New reference curves for head circumference at birth, by gestational age

Macrocephaly and Finger Changes: A Narrative Review

Macrocephaly, characterized by an abnormally large head circumference, often co-occurs with distinctive finger changes, presenting a diagnostic challenge for clinicians. This review aims to provide a current synthetic overview of the main acquired and genetic etiologies associated with macrocephaly and finger changes. The genetic cause encompasses several categories of diseases, including bone marrow expansion disorders, skeletal dysplasias, ciliopathies, inherited metabolic diseases, RASopathies, and overgrowth syndromes. Furthermore, autoimmune and autoinflammatory diseases are also explored for their potential involvement in macrocephaly and finger changes. The intricate genetic mechanisms involved in the formation of cranial bones and extremities are multifaceted. An excess in growth may stem from disruptions in the intricate interplays among the genetic, epigenetic, and hormonal factors that regulate human growth. Understanding the underlying cellular and molecular mechanisms is important for elucidating the developmental pathways and biological processes that contribute to the observed clinical phenotypes. The review provides a practical approach to delineate causes of macrocephaly and finger changes, facilitate differential diagnosis and guide for the appropriate etiological framework. Early recognition contributes to timely intervention and improved outcomes for affected individuals.

Further delineation of the rare GDACCF (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies syndrome): genotype and phenotype of 22 patients with ZNF148 mutations

BACKGROUND

Pathogenic variants in the zinc finger protein coding genes are rare causes of intellectual disability and congenital malformations. Mutations in the ZNF148 gene causing GDACCF syndrome (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies; MIM #617260) have been reported in five individuals so far.

METHODS

As a result of an international collaboration using GeneMatcher Phenome Central Repository and personal communications, here we describe the clinical and molecular genetic characteristics of 22 previously unreported individuals.

RESULTS

The core clinical phenotype is characterised by developmental delay particularly in the domain of speech development, postnatal growth retardation, microcephaly and facial dysmorphism. Corpus callosum abnormalities appear less frequently than suggested by previous observations. The identified mutations concerned nonsense or frameshift variants that were mainly located in the last exon of the ZNF148 gene. Heterozygous deletion including the entire ZNF148 gene was found in only one case. Most mutations occurred de novo, but were inherited from an affected parent in two families.

CONCLUSION

The GDACCF syndrome is clinically diverse, and a genotype-first approach, that is, exome sequencing is recommended for establishing a genetic diagnosis rather than a phenotype-first approach. However, the syndrome may be suspected based on some recurrent, recognisable features. Corpus callosum anomalies were not as constant as previously suggested, we therefore recommend to replace the term 'GDACCF syndrome' with 'ZNF148-related neurodevelopmental disorder'.

Maternal occupational exposure to organic solvents and intrauterine growth in the ELFE cohort

BACKGROUND

In developed countries, about 15% of women are occupationally exposed to solvents. Associations between this maternal occupational exposure and intrauterine fetal growth are inconsistent, but almost no existing study has investigated this relation by solvent family (oxygenated, petroleum, and chlorinated), although they may affect fetal growth differently.

OBJECTIVES

To investigate the relations between maternal occupational solvent exposure, by solvent family, and the risk of neonates born small for gestational age (SGA), or with low birthweight, or with small head circumference (HC).

METHODS

Among the 18,040 women enrolled in the Elfe rather than included in the Elfe birth cohort, we included 13,026 women who worked during pregnancy (72% of the cohort). Information about maternal occupations and industrial activities during pregnancy was collected by questionnaire at the maternity ward, and completed at 2-month when necessary. Using Matgéné job-exposure matrices, we assessed maternal occupational exposure to solvents. Logistic and multiple linear regressions were used to assess the association between maternal occupational solvent exposure and SGA status, birth weight, and HC. Analyses were conducted for exposure during pregnancy and also stratified by the trimester that pregnancy leave began.

RESULTS

We observed a higher risk of SGA newborns among mothers occupationally exposed during pregnancy to petroleum solvents (OR_adjusted = 1.26; 95%CI: 1.01 to 1.57). Among women working until the third trimester of pregnancy, we observed a higher risk of SGA newborns to those occupationally exposed to oxygenated solvents (OR_adjusted = 1.75; 95%CI: 1.11 to 2.75), a significantly lower birthweight for infants of mothers exposed to petroleum solvents (β_adjusted = -47.37 g; -89.33 to -5.42), and a lower HC among newborns of those occupationally exposed to oxygenated solvents (β_adjusted = -0.28; -0.49 to -0.07) and to chlorinated solvents (β_adjusted = -0.29; -0.53 to -0.05).

DISCUSSION

Our results suggest that maternal occupational solvent exposure may influence fetal growth, especially exposure into the third trimester of pregnancy.

Comparison of updated birth weight, length and head circumference charts by gestational age in China with the INTERGROWTH-21st NCSS charts: a population-based study

BACKGROUND

INTERGROWTH-21st Newborn Cross-Sectional Study (NCSS) charts were established and recommended for global application. However, whether one international reference is appropriate for all populations is still unclear. We aim to compare the updated Chinese birth size charts by gestational age with INTERGROWTH-21st NCSS charts.

METHODS

A cross-sectional survey was carried out, and the birth weight, length and head circumference of 24,375 infants born after uncomplicated pregnancies at gestational age ranging from 24⁺⁰ to 42⁺⁶ weeks were measured in 13 cities in China from 2015 to 2018. Growth charts were constructed. The measurements of all these infants were evaluated by the methods of calculating their Z scores using the INTERGROWTH-21st standards. The prevalence of small for gestational age (SGA) and large for gestational age (LGA) based on birth weight was analyzed using Chinese charts and INTERGROWTH-21st charts.

RESULTS

The mean Z scores were 0.10 for birth weight, 0.35 for length and - 0.02 for head circumference. Compared to the INTERGROWTH-21st charts, the Chinese birth weight percentile curves were higher except for the 90th percentile at 29-37 weeks gestational age, and the length percentile curves were higher after 33 weeks gestational age, while the 10th percentile of the head circumference was lower and the other percentiles were similar. The prevalence of SGA was 10.1% [95% confidence interval (CI) = 9.7%-10.5%] using the Chinese birth weight chart and 6.5% (95% CI = 6.2%-6.8%) using the INTERGROWTH-21st birth weight chart. The prevalence of LGA was 9.9% (95% CI = 9.5%-10.2%) and 8.2% (95% CI = 7.9%-8.6%) using the Chinese and INTERGROWTH-21st birth weight charts, respectively.

CONCLUSIONS

Chinese birth size charts based on infants born after uncomplicated pregnancies were different from the INTERGROWTH-21st charts. Differences in the classification of newborns by the two charts should receive attention, and whether the application of INTERGROWTH-21st in Chinese newborns will lead to misclassification needs to be validated in future clinical practice.

Stability of the Gross Motor Function Classification System over time in children with cerebral palsy

AIM

To assess the stability of the Gross Motor Functional Classification System (GMFCS) in children with cerebral palsy (CP) from time of preliminary diagnosis (~2 years of age) to time of diagnosis (~5 years of age), and to examine factors associated with reclassification.

METHOD

We conducted a longitudinal study using a sample from the Canadian CP Registry. Stability was analysed by using the percentage of agreement between timepoints and a weighted prevalence and bias adjusted kappa statistic. Univariate and multivariate logistic regressions were performed to identify variables associated with reclassification.

RESULTS

The study included 1670 children (857 males, 713 females) with a mean age of 11 years 4 months (SD 4 years, range 3 years 5 months-20 years 1 month) at time of data extraction (3rd September 2019), of which 1435 (85.9%) maintained a stable GMFCS, with a weighted kappa of 0.91 (95% confidence interval 0.89-0.92). Univariate logistic regression showed that initial GMFCS level, CP subtype, and the presence of cognitive impairment were associated with the likelihood of change in the GMFCS level (p < 0.1). In the multivariate analysis, however, the likelihood was associated with initial GMFCS level only (odds ratio 7.10-8.88, p < 0.00).

INTERPRETATION

The GMFCS has good stability in early childhood. For the majority of children, it is predictive of their long-term motor function.

WHAT THIS PAPER ADDS

The Gross Motor Function Classification System (GMFCS) rating in early childhood is stable over time. There is no directionality in the reclassification of the GMFCS. The initial GMFCS level was related to the likelihood of change in follow-up GMFCS level.

Neonatal head circumference by gestation reflects adaptation to maternal body size: comparison of different standards

Neonatal head circumference (HC) not only represents the brain size of Homo sapiens, but is also an important health risk indicator. Addressing a lack of comparative studies on head size and its variability in term and preterm neonates from different populations, we aimed to examine neonatal HC by gestation according to a regional reference and a global standard. Retrospective analysis of data on neonatal HC obtained from the Lithuanian Medical Birth Register from 2001 to 2015 (423 999 newborns of 24–42 gestational weeks). The varying distribution by gestation and sex was estimated using GAMLSS, and the results were compared with the INTERGROWTH-21st standard. Mean HC increased with gestation in both sexes, while its fractional variability fell. The 3rd percentile matched that for INTERGROWTH-21st at all gestations, while the 50th and 97th percentiles were similar up to 27 weeks, but a full channel width higher than INTERGROWTH-21st at term. INTERGROWTH-21st facilitates the evaluation of neonatal HC in early gestations, while in later gestations, the specific features of neonatal HC of a particular population tend to be more precisely represented by regional references.

Construction of China national newborn growth standards based on a large low-risk sample

Most published newborn growth references are based on conventional monitoring data that usually included both low- and high-risk pregnancies. We sought to develop a set of neonatal growth standards constructed from only a large sample of low-risk pregnancies. A total of 24,375 naturally conceived singleton live births with gestational ages of 24–42 weeks were collected in 69 hospitals in thirteen Chinese cities between 2015 and 2018. Unhealthy infants or those with high-risk mother were excluded. Smoothed percentile curves of six anthropometric indicators were established using the Generalized Additive Model for Location, Scale and Shape. The 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentile references for birth weight, length, head circumference, weight/length, body mass index, and ponderal index were calculated for neonates with gestational ages of 24–42 weeks. This set of neonatal growth standards with six anthropometric indicators can provide more tools for growth and nutrition assessment and body proportionality in neonatal clinical practice. These standards might also help to show the differences between growth curves based on low-risk and mixed low- and high-risk pregnancies.

Speckle contrast diffuse correlation tomography of cerebral blood flow in perinatal disease model of neonatal piglets

We adapted and tested an innovative noncontact speckle contrast diffuse correlation tomography (scDCT) system for 3D imaging of cerebral blood flow (CBF) variations in perinatal disease models utilizing neonatal piglets, which closely resemble human neonates. CBF variations were concurrently measured by the scDCT and an established diffuse correlation spectroscopy (DCS) during global ischemia, intraventricular hemorrhage, and asphyxia; significant correlations were observed. Moreover, CBF variations associated reasonably with vital pathophysiological changes. In contrast to DCS measurements of mixed signals from local scalp, skull and brain, scDCT generates 3D images of CBF distributions at prescribed depths within the head, thus enabling specific determination of regional cerebral ischemia. With further optimization and validation in animals and human neonates, scDCT has the potential to be a noninvasive imaging tool for both basic neuroscience research in laboratories and clinical applications in neonatal intensive care units.

Association of Maternal-Neonatal Steroids With Early Pregnancy Endocrine Disrupting Chemicals and Pregnancy Outcomes

CONTEXT

Steroids play an important role in fetal development and parturition. Gestational exposures to endocrine-disrupting chemicals (EDCs) affect steroidal milieu and pregnancy outcomes, raising the possibility of steroids serving as biomarkers. Most studies have not addressed the impact of EDC mixtures, which are reflective of real life scenarios.

OBJECTIVE

Assess the association of maternal and neonatal steroids with pregnancy outcomes and early pregnancy EDC levels.

DESIGN

Prospective analysis of mother-infant dyads.

SETTING

University hospital.

PARTICIPANTS

121 mother-infant dyads.

MAIN OUTCOME MEASURES

The associations of maternal and neonatal steroidal hormones from 121 dyads with pregnancy outcomes, the associations of first trimester EDCs individually and as mixtures with maternal and neonatal steroids in a subset of 56 dyads and the influence of body mass index (BMI), age, and offspring sex in modulating the EDC associations with steroids were determined.

RESULTS

Steroid-specific positive or negative associations with pregnancy measures were evident; many maternal first trimester EDCs were negatively associated with estrogens and positively with androgen/estrogen ratios; EDC-steroid associations were influenced by maternal age, pre-pregnancy BMI, and fetal sex; and EDCs individually and as mixtures showed direct and inverse fetal sex-dependent associations with maternal and neonatal steroids.

CONCLUSIONS

This proof-of-concept study indicates association of steroids with pregnancy outcomes depending on maternal age, prepregnancy BMI, and fetal sex, with the effects of EDCs differing when considered individually or as mixtures. These findings suggest that steroidal hormonal measures have potential to serve as biomarkers of impact of EDC exposures and pregnancy outcome.

Maternal vitamin B12 status in early pregnancy and its association with birth outcomes in Canadian mother-newborn Dyads

Vitamin B12 (B12) is a co-enzyme essential for fetal growth and development. Lower maternal B12 status has been associated with preterm birth (<37 gestational weeks) and low birth weight (<2500 g), which are linked to morbidity and mortality across the lifespan. In Canada, 17-25 % of women in early pregnancy had a serum total B12 concentration <148 pmol/l and maternal total B12 concentration decreased throughout pregnancy. This study aimed to determine the association between maternal B12 status and birth outcomes in Canadian mother-newborn dyads. A secondary analysis of 709 mother-newborn dyads in British Columbia (BC), Canada, was conducted. Bio-banked first- (n 656) and second-trimester (n 709) maternal serum samples of apparently healthy South Asian (50 %) and European (50 %) women from the BC Prenatal Genetic Screening Program were quantified for B12 biomarkers (total B12, holotranscobalamin (holoTC), methylmalonic acid (MMA) and total homocysteine (tHcy)). Obstetric history and birth outcome data were obtained from the BC Perinatal Data Registry. All associations were determined using multiple linear regression. Maternal serum total B12, holoTC, MMA and tHcy had a mean weekly decrease of 3·64 pmol/l, 1·04 pmol/l, 1·44 nmol/l and 0·104 μmol/l, respectively (P < 0·001). Despite a total B12 concentration <148 pmol/l among 20-25 % of the women, maternal B12 biomarker concentrations were not associated with birth weight z-score, head circumference z-score and gestational age at birth (P > 0·05). Additional research in women at high risk of adverse birth outcomes and the association between maternal B12 status and functional, for example, cognitive, outcomes is needed.

Maternal lipid levels across pregnancy impact the umbilical cord blood lipidome and infant birth weight

Major alterations in metabolism occur during pregnancy enabling the mother to provide adequate nutrients to support infant development, affecting birth weight (BW) and potentially long-term risk of obesity and cardiometabolic disease. We classified dynamic changes in the maternal lipidome during pregnancy and identified lipids associated with Fenton BW z-score and the umbilical cord blood (CB) lipidome. Lipidomics was performed on first trimester maternal plasma (M1), delivery maternal plasma (M3), and CB plasma in 106 mother-infant dyads. Shifts in the maternal and CB lipidome were consistent with the selective transport of long-chain polyunsaturated fatty acids (PUFA) as well as lysophosphatidylcholine (LysoPC) and lysophosphatidylethanolamine (LysoPE) species into CB. Partial correlation networks demonstrated fluctuations in correlations between lipid groups at M1, M3, and CB, signifying differences in lipid metabolism. Using linear models, LysoPC and LysoPE groups in CB were positively associated with BW. M1 PUFA containing triglycerides (TG) and phospholipids were correlated with CB LysoPC and LysoPE species and total CB polyunsaturated TGs. These results indicate that early gestational maternal lipid levels influence the CB lipidome and its relationship with BW, suggesting an opportunity to modulate maternal diet and improve long-term offspring cardiometabolic health.

Differential gene expression elicited by ZIKV infection in trophoblasts from congenital Zika syndrome discordant twins

Zika virus (ZIKV) causes congenital Zika syndrome (CZS), which is characterized by fetal demise, microcephaly and other abnormalities. ZIKV in the pregnant woman circulation must cross the placental barrier that includes fetal endothelial cells and trophoblasts, in order to reach the fetus. CZS occurs in ~1-40% of cases of pregnant women infected by ZIKV, suggesting that mothers' infection by ZIKV during pregnancy is not deterministic for CZS phenotype in the fetus. Therefore, other susceptibility factors might be involved, including the host genetic background. We have previously shown that in three pairs of dizygotic twins discordant for CZS, neural progenitor cells (NPCs) from the CZS-affected twins presented differential in vitro ZIKV susceptibility compared with NPCs from the non-affected. Here, we analyzed human-induced-pluripotent-stem-cell-derived (hiPSC-derived) trophoblasts from these twins and compared by RNA-Seq the trophoblasts from CZS-affected and non-affected twins. Following in vitro exposure to a Brazilian ZIKV strain (ZIKVBR), trophoblasts from CZS-affected twins were significantly more susceptible to ZIKVBR infection when compared with trophoblasts from the non-affected. Transcriptome profiling revealed no differences in gene expression levels of ZIKV candidate attachment factors, IFN receptors and IFN in the trophoblasts, either before or after ZIKVBR infection. Most importantly, ZIKVBR infection caused, only in the trophoblasts from CZS-affected twins, the downregulation of genes related to extracellular matrix organization and to leukocyte activation, which are important for trophoblast adhesion and immune response activation. In addition, only trophoblasts from non-affected twins secreted significantly increased amounts of chemokines RANTES/CCL5 and IP10 after infection with ZIKVBR. Overall, our results showed that trophoblasts from non-affected twins have the ability to more efficiently activate genes that are known to play important roles in cell adhesion and in triggering the immune response to ZIKV infection in the placenta, and this may contribute to predict protection from ZIKV dissemination into fetuses' tissues.

Maternal occupational exposure to carbonaceous nanoscale particles and small for gestational age and the evolution of head circumference in the French Longitudinal Study of Children - Elfe study

OBJECTIVES

To investigate the association between exposure to unintentionally emitted carbonaceous nanoscale particles (NPs) and small for gestational age (SGA), as well as head circumference (HC) at birth and at two years of age.

METHODS

Mothers from the French Longitudinal Study of Children (Elfe cohort) who worked during pregnancy were selected for our study. Data collected at birth and during follow-up (up to two years) were used. The probability and frequency of maternal occupational exposure to unintentionally emitted carbonaceous NPs was estimated using a job exposure matrix (MatPUF). Multivariate logistic regression, linear regression, and mixed models were applied to estimate any associations. Analyses were carried out depending on whether mothers stopped working during the first, second, or third trimester of pregnancy.

RESULTS

Maternal occupational exposure to unintentionally emitted carbonaceous NPs was associated with SGA in the overall study population by multivariate analysis (ORa = 1.80, 95% CI: 1.29, 2.46), as well as in sub-groups of mothers who stopped working during the second (ORa = 1.84, 95% CI: 1.13, 3.02) or third (ORa = 1.80, 95% CI: 1.10, 2.95) trimesters. There were no significant associations with HC at birth or two years of age.

CONCLUSIONS

We found a significant association between occupational exposure to carbonaceous NPs and SGA, with the effect depending on the period of exposure during pregnancy. These results should encourage further studies concerning the adverse effects of exposure to carbonaceous NPs on the development of offspring.

Sex- and growth-specific characteristics of small for gestational age infants: a prospective cohort study

Background

Asymmetric fetal growth and male sex are both associated with adverse neonatal outcome. However, less is known about the influence of asymmetric growth and fetal sex within SGA neonates, a group of infants already at increased risk for adverse neonatal outcomes. The aim of the present study was to provide insight into variance in risk factors for SGA in a fetal sex- and growth symmetry-specific way.

Methods

For this prospective, multicenter cohort study, data from the Screening for Pregnancy Endpoints (SCOPE) study were used with 5628 nulliparous participants, of which 633 (11.3%) pregnancies were complicated with SGA and 3376 (60.0%) women had uncomplicated pregnancies. Association between risk factors for SGA, SGA subgroups, and uncomplicated pregnancies were assessed with multivariable analyses.

Results

Prevalence of asymmetric growth varied from 45.8% of SGA infants to 5.5% of infants with a customized birthweight > 90th percentile (p < 0.001). Significantly more SGA males had asymmetric growth compared to SGA female infants (51.2% vs 40.4%, p = 0.009). Maternal pre-pregnancy diet and BMI < 20 and ≥ 30 were significantly associated with symmetric SGA but not with asymmetric SGA. Asymmetric SGA infants had not only lower customized birthweight percentile (4.4 (SD 2.8) vs 5.0 (SD 3.0), p < 0.001), but also lower rates of stillbirth (p = 0.041) and less often Apgar scores < 7 (p = 0.060).

Conclusions

Among SGA infants, low customized birthweight percentiles and male sex are associated with asymmetric growth. Only symmetric SGA is significantly associated with maternal risk factors in early pregnancy. There is a substantial variance in risk factors and neonatal outcomes for SGA based on growth symmetry, implying a different pathogenesis.

Trial registration

ACTRN12607000551493

Head Circumference of Babies at Birth in Nigeria

BACKGROUND AND OBJECTIVES

Measuring head circumference (HC) of newborns is an important tool for evaluating intra-uterine brain development. HC reference charts currently in use in Nigeria are not representative of the local population. We thus present locally derived HC reference data for Nigerian infants at birth.

SUBJECTS AND METHODS

We reviewed birth records of all infants at the Jos University Teaching Hospital (JUTH) over a 10 year period from January 2006. JUTH is a tertiary care center offering obstetric services to a large population of women in Jos and its environs. All births with gestational age between 28 and 42 weeks were included in the study. STATA version 14 was used to calculate gestational age associated HC percentile measurements.

RESULTS

We included 18 282 babies to generate the reference values. The mean HC value was 34.4 ± 2.1 cm (M = 34.6 ± 2.16 cm, F = 34.1 ± 2.02 cm, p < 0.001). Our HC reference values significantly differ from the USA and INTERGROWTH-21 charts currently in use in our country. Mean HC was higher in male infants compared with female infants. This difference was uniformly so across all gestational age groups.

CONCLUSIONS

The use of our locally derived HC reference values could be more appropriate in defining normal head growth in Nigerian infant populations thereby improving newborn care.

Congenital brain abnormalities during a Zika virus epidemic in Salvador, Brazil, April 2015 to July 2016

Background

North-eastern Brazil was the region most affected by the outbreak of congenital Zika syndrome that followed the 2015 Zika virus (ZIKV) epidemics, with thousands of suspected microcephaly cases reported to the health authorities, mostly between late 2015 and early 2016. Aim: To describe clinical and epidemiological aspects of the outbreak of congenital brain abnormalities (CBAs) and to evaluate the accuracy of different head circumference screening criteria in predicting CBAs.

Method

Between April 2015 and July 2016, the Centers for Information and Epidemiologic Surveillance of Salvador, Brazil investigated the reported cases suspected of microcephaly and, based on intracranial imaging studies, confirmed or excluded a diagnosis of CBA. Sensitivity, specificity and positive and negative predictive values of different head circumference screening criteria in predicting CBAs were calculated.

Results

Of the 365 investigated cases, 166 (45.5%) had confirmed CBAs. The most common findings were intracranial calcifications and ventriculomegaly in 143 (86.1%) and 111 (66.9%) of the 166 CBA cases, respectively. Prevalence of CBAs peaked in December 2015 (2.24 cases/100 live births). Cases of CBAs were significantly more likely to have been born preterm and to mothers who had clinical manifestations of arboviral infection during pregnancy. None of the head circumference screening criteria performed optimally in predicting CBAs.

Conclusion

This study highlights the magnitude of neurological consequences of the ZIKV epidemic and the limitations of head circumference in accurately identifying children with CBA. Gestational symptoms compatible with ZIKV infection should be combined with imaging studies for efficient detection of suspect CBAs during ZIKV epidemics.

Comparison of the INTERGROWTH-21st standard and a new reference for head circumference at birth among newborns in Southern China

BACKGROUND

Previous studies proposed that there were racial or ethnic disparities in fetal growth, challenging the use of international standards in specific populations. This study was to evaluate the validity of applying the INTERGROWTH-21st standard to a Chinese population for identifying abnormal head circumference (HC), in comparison with a newly generated local reference.

METHODS

There were 24,257 singletons delivered by low-risk mothers in four perinatal health-care centers in Southern China. New HC reference was constructed and comparison in distribution of HC categories was performed between the INTERGROWTH-21st standard and new reference after applying these two tools in study population. Logistic regression was used to examine the association between abnormal HC and adverse neonatal outcomes.

RESULTS

There were 4.40% of the newborns identified with microcephaly (HC > 2 standard deviation below the mean) using the INTERGROWTH-21st standard, comparing to the proportion of 2.83% using new reference. The newborns identified with microcephaly only by the INTERGROWTH-21st standard were not at a higher risk of adverse neonatal outcome, compared with those identified as non-microcephaly by both tools (OR 0.73, 95% CI 0.47-1.13).

CONCLUSION

The new HC reference may be more appropriate for newborn assessment in Chinese populations than the INTERGROWTH-21st standard.

Ultrasound Assessment of Fetal Biometry in Iranian Normal Pregnancies

Background

The objective of this study was to provide biometric charts for Iranian fetuses.

Methods

One thousand four hundred and twenty-two women enrolled. Four hundred and eighty-four were in the second trimester of pregnancy and 940 were in the third trimester. Data were presented as mean ± standard deviation for continuous variables. Percentiles (5^th, 50^th, 75^th, and 90^th) reported.

Results

Mean femoral length ranged from 16 to 53 mm in our study in the second trimester and 55-79 mm in the third trimester. Mean biparietal diameter (BPD) for fetuses with in the second trimester was between 14 and 71 and for fetuses in the third trimester was between 74 and 98 mm. Mean abdominal circumference (AC) in our cases with gestational age between 14 and 41 ranged between 86 and 365 mm.

Conclusions

We have provided normal reference ranges and percentiles for BPD, AC, femur length, and weight during the second and third trimester of pregnancy in an Iranian population.

Clinical Factors That Affect the Relationship between Head Circumference and Brain Volume in Very-Low-Birth-Weight Infants

BACKGROUND AND PURPOSE

Measuring head circumference (HC) in infants is an easy screening procedure with which to detect abnormalities in brain growth. It has been demonstrated that HC can predict total brain volume (TBV) in very-low-birth-weight (VLBW) infants. However, the correlation between HC and TBV was weaker than that observed in healthy term-born toddlers, suggesting that there are factors that influence the relationship between HC and TBV. The aim of this study was to identify the clinical risk factors that caused a deviation from the regression line obtained between HC and TBV.

METHODS

The study population was based on 37 VLBW infants, who underwent a clinical magnetic resonance imaging (MRI) examination at a term-equivalent age, during 2013-2015, at Toyama University Hospital. The HC and the TBV were both adjusted for sex, multiple births, and postmenstrual age. The relationship between TBV/HC and clinical characteristics was evaluated.

RESULTS

There was a positive correlation between HC and TBV (r = .58, P = .000168). Two clinical factors, the lower birth body weight (BBW) (r = .38, P = .02) and dolichocephaly (r = 0.46, P = .006), were identified as factors that negatively affected the TBV/HC ratio. After excluding infants with low BBW or with dolichocephaly, the correlation between HC and TBV was higher (r = .63).

CONCLUSIONS

Although HC has predictive value for TBV in VLBW infants, care should be taken in infants with low BBW (BBW less than 600 g) or dolichocephaly (MRI-based cranial index less than .68), which were related to overestimation of TBV.

An MR-based quantitative intraventricular hemorrhage porcine model for MR-guided focused ultrasound thrombolysis

PURPOSE

Intraventricular hemorrhage (IVH) affects approximately 50% of premature births where 50% further develop post-hemorrhagic ventricular dilation (PHVD). Patients face significant impact to long-term development if PHVD is not managed. Unfortunately, there is no accepted treatment to remove the thrombus caused by IVH. This paper describes an acute and chronic IVH model for use with magnetic resonance-guided focused ultrasound (MRgFUS) thrombolysis.

METHODS

A total of 12 pigs (~ 1 month in age) were used in the model (eight acute and four chronic). A pre-operative brain MRI was obtained for ventricular targeting. 1.25 cm³/kg of autologous blood was injected through a burr hole lateral to the midline and anterior of the coronal suture at a rate of 0.6 cm³/min. A craniotomy was performed to simulate a "fontanelle". Post-operative MRI was used to calculate the clot volume. Chronic piglets were recovered, monitored daily with a neurological scoring system (NSS), and MRI scanned for 21 days.

RESULTS

The clot injection was well tolerated. The average clot size was 3987 mm³ (median = 4330 mm, standard deviation = 739 mm³). Postmortem examination validated the presence of the clot. In the chronic animals, there was an increase in ventricular volume of 30%. Transient neurological impairment immediately followed clot injection and with onset of hydrocephalus in the chronic animals.

CONCLUSIONS

This model establishes a measurable and targetable IVH clot in an MRI-based neonatal porcine model. The progressive post-hemorrhagic ventricular dilation in the chronic model is a potential alterable outcome from MRgFUS thrombolysis.

Congenital microcephaly in Quebec: baseline prevalence, risk factors and outcomes in a large cohort of neonates

OBJECTIVE

We assessed baseline prevalence, risk factors and outcomes of microcephaly in a large population of neonates.

DESIGN

Retrospective cohort study.

SETTING

All hospitals in the province of Quebec, Canada.

PARTICIPANTS

794 microcephalic and 1 944 010 non-microcephalic infants born between 1989 and 2012.

MAIN OUTCOME MEASURES

Baseline prevalence of microcephaly and occurrence of other congenital anomalies. We estimated the association of (1) pregnancy risk factors including TORCH infections (toxoplasmosis, rubella, cytomegalovirus, herpes, other), exposure to teratogens, diabetes and maternal congenital anomalies with risk of microcephaly, and (2) microcephaly with risk of infant mortality and severe morbidity, adjusted for maternal characteristics.

RESULTS

The overall prevalence of microcephaly was 4.1 per 10 000, ranging between 3.0 and 5.3 per 10 000 over time. Only 37% of microcephalic infants presented with other congenital anomalies. Maternal infection during pregnancy was the strongest risk factor, with 32 times the risk of microcephaly (prevalence ratio 32.38; 95% CI 22.42 to 46.75) compared with no infection. Exposure to teratogens was the next most important risk factor, with three times greater risk (prevalence ratio 3.10; 95% CI 2.37 to 4.07). Microcephaly was associated with 20 times the risk of infant mortality compared with no microcephaly (prevalence ratio 20.52; 95% CI 15.57 to 27.04) and significantly greater infant morbidity.

CONCLUSIONS

In Canada, infectious exposure during pregnancy is a strong risk factor for microcephaly, and affected infants are at higher risk of poor birth outcomes. Better monitoring of microcephaly is needed in the event that Zika or other novel viruses affect future risk.

Framework for shape analysis of white matter fiber bundles

Diffusion imaging coupled with tractography algorithms allows researchers to image human white matter fiber bundles in-vivo. These bundles are three-dimensional structures with shapes that change over time during the course of development as well as in pathologic states. While most studies on white matter variability focus on analysis of tissue properties estimated from the diffusion data, e.g. fractional anisotropy, the shape variability of white matter fiber bundle is much less explored. In this paper, we present a set of tools for shape analysis of white matter fiber bundles, namely: (1) a concise geometric model of bundle shapes; (2) a method for bundle registration between subjects; (3) a method for deformation estimation. Our framework is useful for analysis of shape variability in white matter fiber bundles. We demonstrate our framework by applying our methods on two datasets: one consisting of data for 6 normal adults and another consisting of data for 38 normal children of age 11 days to 8.5 years. We suggest a robust and reproducible method to measure changes in the shape of white matter fiber bundles. We demonstrate how this method can be used to create a model to assess age-dependent changes in the shape of specific fiber bundles. We derive such models for an ensemble of white matter fiber bundles on our pediatric dataset and show that our results agree with normative human head and brain growth data. Creating these models for a large pediatric longitudinal dataset may improve understanding of both normal development and pathologic states and propose novel parameters for the examination of the pediatric brain.

Discordant congenital Zika syndrome twins show differential in vitro viral susceptibility of neural progenitor cells

Congenital Zika syndrome (CZS) causes early brain development impairment by affecting neural progenitor cells (NPCs). Here, we analyze NPCs from three pairs of dizygotic twins discordant for CZS. We compare by RNA-Seq the NPCs derived from CZS-affected and CZS-unaffected twins. Prior to Zika virus (ZIKV) infection the NPCs from CZS babies show a significantly different gene expression signature of mTOR and Wnt pathway regulators, key to a neurodevelopmental program. Following ZIKV in vitro infection, cells from affected individuals have significantly higher ZIKV replication and reduced cell growth. Whole-exome analysis in 18 affected CZS babies as compared to 5 unaffected twins and 609 controls excludes a monogenic model to explain resistance or increased susceptibility to CZS development. Overall, our results indicate that CZS is not a stochastic event and depends on NPC intrinsic susceptibility, possibly related to oligogenic and/or epigenetic mechanisms.

Zika virus (ZIKV) infection can cause congenital Zika syndrome (CZS), but the underlying mechanisms are poorly understood. Here, the authors generate neural progenitor cells from dizygotic twins with a discordant phenotype regarding CZS and study their response to ZIKV infection.

Development and Validation of a Sensor Prototype for Near-Infrared Imaging of the Newborn Brain

Imaging brain oxygenation is crucial for preventing brain lesions in preterm infants. Our aim is to build and validate a near-infrared optical tomography (NIROT) sensor for the head of neonates. This sensor, combined with an optoacoustic device, will enable quantitative monitoring of the structural and functional information of the brain. Since the head of preterm infants is small and fragile great care must be taken to produce a comfortable and compact device in which a sufficient number of light sources and detectors can be implemented. Here we demonstrate our first prototype. Heterogeneous silicone phantoms were produced to validate the prototype's data acquisition, data processing, and image reconstruction. Reconstructed optical properties agree well with the target values. The mechanical performance of the new NIROT sensor prototype confirms its suitability for the clinical application.

Fever in pregnancy and offspring head circumference

PURPOSE

To examine whether maternal fever during pregnancy is associated with reduced head circumference and risk of microcephaly at birth.

METHODS

A prospective study of 86,980 live-born singletons within the Danish National Birth Cohort was carried out. Self-reported maternal fever exposure was ascertained in two interviews during pregnancy and information on head circumference at birth was extracted from the Danish Medical Birth Registry.

RESULTS

Fever in pregnancy was reported by 27% of the mothers, and we identified 3370 cases of microcephaly (head circumference less than or equal to third percentile for sex and gestational age) and 1140 cases of severe microcephaly (head circumference less than or equal to first percentile for sex and gestational age). In this study, maternal fever exposure was not associated with reduced head circumference (adjusted β = 0.03, 95% confidence intervals [CI]: 0.01-0.05), increased risk of microcephaly (odds ratio: 0.95, 95% CI: 0.88-1.03) nor severe microcephaly (odds ratio: 1.01, 95% CI: 0.88-1.15) in the offspring. These findings were consistent for increasing numbers of fever episodes, for increasing fever severity, and for exposure in both early pregnancy and midpregnancy.

CONCLUSIONS

In this most comprehensive study to date, we found no indication that maternal fever in pregnancy is associated with small head size in the offspring.

Head Growth Trajectory and Neurodevelopmental Outcomes in Preterm Neonates

OBJECTIVES

To evaluate the association between head growth (HG) during neonatal and postdischarge periods and neurodevelopmental outcomes of preterm neonates of <29 weeks gestational age.

METHODS

We conducted a retrospective cohort study of infants <29 weeks gestational
age admitted between 2009 and 2011 to participating Canadian Neonatal Network
units and followed by Canadian Neonatal Follow-Up Network clinics. Differences in head circumference (ΔHC) z score were calculated for 3 time periods, which include admission to discharge, discharge to follow-up at 16-36 months, and admission to follow-up. These were categorized in 1 reference group (ΔHC z score between -1 and +1) and 4 study groups (ΔHC z score of <-2, between -2 to -1, +1 to +2, and >+2). Neurodevelopmental outcomes were compared with the reference group.

RESULTS

1973 infants met the inclusion criteria. Poor HG occurred frequently during the NICU admission (ΔHC z score <-2 in 24% infants versus 2% infants post-discharge) with a period of "catch-up" growth postdischarge. Significant neurodevelopmental impairment was higher in infants with the poorest HG from admission to follow-up (adjusted odds ratio 2.18, 95% confidence interval 1.50-3.15), specifically cognitive and motor delays. Infants with poor initial HG and catch-up postdischarge have a lower adjusted odds ratio of significant neurodevelopmental impairment (0.35, 95% CI 0.16-0.74). Infants with poor HG received a longer duration of parenteral nutrition and mechanical ventilation and had poor weight gain.

CONCLUSIONS

Poor HG during the neonatal and postdischarge periods was associated with motor and cognitive delays at 16 to 36 months.

Women and schizophrenia: planning for the future

The aim of this narrative review is to provide readers with a summary of the recent literature on women and schizophrenia and to address commonly asked questions about the role of gender in this illness. Important gender distinctions were found in the knowledge base around schizophrenia, particularly in the areas of symptom onset, hormonal and immune effects, and antipsychotic drug kinetics and their consequences. We also discuss and address commonly asked questions about gender and schizophrenia. This review concludes that gender differences influence the effectiveness of various treatments and need to be taken into account when planning comprehensive care services for individuals with schizophrenia.

High-angular resolution diffusion imaging tractography of cerebellar pathways from newborns to young adults

INTRODUCTION

Many neurologic and psychiatric disorders are thought to be due to, or result in, developmental errors in neuronal cerebellar connectivity. In this connectivity analysis, we studied the developmental time-course of cerebellar peduncle pathways in pediatric and young adult subjects.

METHODS

A cohort of 80 subjects, newborns to young adults, was studied on a 3T MR system with 30 diffusion-weighted measurements with high-angular resolution diffusion imaging (HARDI) tractography.

RESULTS

Qualitative and quantitative results were analyzed for age-based variation. In subjects of all ages, the superior cerebellar peduncle pathway (SCP) and two distinct subpathways of the middle cerebellar peduncle (MCP), as described in previous ex vivo studies, were identified in vivo with this technique: pathways between the rostral pons and inferior-lateral cerebellum (MCP cog), associated predominantly with higher cognitive function, and pathways between the caudal pons and superior-medial cerebellum (MCP mot), associated predominantly with motor function.

DISCUSSION

Our findings showed that the inferior cerebellar peduncle pathway (ICP), involved primarily in proprioception and balance appears to have a later onset followed by more rapid development than that exhibited in other tracts. We hope that this study may provide an initial point of reference for future studies of normal and pathologic development of cerebellar connectivity.

Anthropometric Charts for Infants Born Between 22 and 29 Weeks' Gestation

OBJECTIVES

Using a large, racially diverse US dataset, we aimed primarily to: (1) fit and validate sex-specific birth weight and head circumference for gestational age charts for infants born at 22 to 29 weeks' gestation; and (2) fit race-specific birth weight and head circumference for gestational age charts.

METHODS

We used data collected between 2006 and 2014 on 183 243 singleton infants without congenital malformations with gestational age between 22 weeks, 0 days and 29 weeks, 6 days from 852 US members of the Vermont Oxford Network. For the sex-specific charts, the final sample size included 156 587 infants who survived hospital discharge. From these 156 587, we abstracted a subset of 47 005 infants to fit sex-specific charts separately for white, black, and Asian infants. For all charts, we applied quantile regression models to predict infants' birth weight and head circumference percentiles from gestational age expressed in days.

RESULTS

We successfully validated the overall sex-specific charts. Over most of the gestational age range, black infants, either girls or boys, had the lowest predicted birth weight as compared with white and Asian infants for many percentiles.

CONCLUSIONS

We fitted and validated new sex-specific charts using a recent, large, and racially diverse dataset. Future steps include using these charts to examine associations of weight and head circumference at birth with mortality and morbidity.

Association between neonatal morbidities and head growth from birth until discharge in very-low-birthweight infants born preterm: a population-based study

AIM

To evaluate the possible association between major neonatal morbidities and poor head growth from birth to discharge home in very-low-birthweight (VLBW) infants born preterm.

METHOD

Population-based observational study comprising 12 992 infants (6340 male, 6652 female) of 24 to 32 weeks' gestation, and birthweight ≤1500g. Severe head growth failure (HGF) was defined as a decrease in head circumference z-score >2 z-scores, and moderate HGF as a decrease of 1 to 2 z-scores. Multinomial logistic regression analysis was applied to determine morbidities associated with HGF.

RESULTS

Severe HGF occurred in 4.5% and moderate HGF in 20.9% of infants. Each unit increase in head circumference z-score at birth was associated with increased odds for severe and moderate HGF (odds ratios [OR] 5.29, 95% confidence intervals [CI] 4.67-6.00, and OR 2.38, 95% CI 2.23-2.54 respectively). Both severe and moderate HGF were associated with respiratory distress syndrome (OR 2.03, 95% CI 1.58-2.62, and OR 1.66, 95% CI 1.48-1.85 respectively); bronchopulmonary dysplasia (OR 3.38, 95% CI 2.33-4.91, and OR 1.87, 95% CI 1.52-2.30 respectively); necrotizing enterocolitis (OR 2.89, 95% CI 2.04-4.09, and OR 1.72, 95% CI 1.38-2.16 respectively), and sepsis (OR 2.06, 95% CI 1.69-2.50, and OR 1.38, 95% CI 1.24-1.53 respectively).

INTERPRETATION

Major neonatal morbidities were associated with HGF in VLBW infants born preterm. Identification of whether this is a direct effect of these morbidities or mediated through nutritional or growth factors may enable interventions to improve postnatal head growth of infants born preterm.

National curves of foetal growth in singleton foetuses of Greek origin

BACKGROUND

Foetal growth monitoring is an essential component of prenatal care with postnatal impact. The aim of the study was to construct reference ranges for foetal biometric parameters in Greek foetuses and to compare them with previously published models.

MATERIALS AND METHODS

Measurements from 1200 Greek foetuses were used to construct normal curves for biparietal diameter (BPD), occipitofrontal diameter (OFD), head circumference (HC), abdominal circumference (AC), femoral length (FL) and the BPD/FL ratio according to the methodology described by Royston and Wright (1998). The model was validated in a second group of 1200 different foetuses using analysis of the corresponding standardized residuals (z-scores). The z-scores which were derived by our model were compared to those calculated using previously published models from other populations.

RESULTS

BPD, OFD, HC, AC, FL and the BPD/FL ratio are accurately described by simple quadratic equations (R(2) > 0·96 for most of the parameters tested). Statistically significant differences were observed for most of the z-scores when our models were compared to previously published models. Less than 10% of our foetuses were < 5th or > 95th centile of the latter models. About 10% of our foetuses were > 95th centile for FL and HC when the INTERGROWTH-21st formulas were used.

CONCLUSION

We present national foetal biometric references. Using charts from other populations (including INTERGROWTH-21st) may be unrepresentative of local populations and lead to misclassification of foetal growth status.

Systematic review of the methodological quality of studies designed to create neonatal anthropometric charts

Babies all over the world are assessed at birth using neonatal anthropometric charts as a matter of clinical routine. This systematic review evaluated the methodological quality of studies designed to create neonatal anthropometric charts and to highlight features in the charts that could affect clinical decision-making and comparisons between populations. The variety and quality of available charts could affect how newborns at risk are identified, together with the indications for treatment, especially nutritional interventions.

CONCLUSION

The studies that generated the charts currently recommended for clinical use have major methodological limitations and international and regional comparisons are very difficult.

Clinical, morphological, biochemical, imaging and outcome parameters in 21 individuals with mitochondrial maintenance defect related to FBXL4 mutations

FBXL4 deficiency is a recently described disorder of mitochondrial maintenance associated with a loss of mitochondrial DNA in cells. To date, the genetic diagnosis of FBXL4 deficiency has been established in 28 individuals. This paper retrospectively reviews proxy-reported clinical and biochemical findings and evaluates brain imaging, morphological and genetic data in 21 of those patients. Neonatal/early-onset severe lactic acidosis, muscular hypotonia, feeding problems and failure to thrive is the characteristic pattern at first presentation. Facial dysmorphic features are present in 67% of cases. Seven children died (mean age 37 months); 11 children were alive (mean age at follow-up 46 months), three children were lost to follow-up. All survivors developed severe psychomotor retardation. Brain imaging was non-specific in neonates but a later-onset, rapidly progressive brain atrophy was noted. Elevated blood lactate and metabolic acidosis were observed in all individuals; creatine kinase was elevated in 45% of measurements. Diagnostic workup in patient tissues and cells revealed a severe combined respiratory chain defect with a general decrease of enzymes associated with mitochondrial energy metabolism and a relative depletion of mitochondrial DNA content. Mutations were detected throughout the FBXL4 gene albeit with no clear delineation of a genotype-phenotype correlation. Treatment with "mitochondrial medications" did not prove effective. In conclusion, a clinical pattern of early-onset encephalopathy, persistent lactic acidosis, profound muscular hypotonia and typical facial dysmorphism should prompt initiation of molecular genetic analysis of FBXL4. Establishment of the diagnosis permits genetic counselling, prevents patients undergoing unhelpful diagnostic procedures and allows for accurate prognosis.

Short Stature Screening by Accurate Length Measurement in Infants with a Birth Weight <9th Centile

BACKGROUND/AIMS

Intrauterine growth restriction is an indication for growth hormone treatment. Birth length (BL) is needed to evaluate the influence of birth size on childhood short stature. However, BL is commonly measured only approximately, if at all. A single-centre study was undertaken to determine the value of measuring accurate and targeted BL and parental height (PH) for neonates with a birth weight (BW) ≤9th centile, identifying short [BL ≤-2 standard deviation scores (SDS)] and light newborns (BW ≤-2 SDS), and remeasuring short neonates at 2 years in order to detect those not showing catch-up growth.

METHODS

Information was collected on all live births (n = 3,798) in a single maternity unit during a 1-year period.

RESULTS

BW was ≤9th centile in 481 neonates (12.7%) of whom 47 were light but not short, 46 were short, and 60 were both light and short. Of 107 eligible infants, 57 (53%) attended the 2-year follow-up; failure of catch-up growth was identified in 6 infants (11%) of whom only 1 was already known to medical services. PH was measured in both parents of 52/153 (34%) light and/or short infants.

CONCLUSION

Targeted and accurate BL measurement in newborns with a BW ≤9th centile is a promising alternative to the current practices. The feasibility of PH measurement after birth still requires further evaluation. © 2015 S. Karger AG, Basel.