Residential mobility during pregnancy in the north of England

Residential and healthcare mobility during pregnancy among women living with HIV in the UK, 2009-2019

INTRODUCTION

The extent to which individuals living with HIV experience residential and healthcare mobility during pregnancy in the UK is unknown. We aimed to determine a minimum estimate of residential and healthcare mobility during pregnancy in people living with HIV in the UK in 2009-2019 to explore patterns of and factors associated with mobility and to assess whether mobility was associated with specific HIV outcomes.

METHODS

We analyzed data from the Integrated Screening Outcomes Surveillance Service to assess pregnancies with HIV in the UK and included livebirths and stillbirths with estimated delivery in 2009-2019. Residential mobility was defined as changing residential postcode between notification and delivery, and healthcare mobility was defined as changing NHS Trust or Strategic Health Authority (SHA) in that same timeframe. We used logistic regression to determine factors associated with residential and healthcare mobility and with detectable delivery viral load.

RESULTS

Among 10 305 pregnancies, 19.6% experienced residential mobility, 8.1% changed NHS Trust, and 4.5% changed SHA during pregnancy. Mobility was more likely to be experienced by younger women, migrants, and those with new antenatal diagnosis; residential but not healthcare mobility declined over time. In a fully adjusted model, mobility was not associated with having a detectable viral load at delivery. Higher proportions of infants were lost to follow-up after mobile pregnancies than after non-mobile pregnancies.

CONCLUSIONS

This analysis provides new knowledge on mobility during pregnancy in the context of HIV, but further research is needed to understand its broader impacts and its utility as a marker to help identify families requiring additional follow-up and support.

Pregnant women's migration patterns before childbirth after large-scale earthquakes and the added impact of concerns regarding radiation exposure in Fukushima and five prefectures

The 2011 Great East Japan Earthquake (within Fukushima, Iwate, and Miyagi prefectures) was a complex disaster; it caused a tsunami and the Fukushima Daiichi Nuclear Power Plant accident, resulting in radiation exposure. This study investigated the earthquake's effects on the migration patterns of pregnant women and their concerns regarding radiation exposure. We also considered the following large-scale earthquakes without radiation exposure: Great Hanshin-Awaji (Hyogo prefecture), Niigata-Chuetsu, and Kumamoto. Pregnant women were categorized as outflow and inflow pregnant women. Data on the annual number of births three years before and after the earthquake were used as a denominator to calculate the outflow and inflow rates per 100 births. The odds ratios of annual outflow and inflow rates after the earthquake, using three years before the earthquake as the baseline, were calculated. The odds-ratio for outflow significantly increased for Hyogo, Fukushima, Miyagi, and Kumamoto prefectures after the earthquake, particularly for Fukushima, showing a significant increase until three years post the Great East Japan Earthquake (disaster year: odds-ratio: 2.66 [95% confidence interval: 2.44-2.90], 1 year post: 1.37 [1.23-1.52], 2 years post: 1.13 [1.00-1.26], 3 years post: 1.18 [1.05-1.31]), while the remaining three prefectures reported limited increases post one year. The inflow decreased after the earthquake, particularly in Fukushima, showing a significant decrease until 2 years post the Great East Japan Earthquake (disaster year: 0.58 [0.53-0.63], 1 year post: 0.76 [0.71-0.82], 2 years post: 0.83 [0.77-0.89]). Thus, pregnant women's migration patterns changed after large-scale earthquakes, suggesting radiation exposure concerns possibly have a significant effects. These results suggested that plans for receiving assistance and support that considers the peculiarities of disaster related damage and pregnant women's migration patterns are needed in both the affected and non-affected areas.

Association Between Maternal Exposure to SO2 and Congenital Ear Malformations in Offspring: A Population-Based Case-Control Study in Liaoning Province, China

Objectives: To examine associations between maternal sulfur dioxide (SO2) exposure and congenital ear malformations risk in offspring.

Methods: We surveyed 1676 cases with congenital ear malformations and 7950 controls from the Maternal and Child Health Certificate Registry of Liaoning Province between 2010 and 2015. SO2 concentrations were obtained from the Municipal Environment Protection Bureau of Liaoning Province. Multivariable logistic regression models and Restricted cubic splines (RCS) model were used to assess the aforementioned association.

Results: There were significant associations between maternal SO2 exposure and congenital ear malformations risk during the 3 months before conception (OR Q4 vs. Q1 = 1.93, 95% CI = 1.43–2.59) and the 3 months after conception (OR Q4 vs. Q1 = 1.63, 95% CI = 1.22–2.18). Similar results were obtained in the analysis of single-month exposure windows, except for the third month before conception and the third month after conception. Moreover, these findings were broadly consistent across subgroups and robust in sensitivity analyses. There were non-linear dose-response associations between SO2 exposure and congenital ear malformations based on restricted cubic spline model analysis.

Conclusion: Maternal SO2 exposure is associated with increased congenital ear malformations risk in offspring.

Characteristics of movers and predictors of residential mobility in the Atherosclerosis Risk in Communities (ARIC) cohort

Current efforts to characterize movers and identify predictors of moving have been limited. We used the ARIC cohort to characterize non-movers, short-distance movers, and long-distance movers, and employed best subset algorithms to identify important predictors of moving, including interactions between characteristics. Short- and long-distance movers were notably different from non-movers, and important predictors of moving differed based on the distance of the residential move. Importantly, systematic inclusion of interaction terms enhanced model fit and was substantively meaningful. This work has important implications for epidemiologic studies of contextual exposures and those treating residential mobility as an exposure.

Mobile Responsive App-A Useful Additional Tool for Data Collection in the German Pregnancy Register Rhekiss?

Background: The German pregnancy register Rhekiss is designed as a nationwide, web-based longitudinal observational cohort established in 2015. The register follows women with inflammatory rheumatic disease prospectively from child wish or early pregnancy until 2 years post-partum. Information on clinical and laboratory parameters, drug treatment, and (adverse) pregnancy outcomes are documented in pre-specified intervals. Physicians and patients report data for the same time periods via separated accounts and forms into a web-based application (app). As data entry on mobile devices might improve response rates of patients, a responsive app as a further convenient documentation option was developed.

Methods: The Rhekiss-app is available for self-reported data retrieval since August 2017 from the App stores. For the current analysis, Rhekiss register data were used from the start of the register until 30 September 2020. The analyses were performed for forms containing information on devices. Outcome parameters were compared for mobile and desktop users for the quantity and quality of filled forms.

Results: In total, 5,048 forms were received and submitted by 966 patients. About 57% of forms were sent from mobile devices with the highest numbers in patients with child wishes (63%). Users of mobile devices were slightly younger and often had less high-education level (62 vs. 79%) compared with desktop users. The proportion of forms submitted via mobile devices increased steadily from 48% in the fourth quarter of 2018 to 64% in the third quarter of 2020. The proportion of forms received before and after the Rhekiss-app implementation increased with the highest increase of 12% for forms filled at time point 12 months post-partum. Mobile users submitted significantly more forms than desktop users (2.9 vs. 2.1), data sent via desktops were more often complete (88 vs. 86%).

Conclusion: The responsive app is a valuable additional tool for data collection and is well-accepted by patients as indicated by its increasing use in Rhekiss. Apart from desktop/browser developments, the technological adoptions within observational cohorts and registries should take smartphone requirements and developments into account, especially when patient-reported data in young, mobile patients are collected, bearing in mind that data quality could be compromised and concepts for improving data quality should be implemented.

Traffic-related metrics and adverse birth outcomes: A systematic review and meta-analysis

Given the inconsistency of epidemiologic evidence for associations between maternal exposures to traffic-related metrics and adverse birth outcomes, this manuscript aims to provide clarity on this topic. Pooled meta-estimates were calculated using random-effects analyses. Subgroup analyses were conducted by study area, study design, and Newcastle-Ottawa quality score (NOS). Funnel plots and Egger's test were conducted to evaluate the publication bias, and Fail-safe Numbers (Fail-safe N) were measured to evaluate the robustness of models. From the initial 740 studies (last search, July 11, 2019), 26 studies were included in our analysis. The pooled odds ratio for the change in small for gestational age associated with per 500 m decrease in the distance to roads was 1.016 (95% CI: 1.004, 1.029). Subgroup analyses revealed significant positive associations between term low birth weight and traffic density in higher-quality literatures with higher NOS [1.060 (95% CI: 1.002, 1.121)], cohort studies [1.020 (95% CI: 1.006, 1.033)], and studies in North America [1.018 (95% CI: 1.005, 1.131)]. The buffer of traffic density made no difference in the effect size. Traffic density seemed to be a better indicator of traffic pollution than the distance to roads.

Predictors of residential mobility and its impact on air pollution exposure among children diagnosed with early childhood leukemia

Epidemiology studies relying on one address to assign exposures over time share common methodological limitations in failing to account for mobility that may introduce potential exposure misclassification. Using Texas birth certificate and cancer registry data, we identified predictors of residential mobility among mothers of children diagnosed with early childhood leukemia in Texas from 1995 to 2011. We used U.S. Environmental Protection Agency (EPA) National Air Toxics Assessment data to estimate residential levels of benzene and 1,3-butadiene based on addresses at birth and diagnosis and applied mixed-effects ordinal logistic regression models to evaluate differences in exposure classification between the two time periods. In total, 55% of children moved from time of birth to diagnosis, although they generally did not move far (median distance moved was 8 km). Predictors of mobility, at delivery, included younger age, being unmarried and living in neighborhoods with high benzene levels, and, at diagnosis, increasing child's age and living in neighborhoods with low poverty rates. We observed that the odds of being assigned to a higher exposure quartile at diagnosis relative to the time of birth decreased by 31% for 1,3-butadiene (OR = 0.69, 95% CI 0.59-0.82) and by 12% for benzene (OR = 0.88, 95% CI 0.75, 1.05).

Fetal growth, stillbirth, infant mortality and other birth outcomes near UK municipal waste incinerators; retrospective population based cohort and case-control study

BACKGROUND

Some studies have reported associations between municipal waste incinerator (MWI) exposures and adverse birth outcomes but there are few studies of modern MWIs operating to current European Union (EU) Industrial Emissions Directive standards.

METHODS

Associations between modelled ground-level particulate matter ≤10 μm in diameter (PM₁₀) from MWI emissions (as a proxy for MWI emissions) within 10 km of each MWI, and selected birth and infant mortality outcomes were examined for all 22 MWIs operating in Great Britain 2003-10. We also investigated associations with proximity of residence to a MWI. Outcomes used were term birth weight, small for gestational age (SGA) at term, stillbirth, neonatal, post-neonatal and infant mortality, multiple births, sex ratio and preterm delivery sourced from national registration data from the Office for National Statistics. Analyses were adjusted for relevant confounders including year of birth, sex, season of birth, maternal age, deprivation, ethnicity and area characteristics and random effect terms were included in the models to allow for differences in baseline rates between areas and in incinerator feedstock.

RESULTS

Analyses included 1,025,064 births and 18,694 infant deaths. There was no excess risk in relation to any of the outcomes investigated during pregnancy or early life of either mean modelled MWI PM₁₀ or proximity to an MWI.

CONCLUSIONS

We found no evidence that exposure to PM₁₀ from, or living near to, an MWI operating to current EU standards was associated with harm for any of the outcomes investigated. Results should be generalisable to other MWIs operating to similar standards.

Residential mobility during pregnancy in Urban Gansu, China

BACKGROUND

Studies on environmental exposures during pregnancy commonly use maternal residence at time of delivery, which may result in exposure misclassification and biased estimates of exposure and disease association. Studies on residential mobility during pregnancy are needed in various populations to aid studies of the environmental exposure and birth outcomes. However, there is still a lack of studies investigating residential mobility patterns in Asian populations.

METHODS

We analyzed data from 10,542 pregnant women enrolled in a birth cohort study in Lanzhou, China (2010-2012), a major industrial city. Multivariate logistic regression was used to evaluate residential mobility patterns in relation to maternal complications and birth outcomes.

RESULTS

Of the participants, 546 (5.2%) moved during pregnancy; among those who moved, 40.5%, 34.8%, and 24.7% moved during the first, second, and third trimester, respectively. Most movers (97.3%) moved once with a mean distance of 3.75 km (range: 1-109 km). More than half (66.1%) of the movers moved within 3 km, 13.9% moved 3-10 km, and 20.0% moved > 10 km. Pregnant women who were > 30 years or multiparous, or who had maternal complications were less likely to have moved during pregnancy. In addition, movers were less likely to deliver infants with birth defects, preterm births, and low birth weight.

CONCLUSIONS

Residential mobility was significantly associated with several maternal characteristics and complications during pregnancy. The study also showed a lower likelihood of adverse birth outcomes among movers than non-movers, suggesting that moving might be related to reduce exposure to environmental hazards. These results confirm the hypothesis that residential mobility may be important with respect to exposure misclassification and that this misclassification may vary by subpopulations.

Mobility patterns and associated factors among pregnant internal migrant women in China: a cross-sectional study from a National Monitoring Survey

Background

Residential instability during pregnancy has been linked to poor health outcomes. As a first step toward providing better health care to pregnant migrant women, the size and characteristics of this population and factors associated with mobility during pregnancy should be studied.

Methods

Using the “Monitoring Data of Chinese Migrants” for 2012, from the Chinese National Population and Family Planning Commission, this study explored mobility patterns during pregnancy and associated factors among migrants within China. From a library of 158,556 participants, two subsamples were selected. Percentages, with chi-squared tests, and means and standard deviations, with ANOVAs, were adopted to describe mobility patterns during pregnancy (always staying in sending area, mainly staying in sending area, mainly staying in receiving area, and always staying in receiving area) and delivery location choice. Logistic regression analysis was used to explore the associated factors.

Results

We found that the percentage of migrants always or mainly staying in receiving areas during pregnancy rose from nearly 40% in 1985 to more than 80% in 2012, while the percentage of migrants who were mobile between receiving and sending areas during pregnancy fluctuated between 30 and 40% before 1995, and between 40 and 45% after 1995, decreasing to around 40% after 2008. The percentage of respondents who chose to deliver in receiving areas fluctuated but increased from 10% in 1985 to more than 50% in 2011. Among respondents who had delivered during the last year of the survey period, families with older pregnant women (OR = 1.09, 95% CI 1.05–1.13), their own housing (OR = 5.66, 95% CI 2.45–13.05), longer time in the receiving area (OR = 1.14, 95% CI 1.09–1.20), and strong will to integrate (OR = 1.32, 95% CI 1.15–1.51) always stayed in the receiving area during pregnancy, rather than the sending area, and families with broadly similar characteristics were inclined to choose the receiving area for their delivery.

Conclusions

The mobility patterns of pregnant migrant women in China have been changing in recent years, with the percentage of them staying in receiving areas during pregnancy and delivering there increasing. Individual and family characteristics were also associated with mobility patterns and delivery location choice.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1813-2) contains supplementary material, which is available to authorized users.

Factors associated with residential mobility during pregnancy

Our objective was to determine the factors associated with residential moving during pregnancy, as it may increase stress during pregnancy and affect birth outcomes. Data were obtained from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study. Participants were recruited from December 2006 to June 2011 and included 1,448 pregnant women. The average gestational age at enrollment was 23 weeks. The primary outcome of residential mobility was defined as any change in address during pregnancy. Multivariate regression was used to assess the adjusted associations of factors with residential mobility. Out of 1,448 participants, approximately 9 percent moved between baseline (enrollment) and delivery. After adjusting for covariates, mothers with lower educational attainment [less than high school (adjusted odds ratio [aOR] = 3.74, 95% confidence interval [CI] = 1.78, 7.85) and high school/technical school (aOR = 3.57, 95% CI = 2.01, 6.32) compared to college degree or higher], and shorter length of residence in neighborhood were more likely to have moved compared to other mothers. Length of residence was protective of mobility (aOR = 0.91, 95% CI = 0.86, 0.96 per year). Increased understanding of residential mobility during pregnancy may help improve the health of mothers and their children.

Survival, by Birth Weight and Gestational Age, in Individuals With Congenital Heart Disease: A Population-Based Study

BACKGROUND

Congenital heart disease (CHD) survival estimates are important to understand prognosis and evaluate health and social care needs. Few studies have reported CHD survival estimates according to maternal and fetal characteristics. This study aimed to identify predictors of CHD survival and report conditional survival estimates.

METHODS AND RESULTS

Cases of CHD (n=5070) born during 1985-2003 and notified to the Northern Congenital Abnormality Survey (NorCAS) were matched to national mortality information in 2008. Royston-Parmar regression was performed to identify predictors of survival. Five-year survival estimates conditional on gestational age at delivery, birth weight, and year of birth were produced for isolated CHD (ie, CHD without extracardiac anomalies). Year of birth, gestational age, birth weight, and extracardiac anomalies were independently associated with mortality (all P≤0.001). Five-year survival for children born at term (37-41 weeks) in 2003 with average birth weight (within 1 SD of the mean) was 96.3% (95% CI, 95.6-97.0). Survival was most optimistic for high-birth-weight children (>1 SD from the mean) born post-term (≥42 weeks; 97.9%; 95% CI, 96.8-99.1%) and least optimistic for very preterm (<32 weeks) low-birth-weight (<1 SD from mean) children (78.8%; 95% CI, 72.8-99.1).

CONCLUSIONS

Five-year CHD survival is highly influenced by gestational age and birth weight. For prenatal counseling, conditional survival estimates provide best- and worst-case scenarios, depending on final gestational age and birth weight. For postnatal diagnoses, they can provide parents with more-accurate predictions based on their baby's birth weight and gestational age.

Particulate air pollution, fetal growth and gestational length: The influence of residential mobility in pregnancy

BACKGROUND

It remains unclear as to whether neglecting residential mobility during pregnancy introduces bias in studies investigating air pollution and adverse perinatal outcomes, as most studies assess exposure based on residence at birth. The aim of this study was to ascertain whether such bias can be observed in a study on the effects of PM10 on risk of preterm birth and fetal growth restriction.

METHODS

This was a retrospective study using four pregnancy cohorts of women recruited in Connecticut, USA (N=10,025). We ascertained associations with PM10 exposure calculated using first recorded maternal address, last recorded address, and full address histories. We used a discrete time-to-event model for preterm birth, and logistic regression to investigate associations with small for gestational age (SGA) and term low birth weight (LBW).

RESULTS

Pregnant women tended to move to areas with lower levels of PM10. For all outcomes, there was negligible difference between effect sizes corresponding to exposures calculated with first, last and full address histories. For LBW, associations were observed for exposure in second trimester (OR 1.09; 95% CI: 1.04-1.14 per 1μg/m(3) PM10) and whole pregnancy (OR 1.08; 95% CI: 1.02-1.14). For SGA, associations were observed for elevated exposure in second trimester (OR 1.02; 95% CI: 1.00-1.04) and whole pregnancy (OR 1.03; 95% CI: 1.01-1.05). There was insufficient evidence for association with preterm birth.

CONCLUSION

PM10 was associated with both SGA and term LBW. However, there was negligible benefit in accounting for residential mobility in pregnancy in this study.

Residential mobility and associated factors in relation to the assessment of exposure to naturally occurring radiation in studies of childhood cancer

Migration, that is the study subjects moving from one residential address to another, is a complication for epidemiological studies where exposures to the agent of interest depend on place of residence [corrected]. In this paper we explore migration in cases from a large British case-control study of childhood cancer and natural background radiation. We find that 44% of cases had not moved house between birth and diagnosis, and about two-thirds were living within 2 km of their residence at birth. The estimated dose at the diagnosis address was strongly correlated with that at the birth address, suggesting that use of just the birth address in this case-control study does not lead to serious bias in risk estimates. We also review other individual-based studies of naturally occurring radiation, with particular emphasis on those from Great Britain. Interview-based case-control and cohort studies can potentially establish full residential histories for study subjects and make direct measurements of radiation levels in the dwellings in question. However, in practice, because of study size and difficulties in obtaining adequate response rates, interview-based studies generally do not use full residential histories, and a substantial proportion of dose estimates often derive from models rather than direct measurements. More seriously, problems of incomplete response may lead to bias, not just to loss of power. Record-based case-control studies, which do not require direct contact with study subjects, avoid such problems, but at the expense of having only model-based exposure estimates that use databases of measurements.

Socioeconomic patterning in the incidence and survival of teenage and young adult men aged between 15 and 24 years diagnosed with non-seminoma testicular cancer in northern england

PURPOSE

Previous research from developed countries has shown a marked increase in the incidence of testicular cancer in the past 50 years. This has also been demonstrated in northern England, along with improving 5-year survival. The present study aims to determine if socioeconomic factors may play a role in both etiology and survival from non-seminoma testicular cancer.

MATERIALS AND METHODS

We extracted all 214 cases of non-seminoma testicular cancer diagnosed in teenage and young adult men aged between 15 and 24 years during 1968 to 2006 from the Northern Region Young Persons' Malignant Disease Registry, which is a population-based specialist regional registry. Negative binomial regression was used to examine the relationship between incidence and both the Townsend deprivation score (and component variables) and small-area population density. Cox regression was used to analyze the relationship between survival and both deprivation and population density.

RESULTS

Decreased incidence was associated with living in areas of higher household overcrowding for young adults aged between 20 and 24 years (relative risk per 1% increase in household overcrowding = 0.79; 95% CI: 0.66-0.94) but no association was detected for young people aged between 15 and 19 years. Community-level household unemployment was associated with worse survival (hazard ratio per 1% increase in household unemployment = 1.04; 95% CI: 1.00-1.08).

CONCLUSIONS

This study has shown that increased risk of non-seminoma testicular cancer in teenage and young adult men may be associated with some aspect of more advantaged living. In contrast, greater deprivation is linked with worse survival prospects. The study was ecological by design and so these area-based results may not necessarily apply to individuals.

Residential proximity to electromagnetic field sources and birth weight: Minimizing residual confounding using multiple imputation and propensity score matching

Studies have suggested that residential exposure to extremely low frequency (50 Hz) electromagnetic fields (ELF-EMF) from high voltage cables, overhead power lines, electricity substations or towers are associated with reduced birth weight and may be associated with adverse birth outcomes or even miscarriages. We previously conducted a study of 140,356 singleton live births between 2004 and 2008 in Northwest England, which suggested that close residential proximity (≤ 50 m) to ELF-EMF sources was associated with reduced average birth weight of 212 g (95%CI: -395 to -29 g) but not with statistically significant increased risks for other adverse perinatal outcomes. However, the cohort was limited by missing data for most potentially confounding variables including maternal smoking during pregnancy, which was only available for a small subgroup, while also residual confounding could not be excluded. This study, using the same cohort, was conducted to minimize the effects of these problems using multiple imputation to address missing data and propensity score matching to minimize residual confounding. Missing data were imputed using multiple imputation using chained equations to generate five datasets. For each dataset 115 exposed women (residing ≤ 50 m from a residential ELF-EMF source) were propensity score matched to 1150 unexposed women. After doubly robust confounder adjustment, close proximity to a residential ELF-EMF source remained associated with a reduction in birth weight of -116 g (95% confidence interval: -224:-7 g). No effect was found for proximity ≤ 100 m compared to women living further away. These results indicate that although the effect size was about half of the effect previously reported, close maternal residential proximity to sources of ELF-EMF remained associated with suboptimal fetal growth.

Does area deprivation modify the association between exposure to a nitrate and low-dose atrazine metabolite mixture in drinking water and small for gestational age? A historic cohort study

Birth weight may be influenced by environmental and socio-economic factors that could interact. The main objective of our research was to investigate whether area deprivation may modify the association between drinking water exposure to a mixture of atrazine metabolites and nitrates during the second trimester of pregnancy and prevalence of small for gestational age (SGA) neonates. We conducted a historic cohort study in Deux-Sèvres, France between 2005 and 2010, using birth records, population census and regularly performed drinking water withdrawals at community water systems. Exposure to an atrazine metabolite/nitrate mixture in drinking water was divided into six classes according to the presence or absence of atrazine metabolites and to the terciles of nitrate concentrations in each trimester of pregnancy. We used a logistic regression to model the association between SGA and mixture exposure at the second trimester while taking into account the area deprivation measured by the Townsend index as an effect modifier and controlling for the usual confounders. We included 10,784 woman-neonate couples. The risk of SGA when exposed to second tercile of nitrate without atrazine metabolites was significantly greater in women living in less deprived areas (OR = 2.99; 95 % CI (1.14, 7.89)), whereas it was not significant in moderately and more deprived areas. One of the arguments used to explain this result is the presence of competing risk factors in poorer districts.

Pregnant and moving: understanding residential mobility during pregnancy and in the first year of life using a prospective birth cohort

To examine residential mobility (i.e., moving) during pregnancy and in the first year of an infant's life using a large, prospective birth cohort in Rhode Island. Participants were recruited from Women and Infants Hospital of Rhode Island between January 5, 2009 and March 19, 2009. Residential histories were collected from mothers in-person immediately post-partum and by phone at 7 months and at 13 months post-partum. Of 1,040 mothers interviewed at birth, 71% (n = 740) completed the 13 month follow-up interview. Forty-one percent of mothers (n = 300) moved at least once between conception and 1 year post-partum, with the number of moves ranging from 0 to 8. Among movers, 69.0% moved once, 21.0% moved twice, and 10.0% moved three or more times. Mothers who moved tended to be younger, have fewer children, were not White, and had lower household incomes than those who did not move. Mothers who moved during pregnancy had 2.05 (95% CI: 1.40-2.98) times the odds of moving post-partum than mothers who had not moved in the antenatal period. There were statistical differences across socio-demographic groups with regard to when, where, and why mothers moved. Forty percent of movers during pregnancy (n = 61) moved for at least one negative reason, while 32.2% of movers during infancy (n = 64) relocated under negative circumstances. A substantial proportion of mothers moved pre- and post-partum, frequently under negative circumstances. Study findings have important implications for obstetric and pediatric providers who seek to understand, retain, and improve the health of their patient populations.

No improvement in socioeconomic inequalities in birthweight and preterm birth over four decades: a population-based cohort study

BACKGROUND

Birthweight and gestational age are associated with socioeconomic deprivation, but the evidence in relation to temporal changes in these associations is sparse. We investigated changes in the associations between socioeconomic status (SES) and birthweight and gestational age in Newcastle upon Tyne, North of England, during 1961-2000.

METHODS

We used population-based data from hospital neonatal records on all singleton births to mothers resident in Newcastle (births with complete covariate information n = 113,182). We used linear regression to analyse the associations between neighbourhood SES and birthweight over the entire 40-year period and by decade, and logistic regression for associations with low birthweight (LBW) and preterm birth, adjusting for potential confounders.

RESULTS

There was a significant interaction between SES and decade of birth for birthweight (p = 0.028) and preterm birth (p < 0.001). Socioeconomic gradients were similar in each decade for birthweight outcomes, but for preterm birth, socioeconomic disparities were more evident in the later decades [for 1961-70, odds ratio (OR) was 1.1, 95% CI 0.9, 1.3, for the most deprived versus the least deprived quartile, while for 1991-2000, the corresponding OR was 1.5, 95% CI 1.3, 1.7]. In each decade, there was a significant decrease in birthweight adjusted for gestational age for the most deprived compared to the least deprived SES group [1961-1970: -113.4 g (95% CI-133.0, -93.8); 1991-2000: -97.5 g (95% CI-113.0, -82.0)], while there was a significant increase in birthweight in each SES group over time.

CONCLUSIONS

Socioeconomic inequalities did not narrow over the four decades for birthweight and widened for preterm birth. Mean birthweight adjusted for gestational age increased in all socioeconomic groups, suggesting an overall increase in fetal growth.

Drinking-water exposure to a mixture of nitrate and low-dose atrazine metabolites and small-for-gestational age (SGA) babies: a historic cohort study

BACKGROUND

Groundwater, surface water and drinking water are contaminated by nitrates and atrazine, an herbicide. They are present as a mixture in drinking water and with their endocrine-disrupting activity, they may alter fetal growth.

OBJECTIVES

To study an association between drinking-water atrazine metabolites/nitrate mixture exposure and small-for-gestational-age(SGA).

METHODS

A historic cohort study based on birth records and drinking-water nitrate and pesticide measurements in Deux-Sèvres (France) between 2005 and 2009 was carried out. Exposure to drinking-water atrazine metabolites/nitrate mixture was divided into 6 classes according to the presence or absence of atrazine metabolites and to terciles of nitrate concentrations in each trimester of pregnancy. Regression analysis of SGA by mixture exposure at second trimester was subsequently conducted.

RESULTS

We included 11,446 woman-neonate couples of whom 37.0% were exposed to pesticides, while 99.9% of the women were exposed to nitrates. Average nitrate concentration was from 0 to 63.30 mg/L. In the second trimester of pregnancy, the risk of SGA was different with mixture exposure when drinking-water atrazine metabolites, mainly 2 hydroxyatrazine and desethylatrazine, were present and nitrate dose exposure increased: compared to single first tercile of nitrate concentration exposure, single second tercile exposure OR was 1.74 CI 95% [1.10; 2.75] and atrazine metabolites presence in the third tercile of nitrate concentration exposure OR was 0.87 CI 95% [0.45;1.67].

CONCLUSIONS

It is possible that the association found at the second trimester of exposure with regard to birth weight may likewise be observed before birth, with regard to the estimated fetal weight, and that it might change in the event that the atrazine metabolites dose were higher or the nitrate dose lower. It would appear necessary to further explore the variability of effects.

Review of research on residential mobility during pregnancy: consequences for assessment of prenatal environmental exposures

Studies on environmental exposures during pregnancy often have limited residential history (e.g., at delivery), potentially introducing exposure misclassification. We reviewed studies reporting residential mobility during pregnancy to summarize current evidence and discuss research implications. A meaningful quantitative combination of results (e.g., meta-analysis), was infeasible owing to variation in study designs. Fourteen studies were identified, of which half were from the US. Most were case-control studies examining birth defects. Residential history was typically assessed after delivery. Overall mobility rates were 9-32% and highest in the second trimester. Mobility generally declined with age, parity, and socioeconomic status, although not consistently. Married mothers moved less frequently. Findings were dissimilar by race, smoking, or alcohol use. On the basis of the few studies reporting distance moved, most distances were short (median often <10 km). Results indicate potential misclassification for environmental exposures estimated with incomplete residential information. This misclassification could be associated with potential confounders, such as socioeconomics, thereby affecting risk estimates. As most moves were short distances, exposures that are homogenous within a community may be well estimated with limited residential data. Future research should consider the implications of residential mobility during pregnancy in relation to the exposure's spatial heterogeneity and factors associated with the likelihood of moving and distance moved.

Trihalomethanes, chlorite, chlorate in drinking water and risk of congenital anomalies: a population-based case-control study in Northern Italy

BACKGROUND

Epidemiological evidence of an association between disinfection by-products (DBPs) exposure via drinking water and reproductive outcomes is still inconclusive.

OBJECTIVE

The aim of this study was to investigate the association between trihalomethanes (THMs), chlorite and chlorate exposure and congenital anomalies.

METHODS

A case-control study was carried out in Emilia-Romagna Region (Italy). Data on 1917 different congenital anomalies (neural tube, cardiac, diaphragm and abdominal wall, oesophagus, cleft lip and palate, respiratory, urinary tract and chromosomal anomalies) observed in the period 2002-2005 were extracted from the Regional Malformation Registry. Four controls (newborns without anomalies) were randomly selected form the Regional Birth Register and frequency matched to cases according to pregnancy period. The network supplying water during the first trimester of pregnancy was identified on the basis of mother's address: DBPs data, technical and structural information were linked to each subject.

RESULTS

Overall, THMs exposure was very low (mean: 3.8±3.6 μg/l), and no risk excess was observed. Chlorite and chlorate values were fairly high (mean: 427±184 μg/l and 283±79 μg/l, respectively). Women exposed to chlorite level >700 μg/l were at higher risk of newborns with renal defects (OR: 3.30; 95% IC: 1.35-8.09), abdominal wall defects (OR: 6.88; 95% IC: 1.67-28.33) and cleft palate (OR: 4.1; 95% IC: 0.98-16.8); women exposed to chlorate level >200 μg/l were at higher risk of newborns with obstructive urinary defects (OR: 2.88; 95% IC: 1.09-7.63), cleft palate (OR: 9.60; 95% IC:1.04-88.9) and spina bifida (OR: 4.94; 95% IC:1.10-22).

CONCLUSIONS

This was the first study showing an excess risk of different congenital anomalies related to chlorite and chlorate exposure via drinking water: further research is needed to confirm the observed relationships in large datasets, specifically for chlorate, an unregulated DBP.

Seasonality in the incidence of cervical carcinoma in teenagers and young adults in Northern England, 1968-2005

Infection with human papillomavirus is an established risk factor for cervical carcinoma. However, the role of other environmental factors is less well established. To further investigate whether other agents may be involved, the authors have analyzed seasonal variation in cervical cancer with respect to month of birth and separately month of diagnosis. All 85 cases diagnosed in 15-24-yr-olds during the period 1968-2005 were extracted from the specialist population-based Northern Region Young Persons' Malignant Disease Registry. The chi-square heterogeneity test was used to assess overall nonuniform variation in month of birth and separately month of diagnosis. Poisson regression analysis was used to fit sinusoidal (harmonic) models to the data using month of birth and month of diagnosis in separate models. Based on month of birth, there was statistically significant heterogeneity (p=.03) and a significant sinusoidal pattern, with an incidence peak involving births in the autumn months (p=.03). Based on month of diagnosis, there was marginally significant heterogeneity (p=.06). The evidence of seasonal variation around time of birth for cervical carcinoma is highly novel and suggests possible early etiological involvement of environmental factors.

Particulate matter exposure during pregnancy is associated with birth weight, but not gestational age, 1962-1992: a cohort study

BACKGROUND

Exposure to air pollutants is suggested to adversely affect fetal growth, but the evidence remains inconsistent in relation to specific outcomes and exposure windows.

METHODS

Using birth records from the two major maternity hospitals in Newcastle upon Tyne in northern England between 1961 and 1992, we constructed a database of all births to mothers resident within the city. Weekly black smoke exposure levels from routine data recorded at 20 air pollution monitoring stations were obtained and individual exposures were estimated via a two-stage modeling strategy, incorporating temporally and spatially varying covariates. Regression analyses, including 88,679 births, assessed potential associations between exposure to black smoke and birth weight, gestational age and birth weight standardized for gestational age and sex.

RESULTS

Significant associations were seen between black smoke and both standardized and unstandardized birth weight, but not for gestational age when adjusted for potential confounders. Not all associations were linear. For an increase in whole pregnancy black smoke exposure, from the 1(st) (7.4 μg/m(3)) to the 25(th) (17.2 μg/m(3)), 50(th) (33.8 μg/m(3)), 75(th) (108.3 μg/m(3)), and 90(th) (180.8 μg/m(3)) percentiles, the adjusted estimated decreases in birth weight were 33 g (SE 1.05), 62 g (1.63), 98 g (2.26) and 109 g (2.44) respectively. A significant interaction was observed between socio-economic deprivation and black smoke on both standardized and unstandardized birth weight with increasing effects of black smoke in reducing birth weight seen with increasing socio-economic disadvantage.

CONCLUSIONS

The findings of this study progress the hypothesis that the association between black smoke and birth weight may be mediated through intrauterine growth restriction. The associations between black smoke and birth weight were of the same order of magnitude as those reported for passive smoking. These findings add to the growing evidence of the harmful effects of air pollution on birth outcomes.

Ambient air pollution and congenital heart disease: a register-based study

Maternal exposure to ambient air pollution has increasingly been linked to adverse pregnancy outcomes. The evidence linking this exposure to congenital anomalies is still limited and controversial. This case-control study investigated the association between maternal exposure to ambient particulate matter with aerodynamic diameter less than 10 μm (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxide, nitric oxide (NO), ozone (O(3)), and carbon monoxide (CO) and the occurrence of congenital heart disease in the population of Northeast England (1993-2003). Each case and control was assigned weekly average (weeks 3-8 of pregnancy) of pollutant levels measured by the closest monitor to the mother's residential postcode. Using exposure as both continuous and categorical variables, logistic regression models were constructed to quantify the adjusted odds ratios of exposure to air pollutants and the occurrence of each outcome group. We found exposure to CO and NO to be associated with ventricular septal defect and cardiac septa malformations. CO was also associated with congenital pulmonary valve stenosis and NO with pooled cases of congenital heart disease and tetralogy of Fallot. Findings for SO(2), O(3) and PM(10) were less consistent.

Association between maternal exposure to ambient air pollution and congenital heart disease: A register-based spatiotemporal analysis

Recent studies have linked maternal exposure to air pollution with a range of adverse pregnancy outcomes. However, the available evidence linking this exposure to congenital anomalies is still limited and controversial. The present case-control study tested the hypothesis that maternal exposure to ambient black smoke and sulfur dioxide is a risk factor for the occurrence of congenital heart disease. The authors used registry-based data on congenital heart disease for the population of the northeast of England in 1985-1996. A 2-stage spatiotemporal model was developed to predict weekly black smoke and sulfur dioxide levels at each maternal place of residence. Controls were frequency-matched to cases by year of birth (control-to-case ratio of 4:1). Two sets of analyses were performed, using predicted mean values of exposure and 1,000 simulated scenarios of exposure. The analyses were adjusted for birth year, socioeconomic status, infant sex, season of conception, and degree of urbanity. The authors found a weak association between maternal exposure to black smoke and congenital malformations of cardiac chambers and connections only when using exposure as a continuous variable. When the authors used quartiles of exposure, odds ratios did not show a dose-response relation for consecutive quartiles. For sulfur dioxide, the results were not indicative of any association.