Low birth weight in the United States

Ethnoracial Disparities in Perinatal Outcomes Among Women Veterans

Objective: Non-Hispanic Black women have increased rates of preterm birth and low infant birth weight. However, we do not know if these disparities replicate in women veterans, a population that may be at further risk for poor perinatal outcomes. This study sought to examine ethnoracial differences in preterm birth and low infant birth weight in veterans. Methods: A national sample of randomly chosen women veterans (i.e., oversampled for residency in high crime neighborhoods) reported information about all pregnancies they have had in their life, demographic characteristics, and history of childhood trauma exposures. The analytic sample was limited to individuals who identified as Hispanic/Latinx, Black, or White (n = 972). Mixed-effects regression models were used to examine ethnoracial differences in gestational age at delivery and infant birth weight, controlling for age at pregnancy, childhood trauma exposure, pregnancy during military service, income, and education. Results: Both Black and Hispanic/Latinx veterans were significantly more likely to have an infant born at lower gestational age (B = -1.04 and B = -1.11, respectively) and lower infant birth weight (B = -195.83 and B = -144.27, respectively) as compared with White veterans in covariate-adjusted models. Black (odds ratio = 3.24, confidence interval = 1.16, 9.09) veterans were more likely to meet the clinical definition of preterm birth as compared with White veterans. Conclusions: Results align with what is seen in the general population regarding ethnoracial disparities in gestational age at delivery and infant birth weight. Findings highlight the critical need for more research on mechanisms and prevention efforts for ethnoracial disparities in perinatal outcomes.

Determinants of preterm birth among reproductive age women in sub-Saharan Africa: Evidence from the most recent Demographic and Health Survey data-2019-2022

INTRODUCTION

Preterm birth is the leading cause of both infant and neonatal mortality. It also had long-term consequences for the physical and neurological development of a growing child. The majority of these and related problems occur in low- and middle-income countries, particularly in sub-Saharan Africa, due to resource scarcity to sustain the lives of premature babies. Despite this, there is a paucity of recent information on the pooled prevalence and factors associated with preterm birth in sub-Saharan Africa. Therefore, this study aimed to update the pooled prevalence and determinants of preterm birth in sub-Saharan Africa based on the most recent Demographic and Health Survey data.

METHODS

A cross-sectional study design using the most recent demographic and health survey data from eight sub-Saharan African countries was used. We included a total weighted sample of 74,871 reproductive-aged women who gave birth in the five years preceding the survey. We used a multilevel logistic regression model to identify associated factors of preterm birth in sub-Saharan Africa. The adjusted odds ratio at 95% Cl was computed to assess the strength and significance of the association between explanatory and outcome variables. Factors with a p-value of <0.05 are declared statistically significant.

RESULTS

In this study, the pooled prevalence of preterm birth among reproductive-aged women in eight sub-Saharan African countries was 3.11% (95% CI: 2.98-3.25). Working mothers (AOR = 0.61; 95% CI: 0.38-0.97), being married (AOR = 0.63; 95% CI: 0.40-0.99), and having media exposure (AOR = 0.59; 95% CI: 0.36-0.96) decrease the odds of preterm birth. On the other hand, being low birth weight (AOR = 17.7; 95% CI: 10.7-29.3), having multiple pregnancies (AOR = 3.43; 95% CI: 1.82-6.45), having a history of terminated pregnancies (AOR = 1.56; 95% CI: 1.01-2.41), being un-educated (AOR = 3.16; 95% CI: 1.12-8.93), being of a maternal age above 35 (AOR = 1.63; 95% CI: 1.08-2.45), maternal alcohol use (AOR = 19.18; 95% CI: 13.6-38.8), and being in the low socio-economic status (AOR = 1.85; 95% CI: 1.11-3.07) of the community increase the odds of preterm birth.

CONCLUSION

The burden of preterm birth among reproductive-age women in sub-Saharan Africa showed improvements as compared to previous findings. To further lessen the burden, policymakers and other pertinent organizations must prioritize maternal health, expand media access, educate and empower women, and promote a healthy lifestyle for reproductive-age women.

Influence of Preterm Birth and Low Birthweight on Physical Fitness: A Systematic Review, Meta-Analysis, and Meta-Regression

BACKGROUND

Preterm birth and low birthweight (LBW) might be associated with reduced physical fitness, although evidence remains inconclusive.

OBJECTIVE

To examine the influence of preterm birth and LBW on physical fitness, as well as to assess whether variables such as gestational age, birthweight, or age at assessment moderate these effects.

METHODS

PubMed, Scopus, and PsycINFO were systematically searched from inception to 7 December 2023 for case-control and cohort studies analyzing the association between preterm birth or LBW (or gestational age or birthweight as continuous variables) with at least one physical fitness-related outcome (i.e., cardiorespiratory fitness (CRF), muscle strength, flexibility, speed, agility). Random-effects meta-analysis and meta-regression models were used to estimate the pooled effect size, as well as to examine potential associations between the magnitude of the effect and gestational age, birthweight, or age at assessment.

RESULTS

Fifty-two studies (n = 920,603 participants, average age ranging from 4.7 to 34.4 years) were included. Preterm birth was associated with reduced CRF (standardized mean difference (SMD) = -0.38, 95% confidence interval (CI) = -0.51 to -0.25) and muscle strength (SMD = -0.44, 95% CI = -0.79 to -0.08). LBW was associated with reduced CRF (SMD = -0.40, 95% CI = -0.64 to -0.17), muscle strength (SMD = -0.18, 95% CI = -0.24 to -0.13), flexibility (SMD = -0.11, 95% CI = -0.22 to -0.01), and agility (SMD = -0.99, 95% CI = -1.91 to -0.07). Meta-regression analyses showed that a lower gestational age or birthweight were associated with larger reductions in physical fitness, whereas no consistent association was found for the age at assessment.

CONCLUSION

Both preterm birth and LBW seem associated with reduced physical fitness regardless of age, with larger reductions overall observed in individuals with lower gestational age or birthweight. These findings might support the implementation of preventive strategies (e.g., fitness monitoring and physical exercise interventions) in these populations through the life course. PROSPERO registration: CRD42021231845.

The influence of maternal prepregnancy weight and gestational weight gain on the umbilical cord blood metabolome: a case-control study

BACKGROUND

Maternal overweight/obesity and excessive gestational weight gain (GWG) are frequently reported to be risk factors for obesity and other metabolic disorders in offspring. Cord blood metabolites provide information on fetal nutritional and metabolic health and could provide an early window of detection of potential health issues among newborns. The aim of the study was to explore the impact of maternal prepregnancy overweight/obesity and excessive GWG on cord blood metabolic profiles.

METHODS

A case control study including 33 pairs of mothers with prepregnancy overweight/obesity and their neonates, 30 pairs of mothers with excessive GWG and their neonates, and 32 control mother-neonate pairs. Untargeted metabolomic profiling of umbilical cord blood samples were performed using UHPLC‒MS/MS.

RESULTS

Forty-six metabolites exhibited a significant increase and 60 metabolites exhibited a significant reduction in umbilical cord blood from overweight and obese mothers compared with mothers with normal body weight. Steroid hormone biosynthesis and neuroactive ligand‒receptor interactions were the two top-ranking pathways enriched with these metabolites (P = 0.01 and 0.03, respectively). Compared with mothers with normal GWG, in mothers with excessive GWG, the levels of 63 metabolites were increased and those of 46 metabolites were decreased in umbilical cord blood. Biosynthesis of unsaturated fatty acids was the most altered pathway enriched with these metabolites (P < 0.01).

CONCLUSIONS

Prepregnancy overweight and obesity affected the fetal steroid hormone biosynthesis pathway, while excessive GWG affected fetal fatty acid metabolism. This emphasizes the importance of preconception weight loss and maintaining an appropriate GWG, which are beneficial for the long-term metabolic health of offspring.

Pregnancy outcomes in the medical management of glaucoma: An international multicenter descriptive survey

PURPOSE

To determine if glaucoma medications are associated with pregnancy and/or postnatal complications.

METHODS

Multicenter descriptive survey. Subjects were female patients 18-45 years who were previously pregnant with a diagnosis of glaucoma or ocular hypertension prior to pregnancy. Chart review queried diagnosis, glaucoma severity, and race. Survey questions were asked for each pregnancy and queried pregnancy age, medications used, and pregnancy outcomes/complications.

RESULTS

114 pregnancies of 56 patients (mean 2.0 pregnancies per patient) were included. Three pregnancies with therapeutic abortion were excluded from further analysis. Mean age during pregnancy was 29.1 ± 5.7 years. Of the 111 pregnancies, 20 (18.0%) used no medications and 91 (82.0%) used at least one medication. Medications were topical carbonic anhydrase inhibitors (n = 45), beta-blockers (n = 55), alpha-agonists (n = 56), and prostaglandin analogues (n = 28). Outcomes were: preterm contractions/labour (6.3%), miscarriage (4.5%), stillbirth (4.5%), induction of labour (11.9%), emergency/unplanned caesarean delivery (13.9%), neonatal intensive care unit (NICU) stay (15.8%), congenital anomalies (8.1%), and low birth weight (10.9%). Fisher exact test assessed outcome associations with individual agents, use of any agent, and different number of agents. Alpha-agonist use was associated with NICU stay: 25.5% rate (p = 0.012) in alpha-agonist use. Most of the alpha-agonist use NICU stays occurred in pregnancies with third trimester use. All other associations were not statistically significant.

CONCLUSIONS

The data from this survey suggest an overall favourable safety profile for topical glaucoma medications in pregnancy, but further investigation is needed. Caution should be employed regarding third trimester alpha-agonist use owing to association with NICU stay.

Stress During Pregnancy Associated with Newborn Low Birth Weight: Experiences from the State of Rhode Island

PURPOSE

Prenatal stress is a known risk for poor birth outcomes. This study specifically looked at reported stress during pregnancy and low birth weight (LBW) in Rhode Island.

METHODS

Pregnancy Risk Assessment Monitoring System (PRAMS) data from 2016 to 2018 for the state of Rhode Island was utilized. Stress during most recent pregnancy was dichotomized as: 'none to minimal' and 'moderate to high.' LBW was defined as less than 2,500 g. Multivariable regression analysis was performed, accounting for complex survey design.

RESULTS

In this cohort, 24% of pregnant people reported moderate to high stress leading to an adjusted odds of 1.70 (95% CI 1.43-2.03) of having a LBW newborn compared to those with none to minimal stress. Primiparity, previous preterm birth, racism, smoking history, and history of chronic medical problems were also associated with LBW newborns.

CONCLUSION

We recommend screening and provision of support services for stress in all settings where pregnant people access care.

Maternal prenatal social contact during the COVID-19 pandemic predicts infant birth weight

BACKGROUND

Social connectedness and mental health have been associated with infant birth weight, and both were compromised by the COVID-19 pandemic.

AIMS

We sought to examine whether changes in maternal prenatal social contact due to the COVID-19 pandemic were associated with infant birth weight and if maternal prenatal mental health mediated this association.

STUDY DESIGN

A longitudinal study of mothers and their infants born during the first wave of the COVID-19 pandemic.

SUBJECTS

The sample consisted of 282 United States-based mother-infant dyads.

OUTCOME MEASURES

Depressive symptoms were measured with the Beck Depression Inventory-II, anxiety was measured with the State Anxiety Inventory, and stress was measured using the Perceived Stress Scale 14. We also asked participants about pandemic-related changes in social contact across various domains. Adjusted birth weight was calculated from birth records or participant-report when birth records were unavailable.

RESULTS

Decreases in social contact during the pandemic were associated with lower adjusted infant birth weight (B = 76.82, SE = 35.82, p = .035). This association was mediated by maternal prenatal depressive symptoms [Effect = 15.06, 95 % CI (0.19, 35.58)] but not by prenatal anxiety [95 % CI (-0.02, 32.38)] or stress [95 % CI (-0.31, 26.19)].

CONCLUSION

These findings highlight concerns for both mothers and infants in the wake of the COVID-19 pandemic, since birth weight can have long-term health implications and the social restructuring occasioned by the pandemic may lead to lasting changes in social behavior.

Prenatal per- and polyfluoroalkyl substances (PFAS) exposure in relation to preterm birth subtypes and size-for-gestational age in the LIFECODES cohort 2006-2008

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals widely used in consumer and industrial products. Numerous studies have linked prenatal PFAS exposures to increased risks of adverse pregnancy outcomes such as preterm birth (PTB) and small-for-gestational age (SGA).However, limited evidence is available for the effects of PFAS on PTB subtypes and large-for-gestational age (LGA).

OBJECTIVE

To examine the associations of PFAS with PTB [overall, placental (pPTB), spontaneous (sPTB)], BW Z-score, and size-for-gestational age (SGA, LGA).

METHODS

Our nested case-control study included 128 preterm cases and 373 term controls from the LIFECODES cohort between 2006 and 2008 (n = 501). Plasma concentrations of nine PFAS were measured in early pregnancy samples. Logistic regression was used to assess individual PFAS-birth outcome associations, while Bayesian Kernel Machine Regression (BKMR) was used to evaluate the joint effects of all PFAS. Effect modification by fetal sex was examined, and stratified analyses were conducted to obtain fetal sex-specific estimates.

RESULTS

Compared to term births, the odds of pPTB were higher from an interquartile range increase in perfluorodecanoic acid (PFDA) (OR = 1.60, 95% CI: 1.00-2.56), perfluorononanoic acid (PFNA) (OR = 1.67, 95% CI: 1.06-2.61), and perfluoroundecanoic acid (PFUA) (OR = 1.77, 95% CI: 1.00-3.12), with stronger associations observed in women who delivered males. BKMR analysis identified PFNA as the most important PFAS responsible for pPTB (conditional PIP = 0.78), with increasing ORs at higher percentiles of PFAS mixture. For LGA, positive associations were observed with PFDA and perfluorooctanoic acid in females only, and with PFUA in males only. BKMR analysis showed increasing, but null effects of PFAS mixture on LGA.

CONCLUSIONS

The effect of prenatal exposure to single and multiple PFAS on PTB and LGA depended on fetal sex. Future studies should strongly consider examining PTB subtypes and sex-specific effects of PFAS on pregnancy outcomes.

Electronic cigarette use during pregnancy and the risk of adverse birth outcomes: A cross-sectional surveillance study of the US Pregnancy Risk Assessment Monitoring System (PRAMS) population

BACKGROUND

Research on health effects and potential harms of electronic cigarette (EC) use during pregnancy is limited. We sought to determine the risks of pregnancy EC use on pregnancy-related adverse birth outcomes and assess whether quitting ECs reduces the risks.

METHODS

Women with singleton live births who participated in the US Pregnancy Risk Assessment Monitoring System (PRAMS) survey study 2016-2020 were classified into four mutually exclusive groups, by their use of ECs and combustible cigarettes (CCs) during pregnancy: non-use, EC only use, CC only use, and dual use. We determined the risk of preterm birth, low birth weight, and small-for-gestational-age (SGA) by comparing cigarette users to non-users with a modified Poisson regression model adjusting for covariates. In a subset of women who all used ECs prior to pregnancy, we determined whether quitting EC use reduces the risk of preterm birth, low birth weight, and SGA by comparing to those who continued its use. All analyses were weighted to account for the PRAMS survey design and non-response rate.

RESULTS

Of the 190,707 women (weighted N = 10,202,413) included, 92.1% reported cigarette non-use, 0.5% EC only use, 6.7% CC only use, and 0.7% dual use during pregnancy. Compared with non-use, EC only use was associated with a significantly increased risk of preterm birth (adjusted risk ratio [aRR]: 1.29, 95% confidence interval [CI]: 1.00, 1.65) and low birth weight (aRR: 1.38, 95%CI: 1.09, 1.75), but not SGA (aRR: 1.04, 95%CI: 0.76, 1.44). Among 7,877 (weighted N = 422,533) women EC users, quitting use was associated with a significantly reduced risk of low birth weight (aRR: 0.76, 95%CI: 0.62, 0.94) and SGA (aRR: 0.77, 95%CI: 0.62, 0.94) compared to those who continued to use ECs during pregnancy.

CONCLUSIONS

Pregnancy EC use, by itself or dual use with CC, is associated with preterm birth and low birth weight. Quitting use reduces that risk. ECs should not be considered as a safe alternative nor a viable gestational smoking cessation strategy.

Dousing the flame: reviewing the mechanisms of inflammatory programming during stress-induced intrauterine growth restriction and the potential for ω-3 polyunsaturated fatty acid intervention

Intrauterine growth restriction (IUGR) arises when maternal stressors coincide with peak placental development, leading to placental insufficiency. When the expanding nutrient demands of the growing fetus subsequently exceed the capacity of the stunted placenta, fetal hypoxemia and hypoglycemia result. Poor fetal nutrient status stimulates greater release of inflammatory cytokines and catecholamines, which in turn lead to thrifty growth and metabolic programming that benefits fetal survival but is maladaptive after birth. Specifically, some IUGR fetal tissues develop enriched expression of inflammatory cytokine receptors and other signaling cascade components, which increases inflammatory sensitivity even when circulating inflammatory cytokines are no longer elevated after birth. Recent evidence indicates that greater inflammatory tone contributes to deficits in skeletal muscle growth and metabolism that are characteristic of IUGR offspring. These deficits underlie the metabolic dysfunction that markedly increases risk for metabolic diseases in IUGR-born individuals. The same programming mechanisms yield reduced metabolic efficiency, poor body composition, and inferior carcass quality in IUGR-born livestock. The ω-3 polyunsaturated fatty acids (PUFA) are diet-derived nutraceuticals with anti-inflammatory effects that have been used to improve conditions of chronic systemic inflammation, including intrauterine stress. In this review, we highlight the role of sustained systemic inflammation in the development of IUGR pathologies. We then discuss the potential for ω-3 PUFA supplementation to improve inflammation-mediated growth and metabolic deficits in IUGR offspring, along with potential barriers that must be considered when developing a supplementation strategy.

The Interactions between Maternal Iron Supplementation and Iron Metabolism-Related Genetic Polymorphisms on Birth Outcomes: A Prospective Study in Chinese

BACKGROUND

The effect of iron supplementation during pregnancy on birth outcomes may vary with maternal genetic background and needs more investigation.

OBJECTIVES

This prospective study aimed to evaluate the interactions between maternal iron supplementation and iron metabolism-related genetic polymorphisms on birth outcomes.

METHODS

This was a substudy from a community-based randomized control trial conducted in Northwest China, which included 860 women from the 2 micronutrient supplementation groups (folic acid [FA] and FA + iron group). Maternal peripheral blood, sociodemographic and health-related information, and neonatal birth outcomes were collected. Six single nucleotide polymorphisms in iron metabolism-related genes were genotyped. The alleles associated with decreased iron/hemoglobin status were used as the effect alleles. The genetic risk score (GRS) that reflected the genetic risk of low iron/hemoglobin status was estimated using the unweighted and weighted methods. Generalized estimating equations with small-sample corrections were applied to evaluate the interactions between iron supplementation and SNPs/GRS on birth outcomes.

RESULTS

There were significant interactions between maternal iron supplementation and rs7385804 (P = 0.009), rs149411 (P = 0.035), rs4820268 (P = 0.031), the unweighted GRS (P = 0.018), and the weighted GRS (P = 0.009) on birth weight. Compared with FA supplementation only, FA + iron supplementation significantly increased birth weight among women with more effect alleles in rs7385804 (β: 88.8 g, 95% CI: 9.2, 168.3) and the GRSs (the highest unweighted GRS, β: 135.5 g, 95% CI: 7.7, 263.4; the highest weighted GRS, β: 145.9 g, 95% CI: 43.4, 248.5); it had a trend of decreasing birth weight and increasing low birth weight risk among women with fewer effect alleles.

CONCLUSIONS

In our population, maternal genetic background related to iron metabolism plays a significant role in determining the efficacy of iron supplementation. Routine iron supplementation could be more beneficial to fetal weight growth among mothers with higher genetic risk for low iron/hemoglobin status.

Review: Nutritional regulation of muscle growth in neonatal swine

Despite advances in the nutritional support of low birth weight and early-weaned piglets, most experience reduced extrauterine growth performance. To further optimize nutritional support and develop targeted intervention strategies, the mechanisms that regulate the anabolic response to nutrition must be fully understood. Knowledge gained in these studies represents a valuable intersection of agriculture and biomedical research, as low birth weight and early-weaned piglets face many of the same morbidities as preterm and low birth weight infants, including extrauterine growth faltering and reduced lean growth. While the reasons for poor growth performance are multifaceted, recent studies have increased our understanding of the role of nutrition in the regulation of skeletal muscle growth in the piglet. The purpose of this review is to summarize the published literature surrounding advances in the current understanding of the anabolic signaling that occurs after a meal and how this response is developmentally regulated in the neonatal pig. It will focus on the regulation of protein synthesis, and especially the upstream and downstream effectors surrounding the master protein kinase, mechanistic target of rapamycin complex 1 (mTORC1) that controls translation initiation. It also will examine the regulatory pathways associated with the postprandial anabolic agents, insulin and specific amino acids, that are upstream of mTORC1 and lead to its activation. Lastly, the integration of upstream signaling cascades by mTORC1 leading to the activation of translation initiation factors that regulate protein synthesis will be discussed. This review concludes that anabolic signaling cascades are stimulated by both insulin and amino acids, especially leucine, through separate pathways upstream of mTORC1, and that these stimulatory pathways result in mTORC1 activation and subsequent activation of downstream effectors that regulate translation initiation Additionally, it is concluded that this anabolic response is unique to the skeletal muscle of the neonate, resulting from increased sensitivity to the rise in both insulin and amino acid after a meal. However, this response is dampened in skeletal muscle of the low birth weight pig, indicative of anabolic resistance. Elucidation of the pathways and regulatory mechanisms surrounding protein synthesis and lean growth allow for the development of potential targeted therapeutics and intervention strategies both in livestock production and neonatal care.

Relationship between placental pathology and neonatal outcomes

Objective

To evaluate the relationship between maternal vascular malperfusion and acute intrauterine infection/inflammation with neonatal outcomes.

Methods

This was a retrospective study of women with singleton pregnancies who completed placenta pathological examination. The aim was to study the distribution of acute intrauterine infection/inflammation and maternal placental vascular malperfusion among groups with preterm birth and/or rupture of membranes. The relationship between two subtypes of placental pathology and neonatal gestational age, birth weight Z-score, neonatal respiratory distress syndrome, and intraventricular hemorrhage was further explored.

Results

990 pregnant women were divided into four groups, including 651 term, 339 preterm, 113 women with premature rupture of membranes, and 79 with preterm premature rupture of membranes. The incidence of respiratory distress syndrome and intraventricular hemorrhage in four groups were (0.7%, 0.0%, 31.9%, 31.6%, P < 0.001) and (0.9%, 0.9%, 20.0%, 17.7%, P < 0.001), respectively. The incidence of maternal vascular malperfusion and acute intrauterine infection/inflammation were (82.0%, 77.0%, 75.8%, 72.1%, P = 0.06) and (21.9%, 26.5%, 23.1%, 44.3%, P = 0.010), respectively. Acute intrauterine infection/inflammation was associated with shorter gestational age (adjusted difference -4.7 weeks, P < 0.001) and decreased weight (adjusted Z score -2.6, P < 0.001) than those with no lesions in preterm birth. When two subtype placenta lesions co-occurrence, shorter gestational age (adjusted difference -3.0 weeks, P < 0.001) and decreased weight (adjusted Z score -1.8, P < 0.001) were observed in preterm. Consistent findings were observed in preterm births with or without premature rupture of membranes. In addition, acute infection/inflammation and maternal placenta malperfusion alone or in combination were associated with an increased risk of neonatal respiratory distress syndrome (adjusted odds ratio (aOR) 0.8, 1.5, 1.8), but the difference was not statistically significant.

Conclusion

Maternal vascular malperfusion and acute intrauterine infection/inflammation alone or co-occurrence are associated with adverse neonatal outcomes, which may provide new ideas for clinical diagnosis and treatment.

Issue of Data Imbalance on Low Birthweight Baby Outcomes Prediction and Associated Risk Factors Identification: Establishment of Benchmarking Key Machine Learning Models With Data Rebalancing Strategies

BACKGROUND

Low birthweight (LBW) is a leading cause of neonatal mortality in the United States and a major causative factor of adverse health effects in newborns. Identifying high-risk patients early in prenatal care is crucial to preventing adverse outcomes. Previous studies have proposed various machine learning (ML) models for LBW prediction task, but they were limited by small and imbalanced data sets. Some authors attempted to address this through different data rebalancing methods. However, most of their reported performances did not reflect the models' actual performance in real-life scenarios. To date, few studies have successfully benchmarked the performance of ML models in maternal health; thus, it is critical to establish benchmarks to advance ML use to subsequently improve birth outcomes.

OBJECTIVE

This study aimed to establish several key benchmarking ML models to predict LBW and systematically apply different rebalancing optimization methods to a large-scale and extremely imbalanced all-payer hospital record data set that connects mother and baby data at a state level in the United States. We also performed feature importance analysis to identify the most contributing features in the LBW classification task, which can aid in targeted intervention.

METHODS

Our large data set consisted of 266,687 birth records across 6 years, and 8.63% (n=23,019) of records were labeled as LBW. To set up benchmarking ML models to predict LBW, we applied 7 classic ML models (ie, logistic regression, naive Bayes, random forest, extreme gradient boosting, adaptive boosting, multilayer perceptron, and sequential artificial neural network) while using 4 different data rebalancing methods: random undersampling, random oversampling, synthetic minority oversampling technique, and weight rebalancing. Owing to ethical considerations, in addition to ML evaluation metrics, we primarily used recall to evaluate model performance, indicating the number of correctly predicted LBW cases out of all actual LBW cases, as false negative health care outcomes could be fatal. We further analyzed feature importance to explore the degree to which each feature contributed to ML model prediction among our best-performing models.

RESULTS

We found that extreme gradient boosting achieved the highest recall score-0.70-using the weight rebalancing method. Our results showed that various data rebalancing methods improved the prediction performance of the LBW group substantially. From the feature importance analysis, maternal race, age, payment source, sum of predelivery emergency department and inpatient hospitalizations, predelivery disease profile, and different social vulnerability index components were important risk factors associated with LBW.

CONCLUSIONS

Our findings establish useful ML benchmarks to improve birth outcomes in the maternal health domain. They are informative to identify the minority class (ie, LBW) based on an extremely imbalanced data set, which may guide the development of personalized LBW early prevention, clinical interventions, and statewide maternal and infant health policy changes.

Newborn Outcomes Among Veterans Utilizing VHA Maternity Benefits, 2016-2020

INTRODUCTION

Public Law 111-163 Section 206 of the Caregivers and Veteran Omnibus Health Services Act amended the Veterans Health Administration's (VHA) medical benefits package to include 7 days of medical care for newborns delivered by Veterans. We examined the newborn outcomes among a cohort of women Veterans receiving VHA maternity benefits and care coordination.

MATERIALS AND METHODS

We conducted a secondary analysis of phone interview data from Veterans enrolled in the COMFORT (Center for Maternal and Infant Outcomes Research in Translation) study 2016-2020. Multivariable regression estimated associations with newborn outcomes (preterm birth; low birthweight).

RESULTS

During the study period, 829 infants were born to 811 Veterans. Mothers reported "excellent health" for 94% of infants. The prevalence of preterm birth was slightly higher in our cohort (11% vs. 10%), as were low birthweight (9%) deliveries, compared to the general population (8.28%). Additionally, 42% of infants in our cohort required follow-up care for non-routine health conditions; 11% were uninsured at 2 months of age. Adverse newborn outcomes were more common for mothers who were older in age, self-identified as non-white in race and/or of Hispanic ethnicity, had a diagnosis of posttraumatic stress disorder, or had gestational comorbidities.

CONCLUSIONS

The current VHA maternity coverage appears to be an effective policy for ensuring the well-being and health care coverage for the majority of Veterans and their newborns in the first days of life, thereby reducing the risk of inadequate prenatal and neonatal care. Future research should examine costs associated with extending coverage to 14 days or longer, comparing those to the projected excess costs of neonatal health problems. VHA policy should continue to support expanding care and resources through the Maternity Care Coordinator model.

Effect of Adherence to the Mediterranean Diet on Maternal Iron Related Biochemical Parameters during Pregnancy and Gestational Weight Gain

Gestation is a crucial life stage for both women and offspring, and outcomes are affected by many environmental factors, including diet. The Mediterranean dietary pattern (MD) is considered a healthy eating pattern that can provide the nutritional requirements of pregnancy. Meanwhile, iron deficiency anemia is one of the most frequent complications related to pregnancy. This study aimed to evaluate how the level of adherence to the MD influences maternal gestational weight gain and specific iron-related maternal biochemical parameters during the pregnancy. Accordingly, an observational, population-based study using data from pregnant women conducted over the entire course of their pregnancy was carried out. Adherence to the MD was assessed once using the MEDAS score questionnaire. Of the 506 women studied, 116 (22.9%) were classified as demonstrating a high adherence, 277 (54.7%) a medium adherence, and 113 (22.3%) a low adherence to the MD. No differences were observed in gestational weight gain among the MD adherence groups but the adequacy of weight gain did vary among the groups, with the proportions of inadequate (insufficient or excessive) weight gain presenting the most notable differences. Total anemia prevalence was 5.3%, 15.6%, and 12.3%, respectively, during the first, second, and third trimesters. For iron-related biochemical parameters, no differences are observed among the adherence groups during pregnancy. With high adherence to the MD as the reference group, the crude odds of iron deficiency diagnosis are significant in the first trimester for both the medium [OR = 2.99 (1.55-5.75)] and low [OR = 4.39 (2.15-8.96)] adherence groups, with deficient adherence to the Mediterranean dietary pattern being responsible for 66.5% (35.5-82.6) and 77.2% (53.5-88.8) of the risk of iron deficiency diagnosis for medium and low adherence, respectively. However, adjusted odds ratios were not significant, possibly due to the small sample size. Our data suggest that MD adherence could be related to gestational weight gain adequacy and that optimal adherence could reduce iron deficiency and/or anemia during pregnancy in the studied population.

The application of intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) to examine birthweight inequities in New York City

Exploring the intersection of dimensions of social identity is critical for understanding drivers of health inequities. We used multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) to examine the intersection of age, race/ethnicity, education, and nativity status on infant birthweight among singleton births in New York City from 2012 to 2018 (N = 725,875). We found evidence of intersectional effects of various systems of oppression on birthweight inequities and identified U.S.-born Black women as having infants of lower-than-expected birthweights. The MAIHDA approach should be used to identify intersectional causes of health inequities and individuals affected most to develop policies and interventions redressing inequities.

Association between inadequate prenatal care and low birth weight of newborns in Peru: Evidence from a peruvian demographic and health survey

Objective

To assess the association between inadequate prenatal care (IPNC) and Low birth weight (LBW) in newborns of singleton gestation mothers in Peru.

Methods

We performed a secondary analysis of data from the 2019 Demographic and Health Survey. We included a total of 10,186 women of reproductive age (15 - 49 years) who had given birth to a singleton child in the last 5 years. The dependent variable was LBW (< 2500 g). The independent variables were IPNC (inadequate: when at least one of the IPNC components was absent [number of PNC visits ≥ 6, first PNC visit during the first trimester, compliance with PNC visit contents, and PNC visits provided by trained health personnel]) and each of its components. We evaluated the association using logistic regression models to estimate crude odds ratios and adjusted odds ratios (aOR) and their respective 95% confidence intervals (95% CI).

Results

We found that approximately six out of 100 live births had LBW and that seven out of 10 women had received IPNC. We observed that receiving IPNC (aOR: 1.39; 95% CI: 1.09 - 1.77) and having less than six prenatal control visits (aOR: 3.20; 95% CI: 2.48 - 4.13) were associated with higher odds of LBW regardless of the mother's age, educational level, occupation, wealth, region, rural origin, ethnicity, sex of the newborns, and place of delivery. While, regarding to the other PNC components, first prenatal control in the first trimester (aOR: 0.99; 95% CI: 0.76 - 1.28) and compliance with prenatal control contents (aOR: 1.07; 95% CI: 0.86 - 1.34), they were associated with lower and higher odds of LBW, respectively, regardless of the same adjustment variables, but it was not statistically significant.

Conclusions

IPNC and having less than six PNC visits were associated with higher odds of LBW. Therefore, it is very important to implement strategies that ensure access to quality prenatal care is necessary to reduce the consequences of LBW.

Birth weight concerning obesity and diabetes gene expression in healthy infants; a case-control study

Background

Since obesity and diabetes are prevalent worldwide, identifying the factors affecting these two conditions can effectively alter them. We decided to investigate the expression of obesity and diabetes genes in infants with birth weights lower than 2500 g in comparison with infants with normal birth weights.

Methods

215 healthy infants between the ages of 5–6 months were used in the current case-control research, which was conducted at health and treatment facilities in Kermanshah. Infants who were healthy were chosen for the research after their weight and height were measured and compared to the WHO diagram to ensure that they were well-grown and in good health. There were 137 infants in the control group and 78 infants in the case group. All newborns had 5 cc of blood drawn intravenously. To assess the expression of the genes MC4R, MTNR1B, PTEN, ACACB, PPAR-γ, PPAR-α, NRXN3, NTRK2, PCSK1, A2BP1, TMEM18, LXR, BDNF, TCF7L2, FTO and CPT1A, blood samples were gathered in EDTA-coated vials. Chi-square, Mann-Whitney U, and Spearman analyses were used to examine the data.

Results

A significant inverse correlation between birth weight and obesity and diabetes genes, including MTNR1B, NTRK2, PCSK1, and PTEN genes (r= -0.221, -0.235, -0.246, and − 0.418, respectively). In addition, the LBW infant’s expression level was significantly up-regulated than the normal-weight infants (P = 0.001, 0.007, 0.001, and < 0.001, respectively). The expression level of the PPAR-a gene had a significantly positive correlation with birth weight (r = 0.19, P = 0.005). The expression level of the PPAR-a gene in the normal-weight infants was significantly up-regulated than the LBW infants (P = 0.049).

Conclusion

The expression levels of MTNR1B, NTRK2, PCSK1, and PTEN genes were up-regulated in the LBW infants; however, the expression level of PPAR-a gene was significantly down-regulated in the LBW infants compared to the infants with normal birth weight.

Identification of anthropometric surrogate measurements and their cut-off points for the detection of low birth weight and premature newborn babies using ROC Analysis

Despite the fact that health facilities in Ethiopia are being built closer to communities in all regions, the proportion of home deliveries remains high, and there are no studies being conducted to identify low birth weight (LBW) and premature newborn babies using simple, best, alternative, and appropriate anthropometric measurement in the study area. The objective of the present study was to find the simple, best, and alternative anthropometric measurement and identified its cut-off points for detecting LBW and premature newborn babies. A health facility-based cross-sectional study was conducted in the Dire Dawa city administration, Eastern Ethiopia. The study included 385 women who gave birth in health facility. To evaluate the overall accuracy of the anthropometric measurements, a non-parametric receiver operating characteristic curve was used. Chest circumference (AUC = 0⋅95) with 29⋅4 cm and mean upper arm circumference (AUC = 0⋅93) with 7⋅9 cm proved to be the best anthropometric diagnostic measure for LBW and gestational age, respectively. Also, both anthropometric measuring tools are achieved the highest correlation (r = 0⋅62) for LBW and gestational age. Foot length had a higher sensitivity (94⋅8 %) in detecting LBW than other measurements, with a higher negative predictive value (NPV) (98⋅4 %) and a higher positive predictive value (PPV) (54⋅8 %). Chest circumference and mid-upper arm circumference were found to be better surrogate measurements for identifying LBW and premature babies in need of special care. More research is needed to identify better diagnostic interventions in situations like the study area, which has limited resources and a high proportion of home deliveries.

Relationship between historical developments in the percentages of low birthweight and fetal mortality in Spain

OBJECTIVE

To document the differences in low birthweight in different population subgroups and to analyze its possible relationship with fetal mortality rates in Spain.

METHOD

We used the microdata on live births and stillbirths since 1975 to 2020 from the Spanish National Statistics Institute to examine differentials in delivering a low birthweight controlling for different sociodemographic variables and to determine the relationship between low birthweight and fetal mortality. No statistical analysis was necessary beyond the calculation of percentages and rates.

RESULTS

The data at our disposal for Spain confirm the historical increase in the incidence of low birthweight and allow us to link trends in low birthweight with a decrease in the fetal mortality rate. When fetal mortality is high, the incidence of low birthweight is low, given that a natural selection effect takes place.

CONCLUSIONS

The surprising historical increase in the incidence of low birthweight in Spain can be explained by the improvement in mortality rates. As more fetuses of lower gestational age are born alive, cases of low birthweight also increase.

Using network analysis to illuminate the intergenerational transmission of adversity

Objective: The effects of maternal exposure to adverse childhood experiences (ACEs) may be transmitted to subsequent generations through various biopsychosocial mechanisms. However, studies tend to focus on exploring one or two focal pathways with less attention paid to links between different pathways. Using a network approach, this paper explores a range of core prenatal risk factors that may link maternal ACEs to infant preterm birth (PTB) and low birthweight (LBW). Methods: We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC) (n = 8379) to estimate two mixed graphical network models: Model 1 was constructed using adverse infant outcomes, biopsychosocial and environmental risk factors, forms of ACEs, and sociodemographic factors. In Model 2, ACEs were combined to represent a threshold ACEs score (≥4). Network indices (i.e., shortest path and bridge expected influence [1-step & 2-step]) were estimated to determine the shortest pathway from ACEs to infant outcomes, and to identify the risk factors that are vital in activating other risk factors and adverse outcomes. Results: Network analyses estimated a mutually reinforcing web of childhood and prenatal risk factors, with each risk connected to at least two other risks. Bridge influence indices suggested that childhood physical and sexual abuse and multiple ACEs were highly interconnected to others risks. Overall, risky health behaviours during pregnancy (i.e., smoking & illicit drug use) were identified as 'active' risk factors capable of affecting (directly and indirectly) other risk factors and contributing to the persistent activation of the global risk network. These risks may be considered priority candidate targets for interventions to disrupt intergenerational risk transmission. Our study demonstrates the promise of network analysis as an approach for illuminating the intergenerational transmission of adversity in its full complexity.

HIGHLIGHTS

We took a network approach to assessing links between ACEs and birth outcomes.ACEs, other prenatal risk factors, and birth outcomes had complex inter-connectionsHealth behaviours in pregnancy were indicated as optimal intervention targets.

The Associations of Maternal Hemoglobin Concentration in Different Time Points and Its Changes during Pregnancy with Birth Weight Outcomes

Maternal hemoglobin (Hb) is related to nutritional status, which affects neonatal birth weight. However, it is very common for maternal Hb to fluctuate during pregnancy. To evaluate the associations of maternal Hb in different time points and its changes during pregnancy with neonatal birth weight, small for gestational age (SGA)/low birth weight (LBW) and large for gestational age (LGA)/macrosomia, we conducted this study by using data from the Electronic Medical Record System (EMRS) database of Zhoushan Maternal and Child Care Hospital in Zhejiang province, China. The pregnancy was divided into five periods: first, early-second, mediate-second, late-second, early-third and late-third trimesters; we further calculated the maternal Hb changes during pregnancy. Overall, the socio-demographic characteristics, health-related information and childbirth-related information of 24,183 mother−infant pairs were obtained. The average Hb concentration during the different periods were 123.95 ± 10.14, 117.95 ± 9.84, 114.31 ± 9.03, 113.26 ± 8.82, 113.29 ± 8.68 and 115.01 ± 8.85 g/L, respectively. Significant dose−response relationships between maternal Hb and birth weight were observed in the first, late-second and later trimesters (p non-linear < 0.05). Maternal Hb < 100 g/L was related to a high risk of LGA/macrosomia in the late-second (OR: 1.47, 95% CI: 1.18, 1.83) and later trimesters; additionally, high maternal Hb (>140 g/L) increased the risk of SGA/LBW in the first (OR: 1.26, 95% CI: 1.01, 1.57) and late-third trimesters (OR: 1.96, 95% CI: 1.20, 3.18). In addition, the increase in maternal Hb from the late-second to late-third trimesters had a positive correlation with SGA/LBW. In conclusion, maternal Hb markedly fluctuated during pregnancy; the negative dose−response association of maternal Hb in the late-second and third trimesters, and Hb change during pregnancy with neonatal birth weight outcomes were observed, respectively. Furthermore, the phenomenon of high Hb in the first trimester and after the late-second trimester and the increase of maternal Hb from the late-second to late-third trimesters more significantly increasing the risk of SGA/LBW should especially be given more attention. Its biological mechanism needs to be further explored.

A time series analysis of ambient air pollution and low birth weight in Xuzhou, China

The objective of this study was to examine the relationship between weekly specific maternal air pollution exposures and low birth weight. We fitted a distributed lag nonlinear model (DLNM) to analyze the nonlinear exposure-response association and delayed effects of air pollutants on the risk for low birth weight. The model assumed that all live births have 40 gestational weeks.The 1st week lag was the 40th gestational week, and 40th lag week was the 1st gestational week.The study included 71,809 live births (from July 1, 2016, to June 30, 2019), of which 2,391 (3.33%) exhibited low birth weight. The results demonstrated that exposure of pregnant women to PM10 at lag 22-30 weeks was significantly associated with low birth weight risk, with the greatest impact at the lag 30 week. Exposure to SO2 at lag 29-37 weeks was significantly associated with low birth weight risk. The sensitive exposure window for NO2 began at lag 25-37 weeks of pregnancy. The lag 6-10 weeks constituted the susceptible exposure window for O3. Therefore we concluded that maternal exposures to PM10, SO2, NO2, and O3 were associated with increased risk for low birth weight.

Trends in Mortality of Low Birth Weight Infants - China, 2004-2019

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?

Low birth weight (LBW) significantly affects the health of children during the perinatal period, neonatal period, and infancy, and is an important risk factor for neonatal death.

WHAT IS ADDED BY THIS REPORT?

The mortality rate of low birth weight infants(LBWI) decreased from 2004 to 2019 in China, while the proportion of overall infant deaths due to LBW increased.

WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICES?

A key way to reduce child mortality and improve children's health is to reduce the occurrence of LBW and associated mortality.

Joint associations among prenatal metal mixtures and nutritional factors on birth weight z-score: Evidence from an urban U.S. population

The benefits of nutritional factors on birth outcomes have been recognized, however, limited studies have examined the role of nutritional factors in mitigating the detrimental effects of metals exposure during gestation. We used data collected from 526 mother-infant dyads enrolled in the Programming of Intergenerational Stress Mechanisms longitudinal pregnancy cohort to examine the joint effects of prenatal exposure to metals and maternal nutrition on birth weight for gestational age (BWGA) z-scores. We measured concentrations of twelve metals and trace elements in urine samples collected during pregnancy. Maternal nutritional intake was measured using the Block98 Food Frequency Questionnaire and converted into energy-adjusted consumption of individual nutrients. Using multivariable linear regression and Bayesian Kernel Machine Regression, we found that three metals [cobalt (Co), nickel (Ni), and lead (Pb)] and five metals [barium (Ba), caesium (Cs), copper (Cu), Ni, and zinc (Zn)] were associated with BWGA z-score in male and female infants, respectively. When examining the sex-specific interactions between these metals and nutrient groups [macro nutrients, minerals, A vitamins, B vitamins, anti-oxidant, methyl-donor nutrients, and inflammatory (pro- and anti-)] using a Cross-validated Kernel Ensemble model, we identified significant interactions between the macro nutrients and Co (p = 0.05), minerals and Pb (p = 0.04), and A vitamins and Ni (p = 0.001) in males. No significant interactions were found in females. Furthermore, three minerals (phosphorus, iron, potassium) and vitamin A were found to be more crucial than other nutrients in modifying the association between each respective metal and BWGA z-score in males. A better understanding of the sex-specific interactions between nutrients and metals on birth weight can guide pregnant women to protect their neonates from the adverse health impacts of metal exposures by optimizing nutrient intakes accordingly.

RNA-seq reveals insights into molecular mechanisms of metabolic restoration via tryptophan supplementation in low birthweight piglet model

Low birth weight (LBW) is associated with metabolic disorders in early life. While dietary l-tryptophan (Trp) can ameliorate postprandial plasma triglycerides (TG) disposal in LBW piglets, the genetic and biological basis underlying Trp-caused alterations in lipid metabolism is poorly understood. In this study, we collected 24 liver samples from 1-mo-old LBW and normal birth weight (NBW) piglets supplemented with different concentrations of dietary Trp (NBW with 0% Trp, N0; LBW with 0% Trp, L0; LBW with 0.4% Trp, L4; LBW with 0.8% Trp, L8; N = 6 in each group.) and conducted systematic, transcriptome-wide analysis using RNA sequencing (RNA-seq). We identified 39 differentially expressed genes (DEG) between N0 and L0, and genes within “increased dose effect” clusters based on dose-series expression profile analysis, enriched in fatty acid response of gene ontology (GO) biological process (BP). We then identified RNA-binding proteins including SRSF1, DAZAP1, PUM2, PCBP3, IGF2BP2, and IGF2BP3 significantly (P < 0.05) enriched in alternative splicing events (ASE) in comparison with L0 as control. There were significant positive and negative relationships between candidate genes from co-expression networks (including PID1, ANKRD44, RUSC1, and CYP2J34) and postprandial plasma TG concentration. Further, we determined whether these candidate hub genes were also significantly associated with metabolic and cardiovascular traits in humans via human phenome-wide association study (Phe-WAS), and analysis of mammalian orthologs suggests a functional conservation between human and pig. Our work demonstrates that transcriptomic changes during dietary Trp supplementation in LBW piglets. We detected candidate genes and related BP that may play roles on lipid metabolism restoration. These findings will help to better understand the amino acid support in LBW metabolic complications.

Long-Term Consequences of Adaptive Fetal Programming in Ruminant Livestock

Environmental perturbations during gestation can alter fetal development and postnatal animal performance. In humans, intrauterine growth restriction (IUGR) resulting from adaptive fetal programming is known as a leading cause of perinatal morbidity and mortality and predisposes offspring to metabolic disease, however, the prevalence and impact in livestock is not characterized as well. Multiple animal models have been developed as a proxy to determine mechanistic changes that underlie the postnatal phenotype resulting from these programming events in humans but have not been utilized as robustly in livestock. While the overall consequences are similar between models, the severity of the conditions appear to be dependent on type, timing, and duration of insult, indicating that some environmental insults are of more relevance to livestock production than others. Thus far, maternofetal stress during gestation has been shown to cause increased death loss, low birth weight, inefficient growth, and aberrant metabolism. A breadth of this data comes from the fetal ruminant collected near term or shortly thereafter, with fewer studies following these animals past weaning. Consequently, even less is known about how adaptive fetal programming impacts subsequent progeny. In this review, we summarize the current knowledge of the postnatal phenotype of livestock resulting from different models of fetal programming, with a focus on growth, metabolism, and reproductive efficiency. We further describe what is currently known about generational impacts of fetal programming in production systems, along with gaps and future directions to consider.

Decadal change in the association between the status of young mother's Body Mass Index and anaemia with child low birth weight in India

Background

The study aims to investigate the changes in the socio-economic and demographic status of young mothers of age 15–24 years and to examine the association between mothers’ nutrition, i.e., Body Mass Index (BMI) and anaemia with child low birth weight for almost two decades during 1998–2016 in India.

Methods

National Family Health Survey (NFHS) round II and IV were used. The sample of this study included 3405 currently married young mothers from NFHS II and 44,742 from NFHS IV who gave birth at least one child in the last three years preceding the surveys. Logistic regression and Blinder-Oaxaca decomposition analysis have been used in this study to examine the corresponding association between the concerned variables.

Results

The analysis showed that the prevalence of low birth weight (LBW) babies has decreased from 26.1 to 22.8 for the 15 to 19 age group and from 20.4 to 18.7 for the 20 to 24 age group over time. Young mothers with low BMI or severe anaemia have shown higher odds of having LBW babies. For instance, the odds of having a LBW child was 1.44 (p-value = 0.000; 95% CI: 1.05, 1.65) for mothers with low BMI and 1.55 (p-value = 0.000; 95% CI: 1.27, 1.90) with severe anaemia. Over the decade, the association of LBW babies with mothers’ nutrition has decreased. The odds of LBW with mothers with low BMI decreased from 1.63 (p-value = 0.004; 95% CI: 1.21, 2.21) to 1.41 (p-value = 0.000; 95% CI: 1.27, 1.55). Similarly, mothers with severe anaemia, the odds of LBW child decreased from 2.6 (p-value = 0.000; 95% CI: 1.75, 3.8) in 1998 to 1.3 (p-value = 0.024; 95% CI: 1.02, 1.65) in 2016.

Conclusions

The maternal and child health improvement in India has been moderate over the decade. Still, a significant proportion of the women are suffering from poor health and young mothers are at more risk to deliver LBW babies. It is highly recommended to integrate maternal and child health programmes with the ongoing health policies to improve the situation while taking additional care of the young pregnant mother and their nutritional health.

Maternal Hemoglobin Concentrations and Birth Weight, Low Birth Weight (LBW), and Small for Gestational Age (SGA): Findings from a Prospective Study in Northwest China

Birth weight and related outcomes have profound influences on life cycle health, but the effect of maternal hemoglobin concentration during pregnancy on birth weight is still unclear. This study aims to reveal the associations between maternal hemoglobin concentrations in different trimesters of pregnancy and neonatal birth weight, LBW, and SGA. This was a prospective study based on a cluster-randomized controlled trial conducted from July 2015 to December 2019 in rural areas of Northwest China. Information on maternal socio-demographic status, health-related factors, antenatal visits, and neonatal birth outcomes were collected. A total of 3748 women and their babies were included in the final analysis. A total of 65.1% and 46.3% of the participants had anemia or hemoglobin ≥ 130 g/L during pregnancy. In the third trimester, maternal hemoglobin concentration was associated with birth weight in an inverted U-shaped curve and with the risks of LBW and SGA in extended U-shaped curves. The relatively higher birth weight and lower risks for LBW and SGA were observed when hemoglobin concentration was 100–110 g/L. When maternal hemoglobin was <70 g/L or >130 g/L, the neonatal birth weight was more than 100 g lower than that when the maternal hemoglobin was 100 g/L. In conclusion, both low and high hemoglobin concentrations in the third trimester could be adverse to fetal weight growth and increase the risks of LBW and SGA, respectively. In addition to severe anemia, maternal hemoglobin >130 g/L in the third trimester should be paid great attention to in the practice of maternal and child health care.

Association between birth weight and neurodevelopmental disorders assessed using the Korean National Health Insurance Service claims data

The risk of neurodevelopmental disorders in low birth weight (LBW) infants has gained recognition but remains debatable. We investigated the risk of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in school-aged children according to their birth weight. We conducted a retrospective cohort study using the Korean National Health Insurance claims data of 2,143,652 children who were born between 2008 and 2012. Gestational age of infants was not available; thus, outcomes were not adjusted with it. Not only infants with birth weights of < 1.5 kg, but also 2.0–2.4 kg and 1.5–1.9 kg were associated with having ADHD; odds ratio (OR), 1.41 (95% confidence interval [CI] 1.33–1.50), and 1.49 (95% CI 1.33–1.66), respectively. The OR in infants with birth weights of 2.0–2.4 kg and 1.5–1.9 kg was 1.91 (95% CI 1.79–2.05) and 3.25 (95% CI 2.95–3.59), respectively, indicating increased odds of having ASD. Subgroup analysis for children without perinatal diseases showed similar results. In this national cohort, infants with birth weights of < 2.5 kg were associated with ADHD and ASD, regardless of perinatal history. Children born with LBW need detailed clinical follow-up.

A critical biocultural approach to early growth in the United States

OBJECTIVES

A critical biocultural anthropology seeks to link perspectives from social theory and ethnography to human biology. In the United States (U.S.), multiple forms of structural inequalities affect early growth, including racism and poverty. The goal of this paper is to test the effects of social inequalities on birth weight and later height in the U.S. National Health and Nutrition Survey (NHANES), and to contextualize potential pathways of embodiment that link social structure and biology.

METHODS

This study used data from 8392 children ages 0-5 years from the 2005 to 2016 NHANES. Reported birth weight and measured length/height (converted to height-for-age z-scores) were used as outcome variables, while various measures of socioeconomic status and the NHANES-defined race and ethnicity categories were operationalized as social variables. Structural equation modeling (SEM) was chosen to represent the data.

RESULTS

The final model represented an excellent fit to the data. Higher birth weights were associated with higher height-for-age z-scores. The Black racial category was associated with lower birth weight and higher height-for-age z-score, while the "Other" racial category was also associated with lower birth weight. The socioeconomic status factor variable was significantly associated with birth weight and height-for-age z-scores. There were also multiple indirect effects of social variables on height-for-age z-scores mediated via their effects on birth weight.

CONCLUSIONS

Inequalities in race and socioeconomic status persist in birth weight and early childhood stature in the U.S. These findings can be contextualized by a critical biocultural anthropology that integrates lived experiences and pathways of embodiment.

Postnatal exposure to PM2.5 and weight trajectories in early childhood

BACKGROUND

Inconsistent evidence has assessed the impact of air pollution exposure on children's growth trajectories. We investigated the role of 90-day average postnatal fine particulate matter (PM2.5) exposures by estimating the magnitude of effects at different ages, and the change in child weight trajectory by categories of exposure.

METHODS

We obtained weight values from electronic health records at each hospital visit (males = 1859, females = 1601) from birth to 6 years old children recruited into the Boston-based Children's HealthWatch cohort (2009-2014). We applied mixed models, adjusting for individual and maternal confounders using (1) varying-coefficient models allowing for smooth non-linear interaction between age and PM2.5, (2) factor-smooth interaction between age and PM2.5 quartiles. Additionally, we stratified by sex and low birthweight (LBW) status (≤2500 g).

RESULTS

Using varying-coefficient models, we found that PM2.5 significantly modified the association between age and weight in males, with a positive association in children younger than 3 years and a negative association afterwards. In boys, for each 10 µg/m3 increase in PM2.5 we found a 2.6% increase (95% confidence interval = 0.8, 4.6) in weight at 1 year of age and a -0.6% (95% confidence interval = -3.9, 2.9) at 5 years. We found similar but smaller changes in females, and no differences comparing growth trajectories across quartiles of PM2.5. Most of the effects were in LBW children and null for normal birthweight children.

CONCLUSIONS

This study suggests that medium-term postnatal PM2.5 may modify weight trajectories nonlinearly in young children, and that LBW babies are more susceptible than normal-weight infants.

Descriptive and risk factor analysis of infantile cataracts: National Birth Defects Prevention Study, 2000-2011

Using National Birth Defects Prevention Study (NBDPS) data, we sought to estimate birth prevalence, describe clinical characteristics, and examine risk factors for infantile cataracts. We calculated birth prevalence using the numbers of NBDPS-eligible cataract cases and live births in the study area. We described case infants by the presence of associated ipsilateral eye defects (IEDs) and non-eye-related major birth defects. Using maternal exposure information collected via telephone interview, we conducted logistic regression analyses among the interviewed cases and controls. Birth prevalence of infantile cataracts was 1.07/10,000 live births. Unilateral cataracts were more often associated with IEDs, while infants with bilateral cataracts were more often preterm, full-term with low birth weight, or had non-eye-related major birth defects. Unilateral cataracts were positively associated with maternal nulliparity (adjusted odds ratio [aOR] = 1.61, 95% confidence interval [CI] = 1.18, 2.20; reference: multiparity), whereas bilateral cataracts were positively associated with maternal education <12 years (aOR = 2.08, 95% CI = 1.13, 3.82; reference: education >12 years), and foreign-born nativity (aOR = 1.92, 95% CI = 1.04, 3.52; reference: U.S.-born nativity). The current analysis can inform future epidemiological studies aimed at identifying mechanisms underlying the associations between infantile cataracts and complex maternal exposures, such as lower levels of education and foreign-born nativity.

The effect of prenatal temperature and PM2.5 exposure on birthweight: Weekly windows of exposure throughout the pregnancy

BACKGROUND

Birthweight is a strong predictor of normal growth, healthy development, and survival. Several studies have found associations between temperature, fine particulate matter (PM_2.5), and birth weight. However, the relevant timing of exposures varies between studies and is yet unclear. Therefore, we assessed the difference in term birthweight (TBW) associated with weekly exposure to temperature and PM_2.5 throughout 37 weeks of gestation.

METHODS

We included all singleton live term births in Massachusetts, U.S between 2004 and 2015 (n = 712,438). Weekly PM_2.5 and temperature predictions were estimated on a 1 km grid from satellite-based models. We utilized a distributed lag nonlinear model (DLNM) to estimate the difference in TBW associated with weekly exposures from the last menstrual period to 37 weeks of gestation.

RESULTS

We found a nonlinear association with prenatal temperature exposure. Larger effects were observed in warmer temperatures, where higher temperatures were negatively associated with TBW. Temperature effects were larger in the first and final weeks of gestation. We observed a negative difference in TBW associated with PM_2.5 exposure. Overall, a 1 µg/m³ increase in prenatal exposure was associated with 3.9 g lower TBW (95% CI -5.0 g; -2.9 g). PM_2.5 effects were larger in the final weeks of gestation.

CONCLUSION

We found heat and PM_2.5 exposure to be related to lower TBW. Our findings suggest that women are more susceptible to both exposures towards the end of pregnancy. Susceptibility to heat was higher in the initial weeks of pregnancy as well. These critical windows of susceptibility can be communicated to pregnant women during routine prenatal visits to increase awareness and target interventions to reduce exposures.

Under-5 mortality in sub-Saharan Africa: is maternal age at first childbirth below 20 years a risk factor?

OBJECTIVES

This study aimed at examining the association between young maternal age at first childbirth and under-5 mortality in sub-Saharan Africa (SSA).

DESIGN AND SETTING

This cross-sectional study pooled nationally-representative data from the most recent Demographic and Health Surveys conducted in 30 countries in SSA from 2010 to 2019.

PARTICIPANTS

116 379 mothers of children under 5.

RESULTS

The prevalence of adolescent childbirth and death in children under 5 in SSA were 57.36% (95% CI 53.73% to 60.99%) and 4.10% (95% CI 3.65% to 4.54%), respectively. Children born to mothers whose first childbirth occurred at <20 years were 11% more likely to die before the age of 5 compared with those whose mothers' first childbirth occurred at age ≥20 years (adjusted odds ratio (aOR) 1.11; 95% CI 1.05 to 1.18). In terms of the covariates, the likelihood of under-5 mortality was higher among children born to single (aOR 1.54; 95% CI 1.41 to 1.67) and cohabiting mothers (aOR 1.10; 95% CI 1.01 to 1.21) compared with married mothers. Children born to mothers who were obese were more likely to die before the age of 5 compared with those born to mothers with normal body weight (aOR 1.17; 95% CI 1.09 to 1.26). The odds of under-5 mortality were higher among children whose weight at birth was <2500 g compared with those whose weight was ≥2500 g at birth (aOR 1.83; 95% CI 1.64 to 2.03).

CONCLUSIONS

The findings call for the need to enhance policies aimed at reducing under-5 mortality in SSA by reducing adolescent pregnancy and childbirth through family planning, comprehensive sexuality education, and the elimination of child marriage. Again, Since under-5 mortality among adolescent mothers is linked with their poor socio-economic status, there is the need for government and non-governmental organisations in SSA to introduce poverty alleviation programmes and improve access to both formal and informal education as a way of enhancing the socioeconomic status of adolescent mothers. Public health education, through continuous advocacy programmes should be done to encourage adolescent mothers to access antenatal care and health facility deliveries as a way of enhancing the survival status of their children. These interventions should be implemented, taking into consideration other characteristics of mothers such marital status and BMI and child's characteristics such as child's weight, which were found to be associated with high under-5 mortality.

Maternal exposure to fine particulate matter over the first trimester and umbilical cord insertion abnormalities

BACKGROUND

Our hypothesis was that exposure to fine particulate matter (PM2.5) is related to abnormal cord insertion, which is categorized as a form of placental implantation abnormality. We investigated the association between exposure to total PM2.5 and its chemical components over the first trimester and abnormal cord insertion, which contributes to the occurrence of adverse birth outcomes.

METHODS

From the Japan Perinatal Registry Network database, we used data on 83 708 women who delivered singleton births at 39 cooperating hospitals in 23 Tokyo wards (2013-2015). We collected PM2.5 on a filter and measured daily concentrations of carbon and ion components. Then, we calculated the average concentrations over the first trimester (0-13 weeks of gestation) for each woman. A multilevel logistic-regression model with the hospital as a random effect was used to estimate the odds ratios (ORs) of abnormal cord insertion.

RESULTS

Among the 83 708 women (mean age at delivery = 33.7 years), the frequency of abnormal cord insertion was 4.5%, the median concentration [interquartile range (IQR)] of total PM2.5 was 16.1 (3.61) μg/m3 and the OR per IQR for total PM2.5 was 1.14 (95% confidence interval = 1.06-1.23). In the total PM2.5-adjusted models, total carbon, organic carbon, nitrate, ammonium and chloride were positively associated with abnormal insertion. Organic carbon was consistently, and nitrate tended to be, associated with specific types of abnormal insertion (marginal or velamentous cord insertion).

CONCLUSIONS

Exposure to total PM2.5 and some of its components over the first trimester increased the likelihood of abnormal cord insertion.

Birth Weight and Adult-Onset Hearing Loss

OBJECTIVES

Among low-birth-weight infants, exposure to stress or undernutrition in utero may adversely affect cochlear development. As cochlear reserve declines, the risk of hearing loss may increase with age. While low birth weight is associated with a higher risk of neonatal hearing loss, our objective was to examine whether birth weight was associated with adult-onset, self-reported hearing loss in the Nurses' Health Studies (NHS) I and II (n = 113,130).

DESIGN

We used Cox proportional hazards regression to prospectively examine whether birth weight, as well as gestational age at birth, is associated with adult-onset hearing loss. Participants reported their birth weight in 1992 in NHS I and 1991 in NHS II. Mothers of NHS II participants reported gestational age at birth in a substudy (n = 28,590). The primary outcome was adult-onset, self-reported moderate or greater hearing loss, based on questionnaires administered in 2012/2016 in NHS I and 2009/2013 in NHS II.

RESULTS

Our results suggested a higher risk of hearing loss among those with birth weight <5.5 lbs compared with birth weight 7 to <8.5 lbs (pooled multivariable-adjusted hazard ratio 1.14, 95% confidence interval = 1.04-1.23; p trend = 0.01). Additionally, participants with gestational age at birth ≥42 weeks had a higher risk of hearing loss, compared with gestational age 38 to <42 weeks (multivariable-adjusted hazard ratio 1.33, 95% confidence interval = 1.06-1.65).

CONCLUSIONS

Birth weight <5.5 lbs was independently associated with higher risk of self-reported, adult-onset hearing loss. In addition, gestational age at birth ≥42 weeks was also associated with higher risk.

Examining the Causal Impact of Prenatal Home Visiting on Birth Outcomes: A Propensity Score Analysis

OBJECTIVES

In Ohio, African American babies die at 2.5-3 times the rate of White babies. Preterm birth and low birth weight are the leading causes of infant mortality. Home visiting is an evidence-based strategy for serving low-income pregnant women; however, there are relatively few rigorous studies examining its effect on birth outcomes.

METHODS

This study uses a propensity score technique to estimate the causal effect of participation in home visiting on prematurity and low birth weight among a low-income, predominantly African American sample (N = 26,814).

RESULTS

We found that participation in home visiting significantly reduced the odds of experiencing both adverse birth events, with a larger program effect for the low birth weight outcome.

CONCLUSIONS FOR PRACTICE

Results suggest that selective prevention strategies must be accompanied by universal attempts to improve the health and life circumstances of low income and minority women.

Race, ethnicity, WIC participation, and infant health disparities in the United States

PURPOSE

This study examines the association between race and ethnicity, participation in The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), and a series of infant health outcomes including infant mortality, low birth weight, preterm birth, extended infant hospitalization, and stays in the neonatal infant care unit (NICU).

METHODS

Data are from the Pregnancy Risk Assessment Monitoring System (PRAMS), 2009-2017. Moderation analyses were conducted to assess the association between maternal race and ethnicity, WIC participation, and infant health.

RESULTS

Results indicate infants born to Black women and to a lesser extent Hispanic woman are in worse health than those born to White mothers in the United States. However, participation in WIC is associated with reductions in the gap in infant health experienced by racial and ethnic minorities.

CONCLUSIONS

Prenatal WIC participation is associated with improvements in the health of Black and Hispanic infants and reduced racial and ethnic disparities in infant health outcomes.

Using space-time cube to analyze trends in adverse birth outcomes and maternal characteristics in Massachusetts, USA

Rates of preterm births (< 37 gestational weeks) and low birthweight (≤  2500 g) are rising throughout the United States. This study uses singleton live birth data, Empirical Bayes approach, space-time cube and Mann-Kendall statistic to evaluate temporal trends in these adverse birth outcomes (ABO) and maternal characteristics over 15 years (2000-2014) at the census tract level for non-Hispanic white and black women in Massachusetts. In addition to analyzing trends for each variable individually, the study analyzes spatial coincidence of trends to determine which maternal characteristics exhibited trends that most strongly correlated with the ABO trends. The 15-year average rate of ABO was 7.34% for white women, and 12.05% for black women. Results show that more census tracts exhibited an increasing trend than decreasing trend in birth outcomes and in several maternal characteristics for both races (gestational and chronic hypertension, gestational diabetes, and previous preterm birth). Study identified 52 census tracts concurrently experiencing an increasing trend in ABO and in four maternal characteristics for black women, indicating that multiple negative trends in health outcomes are concentrated at the same location creating a potential for even more adverse outcomes in the future. This study provides a novel, spatially explicit analytical framework based on Empirical Bayes rates and space-time cube, which could be extended to analyze trends in other health outcomes at various spatial scales.

SUPPLEMENTARY INFORMATION

The online version supplementary material available at 10.1007/s10708-021-10382-w.

Trends of proximate low birth weight and associations among children under-five years of age: Evidence from the 2016 Ethiopian demographic and health survey data

BACKGROUND

Low birth weight puts a newborn at increased risk of death and illness, and limits their productivity in the adulthood period later. The incidence of low birth weight has been selected as an important indicator for monitoring major health goals by the World Summit for Children. The 2014 World Health Organization estimation of child death indicated that 4.53% of total deaths in Ethiopia were due to low birth weight. The aim of this study was to assess trends of proximate low birth weight and associations of low birth weight with potential determinants from 2011 to 2016.

METHODS

This study used the 2016 Ethiopian Demographic and Health Survey data (EDHS) as data sources. According to the 2016 EDHS data, all the regions were stratified into urban and rural areas. The variable "size of child" measured according to the report of mothers before two weeks of the EDHS takes placed. The study sample refined from EDHS data and used for this further analysis were 7919 children. A logistic regression model was used to assess the association of proximate low birth weight and potential determinates of proximate low birth weight. But, the data were tested to model fitness and were fitted to Hosmer-Lemeshow-goodness of fit.

RESULTS

The prevalence of proximate low birth weight in Ethiopia was 26.9% (2132), (95%CI = 25.4, 27.9). Of the prevalence of child size in year from 2011 to 2016, 17.1% was very small, and 9.8% was small. In the final multivariate logistic regression model, region (AOR = xx), (955%CI = xx), Afar (AOR = 2.44), (95%CI = 1.82, 3.27), Somalia (AOR = 0.73), (95%CI = 0.55, 0.97), Benishangul-Gumz (AOR = 0.48), (95%CI = 0.35, 0.67), SNNPR (AOR = 0.67), (95%CI = 0.48, 0.93), religion, Protestant (AOR = 0.76), (95%CI = 0.60, 0.95), residence, rural (AOR = 1.39), (95%CI = 1.07, 1.81), child sex, female (AOR = 1.43), (95%CI = 1.29, 1.59), birth type, multiple birth during first parity (AOR = 2.18), (95%CI = 1.41, 3.37), multiple birth during second parity (AOR = 2.92), (95%CI = 1.86, 4.58), preparedness for birth, wanted latter child (AOR = 1.26), (95%CI = 1.09, 1.47), fast and rapid breathing (AOR = 1.22), (95%CI = 1.02, 1.45), maternal education, unable to read and write (AOR = 1.46), (95%CI = 1.56, 2.17), and maternal age, 15-19 years old (AOR = 1.86), (95%CI = 1.19, 2.92) associated with proximate low birth weight.

CONCLUSIONS

The proximate LBW prevalence as indicated by small child size is high. Region, religion, residence, birth type, preparedness for birth, fast and rapid breathing, maternal education, and maternal age were associated with proximate low birth weight. Health institutions should mitigating measures on low birth weight with a special emphasis on factors identified in this study.

Estimating the Combined Effects of Natural and Built Environmental Exposures on Birthweight among Urban Residents in Massachusetts

Intrauterine growth has health implications both in childhood and adulthood. Birthweight is partially determined by prenatal environmental exposures. We aim to identify important predictors of birthweight out of a set of environmental, built environment exposures, and socioeconomic environment variables during pregnancy (i.e., fine particulate matter (PM2.5), temperature, greenness, walkability, noise, and economic indices). We included all singleton live births of mothers who resided in urban census block-groups and delivered in Massachusetts between 2001 and 2011 (n = 640,659). We used an elastic-net model to select important predictors of birthweight and constructed a multivariate model including the selected predictors, with adjustment for confounders. We additionally used a weighted quantile sum regression to assess the contribution of each exposure to differences in birthweight. All exposures were selected as important predictors of birthweight. In the multivariate model, lower birthweight was significantly associated with lower greenness and with higher temperature, walkability, noise, and segregation of the "high income" group. Treating the exposures individually, nighttime noise had the highest weight in its contribution to lower birthweight. In conclusion, after accounting for individual confounders, maternal environmental exposures, built environment exposures, and socioeconomic environment during pregnancy were important predictors of birthweight, emphasizing the role of these exposures in fetal growth and development.

Factors associated with low birth weight at term: a population-based linkage study of the 100 million Brazilian cohort

BACKGROUND

Factors associated with low birth weight at term (TLBW), a proxy for intrauterine growth restriction (IUGR), are not well-elucidated in socioeconomically vulnerable populations. This study aimed to identify the factors associated with TLBW in impoverished Brazilian women.

METHODS

Records in the 100 Million Brazilian Cohort database were linked to those in the National System of Information on Live Births (SINASC) to obtain obstetric, maternal, birth and socioeconomic data between 2001 and 2015. Multivariate logistic regression was performed to investigate associations between variables of exposure and TLBW.

RESULTS

Of 8,768,930 term live births analyzed, 3.7% presented TLBW. The highest odds of TLBW were associated with female newborns (OR: 1.49; 95% CI: 1.47-1.50), whose mothers were black (OR: 1.20; 95% CI: 1.18-1.22), had a low educational level (OR: 1.57; 95% CI: 1.53-1.62), were aged ≥35 years (OR: 1.44; 95% CI: 1.43-1.46), had a low number of prenatal care visits (OR: 2.48; 95% CI: 2.42-2.54) and were primiparous (OR: 1.62; 95% CI: 1.60-1.64). Lower odds of TLBW were found among infants whose mothers lived in the North, Northeast and Center-West regions of Brazil compared to those in the South.

CONCLUSION

Multiple aspects were associated with TLBW, highlighting the need to comprehensively examine the mechanisms underlying these factors, especially in more vulnerable Brazilian populations, in order to contribute to the elaboration of health policies and promote better conditions of life for poor and extremely poor mothers and children.

Perinatal epidemiology: Issues, challenges, and potential solutions

Perinatal epidemiology research is concerned with identifying the effects of events during pregnancy on pregnancy outcomes that include maternal, fetal, and neonatal health outcomes. Randomized trials in perinatal research face many challenges, including randomization difficulties, ethical considerations, and inadequate statistical power due to the small number of subjects eligible for participation. For these reasons, most epidemiological studies conducted in this research field are observational and include different types of bias. This review describes the key methodological difficulties in the design and analysis of randomized and observational studies in perinatal epidemiology, and provides potential corrective approaches.

Associations between lifetime stress exposure and prenatal health behaviors

Prenatal health behaviors can strongly influence risk of poor pregnancy birth outcomes. Although stress has been implicated in structuring the likelihood that individuals will engage in various prenatal health behavior patterns, no studies to date have examined life stress exposure occurring across the entire lifespan, and few have investigated how different types of stressors are comparatively associated with these outcomes. To address these issues, we interviewed 164 women at one of two large Midwestern, urban hospitals after delivering their first infant. We used the Stress and Adversity Inventory (STRAIN) to assess women's lifetime stress exposure severity and ordinary least squares regression models to examine associations between participants' life stress exposure and prenatal health behaviors. As hypothesized, greater lifetime stress exposure was associated with engaging in more negative prenatal health behaviors and fewer positive prenatal health behaviors while controlling for relevant sociodemographic factors and current perceived stress levels. These effects were stronger for negative versus positive health behaviors, and they differed substantially as a function of stressor type, exposure timing, and primary life domain. Stressors occurring over the life course thus have negative consequences for prenatal health behaviors, but these effects are not uniform across different types of life stress exposure.