Maternal education level and low birth weight: a meta-analysis

Neonatal mortality rate and determinants among births of mothers at extreme ages of reproductive life in low and middle income countries

Neonatal mortality, which refers to the death of neonates during the first 28 completed days of life, is a critical global public health concern. The neonatal period is widely recognized as one of the most precarious phases in human life. Research has indicated that maternal extreme ages during reproductive years significantly impact neonatal survival, particularly in low- and middle-income countries. Consequently, this study aims to evaluate the neonatal mortality rate and determinants among neonates born to mothers at extreme reproductive ages within these countries. A secondary analysis of demographic and health surveys conducted between 2015 and 2022 in 43 low- and middle-income countries was performed. The study included a total sample of 151,685 live births. Researchers utilized a multilevel mixed-effects model to identify determinants of neonatal mortality. The measures of association were evaluated using the adjusted odds ratio within a 95% confidence interval. The neonatal mortality rate among neonates born to mothers at extreme ages of reproductive life in low- and middle-income countries was 28.96 neonatal deaths per 1000 live births (95% CI 28.13-29.82). Factors associated with higher rates of neonatal mortality include male gender, low and high birth weight, maternal education (no or low), home deliveries, multiple births, short preceding birth intervals, lack of postnatal checkups, and countries with high fertility and low literacy rates. This study sheds light on the neonatal mortality rates among neonates born to mothers at extreme ages of reproductive life in low- and middle-income countries. Notably, we found that neonatal mortality was significantly higher in this group compared to neonatal mortality rates reported regardless of maternal ages. Male babies, low and high birth-weighted babies, those born to mothers with no or low education, delivered at home, singletons, babies born with a small preceding birth interval, and those without postnatal checkups faced elevated risks of neonatal mortality. Additionally, neonates born in countries with high fertility and low literacy rates were also vulnerable. These findings underscore the urgent need for targeted interventions tailored to mothers at extreme ages. Policymakers and healthcare providers should prioritize strategies that address specific risk factors prevalent in these vulnerable populations. By doing so, we can improve neonatal outcomes and ensure the survival of these newborns during the critical neonatal period.

Evaluating causal influence of maternal educational attainment on offspring birthweight via observational study and Mendelian randomization analyses

Background

Although extensive discussions on the influence of maternal educational attainment on offspring birthweight, the conclusion remains controversial, and it is challenging to comprehensively assess the causal association between them.

Methods

To estimate effect of maternal educational attainment on the birthweight of first child, we first conducted an individual-level analysis with UK Biobank participants of white ancestry (n = 208,162). We then implemented Mendelian randomization (MR) methods including inverse variance weighted (IVW) MR and multivariable MR to assess the causal relation between maternal education and maternal-specific birthweight. Finally, using the UK Biobank parent-offspring trio data (n = 618), we performed a polygenic score based MR to simultaneously adjust for confounding effects of fetal-specific birthweight and paternal educational attainment. We also conducted simulations for power evaluation and sensitivity analyses for horizontal pleiotropy of instruments.

Results

We observed that birthweight of first child was positively influenced by maternal education, with 7 years of maternal education as the reference, adjusted effect = 44.8 (95%CIs 38.0-51.6, P = 6.15 × 10-38), 54.9 (95%CIs 47.6-62.2, P = 4.21 × 10-128), and 89.4 (95%CIs 82.1-96.7, P = 4.28 × 10-34) for 10, 15 and 20 years of maternal educational attainment, respectively. A causal relation between maternal education and offspring birthweight was revealed by IVW MR (estimated effect = 0.074 for one standard deviation increase in maternal education years, 95%CIs 0.054-0.093, P = 2.56 × 10-13) and by complementary MR methods. This connection was not substantially affected by paternal education or horizontal pleiotropy. Further, we found a positive but insignificant causal association (adjusted effect = 24.0, 95%CIs -150.1-198.1, P = 0.787) between maternal education and offspring birthweight after simultaneously controlling for fetal genome and paternal education; this null causality was largely due to limited power of small sample sizes of parent-offspring trios.

Conclusion

This study offers supportive evidence for a causal association between maternal education and offspring birthweight, highlighting the significance of enhancing maternal education to prevent low birthweight.

Perinatal health in Spain during and after the Great Recession: Educational selection into fertility as a protective factor in high unemployment contexts

Higher maternal resources have long been associated with superior birth outcomes. This study analyzes the potentially protective role of maternal educational selection into fertility in adverse macroeconomic contexts. We focus on the case of Spain, a country reaching record-high unemployment levels during the Great Recession starting in 2008. First, we examine whether selection into fertility of more educated mothers took place as province-level unemployment rates rose. Secondly, we assess whether maternal education mitigated the impact of higher unemployment levels on different birth outcomes. The analysis combines register data on the universe of live births with aggregate data on province-level unemployment. We cover the period 2007-2019 to ensure sufficient variability of unemployment rates and perform linear regression and linear probability models with fixed effects to hold constant unobserved heterogeneity across provinces. Findings indicate selection into fertility of mothers with university-level education in times of high unemployment. In addition, while unemployment rates did show an adverse impact on certain birth outcomes -birthweight, the occurrence of low and very low birthweight, and the risk of stillbirth - maternal education mitigated the observed relations. It was itself, moreover, consistently and independently associated with better perinatal health. We thus conclude that fertility selectivity by maternal education cushioned the impact of the adverse economic context derived from the Great Recession through two separate pathways.

Body shape trajectories are associated with birth weight, body mass index and sociodemographic conditions in participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): a multiple correspondence analysis

BACKGROUND

Evaluating lifelong weight trajectories is challenging due to the high costs of studies that follow individuals from childhood to adulthood. The use of silhouette scales has been a new approach to assess the body shape trajectory across life as a proxy for body weight trajectory. Depending on body shape trajectories, individuals may be more prone to develop diseases in adulthood. Therefore, identifying factors related to them is essential for public health. This study aimed to evaluate body shape trajectories across the lifespan and to verify associations between them, birth weight, body mass index, and sociodemographic conditions in a Brazilian cohort.

METHODS

This is a cross-sectional analysis conducted with 14,014 participants of first follow-up data collection of Longitudinal Study of Adult Health (ELSA-Brasil). ELSA-Brasil is a multicentric prospective cohort study initiated in 2008 with civil servants of six public institutions in the Northeast, South and Southeast regions of Brazil. We applied a clustering method to longitudinal data to identify body shape trajectories from 5 to 40 years of age and assessed the associations between these trajectories and birth weight, body mass index and sociodemographic conditions (race, education, maternal education and monthly per capita family income) using multiple correspondence analysis.

RESULTS

We found five body shape trajectories for women and three for men. Low birth weight was associated with a slight to moderate increase in shape. High birth weight was associated with maintaining large body size in both sexes and markedly increased body shape in women. Higher sociodemographic status and white race were associated with marked increases in body shape in men and maintenance of medium body shape in women.

CONCLUSIONS

The study shows that variables related to worse lifetime weight status (evaluated by anthropometry), such as presence of obesity, are also associated with worse body shape trajectories, as assessed with silhouette scales. Our results suggest that body shape trajectories are a good indicator of body weight trajectories and may be used when cohort studies are not possible.

Socio-economic differences among low-birthweight infants in Hungary. Results of the Cohort '18 -Growing Up in Hungary birth cohort study

BACKGROUND

As Hungary had the fifth-highest rate of low-birthweight (LBW) in the EU27 in 2020, LBW still remains a public health problem for the country.

OBJECTIVE

Our goal is to examine whether LBW in Hungary is determined by the mothers' educational attainment, adjusted for other maternal characteristics (SES, health behaviour and psychological status during pregnancy) among mothers who gave birth in 2018-2019 in Hungary.

METHODS

Source of data is the first and second wave of the Cohort '18 -Growing Up in Hungary longitudinal birth cohort study (n = 8185). It is based on a nationwide representative sample of pregnant women who gave birth between March 2018 and April 2019. All data were self-reported by mothers. We examined the association between maternal educational attainment and the risk of giving birth to an LBW-child (<2500g) by using logistic regression analysis. The highest educational attainment of the mother is measured by a five-value categorical variable (ISCED 97: 0-1; 2; 3C; 3-4; 5-6).

RESULTS

5.9% of women had LBW children. This rate is 18.0% among the lowest educated women with ISCED 97: 0-1; and it is 3.6% among the highest educated women with ISCED 97: 5-6. The adjusted predicted probabilities of LBW for these two groups of women are 13.5%, and 3.4% respectively, adjusted for household income quantiles, Roma ethnic background, residence place, smoking, alcohol consumption, and depression during pregnancy; controlled for mother's height, age at birth, parity and child's sex. Compared to women with the lowest level of education, the risk of giving birth to an LBW child decreases by 34.6% for those with the second level of education, by 60.1% for those with the third level of education, by 72.5% for those with the fourth level of education and by 77.2% for those with the highest level of education. Smoking during pregnancy significantly increases the risk of giving birth to an LBW by 54.9%. Being depressed at 7th month of pregnancy decreased the risk of giving birth to an LBW child in our sample by 13.2%, however the relationship is not significant.

CONCLUSION

Our analysis confirmed that maternal educational attainment has a significant impact on the risk of LBW net of by other maternal SES and health behaviour factors. Nevertheless, even after adjusting for these covariates, inequality in LBW by maternal educational attainment persists.

Nutritional and health status of Afghan refugee women living in Punjab: A cross-sectional study

Afghan refugees are the world's densely populated community, with 2.6 million registered Afghan refugees living globally, of whom about 2.2 million are in Iran and Pakistan. Pakistan is a densely populated country, and due to its low socioeconomic status, food insecurity, unhygienic conditions, and inadequate access to health care, the Afghan refugees have high chances of being malnourished; the chances of death for these Afghans are 25 times more every year from undernourishment and poverty than those from violence. This study aimed to assess anthropometric and biochemical analyses, their health complications, and the socioeconomic status of Afghan refugee women living in Islamabad Punjab as women are the most vulnerable and highly malnourished group in any community. This cross-sectional study involved 150 Afghan women aged 15-30 years; they were assessed for their nutritional status using Anthropometric, Biochemical, Clinical and Diet (ABCD). The results indicate the prevalence of underweight, normal weight, and overweight at 74.7%, 16.7%, and 8.7%, respectively. Majority of the women have extremely low hemoglobin (Hb) level, which indicates iron deficiency as well as low body mass index for their age. As the results indicate that there are high chances of severe malnutrition among this most vulnerable segment of the population, this situation must be addressed immediately; the main aim of this study is to highlight the current situation of these Afghan refugees in Pakistan. More research is needed to determine how normal body weight women with low hemoglobin levels are compared to women with ideal body mass index ratios.

Secular Trends of Birth Weight in Twins and Singletons in South Korea from 2000 to 2020

Whether the decline of birth weight (BW) reported in developed countries in the early 2000s is ongoing remains unknown. Furthermore, despite recent sharp increases in twin births, comparing secular trends of BW between singletons and twins is difficult, as studies have rarely examined secular trends of BW in twins and singletons simultaneously. Therefore, this study aimed to investigate the most recent 20-year trends (2000-2020) of BW in twins and singletons in South Korea. Annual natality files from 2000 to 2020 obtained from the Korean Statistical Information Service were analyzed. A yearly decrease of BW was 3 g among singletons and 5 to 6 g in twins from 2000 to 2020, indicating a widening gap of BW between twins and singletons with increasing years. Gestational age (GA) also decreased in twins and singletons with yearly decreases of 0.28 days in singletons and 0.41 days in twins. Whereas BW decreased in term (GA ≥ 37 weeks), and very preterm groups (28 weeks ≤ GA < 32 weeks) from 2000 to 2020 in twins and singletons, it increased in moderate to late preterm (32 weeks ≤ GA < 37 weeks) groups, indicating a non-linear relationship between BW and GA. The prevalence of macrosomia (BW > 4000 g) in singletons decreased from 2000 to 2020, whereas low birth weight (LBW; BW < 2500 g) increased in twins and singletons. LBW is associated with adverse health outcomes. Effective public health strategies aiming at reduction in the incidence of LBW in the population should be developed.

Weighting of risk factors for low birth weight: a linked routine data cohort study in Wales, UK

OBJECTIVE

Globally, 20 million children are born with a birth weight below 2500 g every year, which is considered as a low birthweight (LBW) baby. This study investigates the contribution of modifiable risk factors in a nationally representative Welsh e-cohort of children and their mothers to inform opportunities to reduce LBW prevalence.

DESIGN

A longitudinal cohort study based on anonymously linked, routinely collected multiple administrative data sets.

PARTICIPANTS

The cohort, (N=693 377) comprising of children born between 1 January 1998 and 31 December 2018 in Wales, was selected from the National Community Child Health Database.

OUTCOME MEASURES

The risk factors associated with a binary LBW (outcome) variable were investigated with multivariable logistic regression (MLR) and decision tree (DT) models.

RESULTS

The MLR model showed that non-singleton children had the highest risk of LBW (adjusted OR 21.74 (95% CI 21.09 to 22.40)), followed by pregnancy interval less than 1 year (2.92 (95% CI 2.70 to 3.15)), maternal physical and mental health conditions including diabetes (2.03 (1.81 to 2.28)), anaemia (1.26 (95% CI 1.16 to 1.36)), depression (1.58 (95% CI 1.43 to 1.75)), serious mental illness (1.46 (95% CI 1.04 to 2.05)), anxiety (1.22 (95% CI 1.08 to 1.38)) and use of antidepressant medication during pregnancy (1.92 (95% CI 1.20 to 3.07)). Additional maternal risk factors include smoking (1.80 (95% CI 1.76 to 1.84)), alcohol-related hospital admission (1.60 (95% CI 1.30 to 1.97)), substance misuse (1.35 (95% CI 1.29 to 1.41)) and evidence of domestic abuse (1.98 (95% CI 1.39 to 2.81)). Living in less deprived area has lower risk of LBW (0.70 (95% CI 0.67 to 0.72)). The most important risk factors from the DT models include maternal factors such as smoking, maternal weight, substance misuse record, maternal age along with deprivation-Welsh Index of Multiple Deprivation score, pregnancy interval and birth order of the child.

CONCLUSION

Resources to reduce the prevalence of LBW should focus on improving maternal health, reducing preterm births, increasing awareness of what is a sufficient pregnancy interval, and to provide adequate support for mothers' mental health and well-being.

Insights into Prevention of Health Complications in Small for Gestational Age (SGA) Births in Relation to Maternal Characteristics: A Narrative Review

Small for gestational age (SGA) births are a significant clinical and public health issue. The objective of this review was to summarize maternal biological and socio-demographic factors and preventive strategies used to reduce the risk of SGA births. A literature search encompassing data from the last 15 years was conducted using electronic databases MEDLINE/PubMed, Google Scholar and Scopus to review risk factors and preventive strategies for SGA. Current evidence shows that primiparity, previous stillbirths, maternal age ≤24 and ≥35 years, single motherhood, low socio-economic status, smoking and cannabis use during pregnancy confer a significant risk of SGA births. Studies on alcohol consumption during pregnancy and SGA birth weight are inconclusive. Beneficial and preventive factors include the "Mediterranean diet" and dietary intake of vegetables. Periconceptional folic acid supplementation, maternal 25-hydroxyvitamin D, zinc and iron levels are partly associated with birth weight. No significant associations between COVID-19 vaccinations and birthweight are reported. A midwifery-led model based on early and extensive prenatal care reduces the risk of SGA births in women with low socio-economic status. Major preventive measures relate to the awareness of modifiable and non-modifiable risk factors of SGA, leading to changes in parents' lifestyles. These data support that education, monitoring during pregnancy, and implementing preventive strategies are as important as biological determinants in risk reduction of SGA births.

Politically related stress and low-birth-weight infants among Arab, Asian, Hispanic, non-Hispanic Black, and non-Hispanic White women in Michigan

BACKGROUND

Despite the high cost of low birth weight and the persistent challenge of racial inequities affecting the Arab American community, there has been limited research to identify and examine risk factors for these inequities with validated data on Arab American ethnicity and recent population stressors.

OBJECTIVES

This study examined whether the 2016 presidential election is associated with low birth weight among non-Hispanic White, Arab American, Hispanic, and non-Hispanic Black women.

DESIGN

This population-based study of singleton births in Michigan (2008-2017) used an algorithm to identify mothers who were of Arab descent.

METHODS

We used logistic regression to estimate odds ratios and 95% confidence intervals for the association between race/ethnicity and the odds of low birth weight. We examined whether these associations differed before and after the 2016 presidential election and according to maternal education.

RESULTS

There were 1,019,738 births, including 66,272 (6.5%) classified as low birth weight. The odds of having a low-birth-weight infant were higher among all minority women compared to non-Hispanic White women. The association was similar before and after the 2016 presidential election and stronger among women with higher levels of education.

CONCLUSION

This is the first study to estimate low birth weight among Arab American women in the context of political events. There are opportunities for future studies to discuss this issue in depth.

Partnership, living arrangements, and low birth weight: evidence from a population-based study on Spanish mothers

BACKGROUND

Birth weight is considered a crucial indicator of individual and population health, as it determines a newborn's growth and development. An extensive body of research has explored various determinants of perinatal health, including the impact of living arrangements. This population-based study analyzes the relationship between mothers' partnership status and household structure and children's low birth weights. It addresses two basic research objectives: on one hand, how living/not living in a couple affects birth weight; on the other, how partnership status impact on birthweight when mothers live in extended households with other non-nuclear members.

METHODS

A novel database provided by the Spanish Office for National Statistics (INE), which links the 2011 census with births registered from 2011 to 2015 (sample size 22,433) is used. Llogistic regression models are estimated tto obtain adjusted odds ratios (OR) for the relative effects of living arrangements and other covariates such as characteristics of births and mothers' socioeconomic profiles, on birth weight.

RESULTS

Differences in low-birth-weight rates may be attributed to the dissimilar socio-demographic characteristics of the groups of mothers in the different coresidential situations. Although our models revealed that the impact of the covariates on birth weight was similar to that shown by previous studies, this was not the case for the effect of the main explanatory variable. Contrary to expectations, the presence/absence of a male partner in nuclear or in extended households does not reveal significant protection against low birth weight. Children born in households in which the male partner was absent were not more likely to have a low birth weight. On the other hand, analyzing the possible protective effect of extended households, we did not detect significant differences in the likelihood of low birth weight between single mothers without and with non-nuclear coresidents in their households.

CONCLUSIONS

Our analysis provides novel evidence regarding the effect of partnership status and household type on perinatal health in Spain. First, contrary to what has been observed in previous studies in Spain and elsewhere, our study shows that living without a partner has no effect on low birth weight. Second, we reveal that households including non-nuclear coresidents are associated with low birth weight suggesting that even in a basically familist societal context such as the Spanish one, the extended family does not fully protect against poor perinatal outcomes.

Maternal Metals Exposure and Infant Weight Trajectory: The Japan Environment and Children's Study (JECS)

BACKGROUND

To our knowledge, the association of maternal exposure to metallic elements with weight trajectory pattern from the neonatal period has not been investigated.

OBJECTIVES

The goals of this study were to identify infant growth trajectories in weight in the first 3 y of life and to determine the associations of maternal blood levels of lead, cadmium, mercury, selenium, and manganese with growth trajectory.

METHODS

This longitudinal study, part of the Japan Environment and Children Study, enrolled 103,099 pregnant women at 15 Regional Centres across Japan between 2011 and 2014. Lead, cadmium, mercury, selenium, and manganese levels were measured in blood samples collected in the second (14-27 wk gestational age) or third trimester (≥28wk). Growth trajectory of 99,014 children was followed until age 3 y. Raw weight values were transformed to age- and sex-specific weight standard deviation (SD) scores, and latent-class group-based trajectory models were estimated to determine weight trajectories. Associations between maternal metallic element levels and weight trajectory were examined using multinomial logistic regression models after confounder adjustment.

RESULTS

We identified 5 trajectory patterns based on weight SD score: 4.74% of infants were classified in Group I, very small to small; 31.26% in Group II, moderately small; 21.91% in Group III, moderately small to moderately large; 28.06% in Group IV, moderately large to normal; and 14.03% in Group V, moderately large to large. On multinomial logistic regression, higher maternal lead and selenium levels tended to be associated with increased odds ratios (ORs) of poor weight SD score trajectories (Groups I and II), in comparison with Group III. Higher levels of mercury were associated with decreased ORs, whereas higher levels of manganese were associated with increased ORs of "moderately large" trajectories (Groups IV and V).

DISCUSSION

Maternal lead, mercury, selenium, and manganese blood levels affect infant growth trajectory pattern in the first 3 y of life. https://doi.org/10.1289/EHP10321.

Maternal Characteristics and Socio-Economic Factors as Determinants of Low Birth Weight in Indonesia: Analysis of 2017 Indonesian Demographic and Health Survey (IDHS)

Although low birth weight (LBW) is still a major health problem in Indonesia, studies about determinants of LBW with large sample sizes are still limited. This study aimed to examine the association between LBW and maternal characteristics, as well as socio-economic backgrounds in Indonesia. A secondary analysis of 2017 Indonesian Demographic and Health Survey (IDHS) was conducted, specifically using the questionnaires for women of childbearing age. A bivariate chi-square analysis and a multivariate logistic regression analysis were performed. As many as 6.7% of infants were born with LBW. In terms of maternal characteristics, women who gave birth to twins were 20.30 times more likely to have infants with LBW (p < 0.001). Women with birth intervals of <24 and ≥24 months were likely to have LBW infants (p < 0.05). Complications during pregnancy were also associated with LBW (1.99 times higher than women with no complications) (p < 0.001). In terms of socio-economic factors, women with higher education and higher wealth index were less likely to give birth to infants with LBW. Additionally, marital status and type of residence were also significantly associated with a higher risk of LBW. In conclusion, LBW was associated with maternal characteristics and socio-economic backgrounds among women of childbearing age in Indonesia, including twin births, birth interval, and pregnancy complications as well as educational attainment, wealth index, marital status, and type of residence.

Comparable Pregnancy Outcomes for HIV-Uninfected and HIV-Infected Women on Antiretroviral Treatment in Kenya

BACKGROUND

The impact of human immunodeficiency virus (HIV) on pregnancy outcomes for women on antiretroviral therapy (ART) in sub-Saharan Africa remains unclear.

METHODS

Pregnant women in Kenya were enrolled in the second trimester and followed up to delivery. We estimated effects of treated HIV with 3 pregnancy outcomes: loss, premature birth, and low birth weight and factors associated with HIV-positive status.

RESULTS

Of 2113 participants, 311 (15%) were HIV infected and on ART. Ninety-one of 1762 (5%) experienced a pregnancy loss, 169/1725 (10%) a premature birth (<37 weeks), and 74/1317 (6%) had a low-birth-weight newborn (<2500 g). There was no evidence of associations between treated HIV infection and pregnancy loss (adjusted relative risk [aRR], 1.19; 95% confidence interval [CI], .65-2.16; P = .57), prematurity (aRR, 1.09; 95% CI, .70-1.70; P = .69), and low birth weight (aRR, 1.36; 95% CI, .77-2.40; P = .27). Factors associated with an HIV-positive status included older age, food insecurity, lower education level, higher parity, lower gestation at first antenatal clinic, anemia, and syphilis. Women who were overweight or underweight were less likely to be HIV infected compared to those with normal weight.

CONCLUSIONS

Currently treated HIV was not significantly associated with adverse pregnancy outcomes. HIV-infected women, however, had a higher prevalence of other factors associated with adverse pregnancy outcomes.

Ambient temperature and term birthweight in Latin American cities

BACKGROUND

Extreme temperatures may lead to adverse pregnancy and birth outcomes, including low birthweight. Studies on the impact of temperature on birthweight have been inconclusive due to methodological challenges related to operationalizing temperature exposure, the definitions of exposure windows, accounting for gestational age, and a limited geographic scope.

METHODS

We combined data on individual-level term live births (N≈15 million births) from urban areas in Brazil, Chile, and Mexico from 2010 to 2015 from the SALURBAL study (Urban Health in Latin America) with high-resolution daily air temperature data and computed average ambient temperature for every month of gestation for each newborn. Associations between full-term birthweight and average temperature during gestation were analyzed using multi-level distributed lag non-linear models that adjusted for newborn's sex, season of conception, and calendar year of child's birth; controlled for maternal age, education, partnership status, presence of previous births, and climate zone; and included a random term for the sub-city of mother's residence.

FINDINGS

Higher temperatures during the entire gestation are associated with lower birthweight, particularly in Mexico and Brazil. The cumulative effect of temperature on birthweight is mostly driven by exposure to higher temperatures during months 7-9 of gestation. Higher maternal education can attenuate the temperature-birthweight associations.

INTERPRETATION

Our work shows that climate-health impacts are likely to be context- and place-specific and warrants research on temperature and birthweight in diverse climates to adequately anticipate global climate change. Given the high societal cost of suboptimal birthweight, public health efforts should be aimed at diminishing the detrimental effect of higher temperatures on birthweight.

FUNDING

The Wellcome Trust.

Smog and risk of maternal and fetal birth outcomes: A retrospective study in Baoding, China

Pregnant women are more susceptible to smog pollution than the general population. This study focused on the association between smog and birth outcomes, considering both pregnant mothers and their offspring. In this retrospective study, conducted in Baoding between 2013 and 2016, we enrolled 842 participants. Birth outcomes were low birth weight (LBW), pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), and premature rupture of membranes (PROM). The overall prevalence of LBW, PIH, GDM, and PROM was 8.2%, 14.8%, 16.5%, and 12.1%, respectively. Compared with lower pollution level, higher pollution level of fine particulate matter (particulate matter with aerodynamics diameter <2.5 μm) (PM2.5), inhalable particle (particulate matter with aerodynamics diameter <10 μm) (PM10), and CO increased the risk of term with LBW. PM2.5, PM10, and NO2 increased the risk of PIH during different trimesters, while PM10 increased the risk of PROM during trimester 3. In conclusion, smog significantly affects the risk of adverse birth outcomes by different exposure time windows.

Interaction of Maternal Race/Ethnicity, Insurance, and Education Level on Pregnancy Outcomes: A Retrospective Analysis of the United States Vital Statistics Records

OBJECTIVE

The objective is to determine the association between maternal race/ethnicity, insurance, education level, and pregnancy outcomes.

METHODS

We queried the U.S. vital statistics records from 2015 to 2019 to analyze all deliveries. Using a multivariate analysis model, we determined the interaction between maternal race, insurance, education, and pregnancy outcomes. The outcome measures were the 5-min Apgar score, neonatal unit admission, neonates receiving assisted ventilation > 6 hours, mothers requiring blood transfusion, and the intensive care unit admission.

RESULT

There were 13,213,732 deliveries that met our inclusion criteria. In the study population, 52.7% were white, 14.1% blacks, 22.9% Hispanics, and 10.4% belonged to other races. 37.5% of the women had a high school education, 49.1% had a college education, and 12.3% had advanced degrees. Black mothers with high school education were more likely to require blood transfusion following delivery than Whites at the same education level, OR=1.08 (95% CI 1.05-1.11, p < 0.05). They were also more likely to be admitted into intensive care. The difference only disappeared among blacks with advanced education (OR=1.0; 95% CI 0.89-1.12, p > 0.05). Across all races/ethnicities, private insurance and advanced education were associated with better pregnancy outcomes.

CONCLUSION

In the U.S., women with high socioeconomic status have better pregnancy outcomes across all races/ethnicities.

Preconception exposures and adverse pregnancy, birth and postpartum outcomes: Umbrella review of systematic reviews

BACKGROUND

Preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, the reports, statements and guidelines of national and international health organisations vary in what they recommend individuals should monitor, avoid, reduce or practise in the preconception period.

OBJECTIVES

To synthesise and evaluate the evidence across systematic reviews for associations between exposures before conception and adverse pregnancy, birth and postpartum outcomes.

DATA SOURCES

MEDLINE, Embase, Epistemonikos (to May 2020) and reference lists of included reviews, without language or date restrictions.

STUDY SELECTION, DATA EXTRACTION AND SYNTHESIS

Systematic literature reviews of observational and/or interventional studies reporting associations between preconception exposures in women and/or men of reproductive age and pregnancy, birth or postpartum health outcomes were included. The methodological quality of reviews and the certainty of the evidence underlying each exposure-outcome association were assessed using AMSTAR 2 and the GRADE approach.

RESULTS

We identified 53 eligible reviews reporting 205 unique exposure-outcome associations. Methodological quality was generally low with only two reviews rated as 'high' quality and two as 'moderate'. We found high-certainty, randomised trial evidence that maternal folate supplementation reduces the risk of neural tube defects and anomaly-related terminations. Moderate-certainty, observational evidence was found that maternal physical activity is associated with reduced risk of pre-eclampsia and gestational diabetes, and that paternal age of ≥40 years and maternal body mass index (BMI) and interpregnancy weight gain are associated with increased risk of various adverse pregnancy and birth outcomes. Low- and very low-certainty evidence was found for other associations.

CONCLUSIONS

Clinicians and policymakers can be confident that maternal folate supplementation should be encouraged during the preconception period. There is moderate certainty in the evidence base that maternal physical activity, BMI and interpregnancy weight gain and advanced paternal age are important preconception considerations. High-quality research is required to better understand other exposure-outcome associations.

Outcomes and Disease Spectrum of LBW Neonates in a Secondary Health Facility

Globally, 30 million low birth weight (LBW) babies are born every year and 95% of them are from developing countries. LBW neonates are at a high risk of mortality, morbidity, and long-term disability. The objective of this study is to investigate outcomes and disease spectrum among low birth weight neonates. This is a prospective, observational study conducted on 540 neonates admitted in the Mother and Child Hospital, Akure, Ondo State, Nigeria, from 2017 to 2018. Questionnaire, interview, clinical, and diagnostic procedures were used as research tools. There were 137 low birth weight (LBW) neonates, with the mean mothers’ age of 31.92 ± 6.60. Of the 540 neonates, 69 (50.4%) and 68 (49.6%) were term and preterm, respectively. There were 64 female neonates (46.7%) and 73 male neonates (53.3%). The mean weight of the neonates was 1.82 ± 0.44 kg, and mean number of days on admission was 6.42 ± 6.75 days. Neonatal sepsis (NNS) was the highest morbidity 51 (37.2%) among the LBW neonates, followed by prematurity 47 (34.4%) and neonatal jaundice (NNJ) 18 (13.1%). Sex (χ2 = 3.584, $p=0.310$ ), mode of delivery (χ2 = 4.669, $p=0.198$ ), and gestational age (χ2 = 3.904, $p=0.272$ ) were not a significant determinant of outcome among LBW neonates. Men were 2.36 times more likely to be preterm (OR = 2.36, 95% CL = 1.01–5.54, $p=0.048$ ) among LBW neonates. Outcomes of LBW neonates who were delivered by SVD were not significant compared to preterm delivered by CS (OR = 0.46, 95% CL = 0.13–1.65, $p=0.096$ ). Sixty percent (60%) of the mothers had Prolonged Rupture of Membranes (PROM). Morbidities such as hypothermia (72.2%), apnoea (63.6%), haemorrhagic disease of the newborn (HDN) (66.7%), and respiratory distress syndrome (RDS) (66.7%) were more observed with preterm LBW neonates. Importance of qualitative antenatal care (ANC) should be emphasized; anticipation and prevention of LBW births can help mitigate some of the problems they are prone to.

Non-linear and non-additive associations between the pregnancy metabolome and birthweight

BACKGROUND

Birthweight is an indicator of fetal growth and environmental-related alterations of birthweight have been linked with multiple disorders and conditions progressing into adulthood. Although a few studies have assessed the association between birthweight and the totality of exogenous exposures and their downstream molecular responses in maternal urine and cord blood; no prior research has considered a) the maternal serum prenatal metabolome, which is enriched for hormones, and b) non-linear and synergistic associations among exposures.

METHODS

We measured the maternal serum metabolome during pregnancy using an untargeted metabolomics approach and birthweight for gestational age (BWGA) z-score in 410 mother-child dyads enrolled in the PRogramming of Intergenerational Stress Mechanisms (PRISM) cohort. We leveraged a Bayesian factor analysis for interaction to select the most important metabolites associated with BWGA z-score and to evaluate their linear, non-linear and non-additive associations. We also assessed the primary biological functions of the identified proteins using the MetaboAnalyst, a centralized repository of curated functional information. We compared our findings with those of a traditional metabolite-wide association study (MWAS) in which metabolites are individually associated with BWGA z-score.

RESULTS

Among 1110 metabolites, 46 showed evidence of U-shape associations with BWGA z-score. Most of the identified metabolites (85%) were lipids primarily enriched for pathways central to energy production, immune function, and androgen and estrogen metabolism, which are essential for pregnancy and parturition processes. Metabolites within the same class, i.e. steroids and phospholipids, showed synergistic relationships with each other.

CONCLUSIONS

Our results support that the aspects of the maternal metabolome during pregnancy contribute linearly, non-linearly and synergistically to variation in newborn birthweight.

National and subnational trends of birthweight in Peru: Pooled analysis of 2,927,761 births between 2012 and 2019 from the national birth registry

Background

National and subnational characterization of birthweight profiles lacks in low- and middle-income countries, yet these are needed for monitoring the progress of national and global nutritional targets. We aimed to describe birthweight indicators at the national and subnational levels in Peru (2012-2019), and by selected correlates.

Methods

We studied mean birthweight (g), low birthweight (<2,500 g) and small for gestational age (according to international growth curves) prevalences. We analysed the national birth registry and summarized the three birthweight indicators at the national, regional, and province level, also by geographic area (Coast, Highlands, and Amazon). With individual-level data from the mother, we described the birthweight indicators by age, educational level and healthcare provider. Following an ecological approach (province level), we described the birthweight indicators by human development index (HDI), altitude above sea level, proportion of the population living in poverty and proportion of rural population.

Findings

Mean birthweight was always the lowest in the Highlands (2,954 g in 2019) yet the highest in the Coast (3,516 g in 2019). The same was observed for low birthweight and small for gestational age. In regions with Coast and Highlands, the birthweight indicators worsen from the Coast to the Highlands; the largest absolute difference in mean birthweight between Coast and Highlands in the same region was 367 g. All birthweight indicators were the worst in mothers with none/initial education, while they improved with higher HDI.

Interpretation

This analysis suggests that interventions are needed at the province level, given the large differences observed between Coast and Highlands even in the same region.

Funding

Wellcome Trust (214185/Z/18/Z).

Predictors of adverse birth outcomes among pregnant adolescents in Ashanti Region, Ghana

Adolescent pregnancy is associated with adverse birth outcomes. However, the determinants of these outcomes are understudied. The present study sought to identify the predictors of adverse birth outcomes among pregnant adolescents in Ghana. In this prospective health centre-based study, 416 pregnant adolescents, aged 13-19 years old, were followed, and 270 birth outcomes were evaluated. We collected data on socio-demographic variables, eating behaviour, household hunger scale (HHS), lived poverty index (LPI) and compliance to antenatal interventions. The prevalence of low birth weight (LBW) and preterm births (PTB) were 15⋅2 and 12⋅5 %, respectively. Pregnant adolescents with no formal education (AOR 9⋅0; P = 0⋅004; 95 % CI 2⋅1, 39⋅8), those who experienced illness (AOR 3⋅0; P = 0⋅011; 95 % CI 1⋅3, 7⋅0), those who experienced hunger (OR 2⋅9; P = 0⋅010; 95 % CI 1⋅3, 6⋅5) and those with high LPI (OR 2⋅5; P = 0⋅014; 95 % CI 1⋅2, 5⋅3) presented increased odds of delivering preterm babies compared with those who have had secondary education, did not experience any illness, were not hungry or having low LPI, respectively. Pregnant adolescents who used insecticide-treated net (ITN) (AOR 0⋅4; P = 0⋅013; 95 % CI 0⋅2, 0⋅9) presented reduced odds LBW children; while those who experienced illness (AOR 2⋅7; P = 0⋅020; 95 % CI 1⋅2, 6⋅0), poorer pregnant adolescents (OR 2⋅5; P = 0⋅014; 95 % CI 1⋅1, 4⋅8) and those who experienced hunger (AOR 3⋅0; P = 0⋅028; 95 % CI 1⋅1, 8⋅1) presented increased odds of LBW children compared with those who used ITN, were not ill, were not poor or did not experience hunger. Adverse birth outcomes were associated with ANC compliance and socioeconomic factors of the pregnant adolescents. Hence, strengthening antenatal uptake and compliance by pregnant adolescents, promoting their livelihood and socioeconomic status, and interventions to prevent teenage pregnancies are strongly recommended.

Mapping the prevalence and socioeconomic predictors of low birth weight among Bangladeshi newborns: evidence from the 2019 Multiple Indicator Cluster Survey

BACKGROUND

Low birth weight (LBW) remains a global concern for childhood morbidity and mortality. This study examined the socioeconomic factors associated with LBW among Bangladeshi newborns and drew a district-level prevalence map.

METHODS

Data were extracted from the 2019 Multiple Indicator Cluster Survey for Bangladesh. Multivariate logistic regression was used to identify the predictors of LBW.

RESULTS

The prevalence of LBW among Bangladeshi newborns was found to be 14.5%. Overall, the Eastern and South-Eastern regions had a higher burden of LBW. Mothers' educational status, mode of delivery, wealth index quintile of the household and area were identified as independent predictors of newborns' LBW. Mothers who completed primary and secondary education grades had a 1.6- and 1.3-fold higher possibility of having an LBW baby compared with those who completed higher secondary or higher educational grades (adjusted OR=1.62 and 1.32, 95% CI 1.21 to 2.18 and 1.06 to 1.65, respectively). Children belonging to the poorest households and residing in urban areas had a 1.4-fold higher likelihood of being LBW (p<0.05).

CONCLUSIONS

This study indicates that LBW is still highly prevalent in Bangladesh. Immediate public health action is required in the highly prevalent regions identified in this study.

Socioeconomic inequalities in birth outcomes: An 11-year analysis in Colombia

OBJECTIVE

To examine socioeconomic inequalities in birth outcomes among infants born between 2008 and 2018 and assessed trends in inequalities during that period in Colombia, a middle-income country with high levels of inequality emerging from a long internal armed conflict.

METHODS

Using birth certificate data in Colombia, we analysed the outcomes of low birth weight, an Apgar score <7 at 5 minutes after birth and the number of prenatal visits among full-term pregnancies. Maternal education and health insurance schemes were used as socioeconomic position (SEP) indicators. Inequalities were estimated using the prevalence/mean of the outcomes across categories of the SEP indicators and calculating the relative and slope indices of inequality (RII and SII, respectively).

RESULTS

Among the 5,433,265 full-term singleton births analysed, there was a slight improvement in the outcomes analysed over the study period (lower low-birth-weight and Apgar<7 prevalence rates and higher number of prenatal visits). We observed a general pattern of social gradients and significant relative (RII) and absolute (SII) inequalities for all outcomes across both SEP indicators. RII and SII estimates with their corresponding CIs revealed a general picture of no significant changes in inequalities over time, with some particular, time-dependent exceptions. When comparing the initial and final years of our study period, inequalities in low birth weight related to maternal education increased while those in Apgar score <7 decreased. Relative inequalities across health insurance schemes increased for the two birth outcomes but decreased for the number of prenatal visits.

CONCLUSION

The lack of a consistent improvement in the magnitude of inequalities in birth outcomes over an 11-year period is a worrying issue because it could aggravate the cycle of inequality, given the influence of birth outcomes on health, social and economic outcomes throughout the life course. The findings of our analysis emphasize the importance of policies aimed at providing access to quality education and providing a health care system with universal coverage and high levels of integration.

Prevalence of low birth weight and macrosomia estimates based on heaping adjustment method in China

Low birth weight (< 2500 g; LBW) and macrosomia (> 4000 g) are both adverse birth outcomes with high health risk in short- or long-term period. However, national prevalence estimates of LBW and macrosomia varied partially due to methodology limits in China. The aim of this study is to estimate the prevalence of LBW and macrosomia after taking potential birth weight heaping into consideration in Chinese children under 6 years in 2013. The data were from a nationally representative cross-sectional survey in mainland China in 2013, which consists of 32,276 eligible records. Birth weight data and socio-demographic information was collected using standard questionnaires. Birth weight distributions were examined and LBW and macrosomia estimates were adjusted for potential heaping. The overall prevalence of LBW of Chinese children younger than 6 years was 5.15% in 2013, with 4.57% in boys and 5.68% in girls. LBW rate was higher for children who were minority ethnicity, had less educated mothers, mothers aged over 35 years or under 20 years, or were in lower income household than their counterparts. The overall prevalence of macrosomia of Chinese children younger than 6 years was 7.35% in 2013, with 8.85% in boys and 5.71% in girls. The prevalence of macrosomia increased with increasing maternal age, educational level and household income level. Both LBW and macrosomia varied among different regions and socio-economic groups around China. It is found that estimates based on distribution adjustment might be more accurate and could be used as the foundation for policy-decision and health resource allocation. It would be needed to take potential misclassification of birth weight data arising from heaping into account in future studies.

Trends in infants born at low birthweight and disparities by maternal race and education from 2003 to 2018 in the United States

BACKGROUND

Understanding current levels, as well as past and future trends, of the percentage of infants born at low birthweight (LBW) in the United States is imperative to improving the health of our nation. The purpose of this study, therefore, was to examine recent trends in percentage of LBW, both overall and by maternal race and education subgroups. Studying disparities in percentage of LBW by these subgroups can help to further understand the health needs of the population and can inform policies that can close race and class disparities in poor birth outcomes.

METHODS

Trends of percentage of LBW in the U.S. from 2003 to 2018, both overall and by race/ethnicity, and from 2007 to 2018 by education and race by education subgroups were analyzed using CDC WONDER Natality data. Disparities were analyzed using between group variance methods.

RESULTS

Percentage of LBW experienced a significant worsening in the most recent 5 years of data, negating nearly a decade of prior improvement. Stark differences were observed by race/ethnicity and by education, with all subgroups experiencing increasing rates in recent years. Disparities also worsened over the course of study. Most notably, all disparities increased significantly from 2014 to 2018, with annual changes near 2-5%.

CONCLUSIONS

Recent reversals in progress in percentage of LBW, as well as increasing disparities particularly by race, are troubling. Future study is needed to continue monitoring these trends and analyzing these issues at additional levels. Targets must be set and solutions must be tailored to population subgroups to effectively make progress towards equitable birth outcomes and maternal health.

Association Between Household and Maternal Socioeconomic Factors with Birth Outcomes in the Democratic Republic of Congo and South Africa: A Comparative Study

OBJECTIVE

To assess and compare the associations between household socioeconomic (SES) factors with birth outcomes (low birth weight (LBW), small-for-gestational age (SGA) and preterm birth (PTB)) in the Democratic Republic of Congo (DRC) and South Africa (SA).

METHODS

Cross-sectional data of mother-newborn pairs collected in 2017 in the DRC were compared with mother-newborn pairs data from the SA Soweto first 1000-days pregnancy cohort study (2013-2016). Country-specific and pooled multivariable logistic regressions analyses assessed the associations between maternal education, marital status, and housing with LBW, SGA, and PTB adjusted for maternal anthropometry and obstetric factors.

RESULTS

1084 mother-newborn pairs were recruited (DRC: 256; SA: 828). The rates of LBW, PTB and SGA were, 11.5%, 17.1% and 32.8% in the DRC and 15.9%, 10.5% and 20.1% in SA. SES factors differed between countries and sex. In the DRC, being married decreased the odds of having LBW and PTB children by 86% and 80%, respectively. In SA, being a mother with secondary level of education and above was associated with 86% reduced odds of SGA. In the pooled analyses, women with secondary level of education and above had a 2.2-fold increase in odds of giving birth to a PTB newborn. Country of residence and maternal nutritional status were stronger predictors of birth outcomes than SES factors.

CONCLUSION FOR PRACTICE

In sub-Saharan Africa, policies aiming to alleviate women's education combined with improved social support and household SES prior to and during pregnancy are critical to optimal neonatal outcomes and strategic to achieve the Sustainable Development Goals.

Urban social environment and low birth weight in 360 Latin American cities

OBJECTIVE

Using data compiled by the SALURBAL project (Urban Health in Latin America; 'Salud Urbana en América Latina') we quantified variability in low birth weight (LBW) across cities in Latin America, and evaluated the associations of socio-economic characteristics at various levels (maternal, sub-city and city) with the prevalence of LBW.

METHODS

The sample included 8 countries, 360 cities, 1321 administrative areas within cities (sub-city units) and birth registers of more than 4.5 million births for the year 2014. We linked maternal education from birth registers to data on socioeconomic characteristics of sub-cities and cities using the closest available national population census in each country. We applied linear and Poisson random-intercept multilevel models for aggregated data.

RESULTS

The median prevalence of city LBW by country ranged from a high of 13% in Guatemala to a low of 5% in Peru (median across all cities was 7.8%). Most of the LBW variability across sub-cities was between countries, but there were also significant proportions between cities within a country, and within cities. Low maternal education was associated with higher prevalence of LBW (Prevalence rate ratios (PRR) for less than primary vs. completed secondary or more 1.12 95% CI 1.10, 1.13) in the fully adjusted model. In contrast, higher sub-city education and a better city social environment index were independently associated with higher LBW prevalence after adjustment for maternal education and age, city population size and city gross domestic product (PRR 1.04 95% CI 1.03, 1.04 per SD higher sub-city education and PRR 1.02 95% CI 1.00, 1.04 per SD higher SEI). Larger city size was associated with a higher prevalence of LBW (PRR 1.06; 95% CI 1.01, 1.12).

CONCLUSION

Our findings highlight the presence of heterogeneity in the distribution of LBW and the importance of maternal education, local and broader social environments in shaping LBW in urban settings of Latin America. Implementing context-sensitive interventions guided to improve women's education is recommended to tackle LBW in the region.

The influence of the municipal human development index and maternal education on infant mortality: an investigation in a retrospective cohort study in the extreme south of Brazil

Background

Infant mortality is considered an important and sensitive health indicator in several countries, especially in underdeveloped and developing countries. Most of the factors influencing infant mortality are interrelated and are the result of social issues. Therefore, this study performed an investigation of the influence of the MHDI and maternal education on infant mortality in a capital in the extreme south of Brazil.

Methods

It is a retrospective cohort study with data on births and deaths in the first year of life for the period of 2000–2017. The association between the independent variables and the outcome was done by bivariate analysis through simple Poisson regression. The variables that can potentially be considered confounding factors were used in a multiple Poisson regression for robust variances - adjusted model.

Results

The study included 317,545 children, of whom 3107 died. The medium MHDI showed associated with infant death in the first year of life. Maternal education, individually and jointly analyzed with the MHDI, showed association with the outcome of infant death in the first year of life, particularly for children of mothers with lower maternal education (p < 0.001). In relation to other related factors, maternal age; number of Prenatal Care Consultations; gestational age, weight, gender and Apgar Index (5th minute) of the newborn showed association with IM (p < 0.001).

Conclusions

The HDI is considered a good predictor of infant mortality by some authors and the analyzes of the present study also confirm an association of the medium MHDI and its low MHDIE component with infant mortality. In addition, it was maternal education with less than 8 years of study that that demonstrated a higher risk of death, revealing itself to be a social determinant with a relevant impact on infant mortality. Thus, it is possible to conclude that maternal education is available information, and it is superior to the MHDI to assess the infant mortality outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10226-9.

Low birth weight trends in Organisation for Economic Co-operation and Development countries, 2000-2015: economic, health system and demographic conditionings

Background

Low birth weight rates are increasing in both developed and developing countries. Although several maternal factors have been identified as associated with low birth weight, little is known of economic or organization factors influencing this increase. This study aims to ascertain the twenty-first century relationships between the contextual country factors and low birth weight rates.

Methods

We analyse trends of low birth weight rates in Organisation for Economic Co-operation and Development (OECD) countries. Data from 2000 to 2015 were obtained from the OECD data base. Their relationships with demographic and economic variables, health habits, woman-related preventive measures, health care system organization and funding, health care work force and obstetric care were analysed using random-effects linear regression.

Results

Low birth weight rates are higher in Southern Europe (7.61%) and lower in Northern Europe (4.68%). Low birth weight rates escalated about 20% in Southern Europe and to less extent in Easter Europe (7%) and Asian/Oceanian countries, while remained stable in America, Central Europe and Northern Europe. Investment in health care, private health system coverage, ratios of paediatricians and obstetricians, average length of admission due to pregnancy or birth and Caesarean section rate were associated with higher low birth weight rates. Factors associated with lower low birth weight rates were health care coverage, public health system coverage, hospitals per million inhabitants, and ratios of health care workers, physicians, midwives and nurses.

Conclusions

In OECD countries, LBW rates are related to contextual country characteristics such as GDP per capita, which is inversely related to LBW rate. Health care system factors, including health care coverage or investment in public health system, are directly associated with lower LBW rates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03484-9.

Environmental and socio-cultural impacts on global DNA methylation in the indigenous Huichol population of Nayarit, Mexico

Alterations of global DNA methylation have been evaluated in several studies worldwide; however, Long Interspersed Nuclear Elements-1 (LINE-1) methylation in genetically conserved populations such as indigenous communities have not, to our knowledge, been reported. The aim of this study was to evaluate the relationship between LINE-1 methylation patterns and factors such as pesticide exposure and socio-cultural characteristics in the Indigenous Huichol Population of Nayarit, Mexico. A cross-sectional study was conducted in 140 Huichol indigenous individuals. A structured questionnaire was used to determine general and anthropometric characteristics, diet, harmful habits, and pesticide exposure. DNA methylation was determined by pyrosequencing of bisulfite-treated DNA. A lower level of LINE-1 methylation was found in the indigenous population when compared to a Mestizo population previously studied by our group. This difference might be due to the influence of the genetic admixture and differing dietary and lifestyle habits. The males in the indigenous population exhibited increased LINE-1 methylation in comparison to the females. Sex and alcohol consumption showed positive associations with LINE-1 methylation, while weight, current work in the field, current pesticide usage, and folate intake exhibited negative associations with LINE-1 methylation. The results suggest that ethnicity, as well as other internal and environmental factors, might influence LINE-1 methylation.

Geographical Distribution and Risk Factors of Low Birth Weight in Nigeria

BACKGROUND

Low birth weight (LBW) directly or indirectly accounts for 60% to 80% of all neonatal deaths globally, and it has become an issue of serious health concern with Nigeria with one of the highest infant mortality rates (74/1,000) in the world. Despite the severe health impact, little is understood on the geographical differences in maternal socioeconomic and environmental factors that affect LBW across the states in Nigeria.

METHOD

Using the spatial epidemiological approach, this study examined the geographical variations in LBW and associated risk factors in Nigeria with the aid of spatial statistics.

RESULTS

There was a regional LBW corridor in the extreme north with Yobe state with the highest prevalence rate. Maternal educational attainment and acute maternal malnutrition explained 65.4% (ordinary least squares model) and 70.5% (spatial error model, SEM) of the variation in the geographical pattern of LBW.

CONCLUSION

LBW remains an issue of serious health concern in Nigeria. The finding of this study would shed more light on the spatial epidemiology of LBW in Nigeria and also guide public health programs in curtailing the high prevalence rate of LBW.

RECOMMENDATIONS

The study recommends health education on nutrition in pregnancy and the need to improve health literacy among women so as to check the high LBW prevalence.

Are there birth cohort effects in disparities in child obesity by maternal education?

BACKGROUND

Children belonging to the same birth cohort (i.e., born in the same year) experience shared exposure to a common obesity-related milieu during the critical early years of development-e.g., secular beliefs and feeding practices, adverse chemical exposures, food access and nutrition assistance policies-that set the stage for a shared trajectory of obesity as they mature. Fundamental cause theory suggests that inequitable distribution of recent efforts to stem the rise in child obesity may exacerbate cohort-based disparities over time.

METHODS

Data were from electronic health records spanning 2007-2016 linked to birth records for children ages 2-19 years. We used hierarchical age-period-cohort models to investigate cohort effects on disparities in obesity related to maternal education. We hypothesized that maternal education-based disparities in prevalence of obesity would be larger among more recent birth cohorts.

RESULTS

Sex-stratified models adjusted for race/ethnicity showed substantial obesity disparities by maternal education that were evident even at young ages: prevalence among children with maternal education < high school compared to maternal college degree was approximately three times as high among girls and twice as high among boys. For maternal education < high school, disparities compared to maternal college degree were higher in more recent birth cohorts. Among girls, this disparity cohort effect was evident at younger ages (at age 4, the disparity increased by 4 [0.1-8] percentage points per 5 birth years), while among boys it was larger at older ages (at age 16, the disparity increased by 7 [1-14] percentage points per 5 birth years).

CONCLUSIONS

There may be widening maternal education-based disparities in child obesity by birth cohort at some ages.

Determinants of Low Birth Weight in Ghana: Does Quality of Antenatal Care Matter?

OBJECTIVES

Low birth weight is a public health issue that contributes to perinatal and infant mortality, especially in limited-resource settings, but there is limited understanding of the determinants of low birth weight and the contributions of quality antenatal care to maintaining healthy birth weights for newborns in such settings. This study aims at establishing links between birthweight and quality antenatal care in Ghana.

METHODS

We used data collected from the recent 2017 Ghana Maternal Health Survey and applied complementary log-log models to investigate relationships between the quality of antenatal care (screening/diagnostic procedures, clinical interventions, type of health provider) and low birth weight in Ghana.

RESULTS

The results reveal that compared to women who received low quality clinical interventions, those who received high quality interventions were significantly less likely to have a low birth weight baby. Similarly, women who made the recommended number of antenatal visits (at least eight) were significantly less likely to have a baby with low birth weight than women making fewer visits.

CONCLUSION

Our findings suggest that while the number of antenatal visits is important, the quality of care received during such visits is equally relevant to reducing low birth weight in Ghana.

Maternal Education at Birth and Youth Breakfast Consumption at Age 15: Blacks' Diminished Returns

Background

Based on the Marginalization-related Diminished Returns (MDRs) framework, high socioeconomic status (SES) such as parental education shows weaker effects for Blacks than Whites. For example, high SES Black individuals report a high level of depression, anxiety, suicide, chronic disease, smoking, and mortality. Limited knowledge exists on MDRs of parental education on dietary behavior.

Aims

Built on the MDRs framework, we tested the hypothesis of whether the effect of parental education on eating breakfast differs for Black compared to White families. We hypothesized that there is an association between mothers' educational attainment and eating breakfast and compared Blacks and Whites for the effect of mothers' educational attainment on the frequency of eating breakfast.

Methods

The Fragile Families and Child Wellbeing Study is a 15-year follow up study of a random sample of births in cities larger than 200,000 population. The predictor was parental education at birth. The outcome was the frequency of eating breakfast at age 15. Linear regression was used for data analysis.

Results

Maternal educational attainment at birth was positively associated with youth frequency of eating breakfast among Whites, not Blacks. We also found a significant interaction between maternal educational attainment at birth and race, suggesting that the association between maternal education and youth frequency of eating breakfast at age 15 was weaker for Black than White families.

Conclusions

Diminished returns of maternal educational attainment on healthy youth diet may contribute to the racial disparities in poor health of high SES Black families. That is, a smaller protective effect of maternal education on changing health behaviors for Black than White youth may be one of the mechanisms by which health is worse than expected in high SES Black families. The health disparities are not only due to racial differences in SES but also the diminishing returns of socioeconomic status indicators such as education for racial minorities. Research should study contextual and structural factors that reduce Black families' ability to mobilize their human capital and secure health outcomes in urban settings.

Protective Effects of Maternal Education against Low Birth Weight Deliveries: Blacks' Diminished Returns

Background

Racial and economic disparities in low birth weight (LBW) deliveries is among the most well-established differences between Blacks and Whites. As LBW is an established risk factor for chronic diseases such as asthma and diabetes, it is particularly important to understand drivers of racial and economic disparities in LBW deliveries in urban areas.

Aims

Built on the Minorities' Diminished Returns framework, which argues that educational attainment generates fewer positive health outcomes for Black than White Americans, we conducted this study with three aims: 1) to test the association between mothers' educational attainment and LBW of babies born in urban areas, 2) to compare Blacks and Whites for the effect of mothers' educational attainment on LBW, and 3) to test whether LBW is predictive of future chronic diseases 15 years later.

Methods

Data came from the Fragile Families and Child Well-being / included a random sample of births in cities larger than 200,000 population. For the aims 1 and 2, we analyzed data of 2,922 births to Black (n = 2,146) or White (n = 776) mothers. For aim 3, we analyzed data of a subsample of 1,604 Black or White newborns who were followed to age 15. The presence or absence of chronic diseases was determined at age 15. Logistic regression was used for data analysis.

Results

Maternal educational attainment was inversely associated with LBW overall. We, however, found a significant interaction between maternal educational attainment and race, suggesting that the inverse association between maternal education and LBW is weaker for Black than White babies. At the same time, LBW increased the odds of chronic disease 15 years later.

Conclusions

Diminished returns of maternal educational attainment contribute to racial disparities in LBW, which in turn contributes to future racial inequalities in chronic diseases in urban settings. That is, smaller protective effects of maternal education on reducing LBW for Black than White children contribute to the high prevalence of chronic diseases among adolescents in urban settings. Health disparities are not just due to racial differences in socioeconomic status but also diminishing returns of socioeconomic status indicators such as education for racial and ethnic minorities. Research should study contextual factors that reduce Blacks' ability to translate their human capital to health outcomes in urban settings.

Parental Education and Spanking of American Children: Blacks' Diminished Returns

Background

Based on the Minorities' Diminished Returns (MDRs) framework, high socioeconomic status (SES) indicators such as parental education shows weaker protective effects against adverse experiences for Blacks than Whites. For example, Black children with highly educated parents report high levels of depression, anxiety, suicide, smoking, obesity, and chronic disease. Limited knowledge exists on MDRs of parental education on the child's exposure to spanking by the mother.

Aims

Built on the MDRs framework, we tested the hypothesis of whether the effect of parental education on the child's exposure to spanking by the mother differs in Black and White families. We hypothesized that: 1) there is an inverse association between mothers' educational attainment and child spanking, and 2) the effect of mothers' educational attainment on mothers' spanking of the child is weaker for Black than White families.

Methods

We used data from the Fragile Families and Child Well-being Study (FFCWS), a 9-year follow up study of a random sample of births in cities larger than 200,000 population. In this analysis, 2722 Black or White families were followed. The main predictor was parental educational attainment at birth. The outcomes were exposure to spanking at ages 3, 5, and 9. Logistic regression was used for data analysis.

Results

Higher parental educational attainment at birth was inversely associated with the child's exposure to spanking by the mother among Whites, not Blacks. We also found a significant interaction between parental educational attainment at birth and race, suggesting that the associations between parental education and child exposure to spanking by the mother at ages 3, 5, and 9 were weaker for Black than White families.

Conclusions

Diminished returns of parental educational attainment in terms of reducing children's exposure to trauma and stress may be a mechanism that contributes to racial health disparities, particularly poor health of children in highly educated Black families. That is a smaller protective effect of parental education on reducing undesired exposures for Black than White children may be one of the mechanisms that may explain why children develop worse than expected physical, mental, and behavioral health in high SES Black families. Not all health disparities are due to racial differences in SES, but some of them are also secondary to the diminishing returns of socioeconomic status indicators such as parental education for racial minorities. Research should study contextual, structural, family, and behavioral factors that reduce Black families' ability to mobilize their human capital and secure health outcomes for themselves and their children.

College Graduation and Wealth Accumulation: Blacks' Diminished Returns

Background

Based on the Minorities' Diminished Returns (MDRs) framework, indicators of high socioeconomic status (SES), such as high maternal educational attainment, show weaker protective effects on various developmental, behavioral, and health outcomes for Black than White families. As a result of these MDRs, families and individuals with high educational attainment still report high levels of depression, smoking, obesity, and chronic disease. Limited knowledge exists on MDRs of maternal education on indicators of wealth such as home ownership and home value.

Aims

Built on the MDRs framework, we tested the hypothesis of whether the effects of maternal educational attainment at birth on home ownership and home value, as proxies of wealth, vary between Black and White families. We hypothesized that: 1) high maternal education would be associated with more wealth 15 years later, and 2) compared to Whites, Blacks would be less likely to accumulate wealth (own a house) across all educational levels, given a weaker boosting effect of maternal educational attainment on wealth for Black than White families.

Methods

The Fragile Families and Child Well-being Study, is a 15-year follow up study of a random sample of births in cities larger than 200,000 population in the US. A total number of 2004 White or Black youth were included and were followed from birth to the age of 15. The predictor of interest was maternal educational attainment at birth, treated as a categorical variable (college graduation). The outcomes were home ownership and home value (worth - owed) 15 years later, as proxies of wealth. Logistic and linear regression were used for data analysis.

Results

High maternal education at birth was associated with home ownership and higher value of owned home at age 15. We also found that maternal educational attainment at birth and race interact with each other, suggesting that the effects of high maternal educational attainment at birth on home ownership/value at age 15 were weaker for Black than White families.

Conclusions

Diminished returns of maternal educational attainment at birth on wealth accumulation in Black families may be a mechanism that contributes to racial health disparities in high socioeconomic status and also poor outcomes of high SES Black families. That is, a smaller effect of maternal educational attainment on changing the real lives of Black than White youth may be one of the mechanisms by which health remains worse than expected in high SES Black families. Not all of the health, behavioral, and developmental disparities are due to the racial gap in SES but also diminishing returns of socioeconomic status indicators such as maternal educational attainment for racial minorities. Research should study how social stratification, discriminatory mortgage and banking, residential segregation, family formation, employment, and occupational prestige reduce Black families' ability to mobilize their human capital and secure tangible economic and non-economic outcomes.

Family Income and Gang Presence in the Neighborhood: Diminished Returns of Black Families

BACKGROUND

Based on the Minorities' Diminished Returns (MDRs) framework, indicators of high socioeconomic status, such as higher family income, show weaker protective effects on various developmental, behavioral, and health outcomes for Black than White families. As a result of these MDRs, Black families who access education and income still report high levels of depression, smoking, obesity, and chronic disease. Limited knowledge exists on MDRs of income on neighborhood quality.

AIMS

Built on the MDRs framework, this study tested the hypothesis of whether the effect of family income and maternal education at birth on neighborhood gang presence varies between Black and White families. The hypotheses were that: (1) higher income families would report lower gang presence in their neighborhood, and (2) compared to Whites, Blacks would show weaker protective effects of family income on gang presence in their neighborhood.

METHODS

The Fragile Families and Child Wellbeing Study is a 15-year follow up study of a random sample of births in cities with larger than 200,000 population. Two thousand nine hundred and nineteen White or Black families were included and were followed from birth of their child for 15 years. The predictors were family income and maternal education at birth, treated as categorical variables. The outcome was gang presence in the neighborhood at age 15. Logistic regression was used for data analysis.

RESULTS

Higher maternal education at birth was inversely associated with gang presence in the neighborhoods, while family income at birth did not show an effect on reducing gang presence in the neighborhood at age 15. Family income at birth and race interact, suggesting that the association between family income at birth and gang presence in the neighborhood at age 15 was weaker for Black than White families. Our race-stratified models also showed an inverse effect of family income at birth on gang presence in the neighborhood at age 15 in White but not Black families.

CONCLUSIONS

Diminished returns of family income at birth on neighborhood safety and social disorder may be a mechanism that contributes to racial health disparities in higher socioeconomic status and also poor outcomes for Black families across socioeconomic status (SES) levels. That is, a smaller protective effect of family income on changing the real lives of Black compared to White families may be one of the mechanisms by which health is worse than expected in Black families, across the entire SES spectrum. The health, behavioral, and developmental disparities are not only due to the racial gap in SES but also diminishing returns of socioeconomic status indicators such as family income for racial minorities. Research should study contextual and structural factors that reduce Black families' ability to mobilize their human capital and secure health outcomes in urban settings.

Inequalities in birth weight and maternal education: a time-series study from 1996 to 2013 in Brazil

Maternal education represents one of the most important social determinants of inequality in birth weight (BW) in developing countries. The present study sought to investigate secular trends in health inequality considering the difference in mean BW between extremes of maternal educational attainment in Brazil. Using a time-series design, data from 6,452,551 live births which occurred in all Brazilian state capitals from 1996 to 2013 were obtained from the Information System on Live Births. Secular trends of the difference in mean birth weight between low (<8 years of schooling) and high (≥12 years of schooling) educational attainment were analyzed. The main finding was that differences in mean birth weight between the two extremes of maternal educational attainment decreased over time. There was a significant decrease in mean BW in neonates born to mothers with higher educational attainment, and a slight increase in those born to mothers with lower educational attainment. One of the key factors involved in decreasing inequality was an increase in the number of antenatal visits. In view of these results, we conclude, that despite a slight increase of mean birth weight among mothers with low education, the reduction of inequality in pregnancy outcomes over time in Brazil is attributable to a worsening scenario for mothers who are better off rather than to improvements for the most vulnerable group of mothers.

Latent Class Analysis of Low Birth Weight and Preterm Delivery among Australian Women

OBJECTIVES

To identify patterns of health, socioeconomic, behavioral, and psychosocial indicators that may be associated with low birth weight delivery or preterm birth.

STUDY DESIGN

Data were analyzed from the Australian Longitudinal Study on Women's Health. A total of 9075 live singleton births among 3801 women were linked to state perinatal records with birth outcome data. Survey data were used to identify 11 indicators for latent class analysis. Latent classes were tested for association to birth outcomes. These indicators also were used along with covariates in main effect multiple logistic regression analyses of birth outcomes.

RESULTS

Latent class analysis revealed 5 classes, including those characterized by low education, recent drug use, stress/anxiety/depression, smoking/drinking/low education/multi-risk, and a low risk referent group. The stress/anxiety/depression class was associated with preterm delivery (OR 1.87, 95% CI 1.20-2.92), and the smoking/drinking/low education/multirisk class was associated with low birth weight (OR 1.54, 95% CI 1.02-2.30). Traditional logistic regression analyses for main effects identified some measures not captured by the latent classes, and the latent classes identified variable combinations not captured by the main effect analysis.

CONCLUSIONS

Unique latent classes were associated with preterm delivery vs low birth weight. Both latent class analysis and main effects analyses may be combined to improve understanding of birth outcome risks. Clinical and programmatic interventions to reduce risks of low birth weight and preterm delivery may benefit from risk profiles that women experience.

Relationships between maternal characteristics and infant birth weight

PURPOSE

Nowadays, the importance of infant birth weight (IBW) as a key factor in determining the future of physical and mental development of children is a growing concern. The purpose of this paper is to investigate the relationship between maternal characteristics and IBW among pregnant women who were referred to health centers in Qazvin city in the year 2016.

DESIGN/METHODOLOGY/APPROACH

A descriptive-analytical study was conducted among pregnant women in 28-36 weeks of gestation who referred to healthcare centers and facilities affiliated by the Qazvin University of Medical Sciences in April-June 2016. The associations between maternal physical activity, mothers' socioeconomic status and birth weight were examined by SPSS Software Package version 16 through linear and logistic regression tests.

FINDINGS

Linear regression modeling suggested that maternal weight (p=0.001), income (p=0.04), gestational age of delivery (p=0.00) and pre-pregnancy BMI (p=0.02) were positively associated with birth weight, while occupational and heavy physical activity (p=0.003 and 0.008, respectively) were negatively associated with IBW. In this study, low birth weight infants are compared to those with normal weight belonged to mothers who have spent more time in doing heavy physical activities (OR=1.11, 95% CI 1.01-1.23). Also infants with low birth weight compared to others in the normal weight category were born from mothers with lower pre-pregnancy BMI (OR=0.65, 95% CI 0.62-0.78), gestational age of delivery (OR=0.82, 95% CI 0.79-0.86), maternal weight (OR=0.86, 95% CI 0.84-0.88) and income (OR=0.79, 95% CI 0.69-0.83).

PRACTICAL IMPLICATIONS

The study findings revealed that certain maternal characteristics could play a significant role in IBW. Despite the importance, in most of developing countries (particularly Iran), future mothers are not advised about an appropriate weight gain during pregnancy or the optimal level of physical activity in such a period of time. Therefore, counseling pregnant women and giving them proper information on appropriate perinatal care would be helpful in order to have pregnancies with optimal outcomes.

ORIGINALITY/VALUE

The authors applied several statistical methods to analyze IBW among mothers with different maternal characteristics and predict birth weight based on contributing factors.

Low birth weight in a subnormal urban cluster under Family Health Strategy’s care

Abstract Objectives: to identify the prevalence and to analyze the factors associated with low birth weight in a subnormal urban cluster in Pernambuco under Family Health Strategy’s care. Methods: a cross-sectional study with a census sample carried out between July and October in 2015. The variables studied were age and years of maternal schooling, social status, housing, water supply, waste disposal, prenatal care, alcohol consumption and cigarette smoking during pregnancy, along with gender, birth weight and prematurity. Stata 12.1 was utilized in order to understand the factors associated with low birth weight through uni-and-multivariate Poisson analysis, adjusted and gross prevalence ratios, composing a final statistical model considering p value <0.05 for statistical significance. Results: regarding the 294 children the LBW prevalence was 12.2% (CI95% = 8.7-16.5). Children whose mothers reported drinking during pregnancy were 2.78 times more at risk of being born with low birth weight (p<0.001) when compared with children whose mothers did not report this practice in gestation. Conclusions: the study evidenced the relevance maternal habits bears in the newborns’ health.

The relationship between the different low birth weight strata of newborns with infant mortality and the influence of the main health determinants in the extreme south of Brazil

BACKGROUND

Low birth weight (LBW) newborns present different health outcomes when classified in different birth weight strata. This study evaluated the relationship of birth weight with Infant mortality (IM) through the influence of biological, social, and health care factors in a time series.

METHODS

Retrospective cohort study with data collected from Information Systems (Live Births and Mortality). The mortality trends were performed for each birth weight stratum: extremely low, < 1000 g; very low, 1000-1499 g; low, 1500-2499 g; insufficient, 2500-2999 g; adequate, 3000-3900 g; and macrosomia, > 4000 g. Chi-square tests analyzed IM rates. Sequential Poisson regression analyzed the impact of the determinant factors.

RESULTS

A total of 277,982 newborns were included in the study and 2088 died before their first year. There was a tendency for a decrease in mortality in all strata of weight. With the exception of macrosomics, all other strata had a higher risk for IM when compared with adequate birth weight. Extremely LBW newborns presented higher risk for mortality when born in a public hospital. A higher percentage of infant deaths were associated with lower maternal age and lower schooling for all strata. Prenatal care with less than three visits demonstrated a risk for IM in low, insufficient, and adequate birth weight strata. The cesarean section was a protective factor for IM in Extremely and Very LBW strata and it was a risk factor in adequate birth weight stratum.

CONCLUSIONS

LBW had a greater association with IM, especially those children of younger mothers and those born in public hospitals.

The association between household socio-economic status, maternal socio-demographic characteristics and adverse birth and infant growth outcomes in sub-Saharan Africa: a systematic review

Adverse birth outcomes and infant undernutrition remain the leading causes of morbidity and mortality in sub-Saharan Africa (SSA). Impaired infant growth and development, which often begins during foetal development, may persist during the first 2 years of life and has been associated with higher risks of cardiometabolic diseases. This systematic review assessed the associations between maternal demographic characteristics and household socio-economic status (SES), and preterm birth (PTB), small for gestational age, low birth weight (LBW), stunting, wasting and underweight in children under 2 years of age in SSA countries. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, we searched for publications in three electronic databases (PubMed, Scopus and ScienceDirect). Eleven studies on children under 2 years of age, in four SSA regions, published in English between 1990 and 2018, were included. All the studies were observational in design (cross-sectional or cohort studies). Maternal education was the most commonly explored exposure. Most studies (63.3%) focused on undernutrition during the first 2 years of life: LBW, PTB and stunting. Lower maternal education, maternal unemployment and lower household wealth index were the SES factors most commonly associated with adverse birth outcomes and infant undernutrition. Maternal marital status was not associated with any infant outcomes. The definitions of the SES varied, which may explain discrepancies between studies. Nutrition intervention programs in SSA need to promote education and poverty alleviation in women at reproductive age, starting from pre-pregnancy, to optimise infant growth and development and prevent the increase in the prevalence of cardiometabolic diseases.

Prevalence and Severity of Molar-Incisor Hypomineralization, Maternal Education, and Dental Caries: A Cross-Sectional Study of Mexican Schoolchildren with Low Socioeconomic Status

Objectives

The aims of this study were to identify the prevalence of molar-incisor hypomineralization (MIH) in a group of low-income schoolchildren and to evaluate the role of maternal education on MIH and dental caries in these children.

Materials and Methods

This cross-sectional study enrolled 686 schoolchildren. To evaluate dental caries, the International Caries Dental Assessment System II (ICDAS) criteria were utilized. MIH was assessed by using the European Academy of Paediatric Dentistry criteria. Mixed-effects models were applied for the data analysis.

Results

The prevalence of MIH was 35.4% (244). Most children exhibited moderate MIH (163, 67.1%), followed by mild MIH (45, 18.5%) and severe MIH (35, 14.4%). Caries presence in the first permanent molars, evaluated using ICDAS score, indicated that the mean number of noncavitated and cavitated lesions (ICDAS ≥2) was 0.90 (±0.30); the mean number of lesions with ICDAS ≥3 was 0.36 (±0.48). Odds ratio (OR) analysis of MIH severity revealed that the children of mothers with low education were more likely to exhibit MIH (OR 2.13; 95% confidence interval [CI]: 1.25-3.85). Modeling of dental caries (ICDAS ≥3) revealed that low maternal education (OR 2.27; 95% CI: 1.25-4.16) and the presence of MIH (OR 4.37; 95% CI: 3.05-6.25) were associated with dental caries.

Conclusions

There were associations between low maternal education and both MIH and dental caries. The presence of both initial and cavitated caries lesions was associated with MIH. Dentists should offer adequate advice to mothers with children with MIH, based on their educational background.

Demographic surveillance over 12 years helps elicit determinants of low birth weights in India

Background

Low birth weight is an important predictor of maternal and child health. Birth weight is likely to be affected by maternal health, socioeconomic status and quality of health care facilities.

Objective

To assess trends in the birth weight, the proportion of low birth weight, maternal factors and health care facilities for delivery in villages of Western Maharashtra from the year 2004 to 2016 and to analyze factors associated with low birth weight for total birth data of 2004–2016.

Methods

Data collected for 19244 births from 22 villages in Vadu Health and Demographic Surveillance System (HDSS), Pune, Maharashtra, India from the year 2004 to 2016 were used for this analysis.

Results

There was an overall increase in the annual mean birth weight from 2640.12 gram [95% CI 2602.21–2686.84] in the year 2004 to 2781.19 gram [95% CI 2749.49–2797.95] in the year 2016. There was no secular trend to show increase or decrease in the proportion of low weight at birth. Increasing maternal age (>18 years) compounded with better education, reduced parity and increasing number of institutional deliveries were significant trends observed during the past decade. Low birth weight was found to be associated with female gender, first birth order, poor maternal education and occupation as cultivation.

Conclusion

Changes in maternal age, education, occupation, and increased institutionalized deliveries contributed in to increasing birth weights in rural Maharashtra. Female gender, first birth order, poor maternal education and occupation of cultivation are associated with increased risk of low birth weight.

Risk factors of preterm birth and low birth weight neonates among Roma and non-Roma mothers

OBJECTIVE

This study analyses the differences in birth outcomes between Roma and non-Roma mothers and investigates the potential causes of such differences.

METHODS

We conducted a retrospective cohort study of 1,989 non-Roma and 799 Roma mothers who gave birth in 2014 and 2015 at the Gynaecology and Obstetrics Clinic of Louis Pasteur University Hospital in Košice. Data on mothers and new-born infants have been obtained from the birth book and from the reports on mothers at childbirth. For low birth weight we considered the weight of a new-born weighing less than 2,500 grams and as for premature birth we referred to childbirth before pregnancy week 37. The file was split by ethnicity and statistically processed in IBM SPSS Statistics 21.0.

RESULTS

Our results confirmed a lower birth weight among Roma children (-365.4 grams, p < 0.001). The shorter gestation age and higher risk of premature birth were not statistically significant regarding Roma children. Based on the characteristics of Roma mothers, they are at higher risk of giving birth as minor (OR = 23.64; 95% CI = 15.29-36.54; p < 0.001), as single mothers (OR = 7.13; 95% CI = 5.80-8.76; p < 0.001), with basic education or lack of education (OR = 141.31; 95% CI = 100.47-198.76; p < 0.001). They also have a higher risk of smoking during pregnancy (OR = 23.84; 95% CI = 18.06-31.49; p < 0.001); drinking alcohol (OR = 11.71; 95% CI = 3.36-40.90; p < 0.001) and taking drugs (OR = 8.70; 95% CI = 1.81-42.02; p < 0.001). Roma women attended gynaecologists more rarely.

CONCLUSION

It is therefore important to support the work of community health workers and stimulate collaboration between community health professionals, paediatricians and gynaecologists to overcome institutional barriers in maternity and child care for mothers living in Roma settlement.

Association between birth weight and refractive error in adulthood: a Mendelian randomisation study

BACKGROUND

Pathological myopia is one of the leading causes of blindness globally. Lower birth weight (BW) within the normal range has been reported to increase the risk of myopia, although findings conflict. We sought to estimate the causal effect of BW on refractive error using Mendelian randomisation (MR), under the assumption of a linear relationship.

METHODS

Genetic variants associated with BW were identified from meta-analysis of a genome-wide association study (GWAS) for self-reported BW in 162 039 UK Biobank participants and a published Early Growth Genetics (EGG) consortium GWAS (n=26 836). We performed a one-sample MR analysis in 39 658 unrelated, adult UK Biobank participants (independent of the GWAS sample) using an allele score for BW as instrumental variable. A two-sample MR sensitivity analysis and conventional ordinary least squares (OLS) regression analyses were also undertaken.

RESULTS

In OLS analysis, BW showed a small, positive association with refractive error: +0.04 D per SD increase in BW (95% CI 0.02 to 0.07; p=0.002). The one-sample MR-estimated causal effect of BW on refractive error was higher, at +0.28 D per SD increase in BW (95% CI 0.05 to 0.52, p=0.02). A two-sample MR analysis provided similar causal effect estimates, with minimal evidence of directional pleiotropy.

CONCLUSIONS

Our study suggests lower BW within the normal range is causally associated with a more myopic refractive error. However, the impact of the causal effect was modest (range 1.00 D covering approximately 95% of the population).