Association of Intrauterine Growth Restriction and Small for Gestational Age Status With Childhood Cognitive Outcomes: A Systematic Review and Meta-analysis

BMI modifies the effect of pregnancy complications on risk of small- or large-for-gestational-age newborns

BACKGROUND

Maternal physical condition (reflected by maternal body mass index (BMI) at delivery) and pregnancy complications influence neonatal health outcomes. High BMI during pregnancy increases various health problems' risks, but studies about the synthesized effect of these factors on fetal growth, are scarce.

METHODS

The retrospective cohort study was conducted in Zhejiang Province, China from 1 January 2019 to 31 December 2021. The associations between complications and small-for-gestational-age (SGA) and large-for-gestational-age (LGA) were measured by the Fine-Gray model and subgroup analysis. Effect modification and interaction analyses were conducted to explore BMI's modification effect and complications' interaction.

RESULTS

Several complications increased the risk for SGA and LGA, some significance varied in different subgroups. There was a positive effect modification of gestational diabetes mellitus (GDM) across BMI strata on LGA (relative excess risk due to interaction (RERI) [95% CI] = 0.57 [0.09,1.04]). Several pairwise complications' interactions were synergistic (e.g., pregestational diabetes and intraamniotic infection for SGA (ratio of ORs [95% CI] = 8.50 [1.74,41.37]), pregestational diabetes and assisted reproductive technology (ART) for LGA (ratio of ORs [95% CI] = 2.71 [1.11,6.62])), one was antagonistic (placental problems and ART for LGA (ratio of ORs [95% CI] = 0.58 [0.35,0.96])).

CONCLUSIONS

High-BMI positively modified the risk of GDM on LGA. Many interactions existed when two specific pregnancy complications occurred simultaneously.

IMPACT

This is the largest retrospective study covering more than 10 pregnancy complications to date in this aspect. High-BMI (BMI > 28 kg/m2) positively modifies the risk of GDM on LGA. Many pregnancy complications influence the risk of SGA and LGA, with several interactions that may create a "syndrome" effect. Pregnant women with different BMIs should consider the additional risks caused by pregnancy complications for their heterogeneous effects on abnormal fetal growth. Measures should be taken to prevent the occurrence of other exposure factors in the "syndrome". This study may aid in developing a new strategy for improving neonatal outcomes.

Association of preterm birth and birth size status with neurodevelopmental and psychiatric disorders in spontaneous births

Preterm birth (PTB) or small birth size are risk factors for certain neurodevelopmental disorders. The magnitude of these associations in spontaneous births, and of associations for combined PTB and birth size status on neurodevelopmental and psychiatric disorders is unexplored. We investigated whether PTB and small/large for gestational age (SGA/LGA), separately or combined, in spontaneous births, are associated with a wide spectrum of neurodevelopmental and psychiatric disorders. In this population-based registry cohort study, all singleton spontaneous births in Finland from 1996 to 2014 were followed until 2018 (n = 819 764). We show that PTB across gestational ages, and SGA, were associated with higher risks for anxiety disorders, intellectual disabilities, specific developmental disorders (SDD), autism spectrum disorders (ASD), attention-deficit/hyperactivity disorders (ADHD) and other emotional and behavioural disorders (F98). Most of these associations were not attributed to familial factors. Larger effect sizes were observed with lower gestational ages. Extremely PTB was associated at highest risks with intellectual disabilities (HR, 10.70 [95%CI, 8.69-13.17]) and SDD (HR, 8.91 [95%CI, 8.18-9.71]). Moreover, very preterm birth combined with SGA was associated with a higher risk for SDD (HR, 7.55 [95%CI, 6.61-8.62]) than that of very preterm or SGA birth alone. Conversely, LGA birth lowered the risk for SDD and other emotional and behavioural disorders among individuals born very preterm. In conclusion, PTB along with SGA is associated with higher risks for SDD than one exposure alone, whereas LGA lowers the risks for SDD and other emotional and behavioural disorders in individuals born spontaneously.

Causal Pathways Between the Acute Experience of Violence During Pregnancy and Fetal Intrauterine Growth Restriction: A Cohort Study

Introduction: Violence during pregnancy (VDP) is a prevalent global issue with dire consequences for the mother and the developing fetus. These consequences include prematurity, low birthweight, and intrauterine growth restriction (IUGR), but its pathways remain elusive. This study investigated the causal pathways between VDP and IUGR using mediation analysis. Methods: A prospective population-based birth cohort was followed from the beginning of the third gestational trimester to the second year of life. IUGR was defined by the Kramer index, and information on VDP was collected using the WHO-Violence Against Women (WHO VAW) questionnaire. Cases were considered positive only when no other life episodes were reported. Ten different mediators were analyzed as possible pathways based on previous research. Path analysis was conducted to evaluate these relationships. Results: The path analysis model included 755 dyads and presented an adequate fit. Violence during pregnancy showed a direct effect (β = -0.195, p = 0.041) and a total effect (β = -0.276, p = 0.003) on IUGR. Violence was associated with gestational depression or anxiety, tobacco and alcohol consumption, changes in blood pressure, and the need for emergency care, but these did not constitute mediators of its effect on IUGR. The sum of the indirect effects, however, showed a significant association with IUGR (β = -0.081, p = 0.011). Conclusion: The acute experience of violence during pregnancy was associated with IUGR, primarily via a direct pathway. An indirect effect was also present but not mediated through the variables analyzed in this study. The robust strength of these associations underscores the negative health consequences of violence against women for the succeeding generation.

How to enhance the applicability of a risk prediction model for term small-for-gestational-age neonates in clinical settings?

OBJECTIVE

To construct a simple term small-for-gestational-age (SGA) neonate prediction model that is clinically practical.

METHODS

This analysis was based on the Born in Guangzhou Cohort Study (BIGCS). Mothers who had a singleton pregnancy, delivered a term neonate, and had an ultrasonography within 30 + 0 to 32 + 6 weeks of gestation were included. Term SGA was defined with customized population percentiles. Prediction models were constructed with backward selection logistic regression in a four-step approach, where model 1 contained fetal biometrics only, models 2 and 3 included maternal features and a time factor (weeks between ultrasonography and delivery), respectively; and model 4 contained all features mentioned. The prediction performance of individual models was evaluated based on area under the curve (AUC) and a calibration test was performed.

RESULTS

The prevalence of SGA in the study population of 21 346 women was 11.5%. With a complete-case analysis approach, data of 19 954 women were used for model construction and validation. The AUC of the four models were 0.781, 0.793, 0.823, and 0.834, respectively, and all were well-calibrated. Model 3 consisted of fetal biometrics and corrected for time to delivery was chosen as the final model to build risk prediction graphs for clinical use.

CONCLUSION

A prediction model derived from fetal biometrics in early third trimester is satisfactory to predict SGA.

Blocking OLFM4/galectin-3 axis in placental polymorphonuclear myeloid-derived suppressor cells triggers intestinal inflammation in newborns

Fetal growth restriction (FGR) is a major cause of premature and low-weight births, which increases the risk of necrotizing enterocolitis (NEC); however, the association remains unclear. We report a close correlation between placental polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) and NEC. Newborns with previous FGR exhibited intestinal inflammation and more severe NEC symptoms than healthy newborns. Placental PMN-MDSCs are vital regulators of fetal development and neonatal gut inflammation. Placental single-cell transcriptomics revealed that PMN-MDSCs populations and olfactomedin-4 gene (Olfm4) expression levels were significantly increased in PMN-MDSCs in later pregnancy compared to those in early pregnancy and non-pregnant females. Female mice lacking Olfm4 in myeloid cells mated with wild-type males showed FGR during pregnancy, with a decreased placental PMN-MDSCs population and expression of growth-promoting factors (GPFs) from placental PMN-MDSCs. Galectin-3 (Gal-3) stimulated the OLFM4-mediated secretion of GPFs by placental PMN-MDSCs. Moreover, GPF regulation via OLFM4 in placental PMN-MDSCs was mediated via hypoxia inducible factor-1α (HIF-1α). Notably, the offspring of mothers lacking Olfm4 exhibited intestinal inflammation and were susceptible to NEC. Additionally, OLFM4 expression decreased in placental PMN-MDSCs from pregnancies with FGR and was negatively correlated with neonatal morbidity. These results revealed that placental PMN-MDSCs contributed to fetal development and ameliorate newborn intestinal inflammation.

Effects of umbilical vein flow on midbrain growth and cortical development in late onset fetal growth restricted fetuses: a prospective cross-sectional study

OBJECTIVES

To investigate midbrain growth, including corpus callusum (CC) and cerebellar vermis (CV) and cortical development in late fetal growth restricted (FGR) subclassified according to the umbilical vein blood flow (UVBF) values.

METHODS

This was a prospective study on singleton fetuses late FGR with abnormal placental cerebral ratio (PCR). FGR fetuses were further subdivided into normal (≥fifth centile) and abnormal (

RESULTS

The study cohort included 60 late FGR, 31 with normal UVBF/AC and 29 with abnormal UVBF/AC values. The latter group showed significant differences in CC (median (interquartile range (IQR) normal 0.96 (0.73-1.16) vs. abnormal UVBF/AC 0.60 (0.47-0.87); p<0.0001)), CV (normal 1.04 (0.75-1.26) vs. abnormal UVBF (AC 0.76 (0.62-1.18)); p=0.0319), SF (normal 0.83 (0.74-0.93) vs. abnormal UVBF/AC 0.56 (0.46-0.68); p<0.0001), POF (normal 0.80 (0.71-0.90) vs. abnormal UVBF/AC l 0.49 (0.39-0.90); p≤0.0072) and CF (normal 0.83 (0.56-1.01) vs. abnormal UVBF/AC 0.72 (0.53-0.80); p<0.029).

CONCLUSIONS

Late onset FGR fetuses with of reduced umbilical vein flow showed shorter CC and CV length and a delayed cortical development when compared to those with normal umbilical vein hemodynamics. These findings support the existence of a link between abnormal brain development and changes in umbilical vein circulation.

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Key Words

• cerebellar vermis
• corpus callosum
• cortical folding
• fetal growth restriction
• neurosonography
• umbilical vein flow

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MESH Headings

• Humans
• Female
• Fetal Growth Retardation/diagnostic imaging
• Fetal Growth Retardation/physiopathology
• Pregnancy
• Prospective Studies
• Cross-Sectional Studies
• Umbilical Veins/diagnostic imaging
• Adult
• Ultrasonography, Prenatal/methods
• Mesencephalon/diagnostic imaging
• Mesencephalon/blood supply
• Mesencephalon/embryology
• Fetal Development/physiology
• Cerebral Cortex/diagnostic imaging
• Cerebral Cortex/blood supply
• Cerebral Cortex/embryology

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Affiliation(s)

Ilenia Mappa Department of Obstetrics and Gynecology, Fondazione Policlinico Tor Vergata, Università di Roma Tor Vergata, Rome, Italy
Maria Chiara Marra Department of Obstetrics and Gynecology, Fondazione Policlinico Tor Vergata, Università di Roma Tor Vergata, Rome, Italy
Maria Elena Pietrolucci Department of Obstetrics and Gynecology, Fondazione Policlinico Tor Vergata, Università di Roma Tor Vergata, Rome, Italy
Jia Li Angela Lu Department of Obstetrics and Gynecology, Fondazione Policlinico Tor Vergata, Università di Roma Tor Vergata, Rome, Italy
Francesco D'Antonio Department of Obstetrics and Gynecology, Università di Chieti, Chieti, Italy
Giuseppe Rizzo Department of Obstetrics and Gynecology, Fondazione Policlinico Tor Vergata, Università di Roma Tor Vergata, Rome, Italy Department of Obstetrics and Gynecology, Università di Chieti, Chieti, Italy

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Birth weight and head circumference discordance and outcome in preterms: results from the EPIPAGE-2 cohort

OBJECTIVE

To determine whether the relative measurement of birth weight (BW) and head circumference (HC) in preterm infants is associated with neurological outcomes.

METHODS

The EPIPAGE-2 Study included 3473 infants born before 32 weeks' gestation, classified based on their Z-score of BW and HC on the Fenton curves as concordant (≤1 SD apart) or discordant (>1 SD difference). We defined four mutually exclusive categories: discordant smaller BW (sBW) with BW-1SD and concordant small measurement (CsM) with BW and HC concordant and both ≤-1SD. Neurological outcomes at 5.5 years were evaluated with standard tests.

RESULTS

2592 (74.8%) preterm neonates were categorised as CM, 258 (7.4%) CsM, 378 (10.9%) sHC and 239 (6.9%) sBW. Compared with the CM children, those born with CsM had significantly higher risks of cognitive deficiency (adjusted OR (aOR) 1.3, 95% CI (1.0 to 2.0)), developmental coordination disorders (aOR 2.6 (1.5 to 4.4)) and need for special school services (aOR 2.3 (1.5 to 3.7)). Those born with sBW had significantly lower risk of cognitive deficiency (aOR 0.6 (0.4 to 0.9)) and the sHC group significantly higher risk of developmental coordination disorders (aOR 1.8 (1.0 to 3.2)).

CONCLUSIONS

The relative discordance of these preterm infants' BW and HC was associated with their neurological outcomes. It merits further exploration as an indirect indicator of development.

TRIAL REGISTRATION NUMBER

NCT03078439.

Long-Term Neurologic Consequences following Fetal Growth Restriction: The Impact on Brain Reserve

BACKGROUND

Fetal growth restriction (FGR) corresponds to the fetus's inability to achieve an adequate weight gain based on genetic potential and gestational age. It is an important cause of morbidity and mortality.

SUMMARY

In this review, we address the challenges of diagnosis and classification of FGR. We review how chronic fetal hypoxia impacts brain development. We describe recent advances on placental and fetal brain imaging using magnetic resonance imaging and how they offer new noninvasive means to study growth restriction in humans. We go on to review the impact of FGR on brain integrity in the neonatal period, later childhood, and adulthood and review available therapies.

KEY MESSAGES

FGR consequences are not limited to the perinatal period. We hypothesize that impaired brain reserve, as defined by structure and size, may predict some concerning epidemiological data of impaired cognitive outcomes and dementia with aging in this group of patients.

Thyroid hormone analogues: Promising therapeutic avenues to improve the neurodevelopmental outcomes of intrauterine growth restriction

Intrauterine growth restriction (IUGR) is a pregnancy complication impairing fetal growth and development. The compromised development is often attributed to disruptions of oxygen and nutrient supply from the placenta, resulting in a number of unfavourable physiological outcomes with impaired brain and organ growth. IUGR is associated with compromised development of both grey and white matter, predisposing the infant to adverse neurodevelopmental outcomes, including long-lasting cognitive and motor difficulties. Cerebral thyroid hormone (TH) signalling, which plays a crucial role in regulating white and grey matter development, is dysregulated in IUGR, potentially contributing to the neurodevelopmental delays associated with this condition. Notably, one of the major TH transporters, monocarboxylate transporter-8 (MCT8), is deficient in the fetal IUGR brain. Currently, no effective treatment to prevent or reverse IUGR exists. Management strategies involve close antenatal monitoring, management of maternal risk factors if present and early delivery if IUGR is found to be severe or worsening in utero. The overall goal is to determine the most appropriate time for delivery, balancing the risks of preterm birth with further fetal compromise due to IUGR. Drug candidates have shown either adverse effects or little to no benefits in this vulnerable population, urging further preclinical and clinical investigation to establish effective therapies. In this review, we discuss the major neuropathology of IUGR driven by uteroplacental insufficiency and the concomitant long-term neurobehavioural impairments in individuals born IUGR. Importantly, we review the existing clinical and preclinical literature on cerebral TH signalling deficits, particularly the impaired expression of MCT8 and their correlation with IUGR. Lastly, we discuss the current evidence on MCT8-independent TH analogues which mimic the brain actions of THs by being metabolised in a similar manner as promising, albeit underappreciated approaches to promote grey and white matter development and improve the neurobehavioural outcomes following IUGR.

Placental Malaria Induces a Unique Placental Methylation Profile Associated with Fetal Growth Restriction

Background

Fetal growth restriction (FGR) is associated with perinatal death and other adverse birth outcomes, as well as long term complications including increased childhood morbidity, abnormal neurodevelopment, and cardio-metabolic diseases in adulthood. FGR has been associated with placental epigenetic reprogramming, which may mediate these long term outcomes. Placental malaria (PM) is the leading cause of FGR globally, but the impact on placental epigenetics is unknown. We hypothesized that methylomic profiling of placentas from non-malarial and malarial FGR would reveal common and distinct mechanistic pathways associated with FGR.

Results

We used a methylation array to compare the CpG profiles between FGR from a cohort with no malaria exposure and a cohort of pregnancies complicated by both PM and FGR. Non-malarial FGR was associated with 65 differentially methylated CpGs, whereas PM-FGR was associated with 133 DMCs, compared to their corresponding controls. One DMC (cg16389901) was commonly hypomethylated in both groups, corresponding to the promoter region of BMP4 . Comparison of FGR vs. PM-FGR identified 522 DMCs between these two groups, which was not attributable to geographic location or different cellular compositions of these two groups.

Conclusion

Placentas from pregnancies with PM-associated FGR showed distinct methylation profiles as compared to non-malarial FGR, suggesting novel epigenetic reprogramming in response to malaria. There may be distinct long-term health outcomes in FGR pregnancies also complicated by PM.

Long-term neurological outcomes of offspring misdiagnosed with fetal growth restriction

OBJECTIVE

Fetal growth restriction (FGR) is a major determinant of adverse short- and long-term perinatal outcomes. The current definition of FGR (estimated fetal weight measurement < 10th percentile) may lead, at times, to a false diagnosis of fetuses that are eventually born appropriate for gestational age (AGA). Our objective was to investigate the potential association between a misdiagnosis of antepartum fetal growth restriction and long-term neurological outcomes in offspring.

STUDY DESIGN

A population-based cohort analysis was performed including deliveries between the years 1991-2020 in a tertiary medical center. We compared neurological hospitalization during childhood among AGA infants falsely diagnosed as FGR versus AGA infants without a false FGR diagnosis. A Kaplan-Meier survival curve was used to assess cumulative morbidity and a Cox proportional hazards model was employed to control for confounders.

RESULTS

During the study period, 324,620 AGA infants met the inclusion criteria; 3249 of them were falsely classified as FGR. These offspring had higher rates of hospitalizations due to various neurological conditions, as compared to those without an FGR diagnosis (OR 1.431, 95% CI 1.278-1.608; P < 0.001). In addition, cumulative hospitalization incidence was elevated in the FGR group (log-rank P-value < 0.001). When controlling for confounders, a false FGR diagnosis remained independently associated with long-term neurological morbidities (adjusted HR 1.086, 95% CI 1.003-1.177, P = 0.043).

CONCLUSION

Misdiagnosis of FGR in the antepartum period is associated with an increased risk for offspring long-term neurological morbidities.

Early-life matters: The role of fetal adrenal steroids in the relationship between cytokines within the placental circulation and cognitive development among infants in the Philippines

Prenatal exposure to inflammation is related to the risk for cognitive impairment in offspring. However, mechanisms underlying the link between inflammatory cytokines at the maternal-fetal interface and human cognitive development are largely unknown. This study addressed this research gap by examining whether i) cytokines within the placenta are associated with different domains of neurocognitive development during infancy, and ii) if DHEA-S in cord blood mediates these associations. We also explored the role of early-life socioeconomic status (SES) in moderating the effect of fetal adrenal steroids on cognitive development in low- and middle-income country contexts. A cohort of 242 mother-infant dyads in Leyte, the Philippines participated in the study and all of them were followed from early pregnancy until 12-months. Concentrations of pro- and anti-inflammatory cytokines in the placenta, and DHEA-S in cord blood collected at delivery were evaluated. The multifactorial aspects of the infant's cognitive functioning were assessed based on the Bayley Scales of Infant Development, third edition (BSID-III). We used Structural Equation Modelling (SEM) with an orthogonal rotation to examine associated paths among latent variables of pro- and anti-inflammatory cytokines in the placenta, fetal neuroendocrine factors, and cognitive development. Pathway analyses showed that both pro- and anti-inflammatory cytokines in the placenta were indirectly related to cognitive (p < 0.05) and language developmental outcomes (p < 0.1) via DHEA-S in cord blood among the low SES group. Yet, we found no statistically significant indirect effect of pro- or anti-inflammatory cytokines on neurocognitive development among the high SES sub-sample. This study extends our understanding of how early-life socioeconomic conditions modify biological pathways underlying the relationship between prenatal factors and postpartum cognitive development.

Postnatal functional integrity of the brainstem auditory pathway in late preterm infants born of small-for-gestation age: how different from those born of appropriate-for-gestation

It is unclear whether there is any postnatal abnormality in brainstem auditory function in late preterm small-for-gestational-age (SGA) infants. We investigated the functional integrity of the brainstem auditory pathway at 4 months after term in late preterm SGA infants and defined differences from appropriate-for-gestational age (AGA) infants. The maximum length sequence brainstem evoked response (MLS BAER) was recorded and analyzed in 24 SGA (birthweight < 3rd centile) infants and 28 AGA infants (birthweight > 10th centile). All infants were born at 33-36-week gestation without major perinatal and postnatal problems. We found that I-V interval in SGA infants was shorter than in AGA infants at higher click rates and significantly shorter at the highest rate of 910/s. Of the two smaller intervals, I-III interval was significantly shorter in SGA infants than in AGA infants at higher click rates of 455 and 910/s clicks, whereas III-V interval was similar in the two groups. The III-V/I-III interval ratio in SGA infants tended to be greater than in AGA infants at all rates and was significantly greater at 455 and 910/s clicks. The slope of I-III interval-rate functions in SGA infants was moderately smaller than in AGA infants.  Conclusions: The main and fundamental difference between late preterm SGA and AGA infants was a significant shortening in the MLS BAER I-III interval in SGA infants at higher click rates, suggesting moderately faster neural conduction in the caudal brainstem regions. Postnatal neural maturation in the caudal brainstem regions is moderately accelerated in late preterm SGA infants. What is Known: • At 40 weeks of postconceptional age, late preterm SGA infants manifested a mild delay in neural conduction in the auditory brainstem. What is New: • At 56 weeks of postconceptional age, late preterm SGA infants manifested moderately faster neural conduction in the caudal brainstem regions. • Postnatal neural maturation is moderately accelerated in the caudal brainstem regions of late preterm SGA infants.

Perinatal inflammation, fetal growth restriction, and long-term neurodevelopmental impairment in Bangladesh

BACKGROUND

There are limited data on the impact of perinatal inflammation on child neurodevelopment in low-middle income countries and among growth-restricted infants.

METHODS

Population-based, prospective birth cohort study of 288 infants from July 2016-March 2017 in Sylhet, Bangladesh. Umbilical cord blood was analyzed for interleukin(IL)-1α, IL-1β, IL-6, IL-8, and C-reactive protein(CRP). Child neurodevelopment was assessed at 24 months with Bayley-III Scales of Infant Development. We determined associations between cord blood inflammation and neurodevelopmental outcomes, controlling for potential confounders.

RESULTS

248/288 (86%) live born infants were followed until 24 months, among whom 8.9% were preterm and 45.0% small-for-gestational-age(SGA) at birth. Among all infants, elevated concentrations (>75%) of CRP and IL-6 at birth were associated with increased odds of fine motor delay at 24 months; elevated CRP was also associated with lower receptive communication z-scores. Among SGA infants, elevated IL-1α was associated with cognitive delay, IL-8 with language delay, CRP with lower receptive communication z-scores, and IL-1β with lower expressive communication and motor z-scores.

CONCLUSIONS

In rural Bangladesh, perinatal inflammation was associated with impaired neurodevelopment at 24 months. The associations were strongest among SGA infants and noted across several biomarkers and domains, supporting the neurobiological role of inflammation in adverse fetal development, particularly in the setting of fetal growth restriction.

IMPACT

Cord blood inflammation was associated with fine motor and language delays at 24 months of age in a community-based cohort in rural Bangladesh. 23.4 million infants are born small-for-gestational-age (SGA) globally each year. Among SGA infants, the associations between cord blood inflammation and adverse outcomes were strong and consistent across several biomarkers and neurodevelopmental domains (cognitive, motor, language), supporting the neurobiological impact of inflammation prominent in growth-restricted infants. Prenatal interventions to prevent intrauterine growth restriction are needed in low- and middle-income countries and may also result in long-term benefits on child development.

Clinical Chorioamnionitis and Neurodevelopment at 5 Years of Age in Children Born Preterm: The EPIPAGE-2 Cohort Study

OBJECTIVE

To assess the association between clinical chorioamnionitis and neurodevelopmental disorders at 5 years of age in children born preterm.

STUDY DESIGN

EPIPAGE 2 is a national, population-based cohort study of children born before 35 weeks of gestation in France in 2011. We included infants born alive between 240/7 and 346/7 weeks after preterm labor or preterm premature rupture of membranes. Clinical chorioamnionitis was defined as maternal fever before labor (>37.8°C) with ≥2 of the following criteria: maternal tachycardia, hyperleukocytosis, uterine contractions, purulent amniotic fluid, or fetal tachycardia. The primary outcome was a composite, including cerebral palsy, coordination disorders, cognitive disorders, sensory disorders, or behavioral disorders. We also analyzed each of these disorders separately as secondary outcomes. We performed a multivariable analysis using logistic regression models. We accounted for the nonindependence of twins and missing data by generalized estimating equation models and multiple imputations, respectively.

RESULTS

Among 2927 children alive at 5 years of age, 124 (3%) were born in a context of clinical chorioamnionitis. Overall, 8.2% and 9.6% of children exposed and unexposed, respectively, to clinical chorioamnionitis had moderate-to-severe neurodevelopmental disorders. After multiple imputations and multivariable analysis, clinical chorioamnionitis was not associated with the occurrence of moderate-to-severe neurodevelopmental disorders (aOR, 0.9; 95% CI, 0.5-1.8).

CONCLUSIONS

We did not find any association between clinical chorioamnionitis and neurodevelopmental disorders at 5 years of age in children born at <35 weeks of gestation after preterm labor or preterm premature rupture of membrane.

Placentae of small appropriately-grown-for-gestational-age neonates exhibit sexually dimorphic transcriptomic changes representative of placental insufficiency

INTRODUCTION

Previous studies have reported that neonates less than the 25th BWC especially if they were male, were more likely to be associated with birth complications suggesting small neonates often identified as appropriately grown are at risk of adverse outcomes. We have questioned whether smaller neonates not typically categorized as "small for gestational age" may not reach their genetically determined growth due to placental insufficiency.

METHODS

RNA-Seq was performed on the Illumina NovaSeq 600 using term placentae from neonates that were less than the 10th birthweight centile (BWC) (n = 39), between the 10th and the 30th BWC (n = 15) or greater than the 30th BWC (n = 23). Bioinformatic analyses were conducted and statistical significance was assessed at a level of P < 0.05 for single comparisons or FDR <0.05 unless otherwise noted.

RESULTS

Gene set enrichment analysis revealed differences between BWC groups and in relation to the sex of the placenta. Genes associated with hypoxia, inflammatory responses, estrogen responsive genes, and androgen responsive genes were enriched (FDR <0.1) for in placentae of neonates <10th BWC regardless of sex and also in male placentae of neonates between the 10th-30th BWC. Female placenta of neonates between the 10th-30th BWC were comparable to placentae of neonates >30th BWC.

DISCUSSION

These findings provide evidence that small male neonates may be at a greater risk of an adverse outcome than females due to changes in gene expression that are associated with placental dysfunction. The current data raises questions of whether placental pathology for smaller appropriately grown neonates should be scientifically and clinically examined in more depth.

Neonatal resveratrol administration promotes skeletal muscle growth and insulin sensitivity in intrauterine growth-retarded suckling piglets associated with activation of FGF21-AMPKα pathway

BACKGROUND

Skeletal muscle is a major insulin-sensitive tissue with a pivotal role in modulating glucose homeostasis. This study aimed to investigate the effect of resveratrol (RES) intervention during the suckling period on skeletal muscle growth and insulin sensitivity of neonates with intrauterine growth retardation (IUGR) in a pig model.

RESULTS

Twelve pairs of normal birth weight (NBW) and IUGR neonatal male piglets were selected. The NBW and IUGR piglets were fed basal formula milk diet or identical diet supplemented with 0.1% RES from 7 to 21 days of age. Myofiber growth and differentiation, inflammation and insulin sensitivity in skeletal muscle were assessed. Early RES intervention promoted myofiber growth and maturity in IUGR piglets by ameliorating the myogenesis process and increasing thyroid hormone level. Administering RES also reduced triglyceride concentration in skeletal muscle of IUGR piglets, along with decreased inflammatory response, increased plasma fibroblast growth factor 21 (FGF21) concentration and improved insulin signaling. Meanwhile, the improvement of insulin sensitivity by RES may be partly regulated by activation of the FGF21/AMP-activated protein kinase α/sirtuin 1/peroxisome proliferator activated receptor-γ coactivator-1α pathway.

CONCLUSION

Our results suggest that RES has beneficial effects in promoting myofiber growth and maturity and increasing skeletal muscle insulin sensitivity in IUGR piglets, which open a novel field of application of RES in IUGR infants for improving postnatal metabolic adaptation. © 2023 Society of Chemical Industry.

[Factors influencing the occurrence of small for gestational age at different degrees]

OBJECTIVES

To investigate the factors influencing the occurrence of small for gestational age (SGA) at different degrees and provide a basis for early identification of severe SGA cases.

METHODS

Neonatal and maternal prenatal information were retrospectively collected from January 2018 to December 2022 at Peking University People's Hospital. The neonates were divided into three groups: severe SGA group (birth weight below the 3rd percentile for gestational age and sex), mild SGA group (birth weight ≥3rd percentile and <10th percentile), and non-SGA group (birth weight ≥10th percentile). An ordered multinomial logistic regression model was used to analyze the factors influencing the occurrence of SGA at different degrees.

RESULTS

A total of 14 821 neonates were included, including 258 cases (1.74%) in the severe SGA group, 902 cases (6.09%) in the mild SGA group, and 13 661 cases (92.17%) in the non-SGA group. The proportions of preterm births and stillbirths were higher in the severe SGA group compared to the mild SGA and non-SGA groups (P<0.0125). The proportion of neonatal asphyxia was higher in both the severe SGA and mild SGA groups compared to the non-SGA group (P<0.0125). Ordered multinomial logistic regression analysis showed that maternal pre-pregnancy underweight (OR=1.838), maternal pre-pregnancy obesity (OR=3.024), in vitro fertilization-embryo transfer (OR=2.649), preeclampsia (OR=1.743), connective tissue disease during pregnancy (OR=1.795), nuchal cord (OR=1.213), oligohydramnios (OR=1.848), and intrauterine growth restriction (OR=27.691) were all associated with a higher risk of severe SGA (P<0.05). Maternal parity as a multipara (OR=0.457) was associated with a lower likelihood of severe SGA (P<0.05).

CONCLUSIONS

Maternal pre-pregnancy underweight, maternal pre-pregnancy obesity, in vitro fertilization-embryo transfer, preeclampsia, connective tissue disease during pregnancy, oligohydramnios, nuchal cord, and intrauterine growth restriction are closely related to the occurrence of more severe SGA. Maternal parity as a multipara acts as a protective factor against the occurrence of severe SGA.

Intrauterine Growth Restriction: Need to Improve Diagnostic Accuracy and Evidence for a Key Role of Oxidative Stress in Neonatal and Long-Term Sequelae

Intrauterine growth restriction (IUGR) and being small for gestational age (SGA) are two distinct conditions with different implications for short- and long-term child development. SGA is present if the estimated fetal or birth weight is below the tenth percentile. IUGR can be identified by additional abnormalities (pathological Doppler sonography, oligohydramnion, lack of growth in the interval, estimated weight below the third percentile) and can also be present in fetuses and neonates with weights above the tenth percentile. There is a need to differentiate between IUGR and SGA whenever possible, as IUGR in particular is associated with greater perinatal morbidity, prematurity and mortality, as well as an increased risk for diseases in later life. Recognizing fetuses and newborns being "at risk" in order to monitor them accordingly and deliver them in good time, as well as to provide adequate follow up care to ameliorate adverse sequelae is still challenging. This review article discusses approaches to differentiate IUGR from SGA and further increase diagnostic accuracy. Since adverse prenatal influences increase but individually optimized further child development decreases the risk of later diseases, we also discuss the need for interdisciplinary follow-up strategies during childhood. Moreover, we present current concepts of pathophysiology, with a focus on oxidative stress and consecutive inflammatory and metabolic changes as key molecular mechanisms of adverse sequelae, and look at future scientific opportunities and challenges. Most importantly, awareness needs to be raised that pre- and postnatal care of IUGR neonates should be regarded as a continuum.

A nationwide birth cohort in Japan showed increased risk of early childhood hospitalisation in infants born small for gestational age

AIM

To examine associations between children being born small for gestational age and childhood hospitalisation following term and preterm births.

METHODS

This study included 34 564 children from a nationwide population-based longitudinal survey starting in 2010, comprising 32 603 term births and 1961 preterm births. Children's hospitalisation history was examined during two observational periods, 6-18 and 6-66 months of age. Logistic regression analysis was conducted, adjusting for child and parental confounders, with children born appropriate for gestational age as reference.

RESULTS

Children born small for gestational age were more likely to be hospitalised during early childhood than those born appropriate for gestational age. The odds ratio (95% confidence interval) for hospitalisation from 6 to 66 months of age was 1.19 (1.05-1.34) in term children born small for gestational age and 1.47 (1.05-2.06) for preterm children born small for gestational age, compared with those born appropriate for gestational age. The risk of hospitalisation from 6 to 66 months of age in children born small for gestational age was observed for bronchitis/pneumonia.

CONCLUSION

We observed the adverse effects of small for gestational age on hospitalisation during early childhood in both term and preterm births, particularly for bronchitis and pneumonia.

Vulnerable newborn phenotypes in Peru: a population-based study of 3,841,531 births at national and subnational levels from 2012 to 2021

Background

We aimed to examine the national and subnational prevalence of vulnerable newborn phenotypes in Peru, 2012-2021.

Methods

Newborn phenotypes were defined using gestational age (preterm [PT], term [T]), birthweight for gestational age using INTERGROWTH-21st standards (small for gestational age [SGA], appropriate for gestational age [AGA] or large for gestational age [LGA]), and birthweight (low birthweight [LBW], non-LBW) using the Peruvian National Birth Registry as six (by excluding birthweight) and ten newborn phenotypes (using all three outcomes). Small phenotypes (with at least one classification of PT, SGA, or LBW) were further considered. Using individual-level data, we stratified the phenotypes by maternal educational level, maternal age, healthcare insurance, altitude of residence, and geographic region (Coast, Andes, and Amazon).

Findings

The prevalence of the five vulnerable newborn phenotypes for the study period was LGA+T (15.2%), AGA+PT (5.2%), SGA+T (4.6%), LGA+PT (0.8%), and SGA+PT (0.7%). The Coast had a higher prevalence of newborns with large phenotypes (19.4%) and the Highlands a higher prevalence of newborns with small phenotypes (12.5%). Mothers with poor socioeconomic status, extreme ages and living at high altitude had a higher prevalence of newborns with small phenotypes, and mothers who were wealthier, more educated, and older had a higher prevalence of infants with large phenotypes.

Interpretation

Our findings cautiously suggest that socioeconomic and geographic disparities may play a crucial role in shaping vulnerable newborn phenotypes at national and subnational level in Peru. Further studies using longitudinal data are needed to corroborate our findings and to identify individual-level risk factors.

Funding

Ter Meulen Grant from the KNAW Medical Sciences Fund of the Royal Netherlands Academy of Arts and Sciences (KNAWWF/1085/TMB406, KNAWWF/1327/TMB202116), Fogarty Program (D43TW011502).

Associations between maternal urinary rare earth elements during pregnancy and birth weight-for-gestational age: Roles of cord blood vitamin D levels

Prenatal exposure to rare earth elements (REEs) may contribute to adverse birth outcomes in previous studies. Cord blood vitamin D has been suggested to modify or mediate the effects of environmental exposures. However, none has investigated these roles of cord blood vitamin D in the associations of prenatal exposure to REEs with fetal growth. Maternal trimester-specific urinary concentrations of 13 REEs, cord blood total 25-hydroxyvitamin D at delivery, and birth weight (BW)-for-gestational age (GA) were determined in 710 mother-newborn pairs from Wuhan, China. Higher maternal average urinary concentrations of europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), and ytterbium (Yb) across three trimesters, either individually or jointly, were significantly associated with lower BW-for-GA Z-scores and higher odds of small for gestational age (SGA) [β = -0.092; 95 % confidence interval (CI): -0.149, -0.035 for BW-for-GA Z-scores, and odds ratio = 1.60; 95 % CI: 1.14, 2.24 for SGA involved in each unit increase in weighted quantile sum index of REEs mixture]. When stratified by cord blood vitamin D levels, the associations mentioned above persisted in participants with relatively low vitamin D levels (<13.94 μg/L, the first tertile of distribution), but not among those with relatively high levels (≥13.94 μg/L) (all p-values for interaction < 0.05). The mediation analyses taking account of exposure-mediator interaction showed that the relationships between REEs (as individual and mixture) exposure and lower BW-for-GA were partly mediated through decreasing cord blood vitamin D levels. The proportions mediated by cord blood vitamin D levels were 24.48 % for BW-for-GA Z-scores and 29.05 % for SGA corresponding to the REEs mixture exposure. Conclusively, our study revealed that prenatal exposures to Eu, Gd, Dy, Ho, Er, and Yb were related to fetal growth restriction. Cord blood vitamin D might alleviate toxic effects of these REEs and its reduction might partly mediate REE-induced fetal growth restriction.

Associations between placental pathology and poor intrauterine growth among a cohort of mother-infant singleton pairs in Leyte, the Philippines

OBJECTIVE

Poor intrauterine growth has negative impacts for child growth and development and disproportionately affects children living in low-resource settings. In the present study, we investigated relationships between placental pathologies and indicators of poor intrauterine growth.

METHODS

We enrolled a longitudinal cohort of 279 mother-infant pairs from Leyte, the Philippines. Placental measures included characteristics, pathological findings, and immunohistochemistry. At birth, intrauterine growth was assessed using anthropometric measures, weight-for-gestational age, and the clinical assessment of nutritional status score (CANSCORE) for determining fetal malnutrition. Multivariate linear regression and log-binomial regression models were applied, controlling for potential confounding factors.

RESULTS

Maternal vascular malperfusion (MVM) was related to reduced birthweight (P < 0.0001), birth length (P = 0.002), head circumference (P = 0.001), and weight-to-length ratio (P = 0.016). MVM increased the risk for preterm delivery (P = 0.0005) and small for gestational age (SGA) (P = 0.016). Acute chorioamnionitis (P = 0.013) and MVM (P = 0.021) both led to an increased risk for fetal malnutrition defined by CANSORE<25. Villous tissue activated caspase-3 was associated with lower birth length (P = 0.0006), higher weight-to-length ratio (P = 0.004), reduced risks for SGA (P = 0.011) and low weight-to-length ratio for gestational age (P = 0.004).

CONCLUSION

The present study applied comprehensive measures for intrauterine growth and demonstrates that low placental weight and placental pathology, chiefly MVM, contribute to poor intrauterine growth. A better understanding of the mechanistic role of specific placental pathologies on adverse newborn outcomes will provide opportunities for reducing incidence of poor intrauterine growth and associated long-term morbidities.

Association between small-for-gestational age and poor school performance in 2 500 000 children born 1973-2002

AIM

To examine the association between infant weight for gestational age and school performance when leaving school at 16 years of age.

METHODS

Out of 2 525 571 infants born near- or at term, between 1 January 1973 and 31 December 2002, identified from the Swedish Medical Birth Register, 65 912 (2.6%) were born small-for-gestational age (SGA). Outcomes studied were the risk for the need for education in special school, and the final average grades. Modified Poisson regression analyses and weighted linear regression analyses were performed.

RESULTS

An association between SGA and the need for a special school was found, irrespective of restrictions or adjustments (RR between 2.47 and 2.25). SGA was associated with final grades below the 10th and 25th percentile (RR 1.49 and 1.18, respectively). A linear relationship between maternal height and the RR for education in special school (p = 0.005), suggested that SGA is a stronger risk factor among children of tall than of shorter women.

CONCLUSION

SGA increased the risk for poor school performance, and for the need for a special school. We found an association between maternal height and school performance in relation to birthweight, suggesting that maternal height should be considered when estimating the impact of SGA on later outcomes.

Short-term neonatal and long-term neurodevelopmental outcome of children born term low birth weight

This study aimed to examine the impact of term LBW on short-term neonatal and long-term neurodevelopmental outcomes in children 5-7 years of age. This is a population-based cohort study that merged national data from the Korea National Health Insurance claims and National Health Screening Program for Infants and Children. The participants were women who gave birth at a gestational age of ≥ 37 weeks between 2013 and 2015 in the Republic of Korea, and were tracked during 2020 for the neurodevelopmental surveillance of their children. Among 830,806 women who gave birth during the study period, 31,700 (3.8%) of their babies weighed less than 2500 g. By Cox proportional hazard analysis, children aged 5-7 years who had LBW were associated with any developmental, motor developmental delay, cognitive developmental delay, autism spectrum, attention deficit hyperactivity disorders, and epileptic and febrile seizures.Children born with term LBW were more vulnerable to neurodevelopmental disorders at 5-7 years of age than those with normal and large birth weights. This study further substantiates counseling parents regarding the long-term outcomes of children being born underweight.

Associations between gestational weight gain under different guidelines and adverse birth outcomes: A secondary analysis of a randomized controlled trial in rural western China

Several gestational weight gain (GWG) guidelines have been established based on monocenter or multicenter researches. We aimed to examine the associations between categories of GWG under the Institute of Medicine (IOM) recommendation guideline, the Chinese National Health Commission (NHC) guideline, and weight-gain-for-gestational-age z-scores derived from the INTERGROWTH-21st Project and adverse birth outcomes. We used data from an antenatal micronutrient supplementation trial in rural western China between 2002 and 2006. Maternal weekly average GWG during the second and third trimesters was calculated and classified into inadequate, adequate and excessive GWG according to the IOM and NHC, respectively. Weight-gain-for-gestational-age z-scores derived from the INTERGROWTH-21st Project were grouped into three subgroups using two approaches: z-score percentile<25th, 25th to 75th, >75th and z-score <-1, -1 to 1, >1 SD. Infant birth weight and gestational age were measured using standard approaches. Generalized linear model with binomial family and logit link was applied to estimate the odds ratio (OR) and 95% confidential intervals (CI) for GWG categories and adverse birth outcomes. Among 1,239 women with normal weight (18.5 kg/m2 to 23.9 kg/m2) during early pregnancy, 18.0% and 34.2% were classified as adequate GWG according to IOM and NHC, respectively. Less than half of Chinese women reached optimal GWG by any recommendation guideline. According to NHC, excessive GWG showed a significant association with macrosomia (OR 3.75, 95% CI 1.03, 13.74), large-for-gestation-age (LGA) (OR 2.12, 95% CI 1.01, 4.45), and inadequate GWG was associated with post-term birth (OR 2.25, 95% CI 1.21, 4.16), compared with adequate GWG. Inappropriate GWG was associated with adverse birth outcomes even among women with normal weight during early pregnancy. The monitoring and interventions of weight status during pregnancy, especially for the second and third trimesters, are of great public health importance for optimal birth outcomes. Additionally, developing guideline of appropriate GWG ranges should account for the traits of regional population.

Early child development and its determinants: Findings from a large cohort of healthy children growing up in a low-risk environment

BACKGROUND

Despite numerous studies on early child development, there is still much to be discovered about the significance of possible risk factors. This study examines cognitive, motor, and language development of healthy children growing up in a low-risk environment and how various individual and environmental factors are associated with it. The study also considers whether the importance of particular parameters changes depending on child age.

METHODS

Within the framework of the LIFE Child study in Leipzig, Germany, 481 children participated in a total of 832 visits between 1 and 36 months of age. Developmental status was assessed using the Third Edition of the Bayley Scales of Infant and Toddler Development. Linear regression analyses were applied to examine the associations between child development and sex, gestational age, birth weight, birth mode, overweight, height, and parental education.

RESULTS

Mean Bayley composite scores for cognitive, language, and motor development were close to the standard value of 100. Poorer developmental outcomes were significantly associated with lower gestational age, vacuum cup/forceps birth, being overweight, small height, and lower parental education, although some of the associations became insignificant after applying multivariate models. While the association between gestational age and language development became weaker with advancing age, our interaction models found disparities related to parental education to become more apparent in older children across all three domains of early child development.

CONCLUSIONS

Several factors were identified to be associated with early child development. As children grow older, obstetric parameters, for example, gestational age, might become less relevant compared with sociodemographic factors, for example, parental education.

Fetal insular measurements in pregnancy with estimated fetal weight <10th centile and childhood neurodevelopmental outcomes

BACKGROUND

A growing body of evidence suggests that fetal growth restriction is associated with changes in brain structures as a result of chronic hypoxia. However, less is known about the effects of growth restriction on the fetal insula, particularly in less severely affected late-onset growth-restricted fetuses.

OBJECTIVE

This study aimed to (1) compare sonographic insular measurements between fetal-growth restricted, small-for-gestational-age, and appropriate-for-gestational-age control fetuses; and (2) evaluate the association of sonographic insular measurements with perinatal and neurodevelopmental outcomes in fetuses categorized as fetal-growth restricted or small-for-gestational-age.

STUDY DESIGN

This was a cohort study of singleton nonanomalous pregnancies with an estimated fetal weight <10th centile. Using data from the last examination before delivery, fetal insular depth, Sylvian fissure depth, hypoechoic insular zone thickness, circumference, and area were measured. All measurements were adjusted for by head circumference. Neurodevelopmental outcomes were evaluated at 2 to 3 years of age using the Bayley-III scales. Kruskal-Wallis H tests were performed to compare insular measurements between groups. Paired t tests were used to compare insular measurements between appropriate-for-gestational-age fetuses and gestational age-matched growth-restricted fetuses. Insular measurements for patients with and without an adverse perinatal outcome were compared using independent-samples t-tests. Spearman correlations were performed to evaluate the relationship of insular measurements to the percentile scores for each of the 5 Bayley-III subscales and to a summative percentile of these subscales.

RESULTS

A total of 89 pregnancies were included in the study; 68 of these pregnancies had an estimated fetal weight <10th percentile (fetal-growth restricted: n=39; small-for-gestational-age: n=29). The appropriate-for-gestational-age cohort consisted of 21 pregnancies. The gestational age at measurement was similar between fetal-growth restricted and small-for-gestational-age groups, but lower in the appropriate-for-gestational-age group. Differences between groups were noted in normalized insular depth, Sylvian fissure depth, and hypoechoic insular zone (P<.01). Normalized insular depth and hypoechoic insular zone circumference were larger in the growth-restricted cohort (P<.01). Normalized Sylvian fissure depth was smaller in the growth-restricted cohort (P<.01). There were no significant differences in insular measurements between pregnancies with and without an adverse perinatal outcome. Bayley-III results were available in 32 of the growth-restricted cases. Of all insular measurements, hypoechoic insular zone circumference was inversely correlated with the adaptive behavior Bayley-III score.

CONCLUSION

In our cohort, fetuses with estimated fetal weight <10th percentile had smaller Sylvian fissure depths and larger insular depths and hypoechoic insular zone circumferences than normally grown controls. A larger hypoechoic insular zone circumference was substantially correlated with worse neurodevelopmental outcomes in early childhood. We speculate that enlargement of this region may be an indication of accelerated neuronal maturation in growth-restricted fetuses with mild hypoxia.

Small-for-Gestational-Age and Vocabulary and Achievement Test Scores at Age 9 Among Children Born at Term in a Contemporary U.S. Sample

INTRODUCTION

Children that are small-for-gestational-age (SGA) at birth are at an increased risk for cognitive impairment, even if born at term (37-41 weeks). This study examined associations between sex-specific SGA and vocabulary and achievement tests in 9 year old children born at term using a contemporary population-based US sample.

METHODS

A secondary data analysis was conducted on a sample of 2144 children born at term in 1998-2000 who participated in a US birth cohort study that oversampled non-marital births, which in the U.S. are associated with socioeconomic disadvantage and racial minority status. Vocabulary and achievement tests were administered to participants at age 9. Unadjusted and adjusted Ordinary Least Squares and logistic regression models of associations between SGA and test scores were estimated.

RESULTS

Sex-specific SGA was associated with 2-5 point lower test scores and 1-2 times the odds of scores less than 85 (> 1 SD below the national mean) across most outcomes. In adjusted models, measures of SGA were associated with low scores on the Woodcock-Johnson Applied Problems test (OR 2.257; 95% CI 1.434, 3.551) and the Woodcock-Johnson Passage Comprehension test (OR 1.554; 95% CI 1.132, 2.134).

CONCLUSION

The findings validate previous studies of SGA at term and cognitive outcomes and provide further evidence using a contemporary high-risk population-based US sample. The findings suggest that SGA children born at term should be recruited for early interventions to promote improved cognitive functioning in school.

Effects of size at birth on health, growth and developmental outcomes in children up to age 18: an umbrella review

BACKGROUND

Size at birth, an indicator of intrauterine growth, has been studied extensively in relation to subsequent health, growth and developmental outcomes. Our umbrella review synthesises evidence from systematic reviews and meta-analyses on the effects of size at birth on subsequent health, growth and development in children and adolescents up to age 18, and identifies gaps.

METHODS

We searched five databases from inception to mid-July 2021 to identify eligible systematic reviews and meta-analyses. For each meta-analysis, we extracted data on the exposures and outcomes measured and the strength of the association.

FINDINGS

We screened 16 641 articles and identified 302 systematic reviews. The literature operationalised size at birth (birth weight and/or gestation) in 12 ways. There were 1041 meta-analyses of associations between size at birth and 67 outcomes. Thirteen outcomes had no meta-analysis.Small size at birth was examined for 50 outcomes and was associated with over half of these (32 of 50); continuous/post-term/large size at birth was examined for 35 outcomes and was consistently associated with 11 of the 35 outcomes. Seventy-three meta-analyses (in 11 reviews) compared risks by size for gestational age (GA), stratified by preterm and term. Prematurity mechanisms were the key aetiologies linked to mortality and cognitive development, while intrauterine growth restriction (IUGR), manifesting as small for GA, was primarily linked to underweight and stunting.

INTERPRETATION

Future reviews should use methodologically sound comparators to further understand aetiological mechanisms linking IUGR and prematurity to subsequent outcomes. Future research should focus on understudied exposures (large size at birth and size at birth stratified by gestation), gaps in outcomes (specifically those without reviews or meta-analysis and stratified by age group of children) and neglected populations.

PROSPERO REGISTRATION NUMBER

CRD42021268843.

Critical Windows of Maternal Exposure to Biothermal Stress and Birth Weight for Gestational Age in Western Australia

BACKGROUND

There is limited and inconsistent evidence on the risk of ambient temperature on small for gestational age (SGA) and there are no known related studies for large for gestational age (LGA). In addition, previous studies used temperature rather than a biothermal metric.

OBJECTIVES

Our aim was to examine the associations and critical susceptible windows of maternal exposure to a biothermal metric [Universal Thermal Climate Index (UTCI)] and the hazards of SGA and LGA.

METHODS

We linked 385,337 singleton term births between 1 January 2000 and 31 December 2015 in Western Australia to daily spatiotemporal UTCI. Distributed lag nonlinear models with Cox regression and multiple models were used to investigate maternal exposure to UTCI from 12 weeks preconception to birth and the adjusted hazard ratios (HRs) of SGA and LGA.

RESULTS

Relative to the median exposure, weekly and monthly specific exposures showed potential critical windows of susceptibility for SGA and LGA at extreme exposures, especially during late gestational periods. Monthly exposure showed strong positive associations from the 6th to the 10th gestational months with the highest hazard of 13% for SGA (HR = 1.13 ; 95% CI: 1.10, 1.14) and 7% for LGA (HR = 1.07 ; 95% CI: 1.03, 1.11) at the 10th month for the 1st UTCI centile. Entire pregnancy exposures showed the strongest hazards of 11% for SGA (HR = 1.11 ; 95% CI: 1.04, 1.18) and 3% for LGA (HR = 1.03 ; 95% CI: 0.95, 1.11) at the 99th UTCI centile. By trimesters, the highest hazards were found during the second and first trimesters for SGA and LGA, respectively, at the 99th UTCI centile. Based on estimated interaction effects, male births, mothers who were non-Caucasian, smokers, ≥ 35 years of age, and rural residents were most vulnerable.

CONCLUSIONS

Both weekly and monthly specific extreme biothermal stress exposures showed potential critical susceptible windows of SGA and LGA during late gestational periods with disproportionate sociodemographic vulnerabilities. https://doi.org/10.1289/EHP12660.

Long-term pulmonary and neurodevelopmental impairment in a fetal growth restriction rabbit model

Fetal growth restriction (FGR) remains one of the main obstetrical problems worldwide, with consequences beyond perinatal life. Animal models with developmental and structural similarities to the human are essential to understand FGR long-term consequences and design novel therapeutic strategies aimed at preventing or ameliorating them. Herein, we described the long-term consequences of FGR in pulmonary function, structure, and gene expression, and characterized neurodevelopmental sequelae up to preadolescence in a rabbit model. FGR was induced at gestational day 25 by surgically reducing placental blood supply in one uterine horn, leaving the contralateral horn as internal control. Neonatal rabbits born near term were assigned to foster care in mixed groups until postnatal day (PND) 21. At that time, one group underwent pulmonary biomechanical testing followed by lung morphometry and gene expression analysis. A second group underwent longitudinal neurobehavioral assessment until PND 60 followed by brain harvesting for multiregional oligodendrocyte and microglia quantification. FGR was associated with impaired pulmonary function and lung development at PND 21. FGR rabbits had higher respiratory resistance and altered parenchymal biomechanical properties in the lungs. FGR lungs presented thicker alveolar septal walls and reduced alveolar space. Furthermore, the airway smooth muscle content was increased, and the tunica media of the intra-acinar pulmonary arteries was thicker. In addition, FGR was associated with anxiety-like behavior, impaired memory and attention, and lower oligodendrocyte proportion in the frontal cortex and white matter. In conclusion, we documented and characterized the detrimental pulmonary function and structural changes after FGR, independent of prematurity, and beyond the neonatal period for the first time in the rabbit model, and describe the oligodendrocyte alteration in pre-adolescent rabbit brains. This characterization will allow researchers to develop and test therapies to treat FGR and prevent its sequelae.

Neonatal mortality risk of large-for-gestational-age and macrosomic live births in 15 countries, including 115.6 million nationwide linked records, 2000-2020

OBJECTIVE

We aimed to compare the prevalence and neonatal mortality associated with large for gestational age (LGA) and macrosomia among 115.6 million live births in 15 countries, between 2000 and 2020.

DESIGN

Population-based, multi-country study.

SETTING

National healthcare systems.

POPULATION

Liveborn infants.

METHODS

We used individual-level data identified for the Vulnerable Newborn Measurement Collaboration. We calculated the prevalence and relative risk (RR) of neonatal mortality among live births born at term + LGA (>90th centile, and also >95th and >97th centiles when the data were available) versus term + appropriate for gestational age (AGA, 10th-90th centiles) and macrosomic (≥4000, ≥4500 and ≥5000 g, regardless of gestational age) versus 2500-3999 g. INTERGROWTH 21st served as the reference population.

MAIN OUTCOME MEASURES

Prevalence and neonatal mortality risks.

RESULTS

Large for gestational age was common (median prevalence 18.2%; interquartile range, IQR, 13.5%-22.0%), and overall was associated with a lower neonatal mortality risk compared with AGA (RR 0.83, 95% CI 0.77-0.89). Around one in ten babies were ≥4000 g (median prevalence 9.6% (IQR 6.4%-13.3%), with 1.2% (IQR 0.7%-2.0%) ≥4500 g and with 0.2% (IQR 0.1%-0.2%) ≥5000 g). Overall, macrosomia of ≥4000 g was not associated with increased neonatal mortality risk (RR 0.80, 95% CI 0.69-0.94); however, a higher risk was observed for birthweights of ≥4500 g (RR 1.52, 95% CI 1.10-2.11) and ≥5000 g (RR 4.54, 95% CI 2.58-7.99), compared with birthweights of 2500-3999 g, with the highest risk observed in the first 7 days of life.

CONCLUSIONS

In this population, birthweight of ≥4500 g was the most useful marker for early mortality risk in big babies and could be used to guide clinical management decisions.

Circulating exosomes decrease in size and increase in number between birth and age 7: relations to fetal growth and liver fat

Purpose

Exosomes play a key role in cell-to-cell communication by transferring their cargo to target tissues. Little is known on the course of exosome size and number in infants and children.

Methods

Longitudinally, we assessed the size and number of circulating exosomes at birth and at ages 2 and 7 yr in 75 infants/children born appropriate-for-gestational-age (AGA; n=40) or small-for-gestational-age (SGA; n=35 with spontaneous catch-up), and related those results to concomitantly assessed measures of endocrine-metabolic health (HOMA-IR; IGF-1), body composition (by DXA at ages 0 and 2) and abdominal fat partitioning (subcutaneous, visceral and hepatic fat by MRI at age 7).

Results

Circulating exosomes of AGAs decreased in size (on average by 4.2%) and increased in number (on average by 77%) between birth and age 7. Circulating exosomes of SGAs (as compared to those of AGAs) had a larger size at birth [146.8 vs 137.8 nm, respectively; p=0.02], and were in lower number at ages 2 [4.3x1011 vs 5.6x1011 particles/mL, respectively; p=0.01] and 7 [6.3x1011 vs 6.8x1011 particles/mL, respectively; p=0.006]. Longitudinal changes were thus more pronounced in SGAs for exosome size, and in AGAs for exosome number. At age 7, exosome size associated (P<0.0001) to liver fat in the whole study population.

Conclusion

Early-life changes in circulating exosomes include a minor decrease in size and a major increase in number, and these changes may be influenced by fetal growth. Exosome size may become one of the first circulating markers of liver fat in childhood.

Neurodevelopmental Correlates of Brain Magnetic Resonance Imaging Abnormalities in Extremely Low-birth-weight Infants

OBJECTIVE

To evaluate the relationship between impaired brain growth and structural brain abnormalities at term-equivalent age (TEA) and neurodevelopment in extremely low-birth-weight (ELBW) infants over the first 2 years.

METHODS

ELBW infants born from 2009 through 2018 and undergoing brain magnetic resonance imaging (MRI) at TEA were enrolled in this retrospective cohort study. MRI scans were reviewed using a validated quali-quantitative score, including several white and gray matter items. Neurodevelopment was assessed at 6, 12, 18, and 24 months using the Griffiths scales. The independent associations between MRI subscores and the trajectories of general and specific neurodevelopmental functions were analyzed by generalized estimating equations.

RESULTS

One hundred-nine ELBW infants were included. White matter volume reduction and delayed myelination were associated with worse general development (b = -2.33, P = .040; b = -6.88, P = .049 respectively), social skills (b = -3.13, P = .019; b = -4.79, P = .049), and eye-hand coordination (b = -3.48, P = .009; b = -7.21, P = .045). Cystic white matter lesions were associated with poorer motor outcomes (b = -4.99, P = .027), while white matter signal abnormalities and corpus callosum thinning were associated with worse nonverbal cognitive performances (b = -6.42, P = .010; b = -6.72, P = .021, respectively). Deep gray matter volume reduction correlated with worse developmental trajectories.

CONCLUSIONS

Distinctive MRI abnormalities correlate with specific later developmental skills. This finding may suggest that TEA brain MRI may assist with neurodevelopmental prediction, counseling of families, and development of targeted supportive interventions to improve neurodevelopment in ELBW neonates.

Association of co-exposure to metal(loid)s during pregnancy with birth outcomes in the Tibetan plateau

Maternal metal (loid)s exposure has been related to birth outcomes but the results are still inconclusive. Most previous studies have discussed the single metal (loid)s, neglecting the scene of co-exposure. We examined the associations of both single metal (loid)s and metal mixtures with birth outcomes in a birth cohort from the Tibetan Plateau, including body weight, body length, head circumference, small for gestational age (SGA), and Ponderal index (PI). In our analysis of 1069 women, we measured 29 metal (loid)s in urine samples in the third trimester. The associations of single metal (loid)s with categorical or continuous birth outcomes were evaluated using a generalized linear mixed-effects model or linear mixed-effects model, respectively. The least absolute shrinkage and selection operator, Bayesian kernel machine, and Quantile g-computation regression were used to explore the joint association. We also evaluated the interactive effects of ethnicity and altitude on the effect of metal (loid)s on birth outcomes. Copper (Cu) concentration in maternal urine was positively associated with SGA, birth weight, birth length, and head circumference in the single pollutant models. For instance, Cu was associated with an increased risk of SGA [OR (95% CI) = 1.56 (1.23, 1.97); P < 0.001]. We didn't find significant joint association of metal mixtures with birth outcomes except a positive association between the mixture of Cu, Magnesium (Mg), and Iron (Fe) with the risk of SGA when the exposure level was above its 80th percentile, and Cu dominated the adverse association in a non-linear manner. Living altitude modified the associations of Cu with SGA and the positive association was only found in participants living at high altitude. In conclusion, maternal urinary metal (loid)s, especially Cu, was the dominant harmful metal (loid)s when associated with SGA on the Tibetan Plateau.

Reduced pulmonary oxygen diffusion at 36 weeks of postmenstrual age in small-for-gestational-age preterm infants of less than 32 weeks without bronchopulmonary dysplasia

BACKGROUND

Small-for-gestational-age (SGA) preterm infants are at increased risk of developing bronchopulmonary dysplasia (BPD). There is limited information on pulmonary oxygen diffusion of SGA preterm infants, particularly in those without BPD.

OBJECTIVE

To compare the pulmonary oxygen diffusion of SGA to that of appropriate-for-gestational-age (AGA) preterm infants without BPD.

STUDY DESIGN

Preterm infants with a gestational age (GA) between 24.0 and 31.6 weeks were studied. The oxygen saturation (SpO2 ), fraction to inspired oxygen (FiO2 ), and the SpO2 to FiO2 ratio (SFR) were compared between SGA and AGA infants. The association between SGA and SFR at 36 weeks was assessed using a multiple regression analysis. In the subgroup without BPD, SGA were match-paired for GA and gender with AGA infants.

RESULTS

We analyzed 1189 infants surviving at 36 weeks: 194 (16%) were SGA and 995 (84%) AGA. The incidence of BPD was significantly higher in SGA than AGA infants (32% vs. 13%; p = .000). Out of the 995 infants without BPD, 132 (13%) were SGA and 863 (87%) AGA. SGA was negatively associated with the SFR value at 36 weeks, independently from BPD. SGA infants without BPD had significantly higher (better) SFR at birth, but lower (worse) SpO2 and SFR and from 33 to 36 weeks than their matched AGA counterpart. At 36 weeks, median SpO2 and SFR values were 97.7 versus 98.4 (p = .006) and 465 versus 468 (p = .010) in match-paired SGA and AGA, respectively.

CONCLUSION

Among preterm infants of less than 32 weeks and without BPD, SGA infants had a reduced pulmonary oxygen diffusion at 36 weeks in comparison with AGA infants.

Fetal brain volumes and neurodevelopmental outcome of intrauterine growth restricted fetuses

OBJECTIVE

This study aims to investigate the correlation of MRI measured fetal brain volumetrics with long-term neurodevelopmental outcome, among intrauterine growth restricted (IUGR) and apparently healthy fetuses.

STUDY DESIGN

A historical cohort study at a single tertiary referral medical center during 6 years period, of fetuses diagnosed with IUGR due to placental insufficiency, and apparently healthy fetuses, who had fetal brain MRI scan. The volumes of the supratentorial brain region, both hemispheres and the cerebellum were measured by 3D MRI semi-automated volume measurements. The cerebellar to supratentorial ratio (CER/ST) was calculated. Volumes were plotted on normal growth curves. 17 IUGR fetuses, and 53 apparently healthy fetuses adhered to participate in the VABS-II questionnaire, evaluating neurodevelopmental outcome.

RESULTS

70 patients (mean age at conducting VABS-II questionnaire 4.4 ± 2.1 years, 38 males) were evaluated. Among fetuses born in a gestational age of 36 weeks or later, IUGR fetuses demonstrated a significantly larger number of abnormal results in the VABS-II communication domain (p =.049). No significant differences were found in other domains or in overall neurodevelopmental outcome. The CER/ST ratio correlated with the overall neurodevelopmental outcome of the total study population (r = 0.40, p <.001), and of the IUGR group separately (ρ = 0.58, p =.02).

CONCLUSION

CER/ST ratio measured using fetal brain MRI was found to be correlated with long term neurodevelopmental outcome. This result may aid in clinical interpretation of biometric data obtained by fetal brain MRI, linking it with long term neurodevelopmental outcome.

Impact of early-onset fetal growth restriction on the neurodevelopmental outcome of very preterm infants at 24 months: a retrospective cohort study

BACKGROUND

The association between fetal growth restriction (FGR) and childhood neurodevelopmental delay is unclear and the evidence available to the present date shows conflicting results. Our aim was to analyse the impact of early-onset FGR on the neurodevelopmental outcome at 24 months of corrected age in very preterm infants.

METHODS

Retrospective cohort study of very preterm infants (≤ 32 weeks' gestation) admitted to a neonatal intensive care unit between 1 January 2013-31 December 2019. The control group comprised appropriate for gestational age (AGA) newborns. Griffiths III Mental Development Scale was performed at 24 months of corrected age.

RESULTS

132 infants were included: 44 FGR and 88 AGA. Mean Global Development Quotient (GDQ) was lower for FGR infants (p = 0.004) even after adjusting for maternal and perinatal factors (βadjusted -16.703; p = 0.009). The average scores for the neurodevelopmental domains were highest for personal-social-emotional skills (107.02 ± 16.34), followed by eye/hand coordination (105.61 ± 14.20) and foundation of learning skills (102.23 ± 13.74) and were lowest for gross motor (97.90 ± 11.88) and language/communication skills (96.39 ± 18.88). FGR had a significant negative impact on all domains except for gross motor skills. After adjustment, FGR continued to have a significant adverse impact on language/communication (βadjusted -21.924; p = 0.013), eye/hand coordination (βadjusted -15.446; p = 0.015) and foundation of learning skills (βadjusted -15.211; p = 0.013).

CONCLUSIONS

In very preterm infants, FGR was associated with a significantly increased risk of poor neurodevelopmental outcome at 24 months of corrected age compared to age-matched AGA infants.

Neurodevelopmental outcomes of very preterm infants born following early foetal growth restriction with absent end-diastolic umbilical flow

This study aims to assess the impact of time of onset and features of early foetal growth restriction (FGR) with absent end-diastolic flow (AEDF) on pregnancy outcomes and on preterm infants' clinical and neurodevelopmental outcomes up to 2 years corrected age. This is a retrospective, cohort study led at a level IV Obstetric and Neonatal Unit in Bologna, Italy. Pregnant women were eligible if having singleton pregnancies, with no major foetal anomaly detected, and diagnosed with early FGR + AEDF (defined as FGR + AEDF detected before 32 weeks gestation). Early FGR + AEDF was further classified according to time of onset and specific features into very early and persistent (VEP, FGR + AEDF first detected at 20-24 weeks gestation and persistent at the following scans), very early but transient (VET, FGR + AEDF detected at 20-24 weeks gestation and progressively improving at the following scans) and later (LA, FGR + AEDF detected between 25 and 32 weeks gestation). Pregnancy and neonatal outcomes and infant follow-up data were collected and compared among groups. Neurodevelopment was assessed using the revised Griffiths Mental Developmental Scales (GMDS-R) 0-2 years. A regression analysis was performed to identify early predictors of preterm infants' neurodevelopmental impairment. Fifty-two pregnant women with an antenatal diagnosis of early FGR + AEDF were included in the study (16 VEP, 14 VET, 22 LA). Four intrauterine foetal deaths occurred, all in the VEP group (p = 0.010). Compared to LA infants, VEP infants were born with lower gestational age and lower birth weight, had lower arterial cord blood pH and were at higher risk for intraventricular haemorrhage and periventricular leukomalacia (p < 0.05 for all comparisons). At 12 months, VEP infants had worse GMDS-R scores, both in the general quotient (mean [SD] 91.8 [12.4] vs 104.6 [8.7] in LA) and in the performance domain (mean [SD] 93.3 [15.4] vs 108.8 [8.8] in LA). This latter difference persisted at 24 months (mean [SD] 68.3 [17.0] vs 92.9 [17.7] in LA). In multivariate analysis, at 12 months corrected age, PVL was found to be an independent predictor of impaired general quotient, while the features and timing of antenatal Doppler alterations predicted worse scores in the performance domain.   Conclusion: Timing of onset and features of early FGR + AEDF might impact differently on neonatal clinical and neurodevelopmental outcomes. Shared awareness of the importance of FGR + AEDF features between obstetricians and neonatologists may offer valuable tools for antenatal counselling and for tailoring pregnancy management and neonatal follow-up in light of specific antenatal and neonatal risk factors. What is Known: • Foetal growth restriction (FGR), together with antenatal umbilical Doppler abnormalities, is known to affect maternal and neonatal outcomes. • Infants born preterm and growth-restricted face the highest risk for neurodevelopmental impairment, especially when FGR occurs early during pregnancy (early FGR, before 32 weeks gestation). What is New: • The timing of onset and features of FGR and antenatal umbilical Doppler abnormalities impact differently on maternal and neonatal outcomes; when FGR and Doppler abnormalities occur very early, at the limit of neonatal viability, and persist until delivery, infants face the highest risk for neurodevelopmental impairment. • Shared knowledge between obstetricians and neonatologists about timing of onset and features of FGR would provide a valuable tool for informed antenatal counselling in high-risk pregnancies.

Effects of Intrauterine Growth Restriction (IUGR) on Growth and Body Composition Compared to Constitutionally Small Infants

(1) Intrauterine growth restriction (IUGR) is associated with multiple morbidities including growth restriction and impaired neurodevelopment. Small for gestational age (SGA) is defined as a birth weight <10th percentile, regardless of the etiology. The term is commonly used as a proxy for IUGR, but it may represent a healthy constitutionally small infant. Differentiating between IUGR and constitutionally small infants is essential for the nutritional management. (2) Infants born at <37 weeks of gestation between 2017 and 2022, who underwent body composition measurement (FFM: fat-free mass; FM: fat mass) at term-equivalent age, were included in this study. Infants with IUGR and constitutionally small infants (SGA) were compared to infants appropriate for gestational age (AGA). (3) A total of 300 infants (AGA: n = 249; IUGR: n = 40; SGA: n = 11) were analyzed. FFM (p < 0.001) and weight growth velocity (p = 0.022) were significantly lower in IUGR compared to AGA infants, but equal in SGA and AGA infants. FM was not significantly different between all groups. (4) The FFM Z-score was significantly lower in IUGR compared to AGA infants (p = 0.017). Being born constitutionally small compared to AGA had no impact on growth and body composition. These data showed that early aggressive nutritional management is essential in IUGR infants to avoid impaired growth and loss of FFM.

Angiogenic Function of Human Placental Endothelial Cells in Severe Fetal Growth Restriction Is Not Rescued by Individual Extracellular Matrix Proteins

Severe fetal growth restriction (FGR) is characterized by increased placental vascular resistance resulting from aberrant angiogenesis. Interactions between endothelial cells (ECs) and the extracellular matrix (ECM) are critical to the complex process of angiogenesis. We have previously found that placental stromal abnormalities contribute to impaired angiogenesis in severe FGR. The objective of this research is to better characterize the effect of individual ECM proteins on placental angiogenic properties in the setting of severe FGR. ECs were isolated from human placentae, either control or affected by severe FGR, and subjected to a series of experiments to interrogate the role of ECM proteins on adhesion, proliferation, migration, and apoptosis. We found impaired proliferation and migration of growth-restricted ECs. Although individual substrates did not substantially impact migratory capacity, collagens I, III, and IV partially mitigated proliferative defects seen in FGR ECs. Differences in adhesion and apoptosis between control and FGR ECs were not evident. Our findings demonstrate that placental angiogenic defects that characterize severe FGR cannot be explained by a singular ECM protein, but rather, the placental stroma as a whole. Further investigation of the effects of stromal composition, architecture, stiffness, growth factor sequestration, and capacity for remodeling is essential to better understand the role of ECM in impaired angiogenesis in severe FGR.

The Long-Term Effect of Maternal Iron Levels in the Second Trimester on Mild Thinness among Preschoolers: The Modifying Effect of Small for Gestational Age

The supplementation of multiple micronutrients throughout pregnancy can reduce the risk of adverse birth outcomes and various diseases in children. However, the long-term effect of maternal multiple micronutrient levels in the second trimester on the overall development of preschoolers remains unknown. Therefore, 1017 singleton mother-infant pairs and 6-year-old preschoolers were recruited based on the China-Wuxi Birth Cohort Study. Meanwhile, information on the demographic characteristics of pregnant women and preschoolers, maternal copper, calcium, iron, magnesium, and zinc levels in whole blood during the second trimester, and neonatal outcomes, were collected. We aimed to investigate the long-term impact of maternal copper, calcium, iron, magnesium, and zinc levels in the second trimester on mild thinness among 6-year-old preschoolers, and the modifying effect of small for gestational age (SGA), within the Chinese population. Multiple logistic regression models revealed that high-level maternal iron in the second trimester reduced the risk of mild thinness [adjusted OR: 0.46 (95% CI: 0.26, 0.80)] among 6-year-old preschoolers. However, no significant association was found for the remaining four maternal essential metal elements. Additionally, the restricted cubic spline function showed that the risk of mild thinness decreased when maternal iron concentration exceeded 7.47 mmol/L in whole blood during the second trimester. Furthermore, subgroup analysis indicated that the long-term protective effect of high-level maternal iron on mild thinness was only observed in SGA infants. Summarily, high-level maternal iron in the second trimester distinctly lowers the risk of mild thinness among 6-year-old preschoolers, especially in preschoolers with birth outcomes of SGA. Our findings offer evidence for the implementation of iron supplementation in the second trimester as a preventive measure against mild thinness in children.

Early pregnancy imaging predicts ischemic placental disease

INTRODUCTION

To characterize early-gestation changes in placental structure, perfusion, and oxygenation in the context of ischemic placental disease (IPD) as a composite outcome and in individual sub-groups.

METHODS

In a single-center prospective cohort study, 199 women were recruited from antenatal clinics between February 2017 and February 2019. Maternal magnetic resonance imaging (MRI) studies of the placenta were temporally conducted at two timepoints: 14-16 weeks gestational age (GA) and 19-24 weeks GA. The pregnancy was monitored via four additional study visits, including at delivery. Placental volume, perfusion, and oxygenation were assessed at both MRI timepoints. The primary outcome was defined as pregnancy complicated by IPD, with group assignment confirmed after delivery.

RESULTS

In early gestation, mothers with IPD who subsequently developed fetal growth restriction (FGR) and/or delivered small-for gestational age (SGA) infants showed significantly decreased MRI indices of placental volume, perfusion, and oxygenation compared to controls. The prediction of FGR or SGA by multiple logistic regression using placental volume, perfusion, and oxygenation revealed receiver operator characteristic curves with areas under the curve of 0.81 (Positive predictive value (PPV) = 0.84, negative predictive value (NPV) = 0.75) at 14-16 weeks GA and 0.66 (PPV = 0.78, NPV = 0.60) at 19-24 weeks GA.

DISCUSSION

MRI indices showing decreased placental volume, perfusion and oxygenation in early pregnancy were associated with subsequent onset of IPD, with the greatest deviation evident in subjects with FGR and/or SGA. These early-gestation MRI changes may be predictive of the subsequent development of FGR and/or SGA.

The relationship between COVID-19 vaccination status in pregnancy and birthweight

BACKGROUND

Despite findings that maternal COVID-19 infection in pregnancy is associated with low birthweight (weight of ≤2500 g), previous studies demonstrate no difference in low birthweight risk between COVID-19 vaccinated and unvaccinated pregnant persons. Few studies, however, have examined the association between unvaccinated, incomplete vaccination, and complete vaccination on low birthweight, and they have been limited by small sample sizes and lack of adjustment for covariates.

OBJECTIVE

We sought to address key limitations of prior work and evaluate this association between unvaccinated, incomplete, and complete COVID-19 vaccination status in pregnancy and low birthweight. We predicted a protective association of vaccination on low birthweight that varies by number of doses received.

STUDY DESIGN

We performed a population-based retrospective study using the Vizient clinical database, which included data from 192 hospitals in the United States. Our sample included pregnant persons who delivered between January 2021 and April 2022 at hospitals that reported maternal vaccination data and birthweight at delivery. Pregnant persons were categorized into 3 groups as follows: unvaccinated; incompletely vaccinated (1 dose of Pfizer or Moderna); or completely vaccinated (1 dose of Johnson & Johnson or ≥2 doses of Moderna or Pfizer). Demographics and outcomes were analyzed using standard statistical tests. We performed multivariable logistic regression to account for potential confounders between vaccination status and low birthweight in the original cohort. Propensity score matching was used to reduce bias related to the likelihood of vaccination, and the multivariable logistic regression model was then applied to the propensity score-matched cohort. Stratification analysis was performed for gestational age and race and ethnicity.

RESULTS

Of the 377,995 participants, 31,155 (8.2%) had low birthweight, and these participants were more likely to be unvaccinated than those without low birthweight (98.8% vs 98.5%, P<.001). Incompletely vaccinated pregnant persons were 13% less likely to have low birthweight neonates compared to unvaccinated persons (odds ratio, 0.87; 95% confidence interval, 0.73-1.04), and completely vaccinated persons were 21% less likely to have low birthweight neonates (odds ratio, 0.79; 95% confidence interval, 0.79-0.89). After controlling for maternal age, race or ethnicity, hypertension, pregestational diabetes, lupus, tobacco use, multifetal gestation, obesity, use of assisted reproductive technology, and maternal or neonatal COVID-19 infections in the original cohort, these associations remained significant for only complete vaccination (adjusted odds ratio, 0.80; 95% confidence interval, 0.70-0.91) and not incomplete vaccination (adjusted odds ratio, 0.87; 95% confidence interval, 0.71-1.04). In the propensity score-matched cohort, pregnant persons who were completely vaccinated against COVID-19 were 22% less likely to have low birthweight neonates compared to unvaccinated and incompletely vaccinated individuals (adjusted odds ratio, 0.78; 95% confidence interval, 0.76-0.79).

CONCLUSION

Pregnant persons who were completely vaccinated against COVID-19 were less likely to have low birthweight neonates compared to unvaccinated and incompletely vaccinated individuals. This novel association was observed among a large population after adjusting for confounders of low birthweight and factors influencing the likelihood of receiving the COVID-19 vaccine.

Does Growth Velocity Affect Associations between Birth Weight and Neurodevelopment for Infants Born Very Preterm?

OBJECTIVE

To determine how neonatal growth velocity affects the association between birth weight and neurodevelopmental outcomes in infants born preterm.

STUDY DESIGN

This study is a secondary analysis of the Maternal Omega-3 Supplementation to Reduce Bronchopulmonary Dysplasia in Very Preterm Infants (MOBYDIck) randomized multicenter trial conducted in breastfed infants born at <29 weeks of gestation, whose mothers were supplemented with docosahexaenoic acid or placebo during the neonatal period. Neurodevelopmental outcomes were assessed at 18-22 months of corrected age using the Bayley-III cognitive and language composite scores. The role of neonatal growth velocity was assessed with causal mediation and linear regression models. Subgroup analyses were stratified by birth weight z-score categories (<25th, ≥25th-≤75th, and >75th percentiles).

RESULTS

Neurodevelopmental outcomes were available for 379 children (mean gestational age, 26.7 ± 1.5 weeks). Growth velocity partially mediated the relationships between birth weight and cognitive (β = -1.1; 95% CI, -2.2 to -0.02; P = .05) and language scores (β = -2.1; 95% CI, -3.3 to -0.8; P = .002). An increase by 1 g/kg/day in growth velocity was associated with an increase by 1.1 point in the cognitive score (95% CI, -0.03 to 2.1; P = .06) and 1.9 point in the language score (95% CI, 0.7 to 3.1; P = .001), after adjustment for birth weight z-score. For children with birth weight <25th percentile, a 1 g/kg/day increase in growth velocity was associated with an increase by 3.3 points in the cognitive score (95% CI, 0.5 to 6.0; P = .02) and 4.1 points in the language score (95% CI, 1.3 to 7.0; P = .004).

CONCLUSIONS

Postnatal growth velocity mediated the relationship between birth weight and neurodevelopmental performance, with larger effects for children with lower birth weight.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02371460.

Clinical efficacy of low-dose aspirin combined with calcium in preventing preeclampsia: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the clinical effectiveness of low-dose aspirin combined with calcium supplements for the prevention of preeclampsia.

METHODS

China National Knowledge Infrastructure, VIP, Wanfang, PubMed, EMBASE, and Cochrane Library databases were searched from inception until December 2022. Randomized controlled trials investigating the preventive use of aspirin in combination with calcium supplementation for preeclampsia in high-risk pregnant women were included. The quality of the literature was evaluated, and a meta-analysis was conducted using RevMan 5.3 software to analyze the clinical efficacy of low-dose aspirin combined with calcium supplementation in preventing preeclampsia.

RESULTS

Seven randomized controlled trials were included in this meta-analysis, and compared with the control group, the experimental group had lower incidence rates of preeclampsia with gestational hypertension (odds ratios [OR]: 0.17, 95% confidence interval [CI]: 0.11-0.28), preeclampsia (OR: 0.20, 95% CI: 0.10-0.37), gestational hypertension (OR: 0.15, 95% CI: 0.07-0.31), preterm birth (OR: 0.26, 95% CI: 0.16-0.44), postpartum hemorrhage (OR: 0.15, 95% CI: 0.08-0.27), and fetal growth restriction (OR: 0.16, 95% CI: 0.08-0.33).

CONCLUSION

Compared with aspirin alone, low-dose aspirin combined with calcium supplementation was more effective in preventing preeclampsia, reduced the risk of preterm birth and postpartum hemorrhage, and promoted fetal growth. This intervention has clinical value and should be considered for high-risk pregnant women.

Association of Birth Weight Centiles and Gestational Age With Cognitive Performance at Age 5 Years

Importance

Birth weight percentiles (BWPs) are often dichotomized at the 10th percentile and show statistically significant association with later cognitive performance, for both preterm and term-born children. However, research testing nonlinear associations between BWPs and cognitive performance is scarce.

Objective

To investigate culturally invariant, nonlinear associations of BWPs and gestational age with later cognitive performance.

Design, Setting, and Participants

In this cohort study, participants with valid neonatal and cognitive data were combined from 4 observational cohorts, including the Millennium Cohort Study, the National Longitudinal Survey of Youth 1979 Child and Young Adult cohort, Growing Up in Ireland, and the Longitudinal Study of Australian Children, with children born between 2000 and 2002, 1980 and 2010, 2007 and 2008, and 2003 and 2004, respectively. Neonatal data were parent reported before age 1 year. At approximately 5 years of age, multiple cognitive tests were performed. Follow-up at 5 years of age was the predominant focus. Data were analyzed July 17, 2023.

Exposure

The parent-reported neonatal data were used to calculate BWPs according to the Fenton growth chart.

Main Outcome and Measure

Scores for IQ were created from multiple measures of cognition, which were z standardized separately within each cohort.

Results

Of 30 643 participants (50.8% male), 7.5% were born preterm (before 37 weeks gestation) and 92.5% were term born (between 37 and 42 weeks gestation). In the pooled data using multivariate adaptive regression splines, IQ linearly increased by 4.2 points as BWPs increased from the first to the 69th percentile before completely plateauing. For gestational age, IQ linearly increased by 1.3 points per week up until 32 weeks, with the association reducing to 0.3 points per week after 32 weeks. The association of BWP with IQ was not moderated by gestational age. For term-born infants, the estimated IQ score was only clinically meaningfully lower than average when birth weight was below the third percentile. Consistent results were found when instead using multivariable regression where gestational age and BWPs were categorized into groups.

Conclusions and Relevance

In this cohort study, lower BWPs and gestational age were independently associated with lower IQ. For term-born infants, a cutoff of the third percentile would be more appropriate than the traditionally used 10th percentile when the aim is estimating meaningful cognitive differences.