COVID-19 mortality among immigrants by duration of residence in Sweden: a population-based cohort study.

BACKGROUND: Explanations for the disproportional COVID-19 burden among immigrants relative to host-country natives include differential exposure to the virus and susceptibility due to poor health conditions. Prior to the pandemic, immigrants displayed deteriorating health with duration of residence that may be associated with increased susceptibility over time. The aim of this study was to compare immigrant-native COVID-19 mortality by immigrants' duration of residence to examine the role of differential susceptibility. METHODS: A population-based cohort study was conducted with individuals between 18 and 100 years old registered in Sweden between 1 January 2015 and 15 June 2022. Cox regression models were run to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Inequalities in COVID-19 mortality between immigrants and the Swedish-born population in the working-age group were concentrated among those of non-Western origins and from Finland with more than 15 years in Sweden, while for those of retirement age, these groups showed higher COVID-19 mortality HRs regardless of duration of residence. Both age groups of immigrants from Africa and the Middle East showed consistently higher COVID-19 mortality HRs. For the working-age population: Africa: HR<15: 2.46, 95%CI: 1.78, 3.38; HR≥15: 1.49, 95%CI: 1.01, 2.19; and from the Middle East: HR<15: 1.20, 95%CI: 0.90, 1.60; HR≥15: 1.65, 95%CI: 1.32, 2.05. For the retirement-age population: Africa: HR<15: 3.94, 95%CI: 2.85, 5.44; HR≥15: 1.66, 95%CI: 1.32, 2.09; Middle East: HR<15: 3.27, 95%CI: 2.70, 3.97; HR≥15: 2.12, 95%CI: 1.91, 2.34. CONCLUSIONS: Differential exposure, as opposed to differential susceptibility, likely accounted for the higher COVID-19 mortality observed among those origins who were disproportionately affected by the pandemic in Sweden.

Unintended Perinatal Health Consequences Associated With a Swedish Family Policy.

Importance: The 1980 and 1986 Swedish so-called speed premium policies aimed at protecting parents' income-based parental leave benefits for birth intervals shorter than 24 and 30 months, respectively, but indirectly encouraged shorter birth spacing and childbearing at older ages, both risk factors for several perinatal health outcomes. Whether those policy changes are associated with perinatal health remains unknown. Objective: To evaluate the association between the 1980 and 1986 speed premium policies and perinatal health outcomes. Design, Setting, and Participants: This cross-sectional study investigated data from 1 762 784 singleton births in the Swedish Medical Birth Register from January 1, 1974, through December 31, 1991. Data were analyzed from October 11, 2022, to December 12, 2023. Interventions: Speed premium policy introduction (January 1, 1980) and extension (January 1, 1986). Main Outcomes and Measures: Total population register data were used in an interrupted time series analysis with segmented logistic regression to calculate the odds of preterm birth, low birth weight, small for gestational age (SGA) at preterm, and stillbirth measured before and after the speed premium policy reforms. Subgroup analyses by maternal origin were conducted to evaluate changes by different policy responses. Results: Among 1 762 784 births analyzed, 4.8% were preterm (of which 12.0% were SGA), 3.2% had low birth weight, and 0.3% were stillbirths. The 1980 speed premium policy was associated with a 0.3% monthly increase in the odds of preterm birth compared with the period before the reform (odds ratio [OR], 1.0029 [95% CI, 1.002-1.004]), equivalent to a 26.4% increase from January 1, 1980, to December 31, 1985. After the 1986 relaxation of the policy, preterm birth odds decreased 0.5% per month (OR, 0.9951 [95% CI, 0.994-0.996]), equivalent to an 11.1% decrease across the next 6 years. Low birth weight displayed a similar pattern for both reform periods, that is, increased 0.2% (OR, 1.0021; 95% CI, 1.001-1.003) per month in 1980 through 1985 compared with baseline, and decreased 0.3% (OR, 0.9975; 95% CI, 0.996-0.998) per month in the following period, but was attenuated when considering low birth weight at term. Odds of SGA at preterm were decreased after 1980 (OR, 0.9965; 95% CI, 0.994-0.999) but not in 1986 (OR, 1.0009; 95% CI, 0.998-1.003), whereas stillbirths did not change following either reform (1980: OR, 1.0020 [95% CI, 0.999-1.005]; 1986: OR, 1.0002 [95% CI, 0.997-1.003]). Subgroup analyses suggested that perinatal health changes were restricted to births to Swedish- and Nordic-born mothers, the primary groups to adjust their fertility behaviors to the reforms. Conclusions and Relevance: Despite its economic advantages for couples, especially for mothers, the introduction of the speed premium policy was associated with adverse perinatal health consequences, particularly for preterm births. Family policies should be carefully designed with a "Health in All Policies" lens to avoid possible unintended repercussions for fertility behaviors and, in turn, perinatal health.

Duration of residence and offspring birth weight among foreign-born mothers in Spain: a cross-sectional study.

BACKGROUND: Duration of residence has been used to monitor changes in the health of a foreign-born population in a destination country. This study assesses whether the mother's duration of residence influences the relationship between maternal origin and birth weight. METHODS: We conducted a cross-sectional study using Spanish census microdata (2011) linked to Vital Statistics (2011-15). Linear and multinomial logistic regression models were used to estimate birth weight differences between children born to foreign-born mothers by duration of residence and those born to natives. Maternal countries of origin were classified according to the Human Development Index (HDI). RESULTS: Our findings revealed significant differences in birth weight of 109 683 births from both foreign- and native-born mothers. Overall, in descriptive statistics, compared with Spanish mothers, foreign-born mothers gave birth more frequently to high-birth weight (HBW) newborns (8.4% vs. 5.3%, respectively) and less frequently to low-birth weight (LBW) newborns (4.8% vs. 5.1%). According to the model's estimations, the risk of giving birth to HBW babies remains relatively high in foreign-born mothers. Especially, mothers from very high-HDI countries experienced changes in the RRR of HBW (1.59-1.28) and LBW (0.58-0.89) after spending over 10 years in Spain. CONCLUSIONS: Foreign-born mothers residing in Spain are at increased risk of delivering a HBW child regardless of their duration of residence. In fact, given the long-term health consequences associated with HBW, our results highlight the need to improve prenatal care in the foreign-born population.

Advancing migration and health research by examining return migration.

This essay offers an analysis of research on return migration and health by adopting the social determinants of health (SDH) framework proposed by the WHO. Specifically, we argue that the SDH are implicated in the decision to migrate, stay or return, which in itself also contributes to social health inequities. Most theoretical frameworks developed to study migration have predominantly considered primary migration movements. The lack of a fluid consideration of the migration phenomenon has a direct impact on our understanding of the relationship between migration and health. In this essay, we, first, address the challenges of defining and studying return and its implications for health research. Second, we propose to use the WHO's SDH framework to understand how social factors shape migrants' health, influence the decision to return and can contribute to health inequalities. The conceptual approach developed in this paper can help design future studies on the health of return migrants, fostering interdisciplinary collaborations to investigate how social factors are embodied, giving rise to health inequities in society that are intricately linked to the migration experience.

Income mortality paradox by immigrants' duration of residence in Sweden: a population register-based study.

BACKGROUND: Studies have shown that, compared with the general native population, immigrants display weaker or absent income gradients in mortality. The aim of this study is to examine the extent to which the income gradient is modified by immigrants' duration of residence in Sweden. METHODS: Swedish register data from 2004 to 2016 were used to study the association between individual income and all-cause mortality among foreign-born and Swedish-born individuals at ages 25-64 years. Based on relative indices of inequality (RIIs) and slope indices of inequality (SIIs) derived from Poisson regressions, we measured relative and absolute mortality differentials between the least and most advantaged income ranks. The analyses were stratified by sex, immigrants' European or non-European origin, and immigrants' duration of residence in Sweden. RESULTS: The relative income inequality in mortality among immigrant men was less than half (RII: 2.32; 95% CI: 2.15 to 2.50) than that of Swedish-born men (RII: 6.25; 95% CI: 6.06 to 6.44). The corresponding RII among immigrant women was 1.23 (95% CI: 1.13 to 1.34) compared with an RII of 2.75 (95% CI: 2.65 to 2.86) among Swedish-born women. Inequalities in mortality were lowest among immigrants who resided for less than 10 years in Sweden, and most pronounced among immigrants who resided for more than 20 years in the country. Corresponding analyses of absolute income inequalities in mortality based on the SII were largely consistent with the observed relative inequalities in mortality. CONCLUSIONS: Income inequalities in mortality among immigrants differ by duration of residence in Sweden, suggesting that health inequalities develop in the receiving context.

Is duration of residence a proxy for acculturation? The case of health risk behaviors among international immigrants.

AIMS: Among international immigrants, health changes by duration of residence are commonly interpreted as an expression of acculturation to the receiving country context. This study compares changes in immigrants' health risk behaviors by duration of residence to changes by acculturation levels, in order to assess whether duration of residence can be regarded as a proxy for acculturation. METHODS: Using data from a previous systematic review, we identified 17 quantitative studies examining changes in alcohol, tobacco and drug use, physical inactivity, and diet by both duration of residence and acculturation level in the same population. We compared the directionality and consistency of these associations through tabulation and vote counting. RESULTS: The majority of studies reported no or inconsistent changes in health risk behaviors by duration of residence versus by acculturation, including with opposite directionality. Four studies reported significant estimates with consistent directionality, while five reported consistent, non-significant estimates. CONCLUSIONS: Our findings suggest that duration of residence should not be used as a proxy for acculturation when studying health risk behaviors among immigrants. Researchers should consider additional time-dependent factors to explain behavioral changes by duration of residence.

Inequalities in COVID-19 severe morbidity and mortality by country of birth in Sweden.

Migrants have been more affected by the COVID-19 pandemic. Whether this has varied over the course of the pandemic remains unknown. We examined how inequalities in intensive care unit (ICU) admission and death related to COVID-19 by country of birth have evolved over the course of the pandemic, while considering the contribution of social conditions and vaccination uptake. A population-based cohort study was conducted including adults living in Sweden between March 1, 2020 and June 1, 2022 (n = 7,870,441). Poisson regressions found that migrants from Africa, Middle East, Asia and European countries without EU28/EEA, UK and Switzerland had higher risk of COVID-19 mortality and ICU admission than Swedish-born. High risks of COVID-19 ICU admission was also found in migrants from South America. Inequalities were generally reduced through subsequent waves of the pandemic. In many migrant groups socioeconomic status and living conditions contributed to the disparities while vaccination campaigns were decisive when such became available.

Differences in hospitalizations associated with severe COVID-19 disease among foreign- and Swedish-born.

BACKGROUND: Differences in pre-existing health conditions are hypothesized to explain immigrants' excess COVID-19 mortality compared to natives. In this study, we evaluate whether immigrants residing in Sweden before the outbreak were more likely to be hospitalized for conditions associated with severe COVID-19 disease. METHODS: A cohort study using population-register data was conducted with follow-up between 1 January 1997 and 31 December 2017. Poisson regression was fitted to estimate incidence rate ratio (RR) and 95% confident intervals (95% CI) for 10 causes of hospitalization. RESULTS: Compared to Swedish-born individuals, most immigrant groups showed a decreased risk of hospitalization for respiratory chronic conditions, CVD, cancer, chronic liver conditions and neurological problems. All immigrant groups had increased risk of hospitalization for tuberculosis [RR between 88.49 (95% CI 77.21; 101.40) for the Horn of Africa and 1.69 (95% CI 1.11; 2.58) for North America], HIV [RR between 33.23 (95% CI 25.17; 43.88) for the rest of Africa and 1.31 (95% CI 0.93; 1.83) for the Middle East] and, with a few exceptions, also for chronic kidney conditions, diabetes and thalassemia. CONCLUSIONS: Foreign-born individuals-including origins with excess COVID-19 mortality in Sweden-did not show increased risk of hospitalizations for most causes associated with severe COVID-19 disease. However, all groups showed increased risks of hospitalization for tuberculosis and HIV and, with exceptions, for chronic kidney conditions, diabetes and thalassemia. Although studies should determine whether these health conditions explain the observed excess COVID-19 mortality, our study alerts to an increased risk of hospitalization that can be avoidable via treatment or preventive measures.

The effect of parental leave on parents' mental health: a systematic review.

Mental health disorders during the post-partum period are a common morbidity, but parental leave might help alleviate symptoms by preventing or reducing stress. We aim to summarise available evidence on the effect of different types of parental leave on mental health outcomes among parents. For this systematic review, we searched Ovid MEDLINE, Web of Science, PsycINFO, CINAHL, and Scopus from database inception to Aug 29, 2022, for peer-reviewed, quantitative studies written in English. We included studies if the exposure was postnatal parental leave; a relevant comparison group was present (eg, paid vs unpaid leave); and if indicators related to general mental health, including depression, anxiety, stress, and suicide, for either parent were evaluated or recorded at any time after childbirth. The Review is registered with PROSPERO (registration number CRD42021227499). Of the 3441 records screened, 45 studies were narratively synthesised. Studies were done in high-income countries, and they examined generosity by any parental leave (n=5), benefit amount (n=13), and leave duration (n=31). 38 studies were of medium or high quality. Improved mental health was generally observed among women (referred to as mothers in this Review) with more generous parental leave policies (ie, leave duration and paid vs unpaid leave). For example, increased duration of leave was generally associated with reduced risk of poor maternal mental health, including depressive symptoms, psychological distress and burnout, and lower mental health-care uptake. However, the association between fathers' leave and paternal mental health outcomes was less conclusive as was the indirect effect of parental leave use on partners' mental health.

Health Risk Behaviours by Immigrants' Duration of Residence: A Systematic Review and Meta-Analysis.

Objectives: The aim was to systematically review and synthesise international evidence on changes in health risk behaviours by immigrants' duration of residence. Methods: We searched literature databases for peer-reviewed quantitative studies published from 2000 to 2019, examining alcohol, drug and tobacco use; physical inactivity; and dietary habits by duration of residence. Results: Narrative synthesis indicated that immigrants tend to adopt health risk behaviours with longer residence in North America, with larger variation in effect sizes and directionality in other contexts. Random-effects meta-analyses examining the pooled effect across all receiving countries and immigrant groups showed lower odds of smoking (OR 0.54, 0.46-0.63, I 2 = 68.7%) and alcohol use (OR 0.61, 0.47-0.75, I 2 = 93.5%) and higher odds of physical inactivity (OR 1.71, 1.40-2.02, I 2 = 99.1%) among immigrants than natives, but did not provide support for a universal trend by duration of residence. Conclusion: Findings suggest that duration of residence could serve as an effective instrument to monitor immigrants' health changes. However, differences in receiving country contexts and immigrant populations' composition seem to be important to predict the level and direction of behavioural change. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, PROSPERO CRD42018108881.

Immigrant ancestry and birthweight across two generations born in Sweden: an intergenerational cohort study.

INTRODUCTION: Differences in birthweight are often seen between migrants and natives. However, whether migrant-native birthweight inequalities widen, narrow or remain persistent across generations when comparing the descendants of immigrants and natives remains understudied. We examined inequalities in birthweight of mothers (G2) and daughters (G3) of foreign-born grandmothers (G1) compared with those of Swedish-born grandmothers. METHODS: We used population registers with multigenerational linkages to identify 314 415 daughters born in Sweden during the period 1989-2012 (G3), linked to 246 642 mothers (G2) born in Sweden during 1973-1996, and to their grandmothers (G1) who were Swedish or foreign-born. We classified migrants into non-western, Eastern European, the rest of Nordic and Western. We used multivariable methods to examine mean birthweight and low birthweight (<2500 g; LBW). RESULTS: Birthweight between individuals with Swedish background (G1) and non-western groups increased from -80 g to -147 g between G2 (mothers) and G3 (daughters), respectively. Furthermore, the odds of LBW increased among the G3 non-western immigrants compared with those with Swedish grandmothers (OR: 1.38, 95% CI 1.12 to 1.69). Birthweight increased in both descendants of Swedes and non-western immigrants, but less so in the latter (83 g vs 16 g). CONCLUSION: We observed an increase in birthweight inequalities across generations between descendants of non-western immigrants and descendants of Swedes. This finding is puzzling considering Sweden has been lauded for its humanitarian approach to migration, for being one of the most egalitarian countries in the world and providing universal access to healthcare and education.

Investigating the salmon bias effect among international immigrants in Sweden: a register-based open cohort study.

BACKGROUND: Studies of migration and health have hypothesized that immigrants may emigrate when they develop poor health (salmon bias effect), which may partially explain the mortality advantage observed among immigrants in high-income countries. We evaluated the salmon bias effect by comparing the health of immigrants in Sweden who emigrated with those who remained, while also exploring potential variation by macro-economic conditions, duration of residence and region of origin. METHODS: A longitudinal, open cohort study design was used to assess risk of emigration between 1992 and 2016 among all adult (18+ years) foreign-born persons who immigrated to Sweden between 1965 and 2012 (n = 1 765 459). The Charlson Comorbidity Index was used to measure health status, using information on hospitalizations from the Swedish National Patient Register. Poisson regression models were used to estimate incidence rate ratios (RRs) with 95% confidence intervals (CIs) for emigrating from Sweden. RESULTS: Immigrants with low (RR = 0.83; 95% CI: 0.76-0.90) moderate (RR = 0.70; 95% CI: 0.62-0.80) and high (RR = 0.62; 95% CI: 0.48-0.82) levels of comorbidities had decreased risk of emigration relative to those with no comorbidities. There was no evidence of variation by health status in emigration during periods of economic recession or by duration of residence. Individuals with low to moderate levels of comorbidities from some regions of origin had an increased risk of emigration relative to those with no comorbidities. CONCLUSIONS: The study results do not support the existence of a salmon bias effect as a universal phenomenon among international immigrants in Sweden.

Psychiatric consequences of a father's leave policy by nativity: a quasi-experimental study in Sweden.

BACKGROUND: Parental leave use has been found to promote maternal and child health, with limited evidence of mental health impacts on fathers. How these effects vary for minority populations with poorer mental health and lower leave uptake, such as migrants, remains under-investigated. This study assessed the effects of a Swedish policy to encourage fathers' leave, the 1995 Father's quota, on Swedish-born and migrant fathers' psychiatric hospitalisations. METHODS: We conducted an interrupted time series analysis using Swedish total population register data for first-time fathers of children born before (1992-1994) and after (1995-1997) the reform (n=198 589). Swedish-born and migrant fathers' 3-year psychiatric hospitalisation rates were modelled using segmented negative binomial regression, adjusting for seasonality and autocorrelation, with stratified analyses by region of origin, duration of residence, and partners' nativity. RESULTS: From immediately pre-reform to post-reform, the proportion of fathers using parental leave increased from 63.6% to 86.4% of native-born and 37.1% to 51.2% of migrants. Swedish-born fathers exhibited no changes in psychiatric hospitalisation rates post-reform, whereas migrants showed 36% decreased rates (incidence rate ratio (IRR) 0.64, 95% CI 0.47 to 0.86). Migrants from regions not predominantly consisting of Organisation for Economic Cooperation and Development countries (IRR 0.50, 95% CI 0.19 to 1.33), and those with migrant partners (IRR 0.23, 95% CI 0.14 to 0.38), experienced the greatest decreases in psychiatric hospitalisation rates. CONCLUSION: The findings of this study suggest that policies oriented towards promoting father's use of parental leave may help to reduce native-migrant health inequalities, with broader benefits for family well-being and child development.

Preterm disparities between foreign and Swedish born mothers depend on the method used to estimate gestational age. A Swedish population-based register study.

This study aims to examine whether disparities in gestational age outcomes between foreign and Swedish-born mothers are contingent on the measure used to estimate gestational age and, if so, to identify which maternal factors are associated with the discrepancy. Using population register data, we studied all singleton live births in Sweden from 1992-2012 (n = 1,317,265). Multinomial logistic regression was performed to compare gestational age outcomes classified into very (<32 weeks) and late preterm (32-36 weeks), term and post-term derived from the last menstrual period (LMP) and ultrasound estimates in foreign- and Swedish-born women. Compared to Swedish-born women, foreign-born women had similar odds of very preterm birth (OR: 0.98 [95% CI: 0.98, 1.01]) and lower odds of moderately preterm birth (OR: 0.95 [95% CI: 0.92, 0.98]) based on ultrasound, while higher risks based on LMP (respectively, OR: 1.10 [95% CI: 1.07, 1.14] and 1.09 [95% CI: 1.06, 1.13]). Conclusions on disparities in gestational age-related outcomes by mother's country of origin depend on the method used to estimate gestational age. Except for very preterm, foreign-born women had a health advantage when gestational age is based on ultrasound, but a health disadvantage when based on LMP. Studies assessing disparities in very preterm birth by migration status are not affected by the estimation method but caution should be taken when interpreting disparities in moderately preterm and preterm birth rates.

Early pregnancy overweight/obesity and length of residence among immigrants in Sweden: a pooled analysis of Swedish population registers between 1992 and 2012.

OBJECTIVE: To examine whether the association between women's origin and early pregnancy overweight and obesity (OW/OB) varies by length of residence in Sweden. DESIGN: This cross-sectional observational study used pooled Swedish population register data from 1992 to 2012. Logistic regression models were run to estimate odds ratios (OR) of early pregnancy OW/OB and 95 % confidence intervals (95 % CI), comparing Swedish-born and immigrants by length-of-residence categories while adjusting for covariates. SETTING: Sweden. PARTICIPANTS: In total, 1 771 821 pregnant women, 315 992 of whom were immigrants. RESULTS: With longer residence in Sweden, more immigrant women from various origins exhibited higher odds of experiencing early OW/OB compared with Swedish-born women. Findings specifically showed increased odds of early pregnancy OW/OB with increasing length of residence for women born in Latin America, Europe-27 and Southeast Asia. For example, immigrant women from Latin America residing in Sweden for < 6 years showed similar odds as Swedish-born (OR≤ 5 years 0·92, 95 % CI 0·87, 0·98), while their longer residing counterparts showed higher odds than Swedish-born women (OR6-15 years1·21, 95 % CI 1·14, 1·28 and OR≥ 16 years 1·68, 95 % CI 1·59, 1·78). Mixed results were found for other origins. CONCLUSIONS: The current study suggests that host country conditions might play an important role in explaining OW/OB among some groups of immigrant women. Although further studies are needed to disentangle the mechanisms that generate these health inequalities, policy efforts should focus on immigrant reception and early integration to prevent pregnancy-related OW/OB.

Economic arguments in migrant health policymaking: proposing a research agenda.

Welfare states around the world restrict access to public healthcare for some migrant groups. Formal restrictions on migrants' healthcare access are often justified with economic arguments; for example, as a means to prevent excess costs and safeguard scarce resources. However, existing studies on the economics of migrant health policies suggest that restrictive policies increase rather than decrease costs. This evidence has largely been ignored in migration debates. Amplifying the relationship between welfare state transformations and the production of inequalities, the Covid-19 pandemic may fuel exclusionary rhetoric and politics; or it may serve as an impetus to reconsider the costs that one group's exclusion from health can entail for all members of society.The public health community has a responsibility to promote evidence-informed health policies that are ethically and economically sound, and to counter anti-migrant and racial discrimination (whether overt or masked with economic reasoning). Toward this end, we propose a research agenda which includes 1) the generation of a comprehensive body of evidence on economic aspects of migrant health policies, 2) the clarification of the role of economic arguments in migration debates, 3) (self-)critical reflection on the ethics and politics of the production of economic evidence, 4) the introduction of evidence into migrant health policymaking processes, and 5) the endorsement of inter- and transdisciplinary approaches. With the Covid-19 pandemic and surrounding events rendering the suggested research agenda more topical than ever, we invite individuals and groups to join forces toward a (self-)critical examination of economic arguments in migration and health, and in public health generally.

Birthweight of babies born to migrant mothers - What role do integration policies play?

Birthweights of babies born to migrant women are generally lower than those of babies born to native-born women. Favourable integration policies may improve migrants' living conditions and contribute to higher birthweights. We aimed to explore associations between integration policies, captured by the Migrant Integration Policy Index (MIPEX), with offspring birthweight among migrants from various world regions. In this cross-country study we pooled 31 million term birth records between 1998 and 2014 from ten high-income countries: Australia, Belgium, Canada, Denmark, Finland, Japan, Norway, Spain, Sweden and United Kingdom (Scotland). Birthweight differences in grams (g) were analysed with regression analysis for aggregate data and random effects models. Proportion of births to migrant women varied from 2% in Japan to 28% in Australia. The MIPEX score was not associated with birthweight in most migrant groups, but was positively associated among native-born (mean birthweight difference associated with a 10-unit increase in MIPEX: 105 g; 95% CI: 24, 186). Birthweight among migrants was highest in the Nordic countries and lowest in Japan and Belgium. Migrants from a given origin had heavier newborns in countries where the mean birthweight of native-born was higher and vice versa. Mean birthweight differences between migrants from the same origin and the native-born varied substantially across destinations (70 g-285 g). Birthweight among migrants does not correlate with MIPEX scores. However, birthweight of migrant groups aligned better with that of the native-born in destination counties. Further studies may clarify which broader social policies support migrant women and have impacts on perinatal outcomes.

All-cause mortality, age at arrival, and duration of residence among adult migrants in Sweden: A population-based longitudinal study.

BACKGROUND: A mortality advantage has been observed among recently arrived immigrants in multiple national contexts, even though many immigrants experience more social disadvantage compared to natives. This is the first study to investigate the combined influence of duration of residence and age at arrival on the association between region of origin and all-cause mortality among the adult immigrant population in Sweden. METHODS: Using population-based registers, we conducted a follow-up study of 1,363,429 individuals aged 25-64 years from 1990 to 2008. Gompertz parametric survival models were fitted to derive hazard ratios (HR) for all-cause mortality. RESULTS: Compared to native Swedes, we observed a health advantage in all group of immigrants, with the exception of individuals from Finland. However, when information on age at arrival and duration of residence was combined, an excess mortality risk was found among immigrants who arrived before age 18, which largely disappeared after 15 years of residence in Sweden. Non-European immigrants over age 18 showed similar or lower mortality risks than natives in all categories of age at arrival, regardless of duration of residence. CONCLUSIONS: The findings suggest that the mortality advantage commonly observed among immigrants is not universal. Combined information on age at arrival and duration of residence can be used to identify sensitive periods and to identify possible selection bias. The study also suggests that young immigrants are a vulnerable subpopulation. Given the increased number of unaccompanied minors arriving in Europe, targeted health or integration policies should be developed or reviewed.

Length of residence and caesarean section in migrant women in Sweden: a population-based study.

Background: Prior studies have reported substantial differences in caesarean rates between migrant and non-migrant women. In this study we investigate whether the association between maternal country of birth and caesarean section is modified by length of residence in Sweden. Methods: Population-based register study. A total of 106 760 migrant and 473 881 Swedish-born women having singleton, first births were studied using multinomial multiple regression models to estimate odds ratios (OR) and 95% confidence intervals for mode of birth. Random effect meta-analyses were conducted to assess true heterogeneity between categories of length of residence. Results: Longer duration of residence was associated with an increased overall risk of both unplanned and planned caesarean section among migrant women. This pattern was more pronounced among countries grouped as having higher prevalence (compared to Swedes) of unplanned: OR≤1=1.41 (1.32-1.50); OR>1-<6=1.49 (1.42-1.57); OR6-<10=1.61 (1.50-1.72); OR≥10=1.71 (1.64-1.79) and planned caesarean section [OR≤1=1.14 (0.95-1.36); OR>1-<6=1.30 (1.13-1.51); OR6-<10=1.97 (1.64-2.37]; OR≥10=1.82 (1.67-1.98)]. The results were robust to social, obstetric and health adjustments. There were some country-of-origin-specific findings. Conclusions: The fact that the risk of unplanned and planned caesarean section tended to increase with length of residence, even with adjustment for social, obstetric and health factors, suggests that receiving country-specific factors are playing an important role in caesarean section.

Caesarean Birth is Associated with Both Maternal and Paternal Origin in Immigrants in Sweden: a Population-Based Study.

BACKGROUND: To investigate the association between maternal country of birth and father's origin and unplanned and planned caesarean birth in Sweden. METHODS: Population-based register study including all singleton births in Sweden between 1999 and 2012 (n = 1 311 885). Multinomial regression was conducted to estimate odds ratios (OR) for unplanned and planned caesarean with 95% confidence intervals for migrant compared with Swedish-born women. Analyses were stratified by parity. RESULTS: Women from Ethiopia, India, South Korea, Chile, Thailand, Iran, and Finland had statistically significantly higher odds of experiencing unplanned (primiparous OR 1.10-2.19; multiparous OR 1.13-2.02) and planned caesarean (primiparous OR 1.18-2.25; multiparous OR 1.13-2.46). Only women from Syria, the former Yugoslavia and Germany had consistently lower risk than Swedish-born mothers (unplanned: primiparous OR 0.76-0.86; multiparous OR 0.74-0.86. Planned; primiparous OR 0.75-0.82; multiparous OR 0.60-0.94). Women from Iraq and Turkey had higher odds of an unplanned caesarean but lower odds of a planned one (among multiparous). In most cases, these results remained after adjustment for available social characteristics, maternal health factors, and pregnancy complications. Both parents being foreign-born increased the odds of unplanned and planned caesarean in primiparous and multiparous women. CONCLUSIONS: Unplanned and planned caesarean birth varied by women's country of birth, with both higher and lower rates compared with Swedish-born women, and the father's origin was also of importance. These variations were not explained by a wide range of social, health, or pregnancy factors.