Fetal Origin of Childhood Disease

Fetal hemodynamic changes and mitochondrial dysfunction in myocardium and brain tissues in response to anemia: a lesson from hemoglobin Bart's disease

OBJECTIVE

Whether or not the effects of anemia in the early phase, while the fetuses attempts to increase cardiac output to meet oxygen requirement in peripheral organs, is detrimental to the fetal developing vital organs is little-known. The objective of this is to compare prenatal cardiovascular changes and post-abortal cellular damages in the myocardium as a pumping organ and the brain as a perfused organ between anemic fetuses (using fetal Hb Bart's disease as a study model) in pre-hydropic phase and non-anemic fetuses.

METHODS

Fetuses affected by Hb Bart's disease and non-anemic fetuses at 16-22 weeks were recruited to undergo comprehensive fetal echocardiography. Cord blood analysis was used to confirm the definite diagnosis of fetal Hb Bart's disease and normal fetuses. Fetal cardiac and brain tissues were collected shortly after pregnancy termination for the determination of oxidative stress and mitochondrial function, including mitochondrial ROS production and mitochondrial membrane changes.

RESULTS

A total of 18 fetuses affected by Hb Bart's disease and 13 non-anemic fetuses were recruited. The clinical characteristics of both groups were comparable. The affected fetuses showed a significant increase in cardiac dimensions, cardiac function, cardiac output and brain circulation without deteriorating cardiac contractility and preload. However, in the affected fetuses, mitochondrial dysfunction was clearly demonstrated in brain tissues and in the myocardium, as indicated by a significant increase in the membrane potential change (p-value < 0.001), and a significant increase in ROS production in brain tissues, with a trend to increase in myocardium. The findings indicated cellular damage in spite of good clinical compensation.

CONCLUSION

The new insight is that, in response to fetal anemia, fetal heart increases in size (dilatation) and function to increase cardiac output and blood flow velocity to provide adequate tissue perfusion, especially brain circulation. However, the myocardium and brain showed a significant increase in mitochondrial dysfunction, suggesting cellular damage secondary to anemic hypoxia. The compensatory increase in circulation could not completely prevent subtle brain and heart damage.

An analysis of the distribution and spectrum of alpha thalassemia mutations in Rasht City, North of Iran

Background

Alpha thalassemia is one of the most common hereditary hemoglobin disorders worldwide, particularly in the Middle East, including Iran. Therefore, determining the spectrum and distribution of alpha thalassemia mutation is a fundamental component of preventive approaches and management strategies.

Methods

The present study reviews the genetic testing and blood laboratory results of 455 candidates eligible for marriage who were suspected of being thalassemia carriers and on whom genetic testing was performed from 21 March 2013 to 31 December 2020 in Rasht City.

Results

A total of 114 (25.05%) alpha thalassemia cases were identified. Fifteen different alpha mutations were found. The most common mutation among the study population was -α^3.7 deletion in 55 patients (48.24%), followed by Hb Constant Spring (C.S) in 21 patients (18.42%) and poly A2 in 16 (14.03%). Also, most of the patients were silent carriers. The deletion type of mutation was much more common than non-deletion mutations.

Conclusion

Our study reveals genetic heterogeneity and alpha thalassemia diversity among the Rasht City population. We expect that these findings will help guide premarital screening and genetic counseling, prenatal diagnosis of thalassemia, preventive strategy development, as well as a compilation of the alpha thalassemia catalog in Guilan province.

Postnatal glucocorticoid use impacts renal function in VLBW neonates

BACKGROUND

Preterm neonates often require glucocorticoids to manage refractory hypotension, prevent, and treat bronchopulmonary dysplasia. We have investigated the effect of cumulative dose and duration of glucocorticoids on blood pressure and renal function in VLBW infants.

METHODS

In this retrospective cohort study, medical records of infants (GA ≤ 35 weeks) born January 2015 to December 2019 were reviewed to extract demographic and clinical characteristics, dose and duration of steroids, blood pressure (BP), and creatinine at the time of discharge from the neonatal intensive care unit.

RESULTS

Two hundred and eighty-three neonates with average GA (28 ± 3 weeks) and birthweight (1060±381 g). Twenty-eight percent (33/116) of infants who received postnatal steroids developed hypertension versus 16% (27/167) of controls (OR = 2.0, p = 0.011). There was a correlation between the cumulative dosage of postnatal steroids and systolic BP (R² = 0.06, p < 0.001). With increasing steroid dose and total steroid days, there was a significant increase in creatinine clearance at the time of discharge (R² = 0.13, p < 0.001; R² = 0.13, p < 0.001, respectively).

CONCLUSIONS

Cumulative dose of postnatal steroids and duration of use is associated with increased systolic BP in premature infants. Postnatal steroids should be used prudently to prevent long-term cardiovascular and renal morbidity.

IMPACT

Preterm neonates are exposed to a high dose of glucocorticoids during their neonatal intensive care stay. The dose and duration of use of postnatal glucocorticoids was associated with significant increase in blood pressure at the time of discharge in preterm neonates. Postnatal glucocorticoid use is associated with improved creatinine clearance likely due to a state of hyperfiltration and may lead to chronic kidney disease later in life. Postnatal glucocorticoids should be used prudently in this highly vulnerable population.

Epigenetic Mechanisms Responsible for the Transgenerational Inheritance of Intrauterine Growth Restriction Phenotypes

A poorly functioning placenta results in impaired exchanges of oxygen, nutrition, wastes and hormones between the mother and her fetus. This can lead to restriction of fetal growth. These growth restricted babies are at increased risk of developing chronic diseases, such as type-2 diabetes, hypertension, and kidney disease, later in life. Animal studies have shown that growth restricted phenotypes are sex-dependent and can be transmitted to subsequent generations through both the paternal and maternal lineages. Altered epigenetic mechanisms, specifically changes in DNA methylation, histone modifications, and non-coding RNAs that regulate expression of genes that are important for fetal development have been shown to be associated with the transmission pattern of growth restricted phenotypes. This review will discuss the subsequent health outcomes in the offspring after growth restriction and the transmission patterns of these diseases. Evidence of altered epigenetic mechanisms in association with fetal growth restriction will also be reviewed.

Early nutritional influences of cardiovascular health

INTRODUCTION

Increasing evidence shows that nutritional choices during children's formative years, including prenatally, impacts the development of adult onset cardiovascular diseases (CVDs), such as hypertension, myocardial infarction, or stroke.

AREAS COVERED

This literature review aims to synthesize the current body of evidence on nutritional factors, from conception through adolescence, which may influence a person's risk factors for future development of CVD.

EXPERT OPINION

Given the escalating healthcare costs associated with CVD, it is imperative that medical professionals and scientists remain steadfast in prioritizing and promoting early CVD prevention, even within the first few years of life. Though not the only contributing risk factor, diet is a modifiable risk factor and has been shown to have a profound impact on the reduction of cardiovascular morbidity and mortality in adult literature. Nutritional choices should be targeted on multiple levels: prenatally with the mother, individually with the patient, in conjunction with their family unit, and also within the broader community wherein they reside. Healthcare providers can play a key advocacy role for local and national food environment policy changes.

Insights into the Mechanisms of Fetal Growth Restriction-Induced Programming of Hypertension

In recent decades, both clinical and animal studies have shown that fetal growth restriction (FGR), caused by exposure to adverse uterine environments, is a risk factor for hypertension as well as for a variety of adult diseases. This observation has shaped and informed the now widely accepted theory of developmental origins of health and disease (DOHaD). There is a plethora of evidence supporting the association of FGR with increased risk of adult hypertension; however, the underlying mechanisms responsible for this correlation remain unclear. This review aims to explain the current advances in the field of fetal programming of hypertension and a brief narration of the underlying mechanisms that may link FGR to increased risk of adult hypertension. We explain the theory of DOHaD and then provide evidence from both clinical and basic science research which support the theory of fetal programming of adult hypertension. In addition, we have explored the underlying mechanisms that may link FGR to an increased risk of adult hypertension. These mechanisms include epigenetic changes, metabolic disorders, vascular dysfunction, neurohormonal impairment, and alterations in renal physiology and function. We further describe sex differences seen in the developmental origins of hypertension and provide insights into the opportunities and challenges present in this field.

Epigenetic mechanisms involved in intrauterine growth restriction and aberrant kidney development and function

Intrauterine growth restriction (IUGR) due to uteroplacental insufficiency results in a placenta that is unable to provide adequate nutrients and oxygen to the fetus. These growth-restricted babies have an increased risk of hypertension and chronic kidney disease later in life. In rats, both male and female growth-restricted offspring have nephron deficits but only males develop kidney dysfunction and high blood pressure. In addition, there is transgenerational transmission of nephron deficits and hypertension risk. Therefore, epigenetic mechanisms may explain the sex-specific programming and multigenerational transmission of IUGR-related phenotypes. Expression of DNA methyltransferases (Dnmt1and Dnmt3a) and imprinted genes (Peg3, Snrpn, Kcnq1, and Cdkn1c) were investigated in kidney tissues of sham and IUGR rats in F1 (embryonic day 20 (E20) and postnatal day 1 (PN1)) and F2 (6 and 12 months of age, paternal and maternal lines) generations (n = 6-13/group). In comparison to sham offspring, F1 IUGR rats had a 19% decrease in Dnmt3a expression at E20 (P < 0.05), with decreased Cdkn1c (19%, P < 0.05) and increased Kcnq1 (1.6-fold, P < 0.01) at PN1. There was a sex-specific difference in Cdkn1c and Snrpn expression at E20, with 29% and 34% higher expression in IUGR males compared to females, respectively (P < 0.05). Peg3 sex-specific expression was lost in the F2 IUGR offspring, only in the maternal line. These findings suggest that epigenetic mechanisms may be altered in renal embryonic and/or fetal development in growth-restricted offspring, which could alter kidney function, predisposing these offspring to kidney disease later in life.

Early Determinants of Childhood Blood Pressure at the Age of 6 Years: The GECKO Drenthe and ABCD Study Birth Cohorts

Background

There is still uncertainty about the nature and relative impact of early determinants on childhood blood pressure. This study explored determinants of blood pressure at the age of 6 years in 2 Dutch birth cohorts.

Methods and Results

Results of hierarchical multiple linear regression analyses in GECKO (Groningen Expert Center for Kids With Obesity) Drenthe study (n=1613) were replicated in ABCD (Amsterdam Born Children and Their Development) study (n=2052). All analyses were adjusted for child's age, sex, height, and body mass index (BMI), and maternal education and subsequently performed in the combined sample. No associations were found between maternal smoking during pregnancy and childhood blood pressure. In the total sample, maternal prepregnancy BMI was positively associated with systolic blood pressure (SBP) (β [95% CI], 0.09 [0.02–0.16] mm Hg) and diastolic blood pressure (β [95% CI], 0.11 [0.04–0.17] mm Hg). Children of women with hypertension had higher SBP (β [95% CI], 0.98 [0.17–1.79] mm Hg). Birth weight standardized for gestational age was inversely associated with SBP (β [95% CI], −6.93 [−9.25 to −4.61] mm Hg) and diastolic blood pressure (β [95% CI], −3.65 [−5.70 to −1.61] mm Hg). Longer gestational age was associated with lower SBP (β [95% CI] per week, −0.25 [−0.42 to −0.08] mm Hg). Breastfeeding for 1 to 3 months was associated with lower SBP (β [95% CI], −0.96 [−1.82 to −0.09] mm Hg) compared with no or <1 month of breastfeeding. Early BMI gain from the age of 2 to 6 years was positively associated with SBP (β [95% CI], 0.41 [0.08–0.74] mm Hg) and diastolic blood pressure (β [95% CI], 0.37 [0.07–0.66] mm Hg), but no effect modification by birth weight was found.

Conclusions

Higher maternal prepregnancy BMI, maternal hypertension, a relatively lower birth weight for gestational age, shorter gestational age, limited duration of breastfeeding, and more rapid early BMI gain contribute to higher childhood blood pressure at the age of 6 years.

Conflicting Effects of Fetal Growth Restriction on Blood Pressure Between Human and Rat Offspring: A Meta-Analysis

Low birth weight is associated with hypertension. Low birth weight can result from fetal growth restriction (FGR) or prematurity. FGR is postulated to impact blood pressure (BP) by developmental programming. This systematic review and meta-analysis studies BP in human and animal offspring following FGR. Pubmed and Web of Science were searched for studies reporting on BP after placental insufficiency induced FGR compared with normal growth controls. Primary outcome was mean absolute BP difference (ΔBP mm Hg [95% CI]). Meta-analysis was performed using random-effects models. Subgroup analyses were executed on species, sex, age, pregnancy duration, and stress during BP readings. Due to large interspecies heterogeneity, analyses were performed separately for human (n=41) and animal (n=31) studies, the latter restricted to rats (n=27). Human studies showed a ΔBP between FGR and controls of -0.6 mm Hg ([95% CI, -1.7 to 0.6]; I²=91%). Mean ΔBP was -2.6 mm Hg (95% CI, -5.7 to 0.4) in women versus -0.5 mm Hg (95% CI, -3.7 to 2.7) in men. Subgroup analyses did not indicate age, gestational age, and stress during measurements as sources of heterogeneity. In rats, mean BP was 12.0 mm Hg ([95% CI, 8.8-15.2]; I²=81%) higher in FGR offspring. This difference was more pronounced in FGR males (13.6 mm Hg [95% CI, 10.3-17.0] versus 9.1 mm Hg [95% CI, 5.3-12.8]). Subgroup analyses on age showed no statistical interaction. BP readings under restrained conditions resulted in larger BP differences between FGR and control rats (15.3 mm Hg [95% CI, 11.6-18.9] versus 5.7 mm Hg [95% CI, 1.1-10.3]). Rat studies confirm the relation between FGR and offspring BP, while observational studies in humans do not show such differences. This may be due to the observational nature of human studies, methodological limitations, or an absence of this phenomenon in humans. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: CRD42018091819.

Impact of Birth Weight and Length on Primary Hypertension in Children

BACKGROUND

A child's birth parameters not only enable assessment of intrauterine growth but are also helpful in identifying children at risk of developmental defects or diseases occurring in adulthood. Studies show that children born with a body weight that is small for their gestational age (SGA) are at a greater risk of hypertension though the inverse relation between excessive birth weight and the risk of primary hypertension in children is discussed less frequently.

PURPOSE

To assess the impact of both birth weight and length on hypertension occurring in children aged 3-15 years.

METHODS

A total of 1000 children attending randomly selected primary schools and kindergartens were examined. Ultimately, the analyses took into account n = 747 children aged 4-15; 52.6% boys and 47.4% girls. The children's body height and weight were measured; their blood pressure was examined using the oscillometric method. Information on perinatal measurements was retrieved from the children's personal health records.

RESULTS

Compared to the children with small for gestational age (SGA) birth weight, the children with appropriate for gestational age birth weight (AGA) (odds ratio (OR) 1.31; 95% confidence interval (CI) 0.64-2.65) present greater risk for primary hypertension. Infants born with excessive body weight >4000 g irrespective of gestational age, compared to infants born with normal body weight, show increased risk of primary hypertension (OR 1.19; 95% CI 0.68-2.06). Higher risk of hypertension is observed in infants born with greater body length (OR 1.03; 95% CI 0.97-1.08).

CONCLUSIONS

The problem of hypertension may also affect children with birth weight appropriate for gestational age. The prevalence of hypertension in children with AGA birth weight decreases with age. Birth length can be a potential risk factor for hypertension in children and adolescents.

Low Birthweight Is Associated with Higher Risk of High Blood Pressure in Chinese Girls: Results from a National Cross-Sectional Study in China

Objective: To investigate the relationship between low birthweight (LBW) and blood pressure and to assess whether LBW leads to a higher risk of high blood pressure (HBP) by gender in Chinese students aged 6–18 years. Also, to investigate whether the association was affected by childhood obesity. Methods: Data was obtained from a baseline dataset of a national school-based program. Anthropometric parameters, including height, weight, and blood pressure, were measured, while birthweight and other characteristics were obtained from questionnaires. Stratified chi-squared tests were used to compare the prevalence of HBP between LBW and normal birthweight (NBW) groups in each age and sex category. Multivariable logistic regressions were conducted to estimate the HBP risks in each birthweight group. Results: Both systolic and diastolic blood pressure showed a U-shaped relationship with increased birthweight. Compared to NBW groups, LBW girls showed a higher HBP risk, with an odds ratio of 1.29 (95% confidence interval (CI): 1.02, 1.64, p = 0.033), regardless of their current body mass index status, while no significant association in boys was found. Conclusions: Low birthweight is associated with higher HBP risk in adolescent girls, regardless of their childhood BMI status.

Prenatal diagnosis and management of homozygous hemoglobin constant spring disease

OBJECTIVE

To describe fetal management of homozygous hemoglobin constant spring (Hb CS).

METHODS

Six fetuses with homozygous Hb CS disease undergoing intrauterine transfusion (IUT) were comprehensively reviewed. Additionally, when combined with 8 cases previously reported, a total of 14 cases were analyzed.

RESULTS

The first clues of diagnosis were hydropic changes suggesting fetal anemia. Increased cardiothoracic diameter ratio (CTR) was the most sensitive sonographic marker but slowly changed after IUT, whereas MCA-PSV was the most sensitive in response to IUT. Pre-IUT Hb varied from 1.1% to 6.8%. Gestational age at diagnosis was 17-29 (22.8 ± 3.3) weeks. Rates of adverse obstetric outcomes were relatively high; preterm birth: 35.7%, low birthweight: 42.9%, and fetal growth restriction: 28.6%. All showed good response to IUT with disappearance of hydropic signs and all survived without short-term complications. Their anemia gradually improved in childhood and transfusion independent.

CONCLUSION

Homozygous Hb CS can cause severe fetal anemia. Early diagnosis and IUT can improve neonatal outcomes, probably preventing adult diseases caused by fetal programming.

Effect of passive exposure to cigarette smoke on blood pressure in children and adolescents: a meta-analysis of epidemiologic studies

Background

Hypertension is an emerging disease in children and adolescents resulting in future morbidities. Cigarette smoking is one of the most studied contributing factors in this regard; however, there are contradictory results among different studies. Therefore, the present meta-analysis tends to assess the relationship between passive exposure to cigarette smoke and blood pressure in children and adolescents.

Method

Medline, Embase, Scopus, EBSCO, and Web of Sciences were systematically reviewed for observational studies up to May, 2017, in which the relationship between cigarette smoking and hypertension were assessed in children and adolescents. The meta-analysis was performed with a fixed effect or random effects model according to the heterogeneity.

Results

Twenty-nine studies were included in present meta-analysis incorporating 192,067 children and adolescents. Active smoking (pooled OR = 0.92; 95% CI: 0.79 to 1.05) or passive exposure to cigarette smoke (pooled OR = 1.01; 95% CI: 0.93 to 1.10) were not associated with developing hypertension in the study population. Despite the fact that active cigarette smoking did not significantly affect absolute level of systolic and diastolic blood pressure, it was shown that passive exposure to cigarette smoke leads to a significant increase in absolute level of systolic blood pressure (pooled coefficient = 0.26; 95% CI: 0.12 to 0.39).

Conclusion

Both active and passive cigarette smoking were not associated with developing hypertension in children and adolescents. However, passive cigarette smoke was associated with higher level of systolic blood pressure in children and adolescents.

Neonatal hypertension: cases, causes, and clinical approach

Neonatal hypertension is increasingly recognized as dramatic improvements in neonatal intensive care, advancements in our understanding of neonatal physiology, and implementation of new therapies have led to improved survival of premature infants. A variety of factors appear to be important in determining blood pressure in neonates, including gestational age, birth weight, and postmenstrual age. Normative data on neonatal blood pressure values remain limited. The cause of hypertension in an affected neonate is often identified with careful diagnostic evaluation, with the most common causes being umbilical catheter-associated thrombosis, renal parenchymal disease, and chronic lung disease. Clinical expertise may need to be relied upon to decide the best approach to treatment in such patients, as data on the use of antihypertensive medications in this age group are extremely limited. Available data suggest that long-term outcomes are usually good, with resolution of hypertension in most infants. In this review, we will take a case-based approach to illustrate these concepts and to point out important evidence gaps that need to be addressed so that management of neonatal hypertension may be improved.

Developmental origins of nonalcoholic fatty liver disease as a risk factor for exaggerated metabolic and cardiovascular-renal disease

Intrauterine growth restriction (IUGR) is linked to increased risk for chronic disease. Placental ischemia and insufficiency in the mother are implicated in predisposing IUGR offspring to metabolic dysfunction, including hypertension, insulin resistance, abnormalities in glucose homeostasis, and nonalcoholic fatty liver disease (NAFLD). It is unclear whether these metabolic disturbances contribute to the developmental origins of exaggerated cardiovascular-renal disease (CVRD) risk accompanying IUGR. IUGR impacts the pancreas, adipose tissue, and liver, which are hypothesized to program for hepatic insulin resistance and subsequent NAFLD. NAFLD is projected to become the major cause of chronic liver disease and contributor to uncontrolled type 2 diabetes mellitus, which is a leading cause of chronic kidney disease. While NAFLD is increased in experimental models of IUGR, lacking is a full comprehension of the mechanisms responsible for programming of NAFLD and whether this potentiates susceptibility to liver injury. The use of well-established and clinically relevant rodent models, which mimic the clinical characteristics of IUGR, metabolic disturbances, and increased blood pressure in the offspring, will permit investigation into mechanisms linking adverse influences during early life and later chronic health. The purpose of this review is to propose mechanisms, including those proinflammatory in nature, whereby IUGR exacerbates the pathogenesis of NAFLD and how these adverse programmed outcomes contribute to exaggerated CVRD risk. Understanding the etiology of the developmental origins of chronic disease will allow investigators to uncover treatment strategies to intervene in the mother and her offspring to halt the increasing prevalence of metabolic dysfunction and CVRD.

Dose-response relationship between maternal blood pressure in pregnancy and risk of adverse birth outcomes: Ma'anshan birth cohort study

OBJECTIVES

This study depicts the dose-response relationship between blood pressure (BP) during pregnancy and adverse birth outcomes in different trimesters.

STUDY DESIGN

We used restricted cubic spline to quantify the dose-response relationship between maternal BP in different trimesters and risk of adverse birth outcomes (small for gestational age, SGA; and pre-term birth, PTB). The data were from the Ma'anshan birth cohort study in China (N = 3273).

MAIN OUTCOME MEASURES

Risk of SGA and PTB.

RESULTS

There were dose-response associations of both systolic blood pressure (SBP) and diastolic blood pressure (DBP) with risk of SGA in the third trimester and with PTB in both second and third trimesters. In the third trimester, compared with SBP of 120 mmHg, the odds ratios (ORs) and 95% confidence intervals (CI) of SGA were 1.12 (1.01-1.19), 1.32 (1.10-1.60), 1.65 (1.20-2.27) and 2.05 (1.30-3.24) for SBP of 125, 130, 135 and 140 mmHg, respectively. The corresponding ORs and 95% CIs of PTB were 1.15 (1.00-1.32), 1.59 (1.28-1.98), 2.35 (1.66-3.33) and 3.47 (2.10-5.73), respectively. Compared with DBP of 70 mmHg, the ORs and 95% CIs of SGA were 1.44 (1.16-1.78) and 3.04 (2.06-4.50) for DBP of 80 and 90 mmHg, respectively. The corresponding ORs and 95% CIs of PTB were 1.32 (0.93-1.90) and 3.58 (2.21-5.78), respectively.

CONCLUSIONS

A consistent set of dose-response relationships between maternal BP and adverse birth outcomes were observed. Most importantly, we found that moderately elevated maternal BP, even within a normal range, increased the risk of adverse birth outcomes.

Are preterm-born survivors at risk of long-term respiratory disease?

BACKGROUND

To evaluate the long-term impact of preterm birth on respiratory function in female patients born preterm, we undertook spirometric examinations twice, as they reached the age of puberty, then follow-up examinations of part of the same cohort in adulthood. We sought evidence that preterm birth is correlated with poorer spirometric results into adulthood.

METHODS

A total of 70 girls (aged 12.2 ± 1.5 years in 1997) who had been born preterm (at 34.7 ± 1.86 weeks, none having experienced bronchopulmonary dysplasia) took part in spriometric examinations in 1997 and again in 1998. Of those, after a gap of 17 years, a group of 12 were successfully recontacted and participated in the 2015 examination as adults (then aged 27.6 ± 2.6 years, born at 34.5 ± 1.92 weeks). We compared spirometric results across the adolescent and adult examinations, and compared the adult results with an adult reference group.

RESULTS

The percentage values of FEV1 (forced expiratory volume in 1 s), FVC (forced vital capacity) and MVV (maximal voluntary ventilation) showed significant improvement between the two examinations in the early adolescent period. In adulthood, FEV1%pred (percentage predicted forced expiratory volume in 1 s) showed no statistically significant difference. The mean values of both FVC and FVC%pred (percentage predicted forced vital capacity) for the preterm-born group were lower than for the reference group, but this was not statistically significant. The preterm-born group showed lower values of such parameters as forced expiratory flow at 25-75% of FVC, MEF25 (maximal expiratory flow at 25% of forced vital capacity) and FEV1/FVC as compared with the reference group, but again without statistical significance.

CONCLUSIONS

(1) A somewhat below-norm level of respiratory parameters among preterm-born girls entering pubescence may attest to continued negative impact on their respiratory system. (2) A significant improvement in their spirometric results 1 year later may indicate that pubescence helps compensate for the earlier negative effect of preterm birth. (3) No significant differences were seen in lung function in preterm-born adults as compared with a reference group of adults, although the preterm-born group did exhibit lower values of all parameters studied and more frequent obstructive disorders.

Pregnancy as a critical window for blood pressure regulation in mother and child: programming and reprogramming

Pregnancy is a critical time for long-term blood pressure regulation in both mother and child. Pregnancies complicated by placental insufficiency, resulting in pre-eclampsia and intrauterine growth restriction, are associated with a threefold increased risk of the mother to develop hypertension later in life. In addition, these complications create an adverse intrauterine environment, which programmes the foetus and the second generation to develop hypertension in adult life. Female offspring born to a pregnancy complicated by placental insufficiency are at risk for pregnancy complications during their own pregnancies as well, resulting in a vicious circle with programmed risk for hypertension passing from generation to generation. Here, we review the epidemiology and mechanisms leading to the altered programming of blood pressure trajectories after pregnancies complicated by placental insufficiency. Although the underlying mechanisms leading to hypertension remain the subject of investigation, several abnormalities in angiotensin sensitivity, sodium handling, sympathetic activity, endothelial function and metabolic pathways are found in the mother after exposure to placental insufficiency. In the child, epigenetic modifications and disrupted organ development play a crucial role in programming of hypertension. We emphasize that pregnancy can be viewed as a window of opportunity to improve long-term cardiovascular health of both mother and child, and outline potential gains expected of improved preconceptional, perinatal and post-natal care to reduce the development of hypertension and the burden of cardiovascular disease later in life. Perinatal therapies aimed at reprogramming hypertension are a promising strategy to break the vicious circle of intergenerational programming of hypertension.

The Neonatal Research Network: History since 2003, future directions and challenges

The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neontal Research Network (NRN) was established in 1986 in response to the need for rigorous studies to guide care and management of sick and premature newborns. The network is comprise of clinical centers that perform clinical protocols to investigate the safety and efficay of treatment and management strategies for newborn infants as well as a data cordinating center. Infrastructure is set up for observational and interventional studies as well as neurodevelopmental follow-up of patients. The network has conducted trials and observational studies on major neonatal problems including pulmonary disease, neuroprotection, sepsis and infection, necrotizing enterocolitis, vaccine administration to preterm infants, retinopathy of prematurity, cardiovascular issues including blood pressure, human milk, growth and nutrition, hematologic issues, resuscitation, pulmonary hypertension, and neurodevelopmental outcome. This mechanism of clinical research for newborns has led to changes in care practices leading to improved outcomes for high-risk infants.

Blood Pressure Profile in the 7th and 11th Year of Life in Children Born Prematurely

Background

Several research trials have analyzed the impact of prematurity on the prevalence of hypertension (HT). However, prospective long-term studies are lacking.

Objectives

The aim of this study was to evaluate the prevalence of HT at the age of 7 and 11 years in a regional cohort of preterm infants with a birth weight of ≤ 1000 g.

Patients and Methods

This study included 67 children with a birth weight of ≤ 1000 g who were born in Malopolska between September 2002 and August 2004. The control group consisted of 38 children born at term, matched for age. Each child underwent 24-h ambulatory blood pressure measurement (ABPM) twice, once at the age of 7 and again at 11 years. The presence of HT was estimated according to the mean arterial pressure (MAP) and a number of individual measurements.

Results

At aged 7 years, preterm infants had a significantly higher incidence of HT, defined on the basis of MAP (15% vs. 0%; P < 0.02) and on the percent of individual measurements (56% vs. 33%, P < 0.036). After taking into account the group of patients who received anti-HT treatment after the first part of the study, the incidence of HT at the age of 11 years based on MAP was 19% vs. 10%. Based on the individual measurements, it was 36.5% in the preterm infants vs. 24% in the control group. The differences were not statistically significant. At both time points, the preterm group had a higher mean heart rate (HR) than the control group.

Conclusions

Children born prematurely are predisposed to HT in later life, in addition to the persistence of an increased HR.

Glucocorticoid-induced fetal origins of adult hypertension: Association with epigenetic events

Hypertension is a predominant risk factor for cardiovascular diseases and a major health care burden. Accumulating epidemiological and experimental evidence suggest that adult-onset hypertension may have its origins during early development. Upon exposure to glucocorticoids, the fetus develops hypertension, and the offspring may be programmed to continue the hypertensive trajectory into adulthood. Elevated oxidative stress and deranged nitric oxide system are not only hallmarks of adult hypertension but are also observed earlier in life. Endothelial dysfunction and remodeling of the vasculature, which are robustly associated with increased incidence of hypertension, are likely to have been pre-programmed during fetal life. Apparently, genomic, non-genomic, and epigenomic factors play a significant role in the development of hypertension, including glucocorticoid-driven effects on blood pressure. In this review, we discuss the involvement of the aforementioned participants in the pathophysiology of hypertension and suggest therapeutic opportunities for targeting epigenome modifiers, potentially for personalized medicine.

Influence of breastfeeding and postnatal nutrition on cardiovascular remodeling induced by fetal growth restriction

BACKGROUND

Our aim was to determine the influence of breastfeeding and postnatal nutrition on cardiovascular remodeling induced by fetal growth restriction (FGR).

METHODS

A cohort study including 81 children with birthweight <10th centile (FGR) and 121 with adequate fetal growth for gestational age (AGA) was conducted. Cardiovascular endpoints were left ventricular sphericity index (LVSI), carotid intima-media thickness (cIMT), and blood pressure (BP) at 4-5 y of age. The combined effect of FGR and postnatal variables-including breastfeeding, fat dietary intake, and BMI-on cardiovascular endpoints was assessed by linear and robust regressions.

RESULTS

FGR was the strongest predictor of cardiovascular remodeling in childhood, leading to lower LVSI and increased cIMT and BP as compared with AGA. Breastfeeding >6 mo (coefficient: 0.0982) and healthy-fat dietary intake (coefficient: -0.0128) showed an independent beneficial effect on LVSI and cIMT, respectively. Overweight/obesity induced an additional increment of 1 SD on cIMT in FGR children (interaction coefficient: 0.0307) when compared with its effect in AGA. BMI increased systolic BP (coefficient: 0.7830) while weight catch-up increased diastolic BP (coefficient: 4.8929).

CONCLUSIONS

Postnatal nutrition ameliorates cardiovascular remodeling induced by FGR. Breastfeeding and healthy-fat dietary intake improved while increased BMI worsened cardiovascular endpoints, which opens opportunities for targeted postnatal interventions from early life.

Intra-uterine growth restriction as a risk factor for hypertension in children six to 10 years old

Introduction

Intra-uterine growth restriction (IUGR) is present in about 3–10% of live-born newborns and it is as high as 20–30% in developing countries. Since the 1990s, it has been known that abnormalities during foetal growth may result in cardiovascular disease, including hypertension in adulthood.

Methods

This study evaluated blood pressure parameters (using ambulatory blood pressure monitoring) in children aged six to 10 years old, born as small for gestational age (SGA), and compared them to their healthy peers born as appropriate for gestational age (AGA).

Results

In the SGA group, an abnormal blood pressure level (prehypertension or hypertension) was present significantly more often than in the AGA group (50 vs 16%, p < 0.01). This relationship also occurred in association with the type of IUGR (asymmetric p < 0.01, symmetric p < 0.05).

Conclusion

In SGA children, abnormal blood pressure values occurred more frequently than in AGA children.

Circulating insulin-like growth factor-binding protein 3 levels, independent of insulin-like growth factor 1, associate with truncal fat and systolic blood pressure in South Asian and white European preschool children

AIMS

To study the effect of the insulin-like growth factor (IGF) system on growth, adiposity and systolic blood pressure (SBP) in early life in British-born South Asian (SA) and White European (WE) children.

METHODS

The effect of IGF-1 and insulin-like growth factor-binding protein 3 (IGFBP-3) over the first 4 years in 204 healthy SA and WE children was investigated by mixed linear regression modelling. This enabled inclusion of all follow-up observations and adjustment for repeated measures.

RESULTS

At birth, SA babies were shorter and lighter than WE babies. Over 4 years, SA ethnicity was associated with lower height, weight and body mass index (BMI) standard deviation score (SDS), higher subscapular/triceps skinfold thickness (Ss/Tr SFT) and lower SBP (all p < 0.01). IGF-1 was associated with greater height (p = 0.03), weight (p < 0.001) and BMI SDS (p < 0.001), and IGFBP-3 with greater weight SDS (p < 0.001), BMI SDS (p = 0.001), Ss/Tr SFT (p = 0.003) and SBP (p = 0.023).

CONCLUSIONS

Over this first 4-year period of life, SA ethnicity was associated with being shorter, lighter, having more superficial truncal adiposity and lower SBP. IGFBP-3 (and not IGF-1) was independently associated with both superficial truncal adiposity and SBP, suggesting that IGFBP-3 is a potential metabolic and cardiovascular marker in healthy children in the early years of life.

Short- and long-term effects of a maternal low-protein diet on ventilation, O₂/CO₂ chemoreception and arterial blood pressure in male rat offspring

Maternal undernutrition increases the risk of adult arterial hypertension. The present study investigated the short- and long-term effects of a maternal low-protein diet on respiratory rhythm, O₂/CO₂ chemosensitivity and arterial blood pressure (ABP) of the offspring. Male Wistar rats were divided into two groups according to their mothers' diets during gestation and lactation: control (NP, 17% of casein) and low-protein (LP, 8% of casein) groups. Direct measurements of ABP, respiratory frequency (RF), tidal volume (V T) and ventilation (VE), as well as hypercapnia (7% CO₂) and hypoxia (7% O₂) evoked respiratory responses were recorded from the awake male offspring at the 30th and 90th days of life. Blood samples were collected for the analyses of protein, creatinine and urea concentrations. The LP offspring had impaired body weight and length throughout the experiment. At 30 d of age, the LP rats showed a reduction in the concentrations of total serum protein (approximately 24%). ABP in the LP rats was similar to that in the NP rats at 30 d of age, but it was 20% higher at 90 d of age. With respect to ventilatory parameters, the LP rats showed enhanced RF (approximately 34%) and VE (approximately 34%) at 30 d of age, which was associated with increased ventilatory responses to hypercapnia (approximately 21% in VE) and hypoxia (approximately 82% in VE). At 90 d of age, the VE values and CO₂/O₂ chemosensitivity of the LP rats were restored to the control range, but the RF values remained elevated. The present data show that a perinatal LP diet alters respiratory rhythm and O₂/CO₂ chemosensitivity at early ages, which may be a predisposing factor for increased ABP at adulthood.

Aorta structural alterations in term neonates: the role of birth and maternal characteristics

AIM

To evaluate the influence of selected maternal and neonatal characteristics on aorta walls in term, appropriately grown-for-gestational age newborns.

METHODS

Age, parity, previous abortions, weight, height, body mass index before and after delivery, smoking, and history of hypertension, of diabetes, of cardiovascular diseases, and of dyslipidemia were all assessed in seventy mothers. They delivered 34 males and 36 females healthy term newborns who underwent ultrasound evaluation of the anteroposterior infrarenal abdominal aorta diameter (APAO), biochemical profile (glucose, insulin, total cholesterol, HDL and LDL cholesterol, triglycerides, fibrinogen, and D-dimers homeostasis model assessment [HOMAIR]index), and biometric parameters.

RESULTS

APAO was related to newborn length (r = +0.36; P = 0.001), head circumference (r = +0.37; P = 0.001), gestational age (r = +0.40, P = 0.0005), HOMA index (r = +0.24; P = 0.04), and D-dimers (r = +0.33, P = 0.004). Smoke influenced APAO values (odds ratio: 1.80; confidence interval 95%: 1.05-3.30), as well as diabetes during pregnancy (r = +0.42, P = 0.0002). Maternal height influenced neonatal APAO (r = +0.47, P = 0.00003). Multiple regression analysis outlined neonatal D-dimers as still significantly related to neonatal APAO values.

CONCLUSIONS

Many maternal and neonatal characteristics could influence aorta structures. Neonatal D-dimers are independently related to APAO.

Aorta structural alterations in term neonates: the role of birth and maternal characteristics

Aim. To evaluate the influence of selected maternal and neonatal characteristics on aorta walls in term, appropriately grown-for-gestational age newborns. Methods. Age, parity, previous abortions, weight, height, body mass index before and after delivery, smoking, and history of hypertension, of diabetes, of cardiovascular diseases, and of dyslipidemia were all assessed in seventy mothers. They delivered 34 males and 36 females healthy term newborns who underwent ultrasound evaluation of the anteroposterior infrarenal abdominal aorta diameter (APAO), biochemical profile (glucose, insulin, total cholesterol, HDL and LDL cholesterol, triglycerides, fibrinogen, and D-dimers homeostasis model assessment [HOMA_IR]index), and biometric parameters. Results. APAO was related to newborn length (r = +0.36; P = 0.001), head circumference (r = +0.37; P = 0.001), gestational age (r = +0.40, P = 0.0005), HOMA index (r = +0.24; P = 0.04), and D-dimers (r = +0.33, P = 0.004). Smoke influenced APAO values (odds ratio: 1.80; confidence interval 95%: 1.05–3.30), as well as diabetes during pregnancy (r = +0.42, P = 0.0002). Maternal height influenced neonatal APAO (r = +0.47, P = 0.00003). Multiple regression analysis outlined neonatal D-dimers as still significantly related to neonatal APAO values. Conclusions. Many maternal and neonatal characteristics could influence aorta structures. Neonatal D-dimers are independently related to APAO.

Outcomes of small for gestational age infants born at <27 weeks' gestation

OBJECTIVE

To determine whether small for gestational age (SGA) infants born at <27 weeks gestational age (GA) are at increased risk for mortality, morbidity, and growth and neurodevelopmental impairment at 18-22 months corrected age.

STUDY DESIGN

This was a retrospective cohort study from National Institute of Child Health and Human Development Neonatal Research Network's Generic Database and Follow-Up Studies. Infants born at <27 weeks GA between January 2006 and July 2008 were included. SGA was defined as birth weight <10th percentile for GA based on Olsen growth curves. Infants with birth weight ≥ 10th percentile for GA were classified as non-SGA. Maternal and infant characteristics, neonatal outcomes, and neurodevelopmental data were compared in SGA and non-SGA infants. Neurodevelopmental impairment was defined as any of the following: cognitive score <70 on the Bayley Scales of Infant Development III, moderate or severe cerebral palsy, bilateral hearing loss (with and without amplification), or blindness (bilateral vision <20/200). Logistic regression analysis was applied to evaluate the associations between SGA status and death or neurodevelopmental impairment.

RESULTS

The SGA group comprised 385 infants; the non-SGA group, 2586 infants. Compared with mothers of non-SGA infants, mothers of SGA infants were more likely to have a high school education, prenatal care, cesarean delivery, pregnancy-induced hypertension, and antenatal corticosteroid exposure. Compared with non-SGA infants, SGA infants had higher mortality and were more likely to have postnatal growth failure, prolonged mechanical ventilation, and postnatal steroid use. SGA status was associated with increased risk of death or neurodevelopmental impairment (OR, 3.91; 95% CI, 2.91-5.25; P < .001).

CONCLUSION

SGA status in infants born at <27 weeks GA is associated with an increased likelihood of postnatal steroid use, mortality, growth failure, and neurodevelopmental impairment at 18-22 months corrected age.

Birth weight and childhood blood pressure

A large body of literature suggests an inverse relationship between birth weight and blood pressure in children, adolescents and adults. The most persistent findings have been observed in children with a history of low birth weight or intrauterine growth restriction, while a large number of studies carried out in populations with normally distributed birth weight have shown conflicting results. A recently reported strong direct association between high birth weight and blood pressure, and the significant positive effect of postnatal growth on blood pressure suggests that the fetal origins of adult disease hypothesis should be expanded to include the role of excessive fetal and postnatal growth. In this paper, we review recent studies on the relationship between birth weight and blood pressure in childhood, with a focus on confounding variables that may explain the conflicting results of published work in this field.

Low birth weight and end-stage renal disease: demographic analysis by region in Japan

BACKGROUND We have previously shown regional differences in the incidence of end-stage renal disease (ESRD)within Japan, which is ethnically homogenous, suggesting that non-genetic factors may contribute to the differences.We examined regional distribution in the incidence of low birth weight (LBW), a surrogate for low nephron number,in our search for an explanation.

METHODS

Each year, the Ministry of Health, Labour and Welfare of Japan and the Japanese Society for Dialysis Therapy report the number of LBW babies and patients initiating maintenance dialysis in each prefecture of Japan,respectively. In this study, we calculated the annual incidences of LBW and ESRD in 11 regions of Japan over a 24-year period from 1984 to 2007.

RESULTS

There were distinct regional differences in the annual incidences of both LBW and ESRD (p<0.0001).These regional distributions persisted despite consistent increases (p<0.0001) in incidences of both LBW and ESRD during the study period. Compared with the reference group consisting of 3 regions with the lowest LBW incidence, the odds ratios for ESRD (95% confidence interval) of the 5 regions with intermediate LBW incidence and the 3 regions with the highest LBW incidence are 1.09(1.05–1.14) and 1.29 (1.22–1.35), respectively. The annual incidence of LBW was positively correlated with annual incidence of ESRD in their regional distribution across 11 regions (r = 0.66, p = 0.03).

CONCLUSIONS

The present study, relating regional distribution between LBW and ESRD dynamics in a nationwide population of Japan, revealed that the marked regional differences in the incidence of ESRD within Japan could be explained by a similar regional distribution in the incidence of LBW.

Commentary on the symposium: biological embedding, life course development, and the emergence of a new science

A new science of human development is emerging, which has the capacity to transform the way we understand the origins of health and disease; to increase the public health significance of early child development; and to call into question how and when society should act on a range of health problems. It builds on the multidisciplinary evidence that social environments and experiences during sensitive periods in brain and biological development affect health for the balance of the life course through a process called biological embedding. Despite the fact that biological embedding has established credibility in the scientific literature, the transformative power of the new science has yet to be fully realized in policy and practice. To further this transformation, this symposium offers a public health perspective on biological embedding.

Differing attitudes toward fetal care by pediatric and maternal-fetal medicine specialists

OBJECTIVES

The expansion of pediatric-based fetal care raises questions regarding pediatric specialists' involvement in pregnancies when maternal conditions may affect pediatric outcomes. For several such conditions, we compared pediatric and obstetric specialists' attitudes regarding whether and when pediatrics consultation should be offered and their views about seeking court authorization to override maternal refusal of physician recommendations.

METHODS

We used a mail survey of 434 maternal-fetal medicine specialists (MFMs) and fetal care pediatric specialists (FCPs) (response rate: MFM, 60.9%; FCP, 54.2%).

RESULTS

FCPs were more likely than MFMs to indicate that pediatric counseling should occur before decisions regarding continuing or interrupting pregnancies complicated by maternal alcohol abuse (FCP versus MFM: 63% vs 36%), cocaine abuse (FCP versus MFM: 60% vs 32%), use of seizure medications (FCP versus MFM: 62% vs 33%), and diabetes (FCP versus MFM: 56% vs 27%) (all P < .001). For all conditions, MFMs were more than twice as likely as FCPs to think that no pediatric specialist consultation was ever necessary. FCPs were more likely to agree that seeking court interventions was appropriate for maternal refusal to enter a program to discontinue cocaine use (FCP versus MFM: 72% vs 33%), refusal of azidothymidine to prevent perinatal HIV transmission (80% vs 41%), and refusal of percutaneous transfusion for fetal anemia (62% vs 28%) (all P < .001).

CONCLUSIONS

Pediatric and obstetric specialists differ considerably regarding pediatric specialists' role in prenatal care for maternal conditions, and regarding whether to seek judicial intervention for maternal refusal of recommended treatment.

Developmental programming of hypertension and kidney disease

A growing body of evidence supports the concept that changes in the intrauterine milieu during "sensitive" periods of embryonic development or in infant diet after birth affect the developing individual, resulting in general health alterations later in life. This phenomenon is referred to as "developmental programming" or "developmental origins of health and disease." The risk of developing late-onset diseases such as hypertension, chronic kidney disease (CKD), obesity or type 2 diabetes is increased in infants born prematurely at <37 weeks of gestation or in low birth weight (LBW) infants weighing <2,500 g at birth. Both genetic and environmental events contribute to the programming of subsequent risks of CKD and hypertension in premature or LBW individuals. A number of observations suggest that susceptibility to subsequent CKD and hypertension in premature or LBW infants is mediated, at least in part, by reduced nephron endowment. The major factors influencing in utero environment that are associated with a low final nephron number include uteroplacental insufficiency, maternal low-protein diet, hyperglycemia, vitamin A deficiency, exposure to or interruption of endogenous glucocorticoids, and ethanol exposure. This paper discusses the effect of premature birth, LBW, intrauterine milieu, and infant feeding on the development of hypertension and renal disease in later life as well as examines the role of the kidney in developmental programming of hypertension and CKD.

Prematurity-related hypertension in children and adolescents

Due to the functional and structural immaturity of different organ systems, preterms have a higher rate of morbidity and mortality. The prevention and treatment of the complications of prematurity is a major challenge in perinatal health care. Recently, there have been several multicenter research trials analysing the impact of prematurity or low birth weight on the health problems of children and adolescents. Many of these studies deal with the issue of pediatric hypertension. An analysis of 15 studies conducted in the years 1998–2011, in which blood pressure values in ex-preterm children were measured, was performed. Comparison was based on several issues: measurement method, cohorts age, size, and birthweight. It has been proven that hypertension occurs more often in former preterm infants; however the etiologic pathways that cause this condition still remain unclear. Moreover, pediatric hypertension is a significant problem, because of its transformation into adult hypertension and increased cardiovascular risk later in life. Therefore it is crucial to introduce wide-spread screening and detection of elevated blood pressure, especially among prematurely born children.

Hypertension in infancy: diagnosis, management and outcome

Advances in the ability to identify, evaluate, and care for infants with hypertension, coupled with advances in the practice of Neonatology, have led to an increased awareness of hypertension in modern neonatal intensive care units. This review will present updated data on blood pressure values in neonates, with a focus on the changes that occur over the first days and weeks of life in both term and preterm infants. Optimal blood pressure measurement techniques as well as the differential diagnosis of hypertension in the neonate and older infants will be discussed. Recommendations for the optimal immediate and long-term evaluation and treatment, including potential treatment parameters, will be presented. We will also review additional information on outcome that has become available over the past decade.

Feasibility of neonatal dried blood spot retrieval amid evolving state policies (2009-2010): a Children's Oncology Group study

Dried blood spots (DBS) are collected uniformly from US newborns to test for metabolic and other disorders. Because evidence exists for prenatal origins of some diseases, DBS may provide unique prenatal exposure records. Some states retain residual DBS and permit their use in aetiological studies. The primary study aim was to assess the feasibility of obtaining residual DBS from state newborn screening programmes for paediatric and adolescent cancer patients nationwide with parental/subject consent/assent. Families of leukaemia and lymphoma patients aged ≤21 years diagnosed from 1998 to 2007 at randomly selected Children's Oncology Group institutions across the US were questioned (n = 947). Parents/guardians and patients aged ≥18 years were asked to release DBS to investigators in spring 2009. DBS were then requested from states. Overall, 299 families (32%) released DBS. Consenting/assenting patients were born in 39 US states and 46 DBS were obtained from five states; 124 DBS were unobtainable because patients were born prior to dates of state retention. State policies are rapidly evolving and there is ongoing discussion regarding DBS storage and secondary research uses. Currently, population-based DBS studies can be conducted in a limited number of states; fortunately, many have large populations to provide reasonably sized paediatric subject groups.

Blood Ferritin Levels in Pregnant Women and Prediction of the Development of Fetal Intrauterine Growth Restriction

Intrauterine growth restriction is one of the leading causes of perinatal morbidity and mortality. Prediction of intrauterine growth restriction is one of the priority tasks of perinatal protection. The purpose of this study was to evaluate the levels of serum ferritin in pregnant women, which could point to a group of patients in whom possible development of fetal growth restriction could have been expected. In this investigation, we conducted a prospective study of healthy pregnant women between 30 and 32 gestational weeks, who were estimated for ferritin values. Newborn infants of low birth weight for gestational age were recorded in 8.1%. Anemia was not present in any of the patients who delivered low birth weight babies. Ferritin serum levels in mothers of the babies with low birth weight were on average 6.42 μg/L higher than in the mothers with appropriate for gestational age babies (p<0.005). ROC analysis of newborn infants birth weight and maternal blood ferritin levels showed that blood ferritin level had good predictive value. In case the recorded maternal blood ferritin values are above 13.6 μg/L, we can assume with the sensitivity of 64.7% and specificity of 91.7%, that the pregnant woman will develop a condition of intrauterine growth restriction. The missing decrease of ferritin values, erythrocytes, hemoglobin and hematocrit in the blood of healthy pregnant women between 30 and 32 gestational weeks, can with high probability point to the development of fetal intrauterine growth restriction.

Early predictors of hypertension in prematurely born adolescents

OBJECTIVE

 To assess the blood pressure of former preterm and term matched adolescent controls and to identify risk factors associated with blood pressure at 16 years.

DESIGN

  Observational cohort study. Secondary analysis of a randomized clinical trial.

SETTING

Three academic centres participating in the Multicenter Indomethacin IVH Prevention Trial.

PARTICIPANTS

  A total of 296 children born in 1989-1992 with birth weights 600 to <1250 g who participated in the Multicenter Indomethacin IVH Prevention Trial and 95 term controls were evaluated at 16 years.

MAIN OUTCOME MEASURES

  Blood pressure and predictors of blood pressure.

RESULTS

  The adjusted mean difference in blood pressure for preterm adolescents was 5.1 mm Hg; p=0.002 for systolic and 2.1 mm Hg; p=0.027 for diastolic blood pressure. Among preterms, the primary predictors of increased systolic blood pressure were weight gain velocity between birth and 36 months (b=8.54, p<0.001), pre-eclampsia (b=5.67, p=0.020), non-white race (b=3.77, p=0.04) and male gender (b=5.09). Predictors of diastolic blood pressure were weight gain velocity between birth and 36 months (b=4.69, p=0.001), brain injury (b=6.51, p=0.002) and male gender (b=-2.4, p=0.02).

CONCLUSIONS

  Early programming secondary to increased early weight gain velocity, intrauterine stress and neonatal brain injury may all contribute to risk of increased blood pressure among former preterm adolescents.

Prenatal cocaine exposure and childhood obesity at nine years

Little is known about the association between prenatal cocaine exposure and obesity. We tested whether prenatal cocaine exposure increases the likelihood of obesity in 561 9-year-old term children from the Maternal Lifestyle Study (MLS). Overall, 21.6% of children met criterion for obesity (body mass index [BMI] ≥ 95th percentile, age and sex-specific). While there was no overall cocaine effect on obesity, multivariate logistic analysis revealed that children exposed to cocaine but not alcohol were 4 times more likely to be obese (OR 4.11, CI 2.04-9.76) than children not exposed to either drug. No increase in obesity prevalence was found in children exposed to alcohol but not cocaine (OR 1.08, CI .59-1.93) or both (OR 1.21, CI 0.66-2.22). Alcohol exposure may attenuate the effect of cocaine exposure on obesity. Increased obesity associated with cocaine but not alcohol exposure was first observed at 7 years. BMI was also elevated from 3 to 9 years in children exposed to cocaine but not alcohol, due to increasing weight but normal height. Prenatal exposure to cocaine may alter the neuroendocrine system and metabolic processes resulting in increased weight gain and childhood obesity.

No juvenile arterial hypertension in sheep multiples despite reduced nephron numbers

Low birth weight is associated with an increased risk of metabolic dysfunction and arterial hypertension in later life. Because of their reduced birth weight twins have been used repeatedly as a natural model to investigate prenatal programming of hypertension. To reveal an early impact of lower nephron endowment on blood pressure, we performed a longitudinal study on lambs from single, twin and triplet pregnancies. The lambs were studied from birth until adulthood, including regular blood analyses, measurements of body weight and blood pressure and post-mortem estimation of glomerular numbers. Relative weight differences between multiples and singletons at birth were -28% for twins and -44% for triplets, respectively. Some lambs showed rapid catch-up growth. Total nephron number of twins and triplets was reduced by 21 and 37% with respect to that of singletons (p < 0.01). However, multiples did not show increased blood pressure within the time frame of this study. No gender-specific effect was observed. Plasma concentrations of creatinine, urea, electrolytes or osmolality also did not differ. Our data indicate that the previously reported postnatal blood pressure differences between sheep multiples and singletons are a time-limited phenomenon. During infancy and adolescence, a reduced nephron number in sheep multiples is neither associated with increased blood pressure nor reflected by plasma parameters.

Prenatal cocaine exposure differentially causes vascular dysfunction in adult offspring

Epidemiological studies have shown a clear association of adverse intrauterine environment and an increased risk of cardiovascular diseases and hypertension in adult life. The present study tested the hypothesis that prenatal cocaine exposure causes reprogramming of vascular reactivity, leading to an increased risk of hypertension in adult offspring. Pregnant rats received cocaine (30 mg kg(-1) day(-1)) or saline from days 15 to 21 of gestational age, and experiments were conducted in 3-month-old offspring. Cocaine had no effect on the baseline blood pressure but significantly increased norepinephrine-stimulated blood pressure and decreased the baroreflex sensitivity in male but not female offspring. The cocaine treatment significantly increased norepinephrine-induced contractions in pressurized resistance-sized mesenteric arteries but not in aortas, which was primarily because of a loss of endothelial NO synthase-mediated inhibition and an enhanced Ca(2+) sensitivity in mesenteric arteries. In addition, the cocaine treatment significantly attenuated the endothelium-dependent relaxation in mesenteric arteries in male but not female offspring. Endothelial NO synthase protein levels in aortas but not mesenteric arteries were significantly increased in the cocaine-treated animals. However, cocaine significantly decreased phosphorylation levels of endothelial NO synthase in both aortas and mesenteric arteries. The results suggest that prenatal cocaine exposure programs vascular contractility via changes in endothelial NO synthase-regulated Ca(2+) sensitivity of myofilaments in the sex- and tissue-dependent manners in resistance arteries leading to an increased risk of hypertension in male offspring.

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

BACKGROUND

The association between low birth weight (LBW) and increased risk of obesity, hypertension and cardiovascular disease later in life is well documented in epidemiological studies. However, clinical follow-up studies of LBW populations have only partly supported this.

AIMS

Evaluate associations between LBW and body fat, blood pressure (BP), lung and endothelial function, and maximal oxygen uptake (VO(2max)) in 18 year old young adults.

SUBJECTS

Thirty-seven subjects born prematurely with birth weight <1501 g (VLBW group), 47 born at term with low weight (<10th centile) for gestational age (SGA group) and 63 controls with normal birth weight participated in the study.

OUTCOME MEASURES

Anthropometric measurements, BP, endothelial function, lung function and VO(2max) were recorded.

RESULTS

Both LBW groups were shorter, lighter, had smaller head circumference and higher subscapular-to-triceps skinfold-ratio than controls. Systolic and mean arterial BP was higher in the VLBW compared with the control group, whereas there were no differences between the groups in endothelial function. The VLBW group had reduced dynamic lung volumes lower carbon monoxide transfer factor and lower VO(2max) compared with controls. In particular young adults born VLBW who were also growth retarded in utero had higher indices of central body fat, higher BP and lower VO(2max).

CONCLUSION

We found that very preterm birth, but not growth retardation at term, was associated with higher BP and a less favourable fat distribution. In particular, the young adults born VLBW who were also growth retarded in utero had less favourable outcomes.

Does moderate preterm birth lead to altered arterial pressure? Studies in sheep

1. Low birth weight (LBW) is associated with an increased risk of cardiovascular disease. Preterm birth is a major determinant of LBW and has been shown to result in elevated arterial pressure (AP) in humans, but few studies have investigated the effects of preterm birth in the absence of potentially confounding factors. Our aim was to determine whether moderately preterm birth per se alters the postnatal development of AP in lambs. 2. Preterm lambs were delivered approximately 14 days before term (i.e. approximately 133 days of gestation); controls were born at term (approximately 147 days). Mean arterial pressure (MAP), heart rate (HR), blood composition and indices of growth were measured at 4 and 8 weeks post term-equivalent age (PTEA). We also studied a separate cohort of preterm and term sheep as young adults (approximately 1.1 years). 3. Preterm lambs had significantly lower birth weights than term lambs, but bodyweights were not significantly different by Day 12 PTEA. In addition, MAP, HR and most blood variables did not differ between term and preterm lambs at 4 or 8 weeks PTEA. Preterm birth per se did not alter MAP or HR in young adult sheep. 4. Low birth weight due to preterm birth does not result in an altered AP during early postnatal life or at maturity. Moderate intrauterine growth restriction (IUGR) due to twinning, which further reduces birth weight, does not affect MAP in preterm lambs. Other factors, such as the degree of prematurity or IUGR, exposure to corticosteroids or postnatal nutrition, may be important in the later development of elevated AP.

Fetal growth after laser therapy for twin-twin transfusion syndrome

OBJECTIVE

The objective of the study was to compare twin weight discordance and prevalence of intrauterine growth restriction (IUGR) before laser therapy and after birth in pregnancies complicated by twin-twin transfusion syndrome (TTTS).

STUDY DESIGN

Women with TTTS who underwent laser therapy with dual neonatal survivors born at least 28 days after surgery were studied. Estimated fetal weight (EFW) discordance at the preoperative sonogram and birthweight (BW) discordance were calculated. Weights below gestational age-corrected 10th percentile at sonogram and at birth for each twin were designated as IUGR.

RESULTS

Among 211 women studied, the mean EFW discordance measured 26.6% and mean BW discordance was 18.4%, yielding a mean 8.2% decrease in weight discordance (P < .001). Comparing IUGR diagnoses before surgery and at birth, the recipient's proportion was unchanged (9.5% vs 7.1%, P = .353), whereas the donor's proportion decreased (64.5% vs 28.9%, P < .001).

CONCLUSION

Twin weight discordance and donor fetus IUGR appear to improve after laser therapy for TTTS.