Risks for low intellectual performance related to being born small for gestational age are modified by gestational age

Association between prenatal exposure to per- and polyfluoroalkyl substances and infant anthropometry: A prospective cohort study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic organic chemicals with potential endocrine-disrupting effects, and have been found to impair the physical growth of offspring in both experimental and epidemiological studies. We aimed to investigate the effects of prenatal PFAS exposure on repeated measurements of multiple anthropometric indicators in infants.

METHOD

PFAS were measured in serum samples collected from pregnant women at 12-16 gestational weeks. We calculated z-scores for the weight-for-age (WAZ), weight-for-length (WLZ), head circumference-for-age (HCZ), arm circumference-for-age (ACZ), triceps skinfold-for-age (TSZ), and subscapular skinfold-for-age (SSZ) at birth, 6 months, and 12 months of age according to the child growth standards of the World Health Organization (WHO) for anthropometric indicators. A total of 964 mother-infant pairs were included. A multivariate linear regression was performed to examine the associations between prenatal PFAS concentrations and anthropometric indicators at each time point. A generalized estimating equation (GEE) model was used to examine the longitudinal effects of PFAS exposure on repeated measurements of anthropometric indicators. Ultimately, a Bayesian kernel machine regression (BKMR) model was used to assess the joint effects of the PFAS mixture on anthropometric indicators.

RESULTS

In GEE models, perfluorododecanoic acid (PFDoA) in the high tertile group was associated with increased WAZ/WLZ, with β values (95% confidence intervals (CI)) of 0.12 (0.00, 0.23) and 0.18 (0.03, 0.32), respectively. Perfluorononanoic acid (PFNA) was associated with increased ACZ in the middle and high tertile groups. The BKMR models also presented the associations of the PFAS mixture with increased WAZ/WLZ throughout infancy, with more profound effects in females. Meanwhile, a pattern of inverse associations was observed between the perfluorooctanoic acid (PFOA) concentrations in the high tertile group and decreased WAZ, WLZ, and HCZ in males. In addition, the associations between PFAS and increased TSZ/SSZ at birth were identified by both linear regression and BKMR models.

CONCLUSION

Prenatal PFAS exposure (PFNA and PFDoA) was associated with increased infant anthropometry, especially in female infants, while prenatal PFOA exposure was associated with decreased weight, and head and arm circumference in male infants. The findings indicate that prenatal PFAS exposure may impair the growth trajectory of offspring.

Neurodevelopment and physical measurements in infants with birthweight of 500 grams or less

BACKGROUND

In infants born weighing ≤500 g, little has been studied about the association between neurodevelopmental prognosis and growth. This study aimed to evaluate the association between neurodevelopmental impairment (NDI) and z-scores of physical measurements in infants born weighing ≤500 g.

METHODS

A single-center, retrospective cohort study in a level IV neonatal intensive care unit in Japan. Infants born weighing ≤500 g between 2010 and 2019 were eligible. Z-scores in weight, length/height, and head circumference at birth, due date (or discharge), 6 and 18 months of corrected age, and 3 years of age were compared between infants with and without NDI at 3 years of age. Three infants with severe intraventricular hemorrhage or periventricular leukomalacia were excluded from the comparison analyses. NDI was defined as having a developmental quotient of ≤70, cerebral palsy, visual impairment, or hearing impairment.

RESULTS

Of 22 eligible infants, the incidence of NDI at 3 years of age was 54.5%. The z-score was significantly smaller in the NDI group (n = 10) than that in the non-NDI group (n = 9) in head circumference at birth (median, -1.94 vs. -0.75; Z = 0.54; p = 0.020), and in height at 18 months of corrected age (median, -2.84 vs. -1.79; Z = 0.58; p = 0.013) and 3 years of age (median, -2.02 vs. -1.21; Z = 0.47; p = 0.046).

CONCLUSIONS

NDI at 3 years of age was associated with a small head circumference z-score at birth, height at 18 months of corrected age, and height at 3 years of age in infants born weighing ≤500 g.

High level of γH2AX phosphorylation in the cord-blood cells of large-for-gestational-age (LGA) newborns

Newborns can experience adverse effects as a consequence of maternal or in utero exposure, altered growth of the fetus, or placental dysfunctions. Accurate characterization of gestational age allows monitoring of fetal growth, identification of deviations from the normal growth trajectory, and classification of babies as adapted, small, or large for gestational age (AGA, SGA, or LGA). The aim of this work was to evaluate nuclear and oxidative damage in umbilical cord-blood cells of newborns (sampled at birth), by applying the γH2AX assay and the fluorescent probe BODIPY^581/591 C¹¹, to detect DNA DSB and cell membrane oxidation, respectively. No statistically significant differences were observed in the proportion of oxidized cord-blood cells among the groups of newborns, although the LGA group showed the highest value. With regard to genome damage, elevated levels of γH2AX foci were detected in the cell nuclei from LGA newborns as compared to AGA or SGA babies, whose values did not differ from each other. Considering that the observed DNA damage, although still repairable, can represent a risk factor for obesity, metabolic diseases, or other pathologies, monitoring genome and cell integrity at birth can provide useful information for prevention of diseases later in life.

Perinatal factors influence on the neurocognitive development of children born small for gestational age (SGA) during the first 2 years of life

BACKGROUND AND OBJECTIVE

Children born small for gestational age (SGA) show higher risk of neurodevelopmental and cognitive abnormalities. The objective of this study is to determine in children born SGA the neurodevelopment during the first 2 years of life and to establish the influence of anthropometric data, gestational age, multiple gestation and perinatal factors.

PATIENTS AND METHOD

Observational, prospective, descriptive and analytical study of the neurocognitive assessment performed, with Brunet-Lézine test, on SGA children (n = 91) from 3 to 24 months of age, comparing with own controls.

RESULTS

Ninety-one SGA children, 47% girls, 83.5% single pregnancies; mean gestational age 37.7 weeks (standard deviation (SD) 2.1). Weight at birth 2053 g (SD 433.1), length 43.9 cm (SD 2.6) and head circumference 31.7 cm (SD 1.7). The SGA population shows significantly lower neurodevelopment than the control population, with a tendency to improve during the first 2 years of life. There are no differences by sex. SGA children born to multiple gestations have lower neurodevelopment only during the first year of life. There is a direct and positive correlation between weight, length and head circumference with neurocognitive development at 6, 9, 12 and 18 months. Gestational age correlated with better neurodevelopment at 3 and 6 months.

CONCLUSIONS

Children born SGA present lower neurodevelopment than the control population. A greater impact on weight, length, and head circumference at birth is correlated with poorer neurocognitive development. Multiparity does not show significant influence on neurodevelopment evolution.

Perinatal factors influence on the neurocognitive development of children born small for gestational age (SGA) during the first 2 years of life

BACKGROUND AND OBJECTIVE

Children born small for gestational age (SGA) show higher risk of neurodevelopmental and cognitive abnormalities. The objective of this study is to determine in children born SGA the neurodevelopment during the first 2 years of life and to establish the influence of anthropometric data, gestational age, multiple gestation and perinatal factors.

PATIENTS AND METHOD

Observational, prospective, descriptive and analytical study of the neurocognitive assessment performed, with Brunet-Lézine test, on SGA children (n=91) from 3 to 24 months of age, comparing with own controls.

RESULTS

Ninety-one SGA children, 47% girls, 83.5% single pregnancies; mean gestational age 37.7 weeks (standard deviation [SD] 2.1). Weight at birth 2,053g (SD 433.1), length 43.9cm (SD 2.6) and head circumference 31.7cm (SD 1.7). The SGA population shows significantly lower neurodevelopment than the control population, with a tendency to improve during the first 2 years of life. There are no differences by sex. SGA children born to multiple gestations have lower neurodevelopment only during the first year of life. There is a direct and positive correlation between weight, length and head circumference with neurocognitive development at 6, 9, 12 and 18 months. Gestational age correlated with better neurodevelopment at 3 and 6 months.

CONCLUSIONS

Children born SGA present lower neurodevelopment than the control population. A greater impact on weight, length, and head circumference at birth is correlated with poorer neurocognitive development. Multiparity does not show significant influence on neurodevelopment evolution.

Early and Long-term Consequences of Nutritional Stunting: From Childhood to Adulthood

Linear growth failure (stunting) in childhood is the most prevalent form of undernutrition globally. The debate continues as to whether children who become stunted before age 24 months can catch up in growth and cognitive functions later in their lives. The potentially irreparable physical and neurocognitive damage that accompanies stunted growth is a major obstacle to human development. This review aims at evaluation and summarizing the published research covering the different aspects of stunting from childhood to adulthood.

Establishment of a Novel Fetal Growth Restriction Model and Development of a Stem-Cell Therapy Using Umbilical Cord-Derived Mesenchymal Stromal Cells

Fetal growth restriction (FGR) is a major complication of prenatal ischemic/hypoxic exposure and affects 5%-10% of pregnancies. It causes various disorders, including neurodevelopmental disabilities due to chronic hypoxia, circulatory failure, and malnutrition via the placenta, and there is no established treatment. Therefore, the development of treatments is an urgent task. We aimed to develop a new FGR rat model with a gradual restrictive load of uterus/placental blood flow and to evaluate the treatment effect of the administration of umbilical cord-derived mesenchymal stromal cells (UC-MSCs). To create the FGR rat model, we used ameroid constrictors that had titanium on the outer wall and were composed of C-shaped casein with a notch and center hole inside that gradually narrowed upon absorbing water. The ameroid constrictors were attached to bilateral ovarian/uterine arteries on the 17th day of pregnancy to induce chronic mild ischemia, which led to FGR with over 20% bodyweight reduction. After the intravenous administration of 1 × 10⁵ UC-MSCs, we confirmed a significant improvement in the UC-MSC group in a negative geotaxis test at 1 week after birth and a rotarod treadmill test at 5 months old. In the immunobiological evaluation, the total number of neurons counted via the stereological counting method was significantly higher in the UC-MSC group than in the vehicle-treated group. These results indicate that the UC-MSCs exerted a treatment effect for neurological impairment in the FGR rats.

Head circumference at birth and school performance: a nationwide cohort study of 536,921 children

BACKGROUND

Early measures of cognitive function are of great public health interest. We aimed to estimate the association between head circumference at birth, a measure of cerebral size, and school performance.

METHODS

We conducted a nationwide cohort study of all liveborn singletons in Denmark, 1997-2005. The association between birth head circumference z score and test scores in reading and mathematics from a nationwide mandatory computer-based school test program (7-16 years) was estimated by multivariable linear regression adjusted for potential confounders.

RESULTS

The cohort included 536,921 children. Compared to normocephalic children, children with microcephaly [<-2 standard deviations (SD)] had lower mean reading scores: second grade: -0.08 SD (95% CI -0.10 to -0.06), eighth grade: -0.07 SD (95% CI -0.10 to -0.04). Macrocephaly (>+2 SD) was associated with higher scores. In normocephalic children, each SD increase in head circumference was associated with a 0.03 SD (95% CI 0.03 to 0.04) increase in mean reading scores. The results were similar across grades within both reading and mathematics.

CONCLUSION

Prenatal brain growth may be causally related to childhood school performance. The demonstrated differences are unlikely to be clinically relevant at the individual level but may be important at a public health level.

Audiovisual speech perception and language acquisition in preterm infants: A longitudinal study

BACKGROUND

Preterm infants have a higher risk of language delay throughout childhood. The ability to integrate audiovisual speech information is associated with language acquisition in term infants; however, the relation is still unclear in preterm infant.

AIM AND METHODS

This study longitudinally investigated visual preference for audiovisual congruent and incongruent speech during a preferential looking task using eye-tracking in preterm and term infants at 6, 12, and 18 months of corrected age. The infants' receptive and expressive vocabulary at 12 and 18 months were obtained by parent report, using the Japanese MacArthur Communicative Development Inventory.

RESULTS

We found that preterm infants did not clearly show visual preference for the congruent audiovisual display at any age, whereas term infants looked at the congruent audiovisual display longer than the incongruent audiovisual display at 6 and 18 months. Preterm infants' receptive and expressive vocabulary scores were lower than those of term infants at 12 and 18 months. Furthermore, the proportion of looking time toward the congruent audiovisual display at 6 months was positively correlated with receptive vocabulary scores at 12 and 18 months for both groups.

CONCLUSIONS

These findings suggest that better audiovisual speech perception abilities are one factor that results in better language acquisition in preterm as well as term infants. Early identification of behaviors associated with later language in preterm infants may contribute to planning intervention for developmental problems.

Investigating the association between post-term birth and long term cognitive, developmental and educational impacts: a systematic review and Meta-analysis

Purpose: Infants who remain in-utero after their due date are exposed to increasing risk of infection, late stillbirth and delivery complications. Much of the current literature on post-term outcomes is based on short term observations and the impacts may be substantially greater in the long term. The aim of this work is to perform a systematic review and meta-analysis to quantify the cognitive or educational impacts of post term delivery.Methods: Systematic review was performed by the two authors using Medline database (1960-2017). A title search was performed to identify likely relevant literature. Exposure terms were clarified to identify papers where the exposure was related to delivery after the infants' due date. Primary outcome was cognitive score. A quality assessment and data extraction pro forma was completed by both reviewers for all studies deemed to satisfy the inclusion and exclusion criteria. Meta-analysis used adjusted results where available. Small-study bias was assessed visually using a funnel plot and then formally tested using Egger's regression asymmetry test.Results: Medline was searched on the 4 July 2018; and produced a list of 1318 publications. Of these, 43 abstracts were screened, and of these a total of 10 full-text papers were reviewed. A further three papers were identified during this review and contributed to a total of 13 papers. The publications dated from 1969 to 2017. Two studies presented a binary outcome for cognitive measures and combined estimates found that the risk of a low cognitive score was higher in post-term infants compared to term infants (odds ratio [OR] 1.06 [1.04-1.08]). Four papers presented the association with mean cognitive measures and post-term delivery, and all demonstrated a mean reduction in scores in the post-term group. A combined estimate showed strong evidence of a reduction in cognitive scores across the four studies (-1.90 [-3.50 to -0.31]). There was little evidence of heterogeneity in the studies which reported cognitive outcomes (other p-values >.2).Conclusion: This meta-analysis has found that post term birth (>41 + 6 weeks) is associated with small but significant negative effects on cognitive outcomes when compared with delivery at, or around term. The effect, while small, is compounded by a common exposure and appears consistent in the studies identified. Less evidence was found for a measurable impact on early developmental measures or educational outcomes. This may further help inform the debate on the timing of otherwise uncomplicated pregnancies and further trials in this area.

Gestational age at birth and academic performance: population-based cohort study

Background

Numerous studies suggest pre-term birth is associated with cognitive deficit. However, less is known about cognitive outcomes following post-term birth, or the influence of weight variations within term or post-term populations. We examined associations between gestational age (GA) and school performance, by weight-for-GA, focusing on extremely pre- and post-term births.

Method

Record linkage study of Swedish children born 1973-94 ( n =  2 008 102) with a nested sibling comparison ( n =  439 629). We used restricted cubic regression splines to examine associations between GA and the grade achieved on leaving secondary education, comparing siblings to allow stronger causal inference with regard to associations between GA and school performance.

Results

Grade averages of both pre- and post-term children were below those of full-term counterparts and lower for those born small-for-GA. The adjusted grades of extremely pre-term children (at 24 completed weeks), while improving in later study periods, were lower by 0.43 standard deviations (95% confidence interval 0.38-0.49), corresponding with a 21-point reduction (19 to 24) on a 240-point scale. Reductions for extremely post-term children (at 45 completed weeks) were lesser [-0.15 standard deviation (-0.17 to -0.13) or -8 points (-9 to -7)]. Among matched siblings, we observed weaker residual effects of pre-term and post-term GA on school performance.

Conclusions

There may be independent effects of fetal maturation and fetal growth on school performance. Associations among matched siblings, although attenuated, remained consistent with causal effects of pre- and post-term birth on school performance.

Novel Detection of Placental Insufficiency by Magnetic Resonance Imaging in the Nonhuman Primate

The placenta is a vital organ necessary for healthy fetal development. Placental insufficiency creates an in utero environment where the fetus is at risk of insufficient oxygen or nutrient exchange. This is primarily caused by impairment of either maternal or fetal circulation or vascular thrombosis such as placental infarction. As a result of placental dysfunction, affected fetuses may be growth restricted, neurologically impaired, and at risk of increased morbidity and mortality. In a cohort of 4 pregnant Rhesus macaques, we describe antenatal detection of naturally occurring intrauterine growth restriction (IUGR) and aberrant fetal neurodevelopment in 1 animal. Abnormal growth parameters were detected by Doppler ultrasound, and vascular insufficiency in the intervillous space was characterized by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Furthermore, placental oxygen reserve was shown to be reduced compared to control animals by measurements of placental water T2*. To characterize the effects of IUGR on fetal brain development, T2 and diffusion anisotropy images of the fetal brain were acquired in utero. Reduced brain volume and cerebral cortical surface area were apparent macroscopically. Microstructural abnormalities within the developing white matter and cerebral cortex were also observed through analysis of water diffusion anisotropy. After delivery by cesarean section, pathological examination confirmed placental insufficiency with hypoxia. These findings exemplify how DCE-MRI and T2*-based measurements of blood oxygenation within the placenta can provide noninvasive imaging methods for assessing in vivo placental health to potentially identify pregnancies affected by placental insufficiency and abnormal fetal neurodevelopment prior to the onset of fetal and neonatal distress.

Fundamental Frequency Variation of Neonatal Spontaneous Crying Predicts Language Acquisition in Preterm and Term Infants

Spontaneous cries of infants exhibit rich melodic features (i.e., time variation of fundamental frequency [F0 ]) even during the neonatal period, and the development of these characteristics might provide an essential base for later expressive prosody in language. However, little is known about the melodic features of spontaneous cries in preterm infants, who have a higher risk of later language-related problems. Thus, the present study investigated how preterm birth influenced melodic features of spontaneous crying at term-equivalent age as well as how these melodic features related to language outcomes at 18 months of corrected age in preterm and term infants. At term, moderate-to-late preterm (MLP) infants showed spontaneous cries with significantly higher F0 variation and melody complexity than term infants, while there were no significant differences between very preterm (VP) and term infants. Furthermore, larger F0 variation within cry series at term was significantly related to better language and cognitive outcomes, particularly expressive language skills, at 18 months. On the other hand, no other melodic features at term predicted any developmental outcomes at 18 months. The present results suggest that the additional postnatal vocal experience of MLP preterm infants increased F0 variation and the complexity of spontaneous cries at term. Additionally, the increases in F0 variation may partly reflect the development of voluntary vocal control, which, in turn, contributes to expressive language in infancy.

First trimester alcohol exposure alters placental perfusion and fetal oxygen availability affecting fetal growth and development in a non-human primate model

BACKGROUND

Prenatal alcohol exposure leads to impaired fetal growth, brain development, and stillbirth. Placental impairment likely contributes to these adverse outcomes, but the mechanisms and specific vasoactive effects of alcohol that links altered placental function to impaired fetal development remain areas of active research.

OBJECTIVE

Recently, we developed magnetic resonance imaging techniques in nonhuman primates to characterize placental blood oxygenation through measurements of T2* and perfusion using dynamic contrast-enhanced magnetic resonance imaging. The objective of this study was to evaluate the effects of first-trimester alcohol exposure on macaque placental function and to characterize fetal brain development in vivo.

STUDY DESIGN

Timed-pregnant Rhesus macaques (n=12) were divided into 2 groups: control (n=6) and ethanol exposed (n=6). Animals were trained to self-administer orally either 1.5 g/kg/d of a 4% ethanol solution (equivalent to 6 drinks/d) or an isocaloric control fluid from preconception until gestational day 60 (term is G168). All animals underwent Doppler ultrasound scanning followed by magnetic resonance imaging that consisted of T2* and dynamic contrast-enhanced measurements. Doppler ultrasound scanning was used to measure uterine artery and umbilical vein velocimetry and diameter to calculate uterine artery volume blood flow and placental volume blood flow. After noninvasive imaging, animals underwent cesarean delivery for placenta collection and fetal necropsy at gestational day 110 (n=6) or 135 (n=6).

RESULTS

Fetal weight and biparietal diameter were significantly smaller in ethanol-exposed animals compared with control animals at gestational day 110. By Doppler ultrasound scanning, placental volume blood flow was significantly lower (P=.04) at gestational day 110 in ethanol-exposed vs control animals. A significant reduction in placental blood flow was evident by dynamic contrast-enhanced magnetic resonance imaging. As we demonstrated recently, T2* values vary throughout the placenta and reveal gradients in blood deoxyhemoglobin concentration that range from highly oxygenated blood (long T2*) proximal to spiral arteries to highly deoxygenated blood (short T2*). Distributions of T2*throughout the placenta show significant global reduction in T2* (and hence high blood deoxyhemoglobin concentration) in ethanol-exposed vs control animals at gestational day 110 (P=.02). Fetal brain measurements indicated impaired growth and development at gestational day 110, but less so at gestational day 135 in ethanol-exposed vs control animals.

CONCLUSION

Chronic first-trimester ethanol exposure significantly reduces placental perfusion and oxygen supply to the fetal vasculature later in pregnancy. These perturbations of placental function are associated with fetal growth impairments. However, differences between ethanol-exposed and control animals in placental function and fetal developmental outcomes were smaller at gestational day 135 than at gestational day 110. These findings are consistent with placental adaptation to early perturbations that allow for compensated placental function and maintenance of fetal growth.

Low Exercise Capacity Increases the Risk of Low Cognitive Function in Healthy Young Men Born Preterm: A Population-Based Cohort Study

BACKGROUND

Preterm birth is a risk factor for decreased exercise capacity and impaired cognitive functions in later life. The objective of this study was to disentangle the associations between preterm birth, physical fitness and cognitive performance in young adulthood.

METHODS

This population-based cohort study included 218,802 young men born in Sweden 1973-1983. Data on birth characteristics was obtained from the Medical Birth Register and linked to exercise capacity assessed by ergometer cycling and cognitive tests performed at conscription for military service in 1993-2001. Cognitive performance was assessed using stanine (STAndard NINE) scores. The results were adjusted for socioeconomic factors.

RESULTS

Exercise capacity was positively associated with cognitive performance across all gestational ages. The sub-group of men who were born extremely preterm (gestational age <28 weeks) and had low exercise capacity exhibited the lowest odds ratio (OR = 0.26, 95%CI:0.09-0.82) of having a cognitive function above the mean stanine score (2.9) for men born at term with normal birth weight. Men born extremely preterm with a high exercise capacity had similar or even higher ORs for cognitive function (OR = 0.59; 95% CI:0.35-0.99) than men born at term with low Wmax (OR = 0.57; 95% CI:0.55-0.59).

CONCLUSIONS

Physical fitness is associated with higher cognitive function at all gestational ages, also in young men born extremely preterm. Targeting early physical exercise may be a possible intervention to enhance cognitive performance and educational achievements in populations at risk, such as childhood and adult survivors of preterm birth.

Adult Behavior in Male Mice Exposed to E-Cigarette Nicotine Vapors during Late Prenatal and Early Postnatal Life

Nicotine exposure has been associated with an increased likelihood of developing attention deficit hyperactivity disorder (ADHD) in offspring of mothers who smoked during pregnancy. The goal of this study was to determine if exposure to E-cigarette nicotine vapors during late prenatal and early postnatal life altered behavior in adult mice.

Birth outcomes and background exposures to select elements, the Longitudinal Investigation of Fertility and the Environment (LIFE)

Evidence suggests that trace exposures to select elements may increase the risk for adverse birth outcomes. To investigate further, we used multiple regression to assess associations between preconception parental exposures to Pb, Cd, and total Hg in blood, and 21 elements in urine, with n=235 singleton birth outcomes, adjusted for confounders and partner's exposure. Earlier gestational age at delivery (GA) was associated with higher tertiles of urine maternal W (-1.22 days) and paternal U (-1.07 days), but GA was later for higher tertiles of maternal (+1.11 days) and paternal (+1.30 days) blood Hg. Additional analysis indicated shorter GA associated with higher paternal urine Ba, W, and U, and with higher maternal blood Pb for boys, but GA was longer in association with higher maternal urine Cr. Birth weight (BW) was lower for higher tertiles of paternal urine Cs (-237.85g), U (-187.34g), and Zn (-209.08g), and for higher continuous Cr (P=0.021). In contrast, BW was higher for higher tertiles of paternal urine As (+194.71g) and counterintuitively for maternal blood Cd (+178.52g). Birth length (BL) was shorter for higher tertiles of urine maternal W (-1.22cm) and paternal U (-1.10cm). Yet, higher tertiles of maternal (+1.11cm) and paternal (+1.30) blood Hg were associated with longer BL. Head circumference at delivery was lower for higher tertiles of paternal urine U (-0.83cm), and for higher continuous Mo in boys (-0.57cm). Overall, associations were most consistently indicated for GA and measures of birth size with urine W and U, and paternal exposures were more frequently associated than maternal. Though limited by several factors, ours is the largest multi-element investigation of prospective couple-level trace exposures and birth outcomes to date; the novel observations for W and U merit further investigation.

Advanced MR imaging of the placenta: Exploring the in utero placenta-brain connection

The placenta is a vital organ necessary for the healthy neurodevelopment of the fetus. Despite the known associations between placental dysfunction and neurologic impairment, there is a paucity of tools available to reliably assess in vivo placental health and function. Existing clinical tools for placental assessment remain insensitive in predicting and evaluating placental well-being. Advanced MRI techniques hold significant promise for the dynamic, non-invasive, real-time assessment of placental health and identification of early placental-based disorders. In this review, we summarize the available clinical tools for placental assessment, including ultrasound, Doppler, and conventional MRI. We then explore the emerging role of advanced placental MR imaging techniques for supporting the developing fetus and appraise the strengths and limitations of quantitative MRI in identifying early markers of placental dysfunction for improved pregnancy monitoring and fetal outcomes.

Ischemic placental disease and risks of perinatal mortality and morbidity and neurodevelopmental outcomes

Preeclampsia, intrauterine growth restriction, and placental abruption are serious obstetrical complications that constitute the syndrome of ischemic placental disease and account for a disproportionate degree of perinatal morbidity and mortality. We review the risks of stillbirth and neonatal and infant mortality in relation to ischemic placental disease, focusing on population-based studies. We also review the risks of neonatal morbidity and neurodevelopmental outcomes in relation to ischemic placental disease. A synthesis of the findings of the relevant studies relating ischemic placental disease to adverse perinatal outcomes underscores two important observations. First, despite the low prevalence of each of the three obstetrical complications, all are associated with increased risks of adverse perinatal and infant outcomes, as well as neurodevelopmental deficits. Second, the burden of increased perinatal risks appears strongest during the preterm period. Efforts to reduce the risks of ischemic placental disease remain critically important and developing effective clinical interventions will be a target worthy for consideration.

Association of perinatal factors and school performance in primary school Chilean children

The associations between school performance and cognitive abilities with birth characteristics have mostly been studied without taking into consideration the effects of gestational age (GA). Our aim was to study the association between prenatal growth and cognitive function in term-born Chilean school children. A cohort of over 200,000 term-born fourth graders who took the regular national test for school performance was studied. Outcome parameters were language and mathematics test scores in relation to prenatal growth. A total of 256,040 subjects took the test and 220,940 were included in the final study sample. Prenatal growth was modestly, but significantly, associated with school performance. Adjusted β coefficients for 1 cm increase in birth length were 1.28 and 0.77 for mathematics and language, respectively; the corresponding values for 100 g increase in birth weight were 0.59 and 0.34, respectively. Increased GA was associated with lower test scores. Adjusted β coefficients for the birth measurements generally had a lower strength of association than those of socio-economic factors. However, the confounders most strongly associated with educational achievements were socio-economic factors, known to be associated with birth size. Lower socio-economic status is known to negatively influence both prenatal growth and cognitive function, supporting the overall importance of prenatal growth in relation to cognitive outcomes.

Intrauterine growth and neuropsychological performance in very low birth weight preschoolers

In this study we examined the association between intrauterine growth, indexed either as a categorical variable or continuous dimension, and neuropsychological outcome, in a very low birth weight (VLBW) sample of 143 preschoolers. When the commonly used split at the 10th percentile rank was applied to classify intrauterine growth restriction (IUGR), we found that the growth restricted group (n = 25) exhibited significantly poorer performance in the global motor domain, but not on any other neuropsychological measure. In contrast, when adequacy of intrauterine growth was indexed by standardized birth weight, a continuous dimension, this early risk factor explained a unique portion of the variance in global cognitive abilities and visuospatial skills, as well as in global, fine, and gross motor skills. These findings are consistent with recent magnetic resonance imaging data disclosing global neurodevelopmental changes in the brains of preterm infants with IUGR. When cases classified with IUGR (<10th percentile) were excluded, the relationship between adequacy of intrauterine growth and global cognitive abilities remained significant despite range restriction. Hence, an association between appropriateness of intrauterine growth and global intellectual outcome may be observed even within the population of VLBW preschoolers with adequate standardized birth weight.

[Follow-up of the small-for-gestational-age child: clinical guidelines]

INTRODUCTION

In this document the Small for Gestational Age (SGA) Child Working Group of the Spanish Society for Paediatric Endocrinology proposes the guidelines for the management and follow-up of SGA children, highlighting the potential morbidity arising from the SGA condition and its consequences in adulthood.

MATERIAL AND METHODS

There is currently a wide variability in the management of the SGA child between health centres and health professionals. The diagnostic criteria for SGA according to the last international consensus guidelines are defined, which also include preterm SGA patients but excluding those patients in whom low birthweigh is associated with specific syndromes. We also outline the potential abnormalities associated with the SGA condition and recommend specific therapeutic and preventative measures.

CONCLUSIONS

Low birth weight remains a major cause of morbidity in childhood and is associated with an increased risk of health problems later in life. Childhood is a critical window during which some of the risk factors accounting for this sequence are potentially reversible, with healthy lifestyle measures and environmental intervention. Accordingly, these guidelines should be useful not only for Primary Care Paediatricians but also for Neonatologists, Paediatric Endocrinologists, Neuropaediatricians and Pediatric Gastroenterologists, and also for the parents.

Carbohydrate and energy metabolism in the brain of rats with thromboxane A2-induced fetal growth restriction

Fetal growth restriction (FGR) remains a cause of perinatal brain injury, sometimes leading to neurological and intellectual impairment. Although the mechanisms and pathophysiology of CNS injuries have not been elucidated completely, it is possible carbohydrate and energy metabolism may have an important role in the FGR brain. In this study, FGR was induced in rats by administration of synthetic thromboxane A2 (STA2). Pups were delivered by cesarean section. After killing, samples were obtained from the fetuses of both control and FGR rats for evaluation of carbohydrate and energy metabolism in brain tissue. Lactate and pyruvate levels in brain were reduced significantly in the FGR group. Glucose content in brain tissue tended to be increased in the FGR group. In contrast, glycogen content in brain tissue tended to be lower in the FGR group. However, these differences in glucose and glycogen content did not reach statistical significance. Brain high-energy reserves, including ATP, ADP, AMP, and phosphocreatine (P-Cr), were similar in the control and FGR groups. Gluconeogenesis compensated for chronic fetal hypoxia and decreased glycogen storage. Energy metabolism in the FGR brain is likely to be disrupted as a consequence of lower reserves of energy substrates.

Maternal smoking during pregnancy and intellectual performance in young adult Swedish male offspring

Smoking during pregnancy has been linked to an increased risk of several adverse birth outcomes. Associations with deficits in cognitive development have also been suggested. It is unclear whether these associations are due to genetic and/or environmental confounding. In a population-based Swedish cohort study on 205,777 singleton males born to Nordic mothers between 1983 and 1988, we examined the association between maternal smoking during pregnancy and the risk of poor intellectual performance in young adult male offspring. In the cohort analyses, the risk of poor intellectual performance was increased in sons of smoking mothers compared with sons of non-smokers. Stratifying for maternal smoking habits across two pregnancies, there was an increased risk of poor intellectual performance for both sons if the mother was only smoking in the first pregnancy, but in neither son if the mother was only smoking in the second pregnancy. The effect of smoking during pregnancy on intellectual performance was not present when the association was evaluated within sibling pairs. Thus, the association between prenatal smoking exposure and offspring risk of low intellectual performance appears to be completely confounded by familial (genetic and early environmental) factors.

Preterm birth, social disadvantage, and cognitive competence in Swedish 18- to 19-year-old men

OBJECTIVE

The aim was to study the impact of a range of gestational ages (GAs) on cognitive competence in late adolescence and how this effect is modified by contextual social adversity in childhood.

METHODS

This was a register study based on a national cohort of 119664 men born in Sweden from 1973 to 1976. Data on GA and other perinatal factors were obtained from the Medical Birth Register, and information on cognitive test scores was extracted from military conscription at the ages of 18 to 19 years. Test scores were analyzed as z scores on a 9-point stanine scale, whereby each unit is equivalent to 0.5 SD. Socioeconomic indicators of the childhood household were obtained from the Population and Housing Census of 1990. The data were analyzed by multivariate linear regression.

RESULTS

The mean cognitive test scores decreased in a stepwise manner with GA. In unadjusted analysis, the test scores were 0.63 stanine unit lower in men who were born after 24 to 32 gestational weeks than in those who were born at term. The difference in global scores between the lowest and highest category of socioeconomic status was 1.57. Adjusting the analysis for the childhood socioeconomic indicators decreased the effect of GA on cognitive test scores by 26% to 33%. There was also a multiplicative interaction effect of social adversity and moderately preterm birth on cognitive test scores.

CONCLUSIONS

This study confirms previous claims of an incremental association of cognitive competence with GA. Socioeconomic indicators in childhood modified this effect at all levels of preterm birth.

Timing and trajectories of fetal growth related to cognitive development in childhood

The authors investigated timing and trajectories of fetal growth in relation to childhood development in the National Institute of Child Health and Human Development-Scandinavian Study of Successive Small-for-Gestational Age Births (1986-1988) (n = 1,059). Fetal size was assessed by ultrasound at 17, 25, and 33 gestational weeks and at birth. Bayley Scales of Infant Development and the Wechsler Preschool and Primary Scale of Intelligence-Revised tests were conducted at ages 1 and 5 years, respectively, producing mental and psychomotor development indexes and verbal and performance intelligence quotients. Relative fetal size was calculated as a standard deviation score at each data point; growth trajectories were explored with longitudinal mixture models. Fetal size at 17, 25, and 33 weeks was positively associated with mental development index; larger size at 33 weeks and at birth was associated with higher verbal intelligence quotient scores (2.61, 95% confidence interval: 1.06, 4.15 and 1.90, 95% confidence interval: 0.67, 3.13 increase per 1 standard deviation score, respectively); findings were similar for performance intelligence quotient. Seven trajectories were identified; scores were lower for "small" and "medium-to-small" trajectories than for "medium" and "big" (representing normal size) trajectories: mental development index (P < 0.01), performance intelligence quotient (P < 0.001), and verbal intelligence quotient (P < 0.001). Overall, larger fetal size in the second and third trimesters was positively associated with childhood development. Fetal growth trajectories may matter beyond birth.

The influence of birth size on intelligence in healthy children

OBJECTIVE

Birth parameters have been hypothesized to have an influence on IQ. However, studies within the range of normal birth size have been sparse. With this study we examined the associations between birth length, birth weight, head circumference, and gestational age within the normal birth size range in relation to childhood IQ in Asian children.

METHODS

A cohort of 1979 of 2913 Asian children aged 7 to 9 years, recruited from 3 schools in Singapore, were followed yearly from 1999 onward. Birth parameters were recorded by health personnel. Childhood IQ was measured with the Raven's Standard Progressive Matrices at ages 8 to 12.

RESULTS

The mean IQ score across the sample (n = 1645) was 114.2. After controlling for multiple confounders for every 1-cm increment in birth length, 1 kg in birth weight, or 1 cm in head circumference, there was a corresponding increase in IQ of 0.49 points (P for trend < .001), 2.19 points (P for trend = .007) and .62 points (P for trend = .003), respectively. These associations persisted even after exclusion of premature children and children with extreme weights and head circumferences.

CONCLUSIONS

Longer birth length, higher birth weight, or larger head circumferences within the normal birth size range are associated with higher IQ scores in Asian children. Our results suggest that antenatal factors reflected in altered rates of growth but within the normative range of pregnancy experiences play a role in generating cognitive potential. This has implications for targeting early intervention and preventative programs.

Association of Apgar score at five minutes with long-term neurologic disability and cognitive function in a prevalence study of Danish conscripts

BACKGROUND

Apgar score is used for rapid assessment of newborns. Low five-minute Apgar score has been associated with increased risk of severe neurologic outcome, but data on milder outcomes, particularly in the long term, are limited. We aimed to examine the association of five-minute Apgar score with prevalence of neurologic disability and with cognitive function in early adulthood.

METHODS

We conducted a prevalence study among draft-liable men born in Denmark in 1978-1983 and presenting for the mandatory army evaluation in a northern Danish conscription district. We linked records of this evaluation, which includes medical exam and intelligence testing, with the conscripts' records in the Medical Birth Registry, containing perinatal data. We examined prevalence of neurologic disability and of low cognitive function according to five-minute Apgar score.

RESULTS

Less than 1% (136/19,559) of the conscripts had 5-minute Apgar scores <7. Prevalence of neurologic disability was 2.2% (435/19,559) overall; among conscripts with Apgar scores <7, 7-9, and 10 (reference), it was 8.8%, 2.5%, and 2.2% respectively. The corresponding prevalences of low cognitive function (intelligence test score in the bottom quartile) were 34.9%, 27.2%, and 25.0%. The outcomes were more prevalent if Apgar score <7 was accompanied by certain fetal or obstetric adversities. After accounting for perinatal characteristics, 5-minute Apgar score <7 was associated with prevalence ratios of 4.02 (95% confidence interval: 2.24; 7.24) for neurologic disability and 1.33 (0.94; 1.88) for low cognitive function.

CONCLUSION

A five-minute Apgar score <7 has a consistent association with prevalence of neurologic disability and with low cognitive function in early adulthood.

Prenatal nutrition: a critical window of opportunity for mother and child

The prenatal period encompasses a critical window for future health and functioning of mother and child. Attention previously focused on undernutrition risk (i.e., in developing countries and famine conditions) shifted to mismatch between prenatal 'programming' by undernutrition and postnatal overconsumption (i.e., low birthweight vs rapid postnatal growth), now to overconsumption/overweight throughout the reproductive cycle and short- and long-term health risks, including obesity, diabetes, dyslipidemia and cardiovascular disease. Moreover, overconsumption/overweight do not guarantee adequacy of critical nutrients (i.e., against birth defects or for brain development). Multinutrient supplementation - including zinc, iodine, choline and long-chain polyunsaturated fatty acids, especially n-3 - may have advantages over single-nutrient supplements, for example, iron or folate. Future nutritional care for healthy in utero programming may necessitate individual assessment and follow-up, including preconception nutritional preparation, appropriate weight gain, metabolic balance and food-based regimens enhanced by key nutrient fortification and/or supplementation, warranting further research into nutritional optimization of pregnancy outcomes.

Length of prenatal participation in WIC and risk of delivering a small for gestational age infant: Florida, 1996-2004

OBJECTIVE

To assess the association between length of prenatal participation in WIC and a marker of infant morbidity. By focusing on small for gestational age, we consider one of the possible pathways through which prenatal nutrition affects fetal growth.

DESIGN/METHODS

The study sample consists of 369,535 matched mother-infant pairs drawn from all singleton live births in Florida hospitals from 1996 to 2004. All subjects received WIC and Medicaid-funded prenatal services during pregnancy. We controlled for selection bias on observed variables using a generalized propensity scoring approach and performed separate analyses by gestational age category to control for simultaneity bias.

RESULTS

Ten percent increase in the percent of time in WIC was associated with 2.5% decrease (95% CI: 2.1-3.0%) in the risk of a full-term an SGA infant. The risk was also significantly decreased for very preterm and late preterm infants (29-33 and 34-36 weeks gestation) but not for extremely preterm infants (23-28 weeks gestation).

CONCLUSIONS

The observed small negative dose response relationship between percent of pregnancy spent in WIC and fetal growth restriction implies that longer participation in the program confers a small measure of protection against delivering an SGA infant.

Associations of birth size, gestational age, and adult size with intellectual performance: evidence from a cohort of Norwegian men

The influences of prenatal and postnatal growth on intellectual performance are unclear. We examined the associations of birth size and gestational age with intellectual performance and explored whether these associations were influenced by adult body size and social factors. In this nationwide cohort study, the records of 317,761 male infants registered in the Medical Birth Registry of Norway (1967-1979) were linked to the Norwegian Conscript Service (1984-1999). The variation in intelligence test score at age 18 due to birth weight and birth length was evaluated using absolute and standardized (z scores) values. Mean intelligence score increased by gestational age, birth weight, and birth length. However, a decline in intellectual performance was observed for gestational age >41 wk and birth weight >4500 g. There was a strong interaction on intellectual performance between birth size and gestational age (p < 0.0005). Adjusting for adult size strongly attenuated the association of birth size with intellectual performance. The overall R of intellectual performance explained by birth size was <1%; however, adding adult body size and social factors to the model increased R to 12%. In conclusion, the association of birth size with intellectual performance was weak, but still present after adjustment for adult body size and social factors.

An animal model of intrauterine growth retardation induced by synthetic thromboxane a(2)

OBJECTIVE

Intrauterine growth retardation (IUGR) is an important cause of prenatal and neonatal morbidity, and neurologic abnormalities. Although several animal models of IUGR have been developed for scientific investigation, few models approximate the pathophysiology in human fetal growth failure resulting from pregnancy-induced hypertension and preeclampsia. We developed an animal model of IUGR in which fetal growth restriction was induced by administering a synthetic thromboxane A(2) analogue (STA(2)) to the mother.

METHODS

Timed pregnant Sprague-Dawley rats were used in this study. STA(2) was delivered into the peritoneal cavity of the pregnant female at a rate of 20 ng/h from day 13 of pregnancy. The effectiveness of this model was evaluated by monitoring the overall growth of the fetuses and neonates and measuring the weight and biochemical composition of individual organs.

RESULTS

Fetuses and neonates from the STA(2) group showed a highly significant weight reduction throughout the observation period from day 19 of gestation to postnatal day 7. Weight reduction near and at term exceeded 10% and became more pronounced during the first week after birth. Fetuses on the 20th gestational day exhibited a pattern of growth retardation characteristic of asymmetrical IUGR in which the weight reduction was prominent in the liver with relative sparing of the brain. However, the decrease in brain weight was more than 10%. The protein, DNA, and RNA contents of the liver were lower in the STA(2) group. The protein content of the forebrain and brainstem also decreased significantly in the STA(2) group compared with the control; however, the DNA content of the forebrain was higher in the STA(2) group.

CONCLUSIONS

This animal model may mimic human IUGR more closely than previous models because the growth restriction is induced in a truly chronic manner.