Effects of preterm birth and fetal growth retardation on cardiovascular risk factors in young adulthood

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Metabolic and Low-Grade Inflammation Risk in Young Adults with a History of Extrauterine Growth Restriction

Children with a history of extrauterine growth restriction (EUGR), later at prepubertal age, exhibit an increased metabolic risk including risen insulin resistance and low-grade inflammation. However, the progression of such metabolic changes after puberty and the lasting health implications have not yet been investigated. The objective of this study was to ascertain whether young adults with a history of EUGR faced increased vulnerability to metabolic disorders. A study was conducted comparing a group of adults with a history of EUGR with a healthy reference group. A total of 110 young adults (36 from the EUGR group and 74 from the control group) were included. Anthropometric variables, blood pressure (BP), general biochemical parameters, plasma inflammatory biomarkers, and adipokines were assessed. Compared to the reference group, the EUGR group had a shorter height and body weight with higher lean mass and waist circumference, as well as a greater percentage of individuals with high BP. In addition, EUGR patients had higher values of insulin, HOMA-IR, nerve growth factor, and leptin, and lower levels of adiponectin and resistin. The present study suggests that young adults with a history of EUGR present increased metabolic risk factors therefore, clinical follow-up should be considered.

Body composition in adults born preterm with very low birth weight

BACKGROUND

Studies on body composition in preterm very low birth weight (VLBW < 1500 g) survivors are inconsistent and trajectories later in life unknown. We assessed body composition and its change from young to mid-adulthood in VLBW adults.

METHODS

We studied 137 VLBW adults and 158 term-born controls from two birth cohorts in Finland and Norway at mean age 36 years. Body composition was assessed by 8-polar bioelectrical impedance. We compared results with dual-energy x-ray absorptiometry measurements at 24 years.

RESULTS

In mid-adulthood, VLBW women and men were shorter than controls. Fat percentage (mean difference in women 1.1%; 95% CI, -1.5% to 3.5%, men 0.8%; -2.0% to 3.6%) and BMI were similar. VLBW women had 2.9 (0.9 to 4.8) kg and VLBW men 5.3 (2.7 to 8.1) kg lower lean body mass than controls, mostly attributable to shorter height. Between young and mid-adulthood, both groups gained fat and lean body mass (p for interaction VLBW x age>0.3).

CONCLUSION

Compared with term-born controls, VLBW adults had similar body fat percentage but lower lean body mass, largely explained by their shorter height. This could contribute to lower insulin sensitivity and muscular fitness previously found in VLBW survivors and predispose to functional limitations with increasing age.

IMPACT

In mid-adulthood, individuals born preterm with very low birth weight had similar body fat percentage but lower lean body mass than those born at term. This was largely explained by their shorter height. First study to report longitudinal assessments of body size and composition from young to mid-adulthood in very low birth weight adults. Lower lean body mass in very low birth weight adults could contribute to lower insulin sensitivity and muscular fitness and lead to earlier functional limitations with increasing age.

Risk of Obesity and Unhealthy Central Adiposity in Adolescents Born Preterm With Very Low Birthweight Compared to Term-Born Peers

Background: Early-life factors such as preterm birth or very low birthweight (VLBW) are associated with increased cardiovascular disease risk. However, it remains unknown whether this is due to an increased risk of obesity (unhealthy central adiposity) because studies have predominantly defined obesity based on BMI, an imprecise adiposity measure. Objective: Investigate if adolescents born preterm with VLBW have a higher risk of unhealthy central adiposity compared to term-born peers. Study Design: Cross-sectional analysis of data from a prospective cohort study of 177 individuals born preterm with VLBW (<1500 g) and 51 term-born peers (birthweight ≥2500 g). Individuals with congenital anomalies, genetic syndromes, or major health conditions were excluded. Height, weight, waist circumference, skin fold thickness, and dual energy X-ray absorptiometry body composition were measured at age 14 years. We calculated BMI percentiles and defined overweight/obesity as BMI ≥85th percentile for age and sex. We estimated the preterm-term differences in overweight/obesity prevalence and adiposity distribution with multivariable generalized linear models. Results: There was no difference in small for gestational age status or overweight/obesity prevalence. Compared to term, youth born preterm with VLBW had lower BMI z-score [β -0.38, 95% confidence limits (CL) -0.75 to -0.02] but no differences in adiposity apart from subscapular-to-triceps ratio (STR; β 0.18, 95% CL 0.08 to 0.28). Conclusions: Adolescents born preterm with VLBW had smaller body size than their term-born peers and had no differences in central adiposity except greater STR.

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

BACKGROUND

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

OBJECTIVE

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

DATA SOURCES

MEDLINE, EMBASE and CINAHL until October 2022.

STUDY SELECTION AND DATA EXTRACTION

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

SYNTHESIS

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

RESULTS

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

CONCLUSIONS

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

Exercise Capacity in Very Low Birth Weight Adults: A Systematic Review and Meta-Analysis

There is an association between very low birth weight (VLBW) and cardiovascular morbidity and mortality in adulthood. Aerobic fitness, measured as the maximal oxygen consumption (VO2 max), is a good indicator of cardiopulmonary health and predictor of cardiovascular mortality. Our aim was to determine the effect of birth weight on aerobic exercise capacity and physical activity. We systematically identified studies reporting exercise capacity (VO2 max and VO2 peak) and physical activity levels in participants born at VLBW aged eighteen years or older compared to term-born controls from six databases (MEDLINE, OVID, EMBASE, CI NAHL, CENTRAL, and Google Scholar). Meta-analysis of eligible studies was conducted using a random effect model. We screened 6202 articles and identified 15 relevant studies, 10 of which were eligible for meta-analysis. VLBW participants had a lower VO2 max compared to their term counterparts (-3.35, 95% CI: -5.23 to -1.47, p = 0.0005), as did VLBW adults who had developed bronchopulmonary dysplasia (-6.08, 95% CI -11.26 to -0.90, p = 0.02). Five of nine studies reported significantly reduced self-reported physical activity levels. Our systematic review and meta-analysis demonstrated reduced maximal aerobic exercise capacity in adults born at VLBW compared to term-born controls.

Increasing airway obstruction through life following bronchopulmonary dysplasia: a meta-analysis

Background

Few studies exist investigating lung function trajectories of those born preterm; however growing evidence suggests some individuals experience increasing airway obstruction throughout life. Here we use the studies identified in a recent systematic review to provide the first meta-analysis investigating the impact of preterm birth on airway obstruction measured by the forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio.

Methods

Cohorts were included for analysis if they reported FEV1/FVC in survivors of preterm birth (<37 weeks' gestation) and control populations born at term. Meta-analysis was performed using a random effect model, expressed as standardised mean difference (SMD). Meta-regression was conducted using age and birth year as moderators.

Results

55 cohorts were eligible, 35 of which defined groups with bronchopulmonary dysplasia (BPD). Compared to control populations born at term, lower values of FEV1/FVC were seen in all individuals born preterm (SMD -0.56), with greater differences seen in those with BPD (SMD -0.87) than those without BPD (SMD -0.45). Meta-regression identified age as a significant predictor of FEV1/FVC in those with BPD with the FEV1/FVC ratio moving -0.04 sds away from the term control population for every year of increased age.

Conclusions

Survivors of preterm birth have significantly increased airway obstruction compared to those born at term with larger differences in those with BPD. Increased age is associated with a decline in FEV1/FVC values suggesting increased airway obstruction over the life course.

Body composition and physical fitness in adults born small for gestational age at term: a prospective cohort study

There is lack of research on body composition and physical fitness in individuals born small for gestational age (SGA) at term entering mid-adulthood. We aimed to investigate these outcomes in adults born SGA at term. This population-based cohort study included 46 adults born SGA with birth weight < 10th percentile at term (gestational age ≥ 37 weeks) (22 women, 24 men) and 61 adults born at term with birth weight ≥ 10th percentile (35 women, 26 men) at 32 years. Body composition was examined anthropometrically and by 8-polar bioelectrical impedance analysis (Seca® mBCA 515). Fitness was measured by maximal isometric grip strength by a Jamar hand dynamometer, 40-s modified push-up test and 4-min submaximal step test. Participants born SGA were shorter than controls, but other anthropometric measures did not differ between the groups. Men born SGA had 4.8 kg lower grip strength in both dominant (95% CI 0.6 to 9.0) and non-dominant (95% CI 0.4 to 9.2) hand compared with controls. Grip strength differences were partly mediated by height. In conclusion, body composition and physical fitness were similar in adults born SGA and non-SGA at term. Our finding of reduced grip strength in men born SGA may warrant further investigation.

Small for date preterm infants and risk of higher blood pressure in later life: A systematic review and meta-analysis

BACKGROUND

Historical reports suggest that infants born small for gestational age (SGA) are at increased risk for high blood pressure (BP) at older ages after adjustment for later age body size. Such adjustment may be inappropriate since adiposity is a known cause of cardiovascular and metabolic disease.

OBJECTIVES

To assess the association between SGA births and later BP among preterm births, considering potential background confounders and over-adjustment for later body size.

METHODS

A database search of studies up to October 2022 included MEDLINE, EMBASE and CINAHL. Studies were included if they reported BP (systolic [SBP] or diastolic [DBP]) (outcomes) for participants born preterm with SGA (exposure) or non-SGA births. All screening, extraction steps, and risk of bias (using the Risk of Bias In Non-randomised Studies of Interventions [ROBINS-I] tool) were conducted in duplicate by two reviewers. Data were pooled in meta-analysis using random-effects models. We explored potential sources of heterogeneity.

RESULTS

We found no meaningful difference in later BP between preterm infants with and without SGA status at birth. Meta-analysis of 25 studies showed that preterm SGA, compared to preterm non-SGA, was not associated with higher BP at age 2 and older with mean differences for SBP 0.01 mmHg (95% CI -0.10, 0.12, I²  = 59.8%, n = 20,462) and DBP 0.01 mm Hg (95% CI -0.10, 0.12), 22 studies, (I²  = 53.0%, n = 20,182). Adjustment for current weight did not alter the results, which could be due to the lack of differences in later weight status in most of the included studies. The included studies were rated to be at risk of bias due to potential residual confounding, with a low risk of bias in other domains.

CONCLUSIONS

Evidence indicates that preterm infants born SGA are not at increased risk of developing higher BP as children or as adults as compared to non-SGA preterm infants.

Fetal growth restriction followed by very preterm birth is associated with smaller kidneys but preserved kidney function in adolescence

BACKGROUND

Preterm birth and fetal growth restriction (FGR) are associated with structural and functional kidney changes, increasing long-term risk for chronic kidney disease and hypertension. However, recent studies in preterm children are conflicting, indicating structural changes but normal kidney function. This study therefore assessed kidney structure and function in a cohort of adolescents born very preterm with and without verified FGR.

METHODS

Adolescents born very preterm with FGR and two groups with appropriate birthweight (AGA) were included; one matched for gestational week at birth and one born at term. Cortical and medullary kidney volumes and T1 and T2* mapping values were assessed by magnetic resonance imaging. Biochemical markers of kidney function and renin-angiotensin-aldosterone system (RAAS) activation were analyzed.

RESULTS

Sixty-four adolescents were included (13-16 years; 48% girls). Very preterm birth with FGR showed smaller total (66 vs. 75 ml/m²; p = 0.01) and medullary volume (19 vs. 24 ml/m²; p < 0.0001) compared to term AGA. Corticomedullary volume ratio decreased from preterm FGR (2.4) to preterm AGA (2.2) to term AGA (1.9; p = 0.004). There were no differences in T1 or T2* values (all p ≥ 0.34) or in biochemical markers (all p ≥ 0.12) between groups.

CONCLUSIONS

FGR with abnormal fetal blood flow followed by very preterm birth is associated with smaller total kidney and medullary kidney volumes, but not with markers of kidney dysfunction or RAAS activation in adolescence. Decreased total kidney and medullary volumes may still precede a long-term decrease in kidney function, and potentially be used as a prognostic marker. A higher resolution version of the Graphical abstract is available as Supplementary information.

Multidisciplinary and neuroimaging findings in preterm born very low birthweight individuals from birth to 28 years of age: A systematic review of a Norwegian prospective cohort study

BACKGROUND

Children born preterm with very low birthweight (VLBW) face long-lasting neurodevelopmental challenges, where multidisciplinary assessments are warranted. The International Classification of Functioning, Disability and Health (ICF) provides a framework for understanding and conceptualising these outcomes.

OBJECTIVES

We aimed to review clinical and neuroimaging findings from birth to adulthood in a Norwegian cohort of individuals born preterm with VLBW (gestational age <37 weeks, birthweight ≤1500 g) within the framework of ICF.

DATA SOURCES

We searched PubMed and Embase for articles reporting results of the Norwegian University of Science and Technology (NTNU) Low Birth Weight in a Lifetime Perspective study.

STUDY SELECTION AND DATA EXTRACTION

We included original articles reporting proportions of adverse outcomes, mean group differences, risk factors or associations between outcomes. Data were extracted according to ICF's two-level classification. Body functions and structures comprised outcomes of brain structures, cognition, mental health, vision, pain and physical health. Activities and participation comprised motor skills, general and social functioning, education, employment, and health-related quality of life.

SYNTHESIS

We performed a qualitative synthesis of included articles. Where mean (SD) was reported, we calculated group differences in SD units.

RESULTS

Fifty-eight publications were included. Within body functions and structures, increased prevalence of brain structure pathology, lower cognitive performance, mental health problems, visual and physical health impairments through childhood, adolescence and young adulthood were reported among preterm VLBW participants compared with controls. Within activities and participation, motor problems, lower general and social functioning, and lower academic attainment were found. Perinatal factors were associated with several outcomes, and longitudinal findings suggested persistent consequences of being born preterm with VLBW.

CONCLUSIONS

Being born preterm with VLBW has long-term influences on body functions and structures, activities and participation. The ICF is appropriate for assessing general domains of functioning and guiding the management of individuals born preterm with VLBW.

Geographical Differences and Temporal Improvements in Forced Expiratory Volume in 1 Second of Preterm-Born Children: A Systematic Review and Meta-analysis

Importance

Although preterm birth is associated with later deficits in lung function, there is a paucity of information on geographical differences and whether improvements occur over time, especially after surfactant was introduced.

Objective

To determine deficits in percentage predicted forced expiratory volume in 1 second (%FEV1) in preterm-born study participants, including those with bronchopulmonary dysplasia (BPD) in infancy, when compared with term-born control groups.

Data Sources

Eight databases searched up to December 2021.

Study Selection

Studies reporting spirometry for preterm-born participants with or without a term-born control group were identified.

Data Extraction and Synthesis

Data were extracted and quality assessed by 1 reviewer and checked by another. Data were pooled using random-effects models and analyzed using Review Manager and the R metafor package.

Main Outcomes and Measures

Deficits in %FEV1 between preterm-born and term groups. Associations between deficits in %FEV1 and year of birth, age, introduction of surfactant therapy, and geographical region of birth and residence were also assessed.

Results

From 16 856 titles, 685 full articles were screened: 86 with and without term-born control groups were included. Fifty studies with term controls were combined with the 36 studies from our previous systematic review, including 7094 preterm-born and 17 700 term-born participants. Of these studies, 45 included preterm-born children without BPD, 29 reported on BPD28 (supplemental oxygen dependency at 28 days), 26 reported on BPD36 (supplemental oxygen dependency at 36 weeks' postmenstrual age), and 86 included preterm-born participants. Compared with the term-born group, the group of all preterm-born participants (all preterm) had deficits of %FEV1 of -9.2%; those without BPD had deficits of -5.8%, and those with BPD had deficits of approximately -16% regardless of whether they had BPD28 or BPD36. As year of birth increased, there was a statistically significant narrowing of the difference in mean %FEV1 between the preterm- and term-born groups for the all preterm group and the 3 BPD groups but not for the preterm-born group without BPD. For the all BPD group, when compared with Scandinavia, North America and western Europe had deficits of -5.5% (95% CI, -10.7 to -0.3; P = .04) and -4.1% (95% CI, -8.8 to 0.5; P = .08), respectively.

Conclusions and Relevance

Values for the measure %FEV1 were reduced in preterm-born survivors. There were improvements in %FEV1 over recent years, but geographical region had an association with later %FEV1 for the BPD groups.

Explaining the Black-White Disparity in Preterm Birth: A Consensus Statement From a Multi-Disciplinary Scientific Work Group Convened by the March of Dimes

In 2017-2019, the March of Dimes convened a workgroup with biomedical, clinical, and epidemiologic expertise to review knowledge of the causes of the persistent Black-White disparity in preterm birth (PTB). Multiple databases were searched to identify hypothesized causes examined in peer-reviewed literature, 33 hypothesized causes were reviewed for whether they plausibly affect PTB and either occur more/less frequently and/or have a larger/smaller effect size among Black women vs. White women. While definitive proof is lacking for most potential causes, most are biologically plausible. No single downstream or midstream factor explains the disparity or its social patterning, however, many likely play limited roles, e.g., while genetic factors likely contribute to PTB, they explain at most a small fraction of the disparity. Research links most hypothesized midstream causes, including socioeconomic factors and stress, with the disparity through their influence on the hypothesized downstream factors. Socioeconomic factors alone cannot explain the disparity's social patterning. Chronic stress could affect PTB through neuroendocrine and immune mechanisms leading to inflammation and immune dysfunction, stress could alter a woman's microbiota, immune response to infection, chronic disease risks, and behaviors, and trigger epigenetic changes influencing PTB risk. As an upstream factor, racism in multiple forms has repeatedly been linked with the plausible midstream/downstream factors, including socioeconomic disadvantage, stress, and toxic exposures. Racism is the only factor identified that directly or indirectly could explain the racial disparities in the plausible midstream/downstream causes and the observed social patterning. Historical and contemporary systemic racism can explain the racial disparities in socioeconomic opportunities that differentially expose African Americans to lifelong financial stress and associated health-harming conditions. Segregation places Black women in stressful surroundings and exposes them to environmental hazards. Race-based discriminatory treatment is a pervasive stressor for Black women of all socioeconomic levels, considering both incidents and the constant vigilance needed to prepare oneself for potential incidents. Racism is a highly plausible, major upstream contributor to the Black-White disparity in PTB through multiple pathways and biological mechanisms. While much is unknown, existing knowledge and core values (equity, justice) support addressing racism in efforts to eliminate the racial disparity in PTB.

Increased circulating endothelial progenitor cells (EPCs) in prepubertal children born prematurely: a possible link between prematurity and cardiovascular risk

BACKGROUND

Endothelial progenitor cells (EPCs) ensure vascular integrity and neovascularization. No studies have investigated EPCs in preterm-born children beyond infancy.

METHODS

One hundred and thirty-six prepubertal children were enrolled: 63 preterm and 73 born at term (controls). Circulating CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs were measured in preterm-born children compared to controls. Body mass index (BMI), waist-to-hip ratio (WHR), neck circumference, systolic and diastolic blood pressure (SBP and DBP, respectively), fasting glucose, insulin, lipid profile, common carotid and abdominal aortic intima-media thickness (cIMT and aIMT, respectively), endothelium-dependent brachial artery flow-mediated dilation (FMD), and echocardiographic parameters were also assessed.

RESULTS

Circulating CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs were significantly higher in preterm-born children compared to controls (p < 0.001 and p < 0.001, respectively). In total study population and in the preterm-born group, EPCs were significantly lower in children born to mothers with gestational diabetes compared to non-diabetic mothers. Prematurity was associated with higher WHR, neck circumference, SBP, DBP, cIMT, aIMT, mean pressure, and velocity of pulmonary artery; the peak velocity of the brachial artery was significantly lower in children born prematurely. In multiple regression analysis, preterm birth and maternal gestational diabetes were recognized as independent predictors of EPCs.

CONCLUSIONS

Circulating EPCs were increased in prepubertal preterm-born children in comparison with peers born full-term. Maternal gestational diabetes was associated with a decrease in EPCs.

IMPACT

Mounting evidence supports the adverse effect of prematurity on cardiovascular health. However, the underlying mechanisms that could lead to endothelial dysfunction in preterm-born individuals are not fully understood. Endothelial progenitor cells (EPCs) ensure vascular integrity, normal endothelial function and neovascularization. No studies have investigated the EPCs counts in peripheral blood beyond infancy in children born prematurely. Circulating EPCs were significantly higher in preterm-born prepubertal children compared to controls, thus indicating that prematurity is possibly associated with endothelial damage. In total study population and in the preterm-born group, maternal gestational diabetes was associated with decreased EPCs concentrations.

Preterm Birth With Neonatal Interventions Accelerates Collagen Deposition in the Left Ventricle of Lambs Without Affecting Cardiomyocyte Development

Background

Adults born preterm (< 37 weeks’ gestation) exhibit altered cardiac growth and are susceptible to cardiac dysfunction. Sheep studies have shown that moderate preterm birth results in maladaptive structural remodelling of the cardiac ventricles. The aim of this study was to examine ventricular structure in lambs born at a greater severity of preterm birth and ventilated postnatally.

Methods

Former-preterm lambs delivered at 128 days’ gestation, and mechanically ventilated for a week after birth, were compared with unventilated lambs born at term (150 days’ gestation), at 2 months (term: n = 10, former-preterm: n = 8), and 5 months (term: n = 9, former-preterm: n = 8) term-equivalent age. The right ventricle and left ventricle plus septum were analysed using immunohistochemistry, histology, and stereology.

Results

Cardiomyocyte number, cross-sectional area, proliferation, and apoptosis were not affected by preterm birth or age. Left ventricle plus septum interstitial collagen levels increased with age (P = 0.0015) and were exacerbated by preterm birth (P = 0.0006; 2 months term: 0.57% ± 0.07%, former-preterm: 1.44% ± 0.18%; 5 months term: 1.37% ± 0.25%, former-preterm: 2.15% ± 0.31%). Right ventricle interstitial collagen levels increased with age (P = 0.012) but were not affected by preterm birth.

Conclusion

This study is the first to explore the effect of preterm birth combined with modern neonatal interventions on the ventricular myocardium in lambs. There was no adverse impact on cardiomyocyte growth in early postnatal life. Of concern, however, there was increased collagen deposition in the preterm hearts, which has the potential to induce cardiac dysfunction, especially if it becomes exaggerated with ageing.

Risk Factors for Adverse Pregnancy Outcomes among Zhuang Ethnic Pregnant Women: A Cohort Study in Guangxi, China

Risk factors for adverse pregnancy outcomes among Zhuang ethnic pregnant women are unclear. This study analyzed the incidence and risk factors related to preterm birth (PB), low birth weight (LBW) and macrosomia in Zhuang population. We conducted a prospective cohort study of 9965 Zhuang pregnancy women in Guangxi, China. Information on mothers and newborns was obtained by using questionnaires and referring to medical records. Multivariate logistic regression analyses were used to evaluate the association between related factors and adverse pregnancy outcomes. Our results showed that the incidence of PB, LBW and macrosomia in Zhuang people was 5.55%, 5.64% and 2.19%, respectively. Maternal age ≥36 years (OR=2.22, 95% CI: 1.51-3.27) was related to a higher incidence of PB. Those with pre-pregnancy body mass index (BMI) <18.5 kg/m2 (OR=1.91, 95% CI: 1.45-2.51), and had a female fetus (OR=1.74, 95% CI: 1.36-2.23) were more likely to have LBW infants. Maternal age between 31 and 35 years (OR=1.76, 95% CI: 1.03-2.99) and pre-pregnancy overweight or obesity (OR=1.79, 95% CI: 1.15-2.80) were associated with a higher risk of macrosomia. The protective factors of macrosomia were maternal pre-pregnancy BMI <18.5 kg/m2 (OR=0.30, 95% CI: 0.15-0.60) and female fetus (OR=0.41, 95% CI: 0.28-0.59). Our study provided a reference for maternal and childcare administration among Zhuang population.

The Long-Term Effect of Preterm Birth on Renal Function: A Meta-Analysis

The preterm-born adult population is ever increasing following improved survival rates of premature births. We conducted a meta-analysis to investigate long-term effects of preterm birth on renal function in preterm-born survivors. We searched PubMed and EMBASE to identify studies that compared renal function in preterm-born survivors and full-term-born controls, published until 2 February 2019. A random effects model with standardized mean difference (SMD) was used for meta-analyses. Heterogeneity of the studies was evaluated using Higgin’s I² statistics. Risk of bias was assessed using the Newcastle–Ottawa quality assessment scale. Of a total of 24,388 articles screened, 27 articles were finally included. Compared to full-term-born controls, glomerular filtration rate and effective renal plasma flow were significantly decreased in preterm survivors (SMD −0.54, 95% confidence interval (CI), −0.85 to −0.22, p = 0.0008; SMD −0.39, 95% CI, −0.74 to −0.04, p = 0.03, respectively). Length and volume of the kidneys were significantly decreased in the preterm group compared to the full-term controls (SMD −0.73, 95% CI, −1.04 to −0.41, p < 0.001; SMD −0.82, 95% CI, −1.05 to −0.60, p < 0.001, respectively). However, serum levels of blood urea nitrogen, creatinine, and cystatin C showed no significant difference. The urine microalbumin to creatinine ratio was significantly increased in the preterm group. Both systolic and diastolic blood pressures were also significantly elevated in the preterm group, although the plasma renin level did not differ. This meta-analysis demonstrates that preterm-born survivors may be subject to decreased glomerular filtration, increased albuminuria, decreased kidney size and volume, and hypertension even though their laboratory results may not yet deteriorate.

Lost in Transition: Health Care Experiences of Adults Born Very Preterm-A Qualitative Approach

Introduction: Adults Born Very Preterm (ABP) are an underperceived but steadily increasing patient population. It has been shown that they face multiple physical, mental and emotional health problems as they age. Very little is known about their specific health care needs beyond childhood and adolescence. This article focuses on their personal perspectives: it explores how they feel embedded in established health care structures and points to health care-related barriers they face.

Methods: We conducted 20 individual in-depth interviews with adults born preterm aged 20–54 years with a gestational age (GA) below 33 weeks at birth and birth weights ranging from 870–1,950 g. Qualitative content analysis of the narrative interview data was conducted to identify themes related to self-perceived health, health care satisfaction, and social well-being.

Results: The majority (85%) of the study participants reported that their former prematurity is still of concern in their everyday lives as adults. The prevalence of self-reported physical (65%) and mental (45%) long-term sequelae of prematurity was high. Most participants expressed dissatisfaction with health care services regarding their former prematurity. Lack of consideration for their prematurity status by adult health care providers and the invisibility of the often subtle impairments they face were named as main barriers to receiving adequate health care. Age and burden of disease were important factors influencing participants' perception of their own health and their health care satisfaction. All participants expressed great interest in the provision of specialized, custom-tailored health-care services, taking the individual history of prematurity into account.

Discussion: Adults born preterm are a patient population underperceived by the health care system. Longterm effects of very preterm birth, affecting various domains of life, may become a substantial burden of disease in a subgroup of formerly preterm individuals and should therefore be taken into consideration by adult health care providers.

Cardiovascular risk factors in those born preterm - systematic review and meta-analysis

Emerging evidence demonstrates a link between preterm birth (PTB) and later life cardiovascular disease (CVD). We conducted a systematic review and meta-analysis to compare conventional CVD risk factors between those born preterm and at term. PubMed, CINAHL, SCOPUS, and EMBASE databases were searched. The review protocol is registered in PROSPERO (CRD42018095005). CVD risk factors including systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index, lipid profile, blood glucose, and fasting insulin among those born preterm (<37 weeks' gestation) were compared with those born at term (≥37 weeks' gestation). Subgroup analyses based on gender, age, gestational at birth (<32 weeks' gestation and <28 weeks' gestation), and PTB associated with small for gestational age or average for gestational age were also performed. Fifty-six studies provided data on 308,987 individuals. Being born preterm was associated with 3.26 mmHg (95% confidence interval [CI] 2.08 to 4.44) higher mean SBP and 1.32 mmHg (95% CI: 0.61 to 2.04) higher mean DBP compared to being born at term. Subgroup analyses demonstrated that SBP was higher among (a) preterm compared to term groups from early adolescence until adulthood; (b) females born preterm but not among males born preterm compared to term controls; and (c) those born at <32 weeks or <28 weeks compared to term. Our meta-analyses demonstrate higher SBP and DBP among those born preterm compared to term. The difference in SBP is evident from early adolescence until adulthood.

Premature birth, low birth weight, small for gestational age and chronic non-communicable diseases in adult life: A systematic review with meta-analysis

BACKGROUND

Individuals who were born prematurely (PT), with low birth weight (LBW), or small for gestational age (SGA) appear to present a set of permanent changes that make them more susceptible to develop chronic non-communicable diseases (CNCD) in adult life.

AIM

Investigating the association between PT birth, LBW or SGA at birth and CNCD incidence in adult life.

METHODS

Systematic review with meta-analysis of studies available in three databases - two of them are official (PubMed and Web of Science) and one is gray literature (OpenGrey) - based on pre-established search and eligibility criteria.

RESULTS

Sixty-four studies were included in the review, 93.7% of them only investigated one of the exposure variables (46.7% LBW, 35.0% PT and 18.3% SGA at birth), whereas 6.3% investigated more than one exposure variable (50.0% LBW and PT; 50.0% SGA and PT). There was association among all exposure variables in the following outcomes: cardiometabolic (CMD) and glycidic metabolism (GMD) disorders, changes in body composition and risk of developing metabolic syndrome (MS). Female sex was identified as risk factor in the exposure-outcome association. Eighteen (18) articles were included in the meta-analysis. There was positive association between LBW and incidence of CMD (OR: 1.25 [95%CI: 1.11; 1.41]; 07 studies), GMD (OR: 1.70 [95%CI: 1.25; 2.30]; 03 studies) and MS (OR: 1.75 [95%CI: 1.27; 2.40]; 02 studies) in adult life. PT was positively associated with CMD (OR: 1.38 [95%CI: 1.27; 1.51]; 05 studies).

CONCLUSIONS

LBW and PT are associated with CMD and GMD development, as well as with the risk of developing MS in adult life.

Cardiovascular Outcomes in Young Adulthood in a Population-Based Very Low Birth Weight Cohort

OBJECTIVES

To assess differences in left heart structure and function, and endothelial function in a national cohort of very low birth weight (VLBW) young adults and term-born controls.

STUDY DESIGN

The New Zealand VLBW study is a prospective, population-based, longitudinal cohort study which included all infants born <1500 g in 1986. The VLBW cohort (n = 229; 71% of survivors) and term-born controls (n = 100), were assessed at age 26-30 years. Measures of left heart structure and function were evaluated by echocardiography, vascular function was assessed using blood pressure, reactive hyperemia index, and arterioventricular coupling by calculating left ventricular (LV) and arterial elastance.

RESULTS

Compared with controls, those born VLBW had smaller LVs, even when indexed for body surface area (mean LV mass, 89.7 ± 19.3 g/m² vs 95.0 ± 22.3 g/m² [P = .03]; LV end-diastolic volume, 58.3 ± 10.9 mL/m² vs 62.4 ± 12.4 mL/m² [P = .002]; and LV end-systolic volume, 20.8 ± 4.9 mL/m² vs 22.6 ± 5.8 mL/m² [P = .004]). VLBW participants had lower stroke volume (median, 37.2 mL/m² [IQR, 33-42 mL/m²] vs median, 40.1 mL/m² [IQR, 34-45 mL/m²]; P = .0059) and cardiac output (mean, 4.8 ± 1.2 L/min vs 5.1 ± 1.4 L/min; P = .03), but there was no difference in ejection fraction. The VLBW group had higher LV elastance (3.37 ± 0.88 mm Hg/mL vs 2.86 ± 0.75 mm Hg/mL; P < .0001) and arterial elastance (1.84 ± 0.4 vs 1.6 ± 0.4; P < .0001) and lower reactive hyperemia index (0.605 ± 0.28 vs 0.688 ± 0.31; P = .041). These measures were influenced by birth weight and sex, but we found limited associations with other perinatal factors.

CONCLUSIONS

Being born preterm and VLBW is associated with differences in cardiovascular structure and function in adulthood. This population may be more vulnerable to cardiovascular pathology as they age.

TRIAL REGISTRATION

Australian Clinical Trials Registry ACTRN12612000995875.

Non-Hispanic White Women's Exposure to Decreased Neighborhood Income and Small for Gestational Age Births: A Population-Based Study

BACKGROUND

The relationship between non-Hispanic White (NHW) women's decreased neighborhood income between early-life and adulthood, individual risk-status at delivery, and small for gestational age (weight for gestation < 10th percentile, SGA) rates is unknown.

OBJECTIVE

To determine the extent to which NHW women's exposure to decreased neighborhood income is a risk factor for SGA births, and whether their own birth weight modifies this relationship.

METHODS

Stratified and multilevel logistic regression analyses were executed on the Illinois transgenerational dataset of mothers (born 1956-1976) and their infants (born 1989-1991) with appended U.S. census income information. Only NHW women with an early-life residence in top income quartile Chicago neighborhoods were studied.

RESULTS

NHW women (n = 4889) unexposed to decreased neighborhood income between early-life and adulthood had an SGA rate of 7.1%. In contrast, NHW women exposed to slightly (n = 5112), modestly (n = 2158), or severely (n = 339) decreased neighborhood income by the time of delivery had SGA rates of 8.2%, 10.8%, and 10.8%, respectively; RR (95% CI) equaled 1.2 (1.0-1.3), 1.5 (1.3-1.8) and 1.5 (1.1-2.1), respectively. The relationship between maternal exposure to modestly decreased neighborhood income and SGA rates was present only among former non-low birth weight (> 2500 g, non-LBW) mothers. In multilevel logistic regression models, the adjusted (controlling for age, parity, prenatal care usage, and cigarette smoking) OR of SGA birth for former low birth weight (< 2500 g, LBW) and non-LBW NHW women exposed to modestly (compared to no) decreased neighborhood income equaled 0.7 (0.4, 1.4) and 1.3 (1.1-1.6), respectively.

CONCLUSIONS FOR PRACTICE

NHW women's exposure to modestly decreased neighborhood income is associated with an increased risk of SGA birth; this phenomenon is absent among former low birth weight women.

Association of circulating uric acid and angiotensin-(1-7) in relation to higher blood pressure in adolescents and the influence of preterm birth

Elevated serum uric acid increases the risk of hypertension, and individuals born preterm have higher blood pressure (BP) and uric acid, but the mechanisms remain unclear. Preclinical studies demonstrate uric acid increases BP via increased renin-angiotensin system (RAS) expression, especially angiotensin (Ang) II, but the association of uric acid with Ang-(1–7) is unknown. Ang-(1–7), an alternative RAS product, counteracts Ang II by stimulating sodium excretion, vasodilation, and nitric oxide, thus contributing to lower BP. Plasma Ang-(1–7) is lower in preterm-born adolescents. We hypothesized uric acid is associated with a higher ratio of Ang II to Ang-(1–7) in plasma, especially in preterm-born adolescents. We measured BP, serum uric acid, and plasma RAS components in a cross-sectional analysis of 163 14-year-olds (120 preterm, 43 term). We estimated the associations between uric acid and the RAS using generalized linear models adjusted for sex, obesity, sodium intake, and fat intake, stratified by birth status. Uric acid was positively associated with Ang II/Ang-(1–7) (adjusted β (aβ): 0.88 mg/dl, 95% CI 0.17 to 1.58), plasma renin activity (aβ: 0.32 mg/dl, 95% CI 0.07 to 0.56), and aldosterone (aβ: 1.26 mg/dl, 95% CI 0.18 to 2.35), and inversely with Ang-(1–7) (aβ: −1.11 mg/dl, 95% CI −2.39 to 0.18); preterm birth did not modify these associations. Higher Ang II/Ang-(1–7) was associated with higher uric acid in adolescents. As preterm birth is associated with higher BP and uric acid, but lower Ang-(1–7), the imbalance between uric acid and Ang-(1–7) may be an important mechanism for the development of hypertension.

Longitudinal measures of neighborhood poverty and income inequality are associated with adverse birth outcomes in Texas

BACKGROUND

Inequity in adverse birth outcomes between black and white women in the U.S. is persistent, despite decades of research and prevention efforts. Neighborhood environments are plausibly related to pre-pregnancy health and other risk factors for adverse birth outcomes and may help explain black/white inequities. Despite the fact that neighborhoods change over time, most prior work has relied upon cross-sectional measures of neighborhood economic contexts.

METHODS

We used birth certificates for non-Hispanic black and white women in Texas (2009-2011, N = 470,896) to examine whether longitudinal measures of neighborhood economic context (poverty and income inequality, based on census tract data from 1990 to 2010) were associated with preterm birth, low birthweight and small-for-gestational-age (SGA) with hierarchical generalized linear models. We also tested whether (1) the longitudinal measures explained black/white inequities or (2) moderated the effect of race on the birth outcomes. Finally, we compared the models with longitudinal measures to models with cross-sectional measures of neighborhood economic context.

RESULTS

Longitudinal measures of neighborhood economic context were associated with all three birth outcomes, but did not explain racial inequities. Except for income inequality and SGA, there was no evidence of moderation by race. Substituting cross-sectional measures of economic context for longitudinal ones resulted in similar findings.

CONCLUSION

Policies that either address structural neighborhood-level economic disadvantage or mitigate the effects of such disadvantage are warranted to improve the health of mothers and prevent adverse birth outcomes.

Preterm Birth as a Risk Factor for Metabolic Syndrome and Cardiovascular Disease in Adult Life: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine if preterm birth is associated with components of the metabolic syndrome in adult life.

STUDY DESIGN

A structured literature search was performed using PubMed. All comparative studies reported metabolic and cardiovascular outcomes in adults (≥18 years of age) born preterm (<37 weeks of gestation) compared with adults born at term (37-42 weeks of gestation) and published through March 2018 were included. The major outcomes assessed were body mass index, waist circumference, waist-to-hip ratio, fat mass, systolic blood pressure (SBP), diastolic blood pressure (DBP), 24-hour SBP, 24-hour DBP, endothelium-dependent brachial artery flow-mediated dilation, carotid intima-media thickness, pulse wave velocity, fasting glucose and insulin, Homeostasis Model Assessment-Estimated Insulin Resistance Index, and lipid profiles. Quality appraisal was performed using a modified version of the Newcastle-Ottawa scale. A meta-analysis was performed for comparable studies which reported sufficient data.

RESULTS

Forty-three studies were included, including a combined total of 18 295 preterm and 294 063 term-born adults. Prematurity was associated with significantly higher fat mass (P = .03), SBP (P < .0001), DBP (P < .0001), 24-hour SBP (P < .001), and 24-hour DBP (P < .001). Furthermore, preterm-born adults presented higher values of fasting glucose (P = .01), insulin (P = .002), Homeostasis Model Assessment-Estimated Insulin Resistance Index (P = .05), and total cholesterol levels (P = .05) in comparison with adults born at term, in random effect models. No statistically significant difference was found between preterm and term-born adults for the other outcomes studied.

CONCLUSIONS

Preterm birth is strongly associated with a number of components of the metabolic syndrome and cardiovascular disease in adult life.

African-American women's Upward Economic Mobility and Small for Gestational Age Births: A Population-Based Study

Background The relationship between African-American women's upward economic mobility and small for gestational age (weight for gestational < 10th percentile, SGA) rates is incompletely understood. Objective To ascertain the extent to which African-American women's upward economic mobility from early-life impoverishment is coupled with reduced SGA rates. Methods Stratified and multilevel logistic regression analyses were completed on the Illinois transgenerational dataset of African-American infants (1989-1991) and their Chicago-born mothers (1956-1976) with linked U.S. census income information. Results Impoverished-born (defined as lowest quartile of neighborhood income distribution) African-American women (n = 4891) who remained impoverished by the time of delivery had a SGA rate of 19.7%. Individuals who achieved low (n = 5827), modest (n = 2254), or high (n = 732) upward economic mobility by adulthood had lower SGA rates of 17.2, 14.8, and 13.7%, respectively; RR = 0.9 (0.8-0.9), 0.8 (0.7-0.8), and 0.7 (0.6-0.8), respectively. In adjusted (controlling for traditional individual-level risk factors) multilevel regression models, there was a decreasing linear trend in SGA rates with increasing levels of upward economic mobility; the adjusted RR of SGA birth for impoverished-born African-American women who experienced low, modest, of high (compared to no) upward mobility equaled 0.95 (0.91, 0.99), 0.90 (0.83, 0.98), and 0.86 (0.75, 0.98), respectively, p < 0.05. Conclusions African-American women's upward economic mobility from early-life residence in poor urban communities is associated with lower SGA rates independent of adulthood risk status.

Father's Lifetime Socioeconomic Status, Small for Gestational Age Infants, and Infant Mortality: A Population-Based Study

Objective

To ascertain the association between father's lifetime socioeconomic status (SES) and rates of small for gestational age (SGA, defined as weight for gestational age <10th percentile) and infant mortality (defined as <365 days).

Methods

The study sample was limited to the singleton births of African American (n=8,331), non-Latina White (n=18,200), and Latina (n=2,637) women. Stratified and multilevel, multivariable logistic regression analyses were conducted on the Illinois transgenerational dataset of infants (1989-1991) and their Chicago-born parents (1956-1976) with appended US census income data (n=29,168). The median family income of father's census tract residence during childhood and parenthood were used to assess lifetime SES.

Results

Births (n=8,113) to fathers with a lifetime low SES had a SGA rate of 13.3% compared with 6.6% for those (n=10,329) born to fathers with a lifetime high SES, RR = 1.97 (1.79, 2.17). The infant mortality rate of births to fathers with a lifetime low SES exceeded that of infant mortality rate of births to fathers with a lifetime high SES: 13/1,000 vs 5/1,000, respectively; RR = 2.71 (1.94, 3.77). The adjusted (controlling for mother's age, education, marital status, and race/ethnicity) OR of SGA for fathers with childhood, parenthood, and lifetime low (vs high) SES were 1.15 (1.01, 1.31), 1.13 (1.02, 1.26), and 1.19 (1.05, 1.34), respectively. The adjusted OR of infant mortality for births to fathers with childhood, parenthood, and lifetime low (vs high) SES were 1.14 (.78, 1.67), 1.40 (.90, 2.18), and 1.31 (.90, 1.92), respectively.

Conclusions

Low paternal socioeconomic status is a previously unrecognized determinant of SGA birth regardless of mother's demographic status.

Fetal programming and the angiotensin-(1-7) axis: a review of the experimental and clinical data

Hypertension is the primary risk factor for cardiovascular disease that constitutes a serious worldwide health concern and a significant healthcare burden. As the majority of hypertension has an unknown etiology, considerable research efforts in both experimental models and human cohorts has focused on the premise that alterations in the fetal and perinatal environment are key factors in the development of hypertension in children and adults. The exact mechanisms of how fetal programming events increase the risk of hypertension and cardiovascular disease are not fully elaborated; however, the focus on alterations in the biochemical components and functional aspects of the renin-angiotensin (Ang) system (RAS) has predominated, particularly activation of the Ang-converting enzyme (ACE)-Ang II-Ang type 1 receptor (AT1R) axis. The emerging view of alternative pathways within the RAS that may functionally antagonize the Ang II axis raise the possibility that programming events also target the non-classical components of the RAS as an additional mechanism contributing to the development and progression of hypertension. In the current review, we evaluate the potential role of the ACE2-Ang-(1-7)-Mas receptor (MasR) axis of the RAS in fetal programming events and cardiovascular and renal dysfunction. Specifically, the review examines the impact of fetal programming on the Ang-(1-7) axis within the circulation, kidney, and brain such that the loss of Ang-(1-7) expression or tone, contributes to the chronic dysregulation of blood pressure (BP) and cardiometabolic disease in the offspring, as well as the influence of sex on potential programming of this pathway.

Prematurity and cardiovascular risk at early adulthood

BACKGROUND

Theories of early stress exposure and allostatic load offer a lifespan perspective to adult health after prematurity based on these early stressors affecting endocrine and metabolic systems. In this study, we examine cardiovascular and metabolic risk by comparing two groups of preterm infants who experienced a full spectrum of neonatal illness and a term-born group at age 23.

METHODS

Of the 215 infants recruited at birth, 84% participated at age 23. The cohort included 45 full-term (FT), 24 healthy preterm (HPT), and 111 sick preterm (SPT) infants. Socio-economic status was equivalent across groups. Cardiovascular and metabolic outcomes were as follows: blood pressure (BP), fasting glucose and lipid profiles, weight, waist-hip ratio (WHR), and body mass index (BMI). Clinical and subclinical ranges were compared across neonatal groups and gender.

RESULTS

At age 23, the HPT and SPT groups had higher systolic BP compared with the FT group. The SPT group had lower weight compared with the FT and HPT groups. No group differences were found on diastolic BP, glucose, total cholesterol, high-density lipids, low-density lipids, triglycerides, BMI, or WHR. Preterm males had more systolic hypertension and low high-density lipids than FT males. Former preterm males and females had high WHR ratios and BMI at 23 years. Subclinical prehypertensive rates were highest for the HPT female group, followed by the SPT females. Only one (4.2%) HPT adult male was clinically diabetic.

CONCLUSIONS

As young adults, HPT and SPT infants had early indicators of cardiovascular risk but no indicators of metabolic risk. There is utility in using clinical and subclinical ranges to identify early cardiovascular risk in early adulthood.

Epigenetic gestational age acceleration: a prospective cohort study investigating associations with familial, sociodemographic and birth characteristics

Background

Gestational age at delivery is associated with health and social outcomes. Recently, cord blood DNA methylation data has been used to predict gestational age. The discrepancy between gestational age predicted from DNA methylation and determined by ultrasound or last menstrual period is known as gestational age acceleration. This study investigated associations of sex, socioeconomic status, parental behaviours and characteristics and birth outcomes with gestational age acceleration.

Results

Using data from the Avon Longitudinal Study of Parents and Children (n = 863), we found that pre-pregnancy maternal overweight and obesity were associated with greater gestational age acceleration (mean difference = 1.6 days, 95% CI 0.7 to 2.6, and 2.9 days, 95% CI 1.3 to 4.4, respectively, compared with a body mass index < 25 kg/m², p < .001). There was evidence of an association between male sex and greater gestational age acceleration. Greater gestational age acceleration was associated with higher birthweight, birth length and head circumference of the child (mean differences per week higher gestational age acceleration: birthweight 0.1 kg, 95% CI 0.1 to 0.2, p < .001; birth length 0.4 cm, 95% CI 0.2 to 0.7, p < .001; head circumference 0.2 cm, 95% CI 0.1 to − 0.4, p < .001). There was evidence of an association between gestational age acceleration and mode of delivery (assisted versus unassisted delivery, odds ratio = 0.9 per week higher gestational age acceleration, 95% CI 0.7, 1.3 (p = .05); caesarean section versus unassisted delivery, odds ratio = 0.6, 95% CI 0.4 to 0.9 per week higher gestational age acceleration (p = .05)). There was no evidence of association for other parental and perinatal characteristics.

Conclusions

The associations of higher maternal body mass index and larger birth size with greater gestational age acceleration may imply that maternal overweight and obesity is associated with more rapid development of the fetus in utero. The implications of gestational age acceleration for postnatal health warrant further investigation.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0520-1) contains supplementary material, which is available to authorized users.

Pulmonary arterial resistance and compliance in preterm infants

BACKGROUND

Preterm birth is known to be associated with an increased risk of pulmonary arterial hypertension, although how preterm birth influences pulmonary hemodynamics has not been fully understood. Pulmonary arterial resistance (Rp) and compliance (Cp) are important factors to assess the pulmonary circulation. The purpose of this study is to clarify the relationship between Rp and Cp in preterm infants.

METHODS

We performed cardiac catheterization in 96 infants (50 males) with ventricular septal defect, and compared pulmonary hemodynamic parameters including Rp and Cp between preterm and full-term infants.

RESULTS

Thirteen infants were preterm. There were no significant differences in sex, age, preoperative pulmonary arterial pressure, preoperative pulmonary-to-systemic flow ratio, and preoperative Rp between the 2 groups. However, preoperative Cp and resistor-capacitor (RC) time in preterm infants were significantly lower than those in full-term infants (2.1 vs 2.8mL/mmHg/m² and 0.31 vs 0.36s, respectively; p<0.05 and p<0.01, respectively). Postoperative systolic and mean pulmonary arterial pressures were higher in preterm infants than those in full-term infants (29 vs 25mmHg and 18 vs 14mmHg, respectively; both p<0.01). It was also observed that postoperative Cp was lower in preterm infants, although postoperative Rp remained unchanged.

CONCLUSIONS

We demonstrated that preterm infants with pulmonary arterial hypertension had lower Cp than full-term infants, causing a modest increase in pulmonary arterial pressure. It is important to consider the unique pulmonary vasculature characterized by lower Cp, when managing preterm infants with congenital heart disease.

Adult Consequences of Extremely Preterm Birth: Cardiovascular and Metabolic Diseases Risk Factors, Mechanisms, and Prevention Avenues

Extremely preterm babies are exposed to various sources of injury during critical stages of development. The extremely preterm infant faces premature transition to ex utero physiology and undergoes adaptive mechanisms that may be deleterious in the long term because of permanent alterations in organ structure and function. Perinatal events can also directly cause structural injury. These disturbances induce morphologic and functional changes in their organ systems that might heighten their risks for later adult chronic diseases. This review examines the pathophysiology of programming of long-term health and diseases after preterm birth and associated perinatal risk factors.

Effects of preterm birth and fetal growth retardation on life-course cardiovascular risk factors among schoolchildren from Colombia: The FUPRECOL study

BACKGROUND

Both fetal growth restriction and prematurity have been associated with cardiometabolic risk in youth and adults, however, data on their combined effects on cardiometabolic health in youth are scarce.

AIMS

This study aimed at assessing the effects of birth weight and gestational age combined on life-course cardiovascular risk factors and obesity among schoolchildren from Colombia.

STUDY DESIGN

A cross-sectional study.

SUBJECTS

Participants comprised 2510 Colombian schoolchildren (54.8% girls) aged 9-17.9years.

OUTCOME MEASURES

Four groups were created according to WHO criteria: those born at term with an appropriate birth weight (≥2500g to ≤4000g) for gestational age (term AGA); those born preterm (<37 to <42 completed weeks) with an appropriate birth weight for gestational age (preterm AGA); those born at term with low birth weight for gestational age (term SGA); and those born preterm with low birth weight for gestational age (preterm SGA). Anthropometric markers (body mass, height, waist circumference, and body mass index), blood pressure, lipids profile, fasting glucose, and pubertal stage were assessed. The prevalence of metabolic syndrome was determined by de Ferranti definition.

RESULTS

There were differences between the 4 groups for calendar age (p=0.011), body mass (p=0.001), height (p=0.001), and body mass index (p=0.027). Overall, preterm SGA group had a greater risk for having elevated fasting glucose and metabolic syndrome (total sample and in boys) compared with term AGA group (p<0.05). For other cardiovascular risk factors, no significant relationships were observed based on birth characteristics.

CONCLUSIONS

School-age children and adolescents with combined fetal growth restriction and prematurity exhibited an increased prevalence of glucose risk and metabolic syndrome.

Epigenetic Matters: The Link between Early Nutrition, Microbiome, and Long-term Health Development

Epigenetic modifications are among the most important mechanisms by which environmental factors can influence early cellular differentiation and create new phenotypic traits during pregnancy and within the neonatal period without altering the deoxyribonucleic acid sequence. A number of antenatal and postnatal factors, such as maternal and neonatal nutrition, pollutant exposure, and the composition of microbiota, contribute to the establishment of epigenetic changes that can not only modulate the individual adaptation to the environment but also have an influence on lifelong health and disease by modifying inflammatory molecular pathways and the immune response. Postnatal intestinal colonization, in turn determined by maternal flora, mode of delivery, early skin-to-skin contact and neonatal diet, leads to specific epigenetic signatures that can affect the barrier properties of gut mucosa and their protective role against later insults, thus potentially predisposing to the development of late-onset inflammatory diseases. The aim of this review is to outline the epigenetic mechanisms of programming and development acting within early-life stages and to examine in detail the role of maternal and neonatal nutrition, microbiota composition, and other environmental factors in determining epigenetic changes and their short- and long-term effects.

Neonatal outcomes according to different therapies for gestational diabetes mellitus

OBJECTIVES

To compare different neonatal outcomes according to the different types of treatments used in the management of gestational diabetes mellitus.

METHODS

This was a retrospective cohort study. The study population comprised pregnant women with gestational diabetes treated at a public maternity hospital from July 2010 to August 2014. The study included women aged at least 18 years, with a singleton pregnancy, who met the criteria for gestational diabetes mellitus. Blood glucose levels, fetal abdominal circumference, body mass index and gestational age were considered for treatment decision-making. The evaluated neonatal outcomes were: type of delivery, prematurity, weight in relation to gestational age, Apgar at 1 and 5min, and need for intensive care unit admission.

RESULTS

The sample consisted of 705 pregnant women. The neonatal outcomes were analyzed based on the treatment received. Women treated with metformin were less likely to have children who were small for gestational age (95% CI: 0.09-0.66) and more likely to have a newborn adequate for gestational age (95% CI: 1.12-3.94). Those women treated with insulin had a lower chance of having a preterm child (95% CI: 0.02-0.78). The combined treatment with insulin and metformin resulted in higher chance for a neonate to be born large for gestational age (95% CI: 1.14-11.15) and lower chance to be born preterm (95% CI: 0.01-0.71). The type of treatment did not affect the mode of delivery, Apgar score, and intensive care unit admission.

CONCLUSIONS

The pediatrician in the delivery room can expect different outcomes for diabetic mothers based on the treatment received.

Retinopathy of Prematurity Is Associated with Increased Systolic Blood Pressure in Adults Who Were Born Preterm

BACKGROUND

Adults born preterm are at risk of developing cardiovascular morbidities.

OBJECTIVE

The aim of this study was to evaluate the relationship between retinopathy of prematurity (ROP) and blood pressure (BP) and salivary cortisol levels during adulthood.

METHODS

Sixty-nine subjects (mean age 22.6 years) were included. Subjects were adults who were: (a) ex-preterm infants with severe ROP (n = 22), born at gestational age (GA) <30 weeks with a birth weight (BW) <1,000 g, (b) ex-preterm infants with no/mild ROP (n = 21), born at GA <28 weeks with a BW <1,000 g, or (c) full-term controls (n = 26). Anthropometric data, office BP, ambulatory BP, and morning and evening salivary cortisol were analyzed.

RESULTS

As adults, ex-preterm infants with severe ROP had on average 7.4 mm Hg higher systolic office BP than those with no/mild ROP (p = 0.019) and controls (p = 0.007). A high cortisol level, tall height, and severe ROP were independent predictors of higher ambulatory systolic BP during adulthood in forward stepwise regression analysis, independent of GA.

CONCLUSION

Our results indicate that preterm infants with severe abnormal retinal vascular development during the neonatal period may be at an increased risk for increased BP during adulthood. We found no differences between those with no/mild ROP as infants and controls with regard to BP data.

Cardiac Disease after Pregnancy: A Growing Problem

Pregnancy complications, such as hypertensive disorders or preterm delivery, identify families predisposed to cardiovascular problems at other times in life. Whether the pregnancy complication induces cardiac disease or whether the pregnancy stress unmasks an underlying predisposition remains unclear. However, improved survival following severe pregnancy complications for both the mother and, in particular, the offspring - who is often born preterm - has resulted in a growing cohort of individuals who carry this increased cardiovascular risk. Research to understand the underlying pathological mechanisms that link these conditions might ultimately lead to novel therapeutic or prevention strategies for both cardiovascular and pregnancy disease.

Aortic Elastic Properties in Preschool Children Born Preterm

OBJECTIVE

Preterm birth predisposes children to the development of cardiovascular diseases in adulthood. The aim of this study was to characterize elastic properties of the aorta at preschool age and test the hypothesis that prematurity is associated with decreased aortic distensibility and increased stiffness, both of which are predictors of increased cardiovascular risk.

APPROACH AND RESULTS

In an observational study of 76 five- to seven-year-old children born at a gestational age <32 weeks and 79 term-born controls, elastic parameters of the ascending and descending abdominal aorta were determined noninvasively by means of M mode echocardiographic tracings and calculated using computerized wall contour analysis. Compared with children born at term, the preterm group showed significantly reduced distensibility and increased stiffness of the descending abdominal aorta. These results remained significant under multivariable adjustment for birth weight z score, maternal smoking in pregnancy, maternal education, family history of cardiovascular disease, breastfeeding, childhood nutrition, and current body mass index z score (multivariable odds ratios and 95% confidence intervals 5.1, 1.7-15.9; P=0.005 and 2.8, 1.0-7.9; P=0.046, respectively). Further adjustment for intravenous lipid therapy attenuated the strength of association. Elastic properties of the ascending aorta did not differ between the 2 study groups.

CONCLUSIONS

Children born preterm are characterized by decreased elastic properties of the descending abdominal aorta potentially attributable to impaired viscoelastic properties of and lipid damage to the aorta. Clinical follow-up of preterm infants with a focus on aortic elastic properties may be useful for tailoring early prevention programs and counteracting cardiovascular risk in adulthood.

Blood Pressure in Young Adults Born at Very Low Birth Weight: Adults Born Preterm International Collaboration

Adults born preterm at very low birth weight (VLBW; <1500 g) have higher blood pressure than those born at term. It is not known whether all VLBW adults are at risk or whether higher blood pressure could be attributed to some of the specific conditions underlying or accompanying preterm birth. To identify possible risk or protective factors, we combined individual-level data from 9 cohorts that measured blood pressure in young adults born at VLBW or with a more stringent birth weight criterion. In the absence of major heterogeneity, we performed linear regression analysis in our pooled sample of 1571 adults born at VLBW and 777 controls. Adults born at VLBW had 3.4 mm Hg (95% confidence interval, 2.2-4.6) higher systolic and 2.1 mm Hg (95% confidence interval, 1.3-3.0) higher diastolic pressure, with adjustment for age, sex, and cohort. The difference in systolic pressure was present in men (1.8 mm Hg; 95% confidence interval, 0.1-3.5) but was stronger in women (4.7 mm Hg; 95% confidence interval, 3.2-6.3). Among the VLBW group, blood pressure was unrelated to gestational age, maternal smoking, multiple pregnancy, retinopathy of prematurity, or bronchopulmonary dysplasia. Blood pressure was higher than that of controls among VLBW adults unexposed to maternal preeclampsia. Among those exposed, it was even higher, especially if born appropriate for gestational age. In conclusion, although female sex and maternal preeclampsia are additional risk factors, the risk of higher blood pressure is not limited to any etiologic subgroup of VLBW adults, arguing for vigilance in early detection of high blood pressure in all these individuals.

DNA methylations of MC4R and HNF4α are associated with increased triglyceride levels in cord blood of preterm infants

The association of preterm birth with obesity and metabolic syndrome later in life is well established. Although the biological mechanism for this association is poorly understood, epigenetic alterations of metabolic-related genes in early life may have important roles in metabolic dysfunction. Thus, we investigated the associations of DNA methylations of melanocortin 4 receptor (MC4R) and hepatocyte nuclear factor 4 alpha (HNF4α) with metabolic profiles in cord blood of term and preterm infants.We measured metabolic profiles in cord blood samples of 85 term and 85 preterm infants. DNA methylation and mRNA expression levels of MC4R and HNF4α in cord blood cells were quantified using pyrosequencing and real-time PCR. Triglyceride (TG) levels were grouped by percentile as low (<10th percentile), mid (11th-89th percentiles), and high (>90th percentile). A multiple linear regression model was used to assess the differential effects of DNA methylation on metabolic indices in cord blood between term and preterm infants.The beta-coefficients for associations between TG levels and methylation statuses of MC4R-CpG3 and HNF4α-CpG2 in the P1 promoter differed significantly between term and preterm infants (P = 0.04 and P = 0.003, respectively). DNA methylation statuses of MC4R-CpG3 and HNF4α-CpG2 in the P1 promoter were significantly lower in preterm infants in the high-TG group compared with those in the mid- and low-TG groups (P = 0.01). Notably, preterm infants in the high-TG group had higher TG levels in cord blood than term infants in the high-TG group (60.49 vs 54.57 mg/dL). In addition, MC4R and HNF4α expression levels were higher in preterm infants than in term infants (P < 0.05).Epigenetic alterations of the newly identified genes MC4R and HNF4α in early life might contribute to metabolic profile changes, especially increased TG levels, in the cord blood of preterm infants.

Risk for Nonalcoholic Fatty Liver Disease in Young Adults Born Preterm

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. Accelerated catch-up in weight during infancy in subjects born at full term has been associated with increased risk for NAFLD in adulthood, but this association has not been studied in subjects born preterm.

METHODS

In 162 young adults born at a gestational age <36 weeks, we assessed the associations between fatty liver index (FLI, 0-100) and birth weight standard deviation score and first-year weight gain. We performed comparisons between subjects with and without accelerated catch-up in weight in the first year after term age. An FLI score was assigned to each participant to determine the clinical relevance, and regression analyses were performed.

RESULTS

Accelerated weight gain in the first 3 months after term age was associated with FLI as a continuous variable, whereas gestational age and low birth weight were not. Of the subjects with accelerated catch-up in weight-for-length after term age, 7.3% had a high FLI at the age of 21 years, whereas none of the subjects without accelerated catch-up in weight had a high FLI.

CONCLUSION

Our study shows that accelerated weight gain after term age is associated with an increased risk of developing NAFLD in young adults born preterm.

Preterm at birth is not associated with greater cardiovascular risk in adolescence

OBJECTIVE

To determine the effects of preterm birth and gender on subsequent cardiovascular risk factors among urban adolescents in a capital in the Brazilian northeast and to compare them with a group of adolescents term at birth.

METHODS

In a retrospective double cohort, data of birth weight were extracted from hospital registers of children born in a same day of birth, between 1992 and 2002. We classified the preterm as a unique group born before 37 weeks of gestation. A total of 134 adolescents, aged 10-20 years were found and investigated. We measured anthropometric and clinical data, blood lipid profile and glucose after overnight fasting.

RESULTS

Preterm subjects had less years of scholar education, especially between females (p = 0.01). Preterm females also had lower height (p = 0.00) and waist-hip circumference ratio (p = 0.01). Preterm males had lower cesarean delivery (p = 0.05) and greater family history of cardiovascular disease (p = 0.05). Although the differences on clinical or laboratorial measurements were small and non-significant for cardiovascular risk factors, systolic blood pressure (SBP) and diastolic blood pressure (DBP) tended to be higher in preterm groups, especially for females (SBP = 4.1 mmHg and DBP = 1.6 mmHg, p = 0.12 and p = 0.38, respectively).

CONCLUSION

Premature did not increase cardiovascular risk adolescents in this sample. The lower association between premature and poor health outcomes among adolescents in a low average socioeconomic status population from a capital in the Brazilian northeast corroborates previous findings in other countries.

Leukocyte Telomere Length in Young Adults Born Preterm: Support for Accelerated Biological Ageing

BACKGROUND

Subjects born preterm have an increased risk for age-associated diseases, such as cardiovascular disease in later life, but the underlying causes are largely unknown. Shorter leukocyte telomere length (LTL), a marker of biological age, is associated with increased risk of cardiovascular disease.

OBJECTIVES

To compare LTL between subjects born preterm and at term and to assess if LTL is associated with other putative cardiovascular risk factors at young adult age.

METHODS

We measured mean LTL in 470 young adults. LTL was measured using a quantitative PCR assay and expressed as T/S ratio. We analyzed the influence of gestational age on LTL and compared LTL between subjects born preterm (n = 186) and at term (n = 284). Additionally, we analyzed the correlation between LTL and potential risk factors of cardiovascular disease.

RESULTS

Gestational age was positively associated with LTL (r = 0.11, p = 0.02). Subjects born preterm had shorter LTL (mean (SD) T/S ratio = 3.12 (0.44)) than subjects born at term (mean (SD) T/S ratio = 3.25 (0.46)), p = 0.003). The difference remained significant after adjustment for gender and size at birth (p = 0.001). There was no association of LTL with any one of the putative risk factors analyzed.

CONCLUSIONS

Young adults born preterm have shorter LTL than young adults born at term. Although we found no correlation between LTL and risk for CVD at this young adult age, this biological ageing indicator may contribute to CVD and other adult onset diseases at a later age in those born preterm.

Late prematurity and adiposity in adolescents: Evidence from "Children of 1997" birth cohort

OBJECTIVE

The association of late prematurity with later adiposity is unclear, and the mediating role of infant growth is seldom studied. We assessed the association of late prematurity with markers of adiposity in adolescence and tested whether accelerated infant weight gain mediated the association.

METHODS

In the Chinese birth cohort "Children of 1997," we used multivariable linear regression to assess the adjusted association of late premature (n = 295), compared to term (n = 6874), births with markers of adiposity at 14 years. We tested whether any association was mediated by accelerated weight gain from birth to 12 months, i.e., a change in weight z-score ≥0.67.

RESULTS

Late premature births had greater body mass index (BMI) z-score (0.21, 95% confidence interval (CI) 0.07, 0.35), waist-hip ratio z-score (0.16, 95% CI 0.03, 0.29), and waist-height ratio z-score (0.27, 95% CI 0.14, 0.40) than term births in adolescence. The association of late prematurity with higher adolescent BMI, but not waist ratios, was mediated by accelerated infant weight gain.

CONCLUSIONS

Late prematurity was associated with higher BMI and waist ratios in adolescence, but only the association with BMI was mediated by infant weight gain, suggesting vulnerability to metabolic risk in late premature births may arise through multiple pathways.

Masked hypertension in extremely preterm adolescents

AIM

Extremely preterm (EPT, born <28 weeks gestation) or extremely low birthweight (ELBW, birthweight <1000 g) individuals are at increased risk of high blood pressure (BP) and cardiovascular disease. We compared office BP measurements with 24-h ambulatory BP measurement (ABP) in EPT/ELBW individuals at age 18 years and term controls, and determined the sensitivity and specificity of office BP in predicting masked hypertension (24-h ABP measurements > 130/80).

METHODS

All EPT/ELBW individuals and matched term control adolescents born in Victoria, Australia, between 1991 and 1992 were recruited. A subset of this cohort was seen at 18 years, and researchers blinded to birth status measured office BP and ABP. We established the office BP thresholds that had the highest sensitivity and specificity in predicting masked hypertension.

RESULTS

EPT/ELBW (N = 120) individuals had higher mean BP measurements at 18 years, compared with controls (N = 71). Although there were no significant differences in rates of high BP between groups, high proportions of both EPT/ELBW (43.3%) and term control (36.6%) participants met criteria for masked systolic hypertension. In EPT/ELBW individuals, office systolic BP measurement of ≥122.5 mmHg predicted masked systolic hypertension (sensitivity 79%, specificity 74%). Office diastolic BP measurement of ≥75.5 mmHg predicted masked diastolic hypertension (sensitivity 77%, specificity, 77%).

CONCLUSIONS

At age 18 years, EPT/ELBW individuals have higher systolic and diastolic BP, compared with controls. Office BP may be an adequate screen for masked hypertension in EPT/ELBW survivors, but further research is needed to identify accurate ABP thresholds for masked hypertension for young Australians.

Preterm birth may be a larger risk factor for increased blood pressure than intrauterine growth restriction

AIM

Very low birthweight (VLBW) and prematurity have been associated with an increased risk of high blood pressure (BP). We compared BP and salivary cortisol responses to a stressful situation between adolescents with a VLBW and controls.

METHODS

We compared three groups aged 12-17 years: 30 born VLBW but appropriate for gestational age (AGA) at a mean of 27 weeks, 19 born VLBW but small for gestational age (SGA) at a mean of 31 weeks and 43 term-born AGA controls. Three consecutive BP measurements were performed before a magnetic resonance imaging (MRI) examination. Salivary cortisol and perceived stress were assessed before and after the MRI.

RESULTS

Systolic and diastolic BP decreased significantly for each repeated measurement in the VLBW-SGA group and controls, but remained unchanged in the VLBW-AGA group. The third systolic BP measurement was 9-12 mmHg higher in the VLBW-AGA group than the other groups (p < 0.05). There were no differences in salivary cortisol between the groups, before and after the MRI or between the sexes.

CONCLUSION

Dynamic BP responses differed between adolescents born VLBW-AGA and the other groups, indicating that extremely preterm birth may be a larger risk factor for increased BP than intrauterine growth restriction.