Persisting inequalities in birth outcomes related to neighbourhood deprivation

Exploring psychosocial vulnerability among Dutch pregnant women: a register study

In the Netherlands adverse perinatal outcomes are also associated with non-medical factors which vary across geographical locations. This study analyses the presence of non-medical vulnerabilities in pregnant women in two regions with high numbers of psychosocial adversity using the same definition for vulnerability in both regions. A register study was performed in 2 regions. Files from women in midwife-led care were analyzed using a standardized case report form addressing non-medical vulnerability based on the Rotterdam definition for vulnerability: measurement A in Groningen (n = 500), measurement B in South-Limburg (n = 538). Only in South-Limburg a second measurement was done after implementing an identification tool for vulnerability (C (n = 375)). In both regions about 10% of pregnant women had one or more urgent vulnerabilities and almost all of these women had an accumulation of several urgent and non-urgent vulnerabilities. Another 10% of women had an accumulation of three or more non-urgent vulnerabilities. This study showed that by using the Rotterdam definition of vulnerability in both regions about 20% of pregnant women seem to live in such a vulnerable situation that they may need psychosocial support. The definition seems a good tool to determine vulnerability. However, without considering protective factors it is difficult to establish precisely women's vulnerability. Research should reveal whether relevant women receive support and whether this approach contributes to better perinatal and child outcomes.

Socioeconomic inequalities in the uptake of postpartum care at home across Dutch neighbourhoods

BACKGROUND

Postpartum care focuses on prevention of health problems by performing medical check-ups and through enhancing maternal empowerment, the parent-infant interaction and knowledge about mother's own health and that of her newborn. We aimed to investigate whether there was significant clustering within neighbourhoods regarding the uptake of postpartum care and to what extent neighbourhood-level differences are explained by individual socio-demographic factors, pregnancy-related factors and neighbourhood-level determinants (i.e. deprivation and urbanization).

METHODS

A nationwide population-based observational study was carried out using linked routinely collected healthcare data from appropriate-for-gestational-age weight live-born term singleton deliveries (2015-18) in the Netherlands. We performed two-level multivariable logistic regression analyses, using three different models. Model 1 contained no explanatory variables and was used to assess clustering of postpartum care uptake within neighbourhoods. In model 2, individual-level determinants were added one by one and in model 3, neighbourhood-level determinants were added.

RESULTS

About 520 818 births were included. Multilevel modelling showed that 11% of the total variance in postpartum care uptake could be attributed to the neighbourhood of residence. Individual characteristics explained 38% of the neighbourhood variance, of which income and migration background were the most important contributors. An additional 6% of the variation could be explained by neighbourhood-level determinants.

CONCLUSION

We found substantial neighbourhood differences in postpartum care uptake. These differences are influenced by a complex interplay between individual-level and neighbourhood-level determinants, highlighting the importance of addressing both individual and neighbourhood-level determinants to improve the uptake of postpartum care and therewith overall community health.

Deprived areas and adverse perinatal outcome: a systematic review

PURPOSE

This systematic review aimed to assess if women living in deprived areas have worse perinatal outcomes than those residing in high-income areas.

METHODS

Datasets of PubMed, ScienceDirect, CENTRAL, Embase, and Google Scholar were searched for studies comparing perinatal outcomes (preterm birth, small-for-gestational age, and stillbirth) in deprived and non-deprive areas.

RESULTS

A total of 46 studies were included. The systematic review of the literature revealed a higher risk for adverse perinatal outcomes such as preterm birth, small for gestational age, and stillbirth in deprived areas.

CONCLUSION

Deprived areas are associated with adverse perinatal outcomes. More multifactorial studies are needed to assess the weight of each factor that composes the socioeconomic gradient of health in adverse perinatal outcomes.

Do women living in a deprived neighborhood have higher maternity care costs and worse pregnancy outcomes? A retrospective population-based study

BACKGROUND

Living in a deprived neighborhood is associated with poorer health, due to factors such as lower socio-economic status and an adverse lifestyle. There is little insight into whether living in deprived neighborhood is associated with adverse maternity care outcomes and maternity health care costs. We expect women in a deprived neighborhood to experience a more complicated pregnancy, with more secondary obstetric care (as opposed to primary midwifery care) and higher maternity care costs. This study aimed to answer the following research question: to what extent are moment of referral from primary to secondary care, mode of delivery, (extreme or very) preterm delivery and maternity care costs associated with neighborhood deprivation?

METHODS

This retrospective cohort study used a national Dutch database with healthcare claims processed by health insurers. All pregnancies that started in 2018 were included. The moment of referral from primary to secondary care, mode of delivery, (extreme or very) preterm delivery and maternity care costs were compared between women in deprived and non-deprived neighborhoods. We reported descriptive statistics, and results of ordinal logistic, multinomial and linear regressions to assess whether differences between the two groups exist.

RESULTS

Women in deprived neighborhoods had higher odds of being referred from primary to secondary care during pregnancy (adjusted OR 1.49, 95%CI 1.41-1.57) and to start their pregnancy in secondary care (adjusted OR 1.55, 95%CI 1.44-1.66). Furthermore, women in deprived neighborhoods had lower odds of assisted delivery than women in non-deprived neighborhoods (adjusted OR 0.73, 95%CI 0.66-0.80), and they had higher odds of a cesarean section (adjusted OR 1.19, 95%CI 1.13-1.25). On average, women in a deprived neighborhood had higher maternity care costs worth 156 euros (95%CI 104-208).

CONCLUSION

This study showed that living in a deprived neighborhood is associated with more intensive maternal care and higher maternal care costs in the Netherlands. These findings support the needs for greater attention to socio-economic factors in maternity care in the Netherlands.

Living in a low socioeconomic status neighbourhood is associated with lower cumulative ongoing pregnancy rate after IVF treatment

RESEARCH QUESTION

Does an association exist between neighbourhood socioeconomic status (SES) and the cumulative rate of ongoing pregnancies after 2.5 years of IVF treatment?

DESIGN

A retrospective observational study involving 2669 couples who underwent IVF or IVF and intracytoplasmic sperm injection treatment between 2006 and 2020. Neighbourhood SES for each couple was determined based on their residential postal code. Subsequently, SES was categorized into low (p80). Multivariable binary logistic regression analyses were conducted, with the cumulative ongoing pregnancy within 2.5 years as the outcome variable. The SES category (reference category: high), female age (reference category: 32-36 years), body mass index (reference category: 23-25 kg/m2), smoking status (yes/no), number of oocytes after the first ovarian stimulation, embryos usable for transfer or cryopreservation after the first cycle, duration of subfertility before treatment and insemination type were used as covariates.

RESULTS

A variation in ongoing pregnancy rates was observed among SES groups after the first fresh embryo transfer. No difference was found in the median number of IVF treatment cycles carried out. The cumulative ongoing pregnancy rates differed significantly between SES groups (low: 44%; medium: 51%; high: 56%; P < 0.001). Low neighbourhood SES was associated with significantly lower odds for achieving an ongoing pregnancy within 2.5 years (OR 0.66, 95% CI 0.52 to 0.84, P < 0.001).

CONCLUSION

Low neighbourhood SES compared with high neighbourhood SES is associated with reducing odds of achieving an ongoing pregnancy within 2.5 years of IVF treatment.

Does the evidence support in utero influences on later health and disease? A systematic review of highly cited Barker studies on developmental origins

The developmental origins of health and disease hypothesis proposes that early exposure to adverse conditions during fetal development and early life have strong detrimental consequences on long-term health and susceptibility to chronic diseases. We conducted a systematic review to critically appraise Barker's highest cited publications using the risk-of-bias assessment tool (ROBINS-I) and investigate effects of overadjustment by later body weight. Our findings revealed that all included studies displayed high risks of bias, with particular concerns regarding confounding (8/8), selection of reported results (8/8), classification of exposure (7/8), selection of participants (5/8) and high rates of missing data (ranged from 15 to 87%). Later body weight was over-adjusted in most (6/8) of the studies. As all studies displayed high bias risk due to confounding, missing data and overadjustment, evidence is insufficient to support causal relationships between low birthweight and adult disease, warranting caution in clinical application. PROTOCOL REGISTRATION: PROSPERO CRD42023433179.

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.

Small for gestational age preterm infants and later adiposity and height: A systematic review and meta-analysis

BACKGROUND

Overweight and obesity and their consequent morbidities are important worldwide health problems. Some research suggests excess adiposity origins may begin in fetal life, but unknown is whether this applies to infants born preterm.

OBJECTIVE

The objective of the study was to assess the association between small for gestational age (SGA) birth and later adiposity and height among those born preterm.

DATA SOURCES

MEDLINE, EMBASE and CINAHL until October 2022.

STUDY SELECTION AND DATA EXTRACTION

Studies were included if they reported anthropometric (adiposity measures and height) outcomes for participants born preterm with SGA versus non-SGA. Screening, data extraction and risks of bias assessments were conducted in duplicate by two reviewers.

SYNTHESIS

We meta-analysed across studies using random-effects models and explored potential heterogeneity sources.

RESULTS

Thirty-nine studies met the inclusion criteria. In later life, preterm SGA infants had a lower body mass index (-0.66 kg/m2 , 95% CI -0.79, -0.53; 32 studies, I2  = 16.7, n = 30,346), waist circumference (-1.20 cm, 95% CI -2.17, -0.23; 13 studies, I2  = 19.4, n = 2061), lean mass (-2.62 kg, 95% CI -3.45, 1.80; 7 studies, I2  = 0, n = 205) and height (-3.85 cm, 95% CI -4.73, -2.96; 26 studies, I2  = 52.6, n = 4174) compared with those preterm infants born non-SGA. There were no differences between preterm SGA and preterm non-SGA groups in waist/hip ratio, body fat, body fat per cent, truncal fat per cent, fat mass index or lean mass index, although power was limited for some analyses. Studies were rated at high risk of bias due to potential residual confounding and low risk of bias in other domains.

CONCLUSIONS

Compared to their preterm non-SGA peers, preterm infants born SGA have lower BMI, waist circumference, lean body mass and height in later life. No differences in adiposity were observed between SGA preterm infants and non-SGA preterm infants.

Cumulative Risk Evaluation of Phthalates Under TSCA

The U.S. Environmental Protection Agency (EPA) is currently conducting separate Toxic Substances Control Act (TSCA) risk evaluations for seven phthalates: dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DIBP), dicyclohexyl phthalate (DCHP), di-isodecyl phthalate (DIDP), and diisononyl phthalate (DINP). Phthalates are highly abundant plastic additives used primarily to soften materials and make them flexible, and biomonitoring shows widespread human exposure to a mixture of phthalates. Evidence supports biological additivity of phthalate mixture exposures, including the enhancement of toxicity affecting common biological targets. Risk estimates based on individual phthalate exposure may not be protective of public health. Thus, a cumulative risk approach is warranted. While EPA initially did not signal that it would incorporate cumulative risk assessment (CRA) as part of its current risk evaluation for the seven phthalates, the agency recently announced that it is reconsidering if CRA for phthalates would be appropriate. Based on our review of existing chemical mixtures risk assessment guidance, current TSCA scoping documents for the seven phthalates, and pertinent peer-reviewed literature, we delineate a CRA approach that EPA can easily implement for phthalates. The strategy for using CRA to inform TSCA risk evaluation for existing chemicals is based upon integrative physiology and a common adverse health outcome algorithm for identifying and grouping relevant nonchemical and chemical stressors. We recommend adjustments for how hazard indices (HIs) or margins of exposure (MOEs) based on CRA are interpreted for determining "unreasonable risk" under TSCA.

Decrease in perinatal mortality after closure of obstetric services in a community hospital in Amsterdam, The Netherlands. A retrospective cohort study

OBJECTIVE

To assess differences in adverse maternal and neonatal outcomes before and after closure of a secondary obstetric care unit of a community hospital in an urban district.

STUDY DESIGN

Retrospective cohort study using aggregated data from National Perinatal Registry of the Netherlands (PERINED) in the very urban region of Amsterdam, consisting of data of five secondary and two tertiary hospitals. We assessed maternal and neonatal outcomes in singleton hospital births between 24⁺⁰ weeks of gestational age (GA) up to 42⁺⁶ weeks. Data of 78.613 births were stratified in two groups: before closure (years 2012-2015) and after closure (2016-2019).

RESULTS

Perinatal mortality decreased significantly from 0.84 % to 0.63 % (p = 0.0009). The adjusted odds ratio (aOR) of the closure on perinatal mortality was 0.73 (95 % CI 0.62-0.87). Both antepartum death (0.46 % vs 0.36 %, p = 0.02) and early neonatal death (0.38 % vs 0.28 %, p = 0.015) declined after closure of the hospital. The number of preterm births decreased significantly (8.7 % vs 8.1 %, p=<0.007) as well as number of neonates with congenital abnormalities (3.2 % vs2.2 %, p=<0.0001). APGAR < 7 after 5 min increased (2.3 % vs 2.5 %, p = 0.04). There was no significant difference in SGA or NICU admission. Postpartum hemorrhage increased significantly from 7.7 % to 8.2 % (p=<0.003). Perinatal mortality from 32 weeks onwards was not significantly different after closure 0.29 % to 0.27 %.

CONCLUSIONS

After closure of an obstetric unit in a community hospital in Amsterdam, there was a significant decrease in perinatal, intrapartum and early neonatal mortality in neonates born from 24⁺⁰ onwards. The mortality decrease coincides with a reduction of preterm deliveries. The increasing trend in asphyxia and postpartum hemorrhage is of concern.. Centralization of care and increasing birth volume per hospital may lead to improvement of quality of care. A broad integrated, multidisciplinary maternity healthcare system linked with the social domain can achieve health gains in maternity care for all women.

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.

Analysis of association between low birth weight and socioeconomic deprivation level in Japan: an ecological study using nationwide municipal data

BACKGROUND

Several international studies have indicated an association between socioeconomic deprivation levels and adverse birth outcomes. In contrast, those investigating an association between socioeconomic status and low birth weight using nationwide data are limited in Japan. In this study, we investigated an association between municipal socioeconomic deprivation level and low birth weight by an ecological study.

METHODS

Nationwide municipal-specific Vital Statistics data from 2013 to 2017 were used. We calculated the low birth weight rate and standardized incidence ratio (SIR) for low birth weight for each municipality and plotted them on a Japanese map. Furthermore, the correlation coefficient between them and the deprivation level were calculated. In addition, a spatial regression model including other municipal characteristics was used to investigate an association between low birth weight and the deprivation level.

RESULTS

Municipalities with relatively high SIR for low birth weight were dispersed across all of Japan. The correlation coefficient between the socioeconomic deprivation level and low birth weight rate was 0.196 (p-value < 0.001) among municipalities, and that between the socioeconomic deprivation level and the SIR for low birth weight was 0.260 (p-value < 0.001). In addition, the spatial regression analysis showed the deprivation level was significantly and positively associated with low birth weight.

CONCLUSIONS

The socioeconomic deprivation level and low birth weight were positively associated, and a further study using individual data is warranted to verify reasons for the association.

Deprived neighborhoods and spontaneous preterm birth: A national cohort study

OBJECTIVE

Spontaneous preterm birth is the leading cause of infant morbidity and mortality in the developed world. Environmental socio-economic factors, such as neighborhood deprivation, are known to negatively affect birth outcomes, including overall preterm birth. However, the role of neighborhood deprivation in spontaneous preterm birth (SPTB) is unclear. The aim of the study is to 1) to determine the effect of neighborhood deprivation on SPTB birth and 2) to investigate the trend in rates of SPTB between 2010 and 2019 for each quintile of neighborhood deprivation.

STUDY DESIGN

Based on the national perinatal registry, we included 1,584,225 singleton pregnancies resulting in a birth from 22 to 42 completed weeks of gestation between 2010 and 2019 in the Netherlands. Deprivation scores per neighborhood were derived from the Netherlands Institute of Social Research and were linked to the perinatal registry data, using the woman's home address. The scores were divided into quintiles (Q). Rates of SPTB were calculated, categorized into <37 weeks, <32 weeks and <28 weeks of gestation. We used logistic regression analysis to adjust for maternal age, parity and ethnicity.

RESULTS

Compared to the most affluent neighborhoods (Q1), women in all other quintiles had a statistically significant increased risk for SPTB. The largest effect was observed in the most deprived neighborhoods (Q5); adjusted odds ratio 1.16 (95% confidence interval 1.13 - 1.19). From 2010 to 2019, we observed an overall decrease of 0.21% in SPTB < 37 weeks (p < 0.0001). All quintiles showed a decrease in SPTBs < 37 weeks, but only in Q1, Q2 & Q5 this decline in SPTB was statistically significant.

CONCLUSIONS

Pregnant women in deprived neighborhoods in the Netherlands are more at risk for spontaneous preterm birth. From 2010 to 2019, the rate of spontaneous preterm birth decreased. Efforts should be made by both governmental and medical professionals to develop intervention programs to reduce spontaneous preterm birth in more deprived neighborhoods.

Can an Ecological Index of Deprivation Be Used at the Country Level? The Case of the French Version of the European Deprivation Index (F-EDI)

Most ecological indices of deprivation are constructed from census data at the national level, which raises questions about the relevance of their use, and their comparability across a country. We aimed to determine whether a national index can account for deprivation regardless of location characteristics. In Metropolitan France, 43,853 residential census block groups (IRIS) were divided into eight area types based on quality of life. We calculated score deprivation for each IRIS using the French version of the European Deprivation Index (F-EDI). We decomposed the score by calculating the contribution of each of its components by area type, and we assessed the impact of removing each component and recalculating the weights on the identification of deprived IRIS. The set of components most contributing to the score changed according to the area type, but the identification of deprived IRIS remained stable regardless of the component removed for recalculating the score. Not all components of the F-EDI are markers of deprivation according to location characteristics, but the multidimensional nature of the index ensures its robustness. Further research is needed to examine the limitations of using these indices depending on the purpose of the study, particularly in relation to the geographical grid used to calculate deprivation scores.

Socio-economic determinants of healthcare costs in early life: a register-based study in the Netherlands

Background

Children with low socioeconomic status (SES) have an increased risk of a suboptimal start in life with ensuing higher healthcare costs. This study aims to investigate the effects of individual- (monthly household income) and contextual-level SES (household income and neighborhood deprivation), and perinatal morbidity (preterm birth and small for gestational age ((<10th percentile), SGA)) on healthcare costs in early life (0–3 years of age).

Methods

Individual-linked data from three national registries (Perinatal Registry Netherlands, Statistics Netherlands, and Healthcare Vektis) were obtained of all children born between 2011 and 2014 (N = 480,471) in the Netherlands. Binomial logistic regression was used to model annual healthcare costs as a function of their household income (per €1000), neighborhood deprivation index (range − 13.26 – 10.70), their perinatal morbidity and demographic characteristics. Annual healthcare cost were dichotomized into low healthcare costs (Q1-Q3 below €1000) and high healthcare costs (Q4 €1000 or higher).

Results

Children had a median of €295 annual healthcare costs, ranging from €72 to €4299 (5–95%). Binomial logistic regression revealed that for every €1000 decrease in monthly household income, the OR for having high healthcare costs is 0.99 (0.99–0.99). Furthermore, for every one-unit increase in neighborhood deprivation the OR for having high healthcare costs increase 1.02 (1.01–1.02). Finally, the model revealed an OR of 2.55 (2.48–2.61) for preterm born children, and an OR of 1.44 (1.41–1.48) for children SGA, to have high healthcare costs compared to their healthy peers.

Conclusion

More neighborhood deprivation was directly related to higher healthcare costs in young children. On top of this, lower household income was consistently and independently related to higher healthcare costs. By optimizing conditions for low SES populations, the impact of low SES circumstances on their healthcare costs can be positively influenced. Additionally, policies that influence more timely and appropriate healthcare use in low SES populations can reduce healthcare costs further.

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

Importance

The association between household income and perinatal health outcomes has been understudied. Examining disparities in perinatal mortality within strata of gestational age and before and after adjusting for birth weight centile can reveal how the income gradient is associated with gestational age, birth weight, and perinatal mortality.

Objectives

To investigate the association between household income and perinatal mortality, separately by gestational age strata and time of death, and the potential role of birth weight centile in mediating this association.

Design, Setting, and Participants

This cross-sectional study used individually linked data of all registered births in the Netherlands with household-level income tax records. Singletons born between January 1, 2004, and December 31, 2016, at 24 weeks to 41 weeks 6 days of gestation with complete information on birth outcomes and maternal characteristics were studied. Data analysis was performed from March 1, 2018, to August 30, 2021.

Exposures

Household income rank (adjusted for household size).

Main Outcomes and Measures

Perinatal mortality, stillbirth (at ≥24 weeks of gestation), and early neonatal mortality (at ≤7 days after birth). Disparities were expressed as bottom-to-top ratios of projected mortality among newborns with the poorest 1% of households vs those with the richest 1% of households. Generalized additive models stratified by gestational age categories, adjusted for potential confounding by maternal age at birth, maternal ethnicity, parity, sex, and year of birth, were used. Birth weight centile was included as a potential mediator.

Results

Among 2 036 431 singletons in this study (1 043 999 [51.3%] males; 1 496 579 [73.5%] with mother of Dutch ethnicity), 121 010 (5.9%) were born before 37 weeks of gestation, and 8720 (4.3 deaths per 1000) died during the perinatal period. Higher household income was positively associated with higher rates of perinatal survival, with an unadjusted bottom-to-top ratio of 2.18 (95% CI, 1.87-2.56). The bottom-to-top ratio decreased to 1.30 (95% CI, 1.22-1.39) after adjustment for potential confounding factors and inclusion of birth weight centile as a possible mediator. The fully adjusted ratios were lower for stillbirths (1.27; 95% CI, 1.20-1.36) than for early neonatal deaths (1.35; 95% CI, 1.14-1.66). Inequalities in perinatal mortality were found for newborns at greater than 26 weeks of gestation but not between 24 and 26 weeks of gestation (fully adjusted bottom-to-top ratio, 0.89; 95% CI, 0.77-1.04).

Conclusions and Relevance

The results of this large nationally representative cross-sectional study suggest that a large part of the increased risk of perinatal mortality among low-income women is mediated via a lower birth weight centile. The absence of disparities at very low gestational ages suggests that income-related risk factors for perinatal mortality are less prominent at very low gestational ages. Further research should aim to understand which factors associated with preterm birth and lower birth weight can reduce inequalities in perinatal mortality.

Association of neighbourhood socioeconomic trajectories with preterm birth and small-for-gestational-age in the Netherlands: a nationwide population-based study

BACKGROUND

Adverse birth outcomes have serious health consequences, not only during infancy but throughout the entire life course. Most evidence linking neighbourhood socioeconomic status (SES) to birth outcomes is based on cross-sectional SES measures, which do not reflect neighbourhoods' dynamic nature. We investigated the association between neighbourhood SES trajectories and adverse birth outcomes, i.e. preterm birth and being small-for-gestational-age (SGA), for births occurring in the Netherlands between 2003 and 2017.

METHODS

We linked individual-level data from the Dutch perinatal registry to the Netherlands Institute for Social Research neighbourhood SES scores. Based on changes in their SES across four-year periods, neighbourhoods were categorised into seven trajectories. To investigate the association between neighbourhood SES trajectories and birth outcomes we used adjusted multilevel logistic regression models.

FINDINGS

Data on 2 334 036 singleton births were available for analysis. Women living in stable low-SES neighbourhoods had higher odds of preterm birth (OR[95%CI]= 1·12[1·07-1·17]) and SGA (OR[95%CI]= 1·19[1·15-1·23]), compared to those in high SES areas. Higher odds of preterm birth (OR[95%CI]= 1·12[1·05-1·20]) and SGA (OR[95%CI]=1·12[1·06-1·18]) were also observed for those living in areas declining to low SES. Women living in a neighbourhood where SES improved from low to medium showed higher odds of preterm birth (OR[95%CI]= 1·09[1·02-1·18]), but not of SGA (OR[95%CI]= 1·04[0.98-1·10]). The odds of preterm or SGA birth in other areas were comparable to those seen in high SES areas.

INTERPRETATION

In the Netherlands, disadvantaged neighbourhood SES trajectories were associated with higher odds of adverse birth outcomes. Longitudinal neighbourhood SES measures should also be taken into account when selecting a target population for public health interventions.

FUNDING

Erasmus Initiative Smarter Choices for Better Health.

Addressing perinatal health inequities in Dutch municipalities: Protocol for the Healthy Pregnancy 4 All-3 programme

BACKGROUND

Health inequities are already present at birth and affect individuals' health and socioeconomic outcomes across the life course. Addressing these inequities requires a cross-sectoral approach, covering the first 1,000 days of life. We believe that - in the Dutch context - municipal governments can be the main responsible actor to drive such an approach, since they are primarily responsible for organising adequate public health. Therefore, we aim to identify and develop transformative change towards the implementation of perinatal health into municipal approaches and policies concerning health inequities.

METHODS

A transition analysis will be combined with action research in six Dutch municipalities. Interviews and interactive group sessions with professionals and organisations that are relevant for the institutional embedding of perinatal health into approaches and policies regarding health inequities, will be organised in each municipality. As a follow-up, a questionnaire will be administered among all participants one year after completion of the group sessions.

DISCUSSION

We expect to gain insights into the role of municipalities in addressing perinatal health inequities, learn more about the interaction between different key stakeholders, and identify barriers and facilitators for a cross-sectoral approach to perinatal health. This knowledge will serve to inform the development of approaches to perinatal health inequities in areas with relatively poor perinatal health outcomes, both in the Netherlands and abroad.

Impact of COVID-19 mitigation measures on the incidence of preterm birth: a national quasi-experimental study

Background

Preterm birth is the leading cause of child mortality globally, with many survivors experiencing long-term adverse consequences. Preliminary evidence suggests that numbers of preterm births greatly reduced following implementation of policy measures aimed at mitigating the effects of the COVID-19 pandemic. We aimed to study the impact of the COVID-19 mitigation measures implemented in the Netherlands in a stepwise fashion on March 9, March 15, and March 23, 2020, on the incidence of preterm birth.

Methods

We used a national quasi-experimental difference-in-regression-discontinuity approach. We used data from the neonatal dried blood spot screening programme (2010–20) cross-validated against national perinatal registry data. Stratified analyses were done according to gestational age subgroups, and sensitivity analyses were done to assess robustness of the findings. We explored potential effect modification by neighbourhood socioeconomic status, sex, and small-for-gestational-age status.

Findings

Data on 1 599 547 singleton neonates were available, including 56 720 births that occurred after implementation of COVID-19 mitigation measures on March 9, 2020. Consistent reductions in the incidence of preterm birth were seen across various time windows surrounding March 9 (± 2 months [n=531 823] odds ratio [OR] 0·77, 95% CI 0·66–0·91, p=0·0026; ± 3 months [n=796 531] OR 0·85, 0·73–0·98, p=0·028; ± 4 months [n=1 066 872] OR 0·84, 0·73–0·97, p=0·023). Decreases in incidence observed following the March 15 measures were of smaller magnitude, but not statistically significant. No changes were observed after March 23. Reductions in the incidence of preterm births after March 9 were consistent across gestational age strata and robust in sensitivity analyses. They appeared confined to neighbourhoods of high socioeconomic status, but effect modification was not statistically significant.

Interpretation

In this national quasi-experimental study, initial implementation of COVID-19 mitigation measures was associated with a substantial reduction in the incidence of preterm births in the following months, in agreement with preliminary observations elsewhere. Integration of comparable data from across the globe is needed to further substantiate these findings and start exploring underlying mechanisms.

Funding

None.