Association Between Income and Perinatal Mortality in the Netherlands Across Gestational Age

Sociodemographic and regional differences in neonatal and infant mortality in Switzerland in 2011-2018: the Swiss National Cohort

BACKGROUND AND AIMS

Despite a well-funded healthcare system with universal insurance coverage, Switzerland has one of the highest neonatal and infant mortality rates among high-income countries. Identifying avoidable risk factors targeted by evidence-based policies is a public health priority. We describe neonatal and infant mortality in Switzerland from 2011 to 2018 and explore associations with neonatal- and pregnancy-related variables, parental sociodemographic information, regional factors and socioeconomic position (SEP) using data from a long-term nationwide cohort study.

METHODS

We included 680,077 live births, representing 99.3% of all infants born in Switzerland between January 2011 and December 2018. We deterministically linked the national live birth register with the mortality register and with census and survey data to create a longitudinal dataset of neonatal- and pregnancy-related variables; parental sociodemographic information, such as civil status, age, religion, education, nationality; regional factors, such as urbanity, language region; and the Swiss neighbourhood index of socioeconomic position (Swiss-SEP index). Information on maternal education was available for a random subset of 242,949 infants. We investigated associations with neonatal and infant mortality by fitting multivariable Poisson regression models with robust standard errors. Several sensitivity analyses assessed the robustness of our findings.

RESULTS

Overall, neonatal mortality rates between 2011 and 2018 were 3.0 per 1000 live births, with regional variations: 3.2 in German-speaking, 2.4 in French-speaking and 2.1 in Italian-speaking Switzerland. For infant mortality, the rates were 3.7 per 1000 live births overall, and 3.9 in the German-speaking, 3.3 in the French-speaking and 2.9 in the Italian-speaking region. After adjusting for sex, maternal age, multiple birth and birth rank, neonatal mortality remained significantly associated with language region (adjusted rate ratio [aRR] 0.72, 95% confidence interval [CI]: 0.64-0.80 for the French-speaking region and aRR 0.66, 95% CI: 0.51-0.87 for the Italian-speaking region vs German-speaking region), with marital status (aRR 1.55, 95% CI: 1.40-1.71 for unmarried vs married), nationality (aRR 1.40, 95% CI: 1.21-1.62 for non-European Economic Area vs Swiss) and the Swiss-SEP index (aRR 1.17, 95% CI: 1.00-1.36 for lowest vs highest SEP quintile). In the subset, we showed a possible association of neonatal mortality with maternal education (aRR 1.24, 95% CI: 0.95-1.61 for compulsory vs tertiary education).

CONCLUSION

We provide detailed evidence about the social patterning of neonatal and infant mortality in Switzerland and reveal important regional differences with about 30% lower risks in French- and Italian-speaking compared with German-speaking regions. Underlying causes for such regional differences, such as cultural, lifestyle or healthcare-related factors, warrant further exploration to inform and provide an evidence base for public health policies.

Factors associated with perinatal mortality in sub-Saharan Africa: A multilevel analysis

BACKGROUND

Perinatal mortality is a major global public health concern, especially in sub-Saharan Africa (SSA). Despite perinatal mortality being a major public health concern in SSA, there are very limited studies on the incidence and factors associated with perinatal mortality. Therefore, we aimed to investigate the factors associated with perinatal mortality in SSA.

METHODS

A secondary data analysis was conducted based on the Demographic and Health Survey (DHS) data of 27 SSA countries. About 314,099 births in the preceding five years of the surveys were considered for the analysis. A multilevel binary logistic regression model was fitted to identify factors associated with perinatal mortality. Deviance (-2Log-Likelihood Ratio (LLR)) was used for model comparison. The Adjusted Odds Ratio (AOR) with the 5% Confidence Interval (CI) of the best-fitted model was used to verify the significant association between factors and perinatal mortality.

RESULTS

The perinatal mortality rate in sub-Saharan Africa (SSA) was 37.31 per 1,000 births (95% CI: 36.65, 37.98). In the final best-fit model, factors significantly associated with higher perinatal mortality included media exposure (AOR: 1.12, 95% CI: 1.08, 1.17), maternal age ≥ 35 years (AOR: 1.13, 95% CI: 1.06, 1.21), health facility delivery (AOR: 1.10, 95% CI: 1.06, 1.15), having 2-4 births (AOR: 1.35, 95% CI: 1.25, 1.47), five or more births (AOR: 1.69, 95% CI: 1.53, 1.86), residence in West Africa (AOR: 1.30, 95% CI: 1.24, 1.36) or Central Africa (AOR: 1.05, 95% CI: 1.00, 1.11), rural residency (AOR: 1.08, 95% CI: 1.02, 1.13), and difficulty accessing a health facility (AOR: 1.06, 95% CI: 1.02, 1.10). In contrast, factors significantly associated with lower perinatal mortality were a preceding birth interval of 2-4 years (AOR: 0.70, 95% CI: 0.67, 0.74) or five or more years (AOR: 0.91, 95% CI: 0.84, 0.97), Antenatal Care (ANC) visit (AOR: 0.66, 95% CI: 0.63, 0.69), higher education levels (AOR: 0.82, 95% CI: 0.73, 0.93), middle household wealth (AOR: 0.93, 95% CI: 0.88, 0.98), and richer household wealth (AOR: 0.93, 95% CI: 0.87, 0.99).

CONCLUSION

Perinatal mortality was a major public health problem in SSA. Maternal socio-demographic, obstetrical, and healthcare-related factors are significantly associated with perinatal mortality. The findings of this study highlighted the need for holistic healthcare interventions targeting enhancing maternal healthcare services to reduce the incidence of perinatal mortality.

Family poverty, neighbourhood greenspace and perinatal outcomes

OBJECTIVE

The relationship between low income and adverse perinatal outcomes, such as low birth weight and developmental delays, is well established making the search for protective factors important. One such factor may be neighbourhood greenspace. This study elucidates the role of urban neighbourhood greenspace in the relationship between income and perinatal outcomes in a nationally representative birth cohort from the UK.

METHODS

Data on 14 050 infants participating in the initial wave at age 9 months of the Millennium Cohort Study were used (51% male, 20% non-white, 52% living in disadvantaged areas). We tested whether the association between income and perinatal outcomes is moderated by urban greenspace (measured in deciles) before and after adjustments for confounding. The perinatal outcomes included birth weight, gestational age (in days), communication and motor delays. The models were adjusted for the infant's sex and ethnicity, mother's age, education, substance use and mental health as well as area disadvantage and air pollution.

RESULTS

Neighbourhood greenspace moderated the association between income and gestational age, even after adjustment for all confounders, b=-0.11, 95% CI (-0.215, -0.004). For births in low-income households, in particular, it was associated with an increase in gestational age by an average of approximately 3 days. However, after adjustment, greenspace was not found to influence birth weight, communication or motor delays at age 9 months.

CONCLUSION

The biophilic design of urban environments is a modifiable factor for improving perinatal outcomes in the UK as urban greenspaces appear to be mitigating the risk of preterm birth associated with family poverty.

Maternal Migration Background and Mortality Among Infants Born Extremely Preterm

Importance

Extremely preterm infants require care provided in neonatal intensive care units (NICUs) to survive. In the Netherlands, a decision is made regarding active treatment between 24 weeks 0 days and 25 weeks 6 days after consultation with the parents.

Objective

To investigate the association between maternal migration background and admissions to NICUs and mortality within the first year among extremely preterm infants.

Design, Setting, and Participants

This cross-sectional study linked data of registered births in the Netherlands with household-level income tax records and municipality and mortality registers. Eligible participants were households with live births at 24 weeks 0 days to 25 weeks 6 days gestation between January 1, 2010, and December 31, 2017. Data linkage and analysis was performed from March 1, 2020, to June 30, 2023.

Exposure

Maternal migration background, defined as no migration background vs first- or second-generation migrant mother.

Main Outcomes and Measures

Admissions to NICUs and mortality within the first week, month, and year of life. Logistic regressions were estimated adjusted for year of birth, maternal age, parity, household income, sex, gestational age, multiple births, and small for gestational age. NICU-specific fixed effects were also included.

Results

Among 1405 live births (768 male [54.7%], 546 [38.9%] with maternal migration background), 1243 (88.5%) were admitted to the NICU; 490 of 546 infants (89.7%) born to mothers with a migration background vs 753 of 859 infants (87.7%) born to mothers with no migration background were admitted to NICU (fully adjusted RR, 1.03; 95% CI, 0.99-1.08). A total of 652 live-born infants (46.4%) died within the first year of life. In the fully adjusted model, infants born to mothers with a migration background had lower risk of mortality within the first week (RR, 0.81; 95% CI, 0.66-0.99), month (RR, 0.84; 95% CI, 0.72-0.97), and year of life (RR, 0.85; 95% CI, 0.75-0.96) compared with infants born to mothers with no migration background.

Conclusions

In this nationally representative cross-sectional study, infants born to mothers with a migration background at 24 weeks 0 days to 25 weeks 6 days of gestation in the Netherlands had lower risk of mortality within the first year of life than those born to mothers with no migration background, a result that was unlikely to be explained by mothers from different migration backgrounds attending different NICUs or differential preferences for active obstetric management across migration backgrounds. Further research is needed to understand the underlying mechanisms driving these disparities, including parental preferences for active care of extremely preterm infants.

Associations of family income and healthy lifestyle with all-cause mortality

Background

There is a lack of evidence on whether combined lifestyle factors mediate the association between family income and all-cause mortality, as well as the joint relations between family income and lifestyle factors with mortality.

Methods

Using data on family income and lifestyle factors of participants in the US National Health Interview Survey 2016-2018, we performed multivariable logistic regression models to estimate the odds ratios (ORs) and 95% confidence intervals (CI) for the association of all-cause mortality with said data.

Results

We included 73 729 participants with a mean age of 47.1 years (standard deviation (SD) = 18.0), 51% of whom were women and 65% of whom were non-Hispanic Whites. There were 2284 deaths documented. After multivariable adjustment, middle-income participants had an OR of 0.73 (95% CI = 0.61-0.88) for mortality, while high-income participants had an OR of 0.47 (95% CI = 0.37-0.60) compared with low-income participants. We found that lower all-cause mortality was related to higher lifestyle scores. Adults from high-income families with lifestyle scores of 3 and 4 had an OR for mortality of 0.44 (95% CI = 0.30-0.65) compared to those from low-income families and lifestyle scores of 0 or 1. When comparing those in highest vs lowest income groups in the mediation analysis, 9.8% (95% CI = 7.4-13.0) of the relation for all-cause mortality was mediated by lifestyles. Adults from high-income families with lifestyle scores of 3 or 4 had an OR of 0.23 (95% CI = 0.17-0.33) for mortality compared with those from low-income families and lifestyle scores of 0 or 1.

Conclusions

A lower risk of all-cause mortality was linked to higher family income and healthier lifestyles. Furthermore, lifestyle factors mediated a small proportion of the association between family income and mortality among US adults. Economic disparity in health may not be eliminated by changing only one's lifestyle. Therefore, besides promoting a healthy lifestyle, we should stress how family income inequality affects health outcomes.

Perinatal deaths from birth defects in Hunan Province, China, 2010-2020

OBJECTIVE

To describe the perinatal mortality rate (PMR) of birth defects and to define the relationship between birth defects (including a broad range of specific defects) and a broad range of factors.

METHODS

Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2010-2020. The prevalence rate (PR) of birth defects is the number of birth defects per 1000 fetuses (births and deaths at 28 weeks of gestation and beyond). PMR is the number of perinatal deaths per 100 fetuses. PR and PMR with 95% confidence intervals (CI) were calculated using the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in PR and PMR by year, maternal age, income, education level, parity, and gestational age of termination. Crude odds ratios (ORs) were calculated to examine the association of each maternal characteristic with perinatal deaths attributable to birth defects.

RESULTS

Our study included 1,619,376 fetuses, a total of 30,596 birth defects, and 18,212 perinatal deaths (including 16,561 stillbirths and 1651 early neonatal deaths) were identified. The PR of birth defects was 18.89‰ (95%CI: 18.68-19.11), and the total PMR was 1.12%(95%CI: 1.11-1.14). Birth defects accounted for 42.0% (7657 cases) of perinatal deaths, and the PMR of birth defects was 25.03%. From 2010 to 2020, the PMR of birth defects decreased from 37.03% to 2010 to 21.00% in 2020, showing a downward trend (χ2trend = 373.65, P < 0.01). Congenital heart defects caused the most perinatal deaths (2264 cases); the PMR was 23.15%. PMR is highest for encephalocele (86.79%). Birth defects accounted for 45.01% (7454 cases) of stillbirths, and 96.16% (7168 cases) were selective termination of pregnancy. Perinatal deaths attributable to birth defects were more common in rural than urban areas (31.65% vs. 18.60%, OR = 2.03, 95% CI: 1.92-2.14) and in females than males (27.92% vs. 22.68%, OR = 1.32, 95% CI: 1.25-1.39). PMR of birth defects showed downward trends with rising maternal age (χ2trend = 200.86, P < 0.01), income (χ2trend = 54.39, P < 0.01), maternal education level (χ2trend = 405.66, P < 0.01), parity (χ2trend = 85.11, P < 0.01) and gestational age of termination (χ2trend = 15297.28, P < 0.01).

CONCLUSION

In summary, birth defects are an important cause of perinatal deaths. Rural areas, female fetuses, mothers with low maternal age, low income, low education level, low parity, and low gestational age of termination were risk factors for perinatal deaths attributable to birth defects. Future studies should examine the mechanisms. Our study is helpful for intervention programs to reduce the PMR of birth defects.

Analysis of an Association between Preterm Birth and Parental Educational Level in Japan Using National Data

Preterm birth rate depending on parental educational level in recent years has not been surveyed in Japan. In this study, we showed the trend in preterm birth rate depending on parental educational level from 2000 to 2020 by linking data from the Census regarding individuals' educational level and parents in birth data of the vital statistics. Four types of parental educational level, namely junior high school, high school, technical school or junior college, and university or graduate school, were compared. Slope and relative indexes of inequality for preterm birth by educational level were computed by binomial models. Data on 3,148,711 births and 381,129,294 people were used in the analysis, and data on 782,536 singleton births were used after data linkage. The preterm birth rate (%) for junior high school graduate mothers and fathers was 5.09 and 5.20 in 2020, respectively. Contrarily, the preterm birth rate (%) for parents who graduated from a university or graduate school was 4.24 for mothers and 4.39 for fathers, and the rate tended to increase as educational level decreased, irrespective of parental gender. Results of inequality indexes showed that a statistically significant inequality by parental educational level persisted from 2000 to 2020.

Prenatal Exposure to Mercury, Manganese, and Lead and Adverse Birth Outcomes in Suriname: A Population-Based Birth Cohort Study

Globally, adverse birth outcomes are increasingly linked to prenatal exposure to environmental contaminants, such as mercury, manganese, and lead. This study aims to assess an association between prenatal exposure to mercury, manganese, and lead and the occurrence of adverse birth outcomes in 380 pregnant women in Suriname. The numbers of stillbirths, preterm births, low birth weights, and low Apgar scores were determined, as well as blood levels of mercury, manganese, lead, and relevant covariates. Descriptive statistics were calculated using frequency distributions. The associations between mercury, manganese, and lead blood levels, on the one hand, and adverse birth outcomes, on the other hand, were explored using contingency tables, tested with the χ2-test (Fisher's exact test), and expressed with a p value. Multivariate logistic regression models were computed to explore independent associations and expressed as (adjusted) odds ratios (aOR) with 95% confidence intervals (CI). The findings of this study indicate no statistically significant relationship between blood mercury, manganese, or lead levels and stillbirth, preterm birth, low birth weight, and low Apgar score. However, the covariate diabetes mellitus (aOR 5.58, 95% CI (1.38-22.53)) was independently associated with preterm birth and the covariate hypertension (aOR 2.72, 95% CI (1.081-6.86)) with low birth weight. Nevertheless, the observed high proportions of pregnant women with blood levels of mercury, manganese, and lead above the reference levels values of public health concern warrants environmental health research on risk factors for adverse birth outcomes to develop public health policy interventions to protect pregnant Surinamese women and their newborns from potential long-term effects.