled in. RESULTS: Both maternal and paternal reports on eczema were significantly associated with eczema in index child. Reporting family eczema-history at 1 year (N = 3087), "eczema sibling only" [adjusted odds ratio (aOR) = 3.13 (2.27-4.33)] as well as all other family-groups containing siblings with eczema were strongly associated with eczema 2 years. When family eczema-history was reported at 6 weeks (N = 2657), reporting of "eczema sibling only" was not associated to reported eczema at 2 years in index child [aOR = 1.31 (0.77-2.23)]. CONCLUSIONS: Having sibling(s) with eczema strengthened the associations between maternal and paternal reports on eczema with eczema in index child only when exposure was reported at 1 year. These findings indicate that results from questionnaires-based studies of family eczema-history depend on whether or not index child has yet developed eczema.

A primary health-care intervention on pre- and postnatal risk factor behavior to prevent childhood allergy. The Prevention of Allergy among Children in Trondheim (PACT) study.

BACKGROUND: This study aimed to evaluate the impact of a primary prevention intervention program on risk behavior for allergic diseases among children up to 2 years of age. The setting was in ordinary pre- and postnatal primary health care in Trondheim, Norway. METHODS: The Prevention of Allergy among Children in Trondheim, Norway (PACT) study invited all pregnant women and parents to children up to 2 years of age in the community to participate in a non-randomized, controlled, multiple life-style intervention study. Interventional topics was increased dietary intake of cod liver oil and oily fish for women during pregnancy and for infants during the first 2 years of life, reduced parental smoking and reduced indoor dampness. A control cohort was established prior to the intervention cohort with "follow up as usual". Questionnaires were completed in pregnancy, 6 weeks after birth and at 1 and 2 years of age. Trends in exposure and behavior are described. RESULTS: Intake of oily fish and cod liver oil increased statistically significantly among women and infants in the intervention cohort compared to the control cohort. There was a low postnatal smoking prevalence in both cohorts, with a trend towards a decreasing smoking prevalence in the control cohort. There was no change in indoor dampness or in behavior related to non- intervened life-style factors. CONCLUSIONS: The dietary intervention seemed to be successful. The observed reduced smoking behavior could not be attributed to the intervention program, and the latter had no effect on indoor dampness. TRIAL REGISTRATIONS: (Current Controlled Trials registration number: ISRCTN28090297).

Do early intake of fish and fish oil protect against eczema and doctor-diagnosed asthma at 2 years of age? A cohort study.

BACKGROUND: There are ambiguous results regarding the role n-3 polyunsaturated fatty acids and fish might play in primary prevention of allergic diseases. The aim was to investigate the association between cod liver oil and fish consumption during pregnancy and in the first year of life and asthma and eczema at 2 years of age. METHODS: From the Prevention of Allergy among Children in Trondheim study, a prospective birth cohort study in primary healthcare in Trondheim, Norway, 3086 children were followed prospectively from 1 year to approximately 2 years of age. The primary outcome variable was parental reported asthma and eczema at 2 years. RESULTS: The mean age for introducing fish in the diet was 9.1 months. Excluding children with incident eczema before 1 year, a reduced risk of developing eczema was found if the child was eating fish once a week or more, adjusted OR (aOR) for any kind of fish 0.62 (95% CI 0.42 to 0.91 p=0.02), for oily fish aOR 0.21 (95% CI 0.05 to 0.86 p=0.03) and for lean fish aOR 0.67 (95% CI 0.41 to 1.08 p=0.10). The associations between maternal diet and eczema at 2 years and between the dietary factors and doctor-diagnosed asthma were all insignificant. CONCLUSIONS: Fish consumption in infancy was more important than maternal fish intake during pregnancy in preventing eczema in childhood. The intake of fish per se, not specifically n-3 polyunsaturated fatty acids, was most important in preventing eczema.

Maternal smoking cessation in early pregnancy and offspring weight status at four years of age. A prospective birth cohort study.

BACKGROUND: Maternal smoking during pregnancy is associated with fetal growth restriction, but also with increased risk for overweight in childhood. If the mother stops smoking in early pregnancy fetal growth is not restricted, but whether the risk for later overweight persists is unclear. AIM: To study if four year old children of mothers who stopped smoking in early pregnancy have higher mean body mass index (BMI) and/or increased odds of being overweight compared with children of non-smokers. STUDY DESIGN: Prospective population based study on Norwegian mothers and children. SUBJECTS: Among 711 children available for analysis, 540 were children of never smoking mothers, 114 of mothers who stopped smoking in early pregnancy, and 57 of mothers who continued to smoke throughout pregnancy. OUTCOME MEASURES: BMI and overweight defined by international criteria at age four. RESULTS: Compared with children of never smoking mothers, children of smoking mothers had higher mean BMI (mean difference: 0.47; 95% CI: 0.10, 0.84 kg/m(2)), whereas mean BMI was not higher among children of mothers who stopped smoking (mean difference: 0.02; 95% CI: -0.24, 0.28 kg/m(2). Similarly, children of smoking mothers had increased odds for overweight (adjusted OR: 2.83; 95% CI: 1.13, 7.10), whereas children of mothers who stopped smoking did not have increased odds (adjusted OR: 1.29; 95% CI: 0.62, 2.68) compared with children of never smoking mothers. CONCLUSIONS: In this study, the association between smoking exposure and childhood overweight did not persist in children of mothers who stopped smoking early in pregnancy.

The impact of a minimal smoking cessation intervention for pregnant women and their partners on perinatal smoking behaviour in primary health care: a real-life controlled study.

BACKGROUND: There is a demand for strategies to promote smoking cessation in high-risk populations like smoking pregnant women and their partners. The objectives of this study were to investigate parental smoking behaviour during pregnancy after introduction of a prenatal, structured, multi-disciplinary smoking cessation programme in primary care, and to compare smoking behaviour among pregnant women in the city of Trondheim with Bergen and Norway. METHODS: Sequential birth cohorts were established to evaluate the intervention programme from September 2000 to December 2004 in primary care as a part of the Prevention of Allergy among Children in Trondheim study (PACT). The primary outcome variables were self reported smoking behaviour at inclusion and six weeks postnatal. Data from the Medical Birth Registry of Norway (MBR) were used to describe smoking cessation during pregnancy in Trondheim, Bergen and Norway 1999-2004. RESULTS: Maternal smoking prevalence at inclusion during pregnancy were 5% (CI 95% 4-6) in the intervention cohort compared to 7% (CI 95% 6-9), p = 0.03, in the control cohort. Of the pre-pregnancy maternal smokers 25% (CI 95% 20-31) and 32% (CI 95% 26-38), p = 0.17, were still smoking at inclusion in the intervention and control cohorts, respectively. Six weeks postnatal 72% (CI 95% 59-83) and 68% (CI 95% 57-77), p = 0.34 of the maternal smokers at inclusion still smoked. No significant difference in paternal smoking between the cohorts was found after the intervention period. Data from the MBR showed a significantly higher proportion of women who stopped smoking during pregnancy in Trondheim than in Bergen in 2003 and 2004, p = 0.03 and < 0.001, respectively. CONCLUSION: No impact on parental smoking behaviour between the cohorts was observed after the smoking intervention programme. Of the women who stopped smoking during pregnancy most of them stopped smoking before the intervention. However, we observed a significantly higher quitting rate in Trondheim than in Bergen in 2003 and 2004 which may have been facilitated by the supplemental attention on smoking behaviour the PACT study initiated.

Assessing atopic disease in children two to six years old: reliability of a revised questionnaire.

BACKGROUND: Primary intervention - reducing second hand smoking (SHS), indoor dampness, and increased intake of omega-3-fatty acids - for allergic diseases such as asthma, rhinoconjunctivitis, and eczema/dermatitis in children was started in Trondheim in 2002. To our knowledge, no validated or reliable questionnaires for the study age groups were available. AIMS: To test the reliability of a revised questionnaire for studying atopic disease in children two to six years old in Trondheim. METHODS: Seventy-seven families were invited to fill in a questionnaire adapted from the ISAAC protocol which was made appropriate for the age group studied. Completed questionnaires and information from medical records were compared, and the agreement was analysed by Kappa statistics and proportional agreement. RESULTS: Agreement was excellent for questions reporting current information such as doctor-diagnosed asthma (kappa=0.88), whether or not the child had had an allergy test (kappa=0.82), and use of antibiotics (kappa=0.81). The agreement was good for questions concerning doctor or hospital treatment for asthma (kappa=0.59), medication for asthma (kappa=0.58), symptoms of eczema (kappa=0.56), medication for allergic disease (kappa=0.45), and past infections (kappa=0.53). CONCLUSION: Questions on asthma diagnosis, allergy testing, and use of antibiotics were reliable. Questions on medical treatment for eczema, allergic rhinoconjunctivitis and infections were less reliable, representing a potential source of information bias and possible misclassification.