Abnormal brain microstructure and metabolism in small-for-gestational-age term fetuses with normal umbilical artery Doppler

Prediction of small-for-gestational age and fetal growth restriction at routine ultrasound examination at 35-37 weeks' gestation

OBJECTIVE

To evaluate the performance of sonographic fetal biometry and Doppler parameters assessed at routine third-trimester ultrasound examination for predicting small-for-gestational age (SGA) and fetal growth restriction (FGR).

METHODS

This was a retrospective cohort study of low-risk singleton pregnancies undergoing routine ultrasound examination between 35 + 0 and 37 + 6 weeks' gestation and delivered at St George's University Hospital, London, UK, between December 2019 and February 2024. The study outcomes were SGA (birth weight < 5th centile) and FGR (birth weight < 3rd centile or birth weight < 10th centile with composite adverse perinatal outcome). Composite adverse perinatal outcome comprised intrauterine death, neonatal death or admission to the neonatal intensive care unit. Demographic characteristics, estimated fetal weight (EFW) and abdominal circumference centiles, as well as Doppler indices, including pulsatility indices (PI) of the umbilical artery (UA), middle cerebral artery (MCA) and uterine artery (UtA) were evaluated. The cerebroplacental ratio (CPR) was calculated, and all indices were converted to multiples of the median (MoM). Multivariable logistic regression analysis was performed to identify and adjust for confounders. The area under the receiver-operating-characteristics curve (AUC) was used to evaluate the model's performance for predicting small neonates.

RESULTS

A total of 14 161 pregnancies were included in the study. The prevalence of SGA and FGR neonates was 3.1% and 1.5%, respectively. Independent predictors of SGA and FGR, respectively, were: EFW centile (adjusted odds ratio (aOR) 0.91 (95% CI, 0.90-0.92); P < 0.001 and aOR 0.90 (95% CI, 0.89-0.91); P < 0.001); AC centile (aOR 0.91 (95% CI, 0.90-0.92); P < 0.001 and aOR 0.91 (95% CI, 0.90-0.92); P <0.001); UA-PI MoM (aOR 4.60 (95% CI, 2.19-9.64); P < 0.001 and aOR 2.53 (95% CI, 1.05-6.10); P = 0.038); MCA-PI MoM (aOR 0.37 (95% CI, 0.20-0.70); P = 0.002 and aOR 0.26 (95% CI, 0.12-0.59); P = 0.001); CPR MoM (aOR 0.23 (95% CI, 0.13-0.42); P < 0.001 and aOR 0.25 (95% CI, 0.12-0.53); P < 0.001); and UtA-PI MoM (aOR 2.54 (95% CI, 1.68-3.83); P < 0.001 and aOR 2.16 (95% CI, 1.31-3.58); P = 0.003). The EFW centile alone was associated with an AUC of 0.917 (95% CI, 0.907-0.929) for the prediction of SGA and 0.925 (95% CI, 0.908-0.939) for the prediction of FGR. This was similar to AUCs of around 0.92 for the prediction of SGA and AUCs of around 0.93 for the prediction of FGR when the EFW centile was combined with any Doppler parameters.

CONCLUSIONS

Sonographic fetal biometry evaluation in the late third trimester can predict delivery of a neonate affected by SGA or FGR, including those at risk for adverse perinatal outcomes. In an unselected population, fetal arterial Doppler parameters were independent predictors of SGA and FGR, but the addition of Doppler parameters to fetal biometry did not improve prediction of the incidence of small neonates. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Fetal brain development in fetal growth restriction using MRI: a systematic review

BACKGROUND

This systematic review investigates potential differences in brain development between growth restricted (FGR)-fetuses compared to appropriate for gestational age (AGA) fetuses using MRI.

METHODS

PubMed, Embase, Cochrane Library and Web of Science databases were searched from 1985 to 2023. FGR was defined as an estimated fetal weight (EFW) < p10 and/or an abdominal circumference (AC) < p10, or 20% reduction in EFW or AC using a minimum interval of two weeks. Outcomes included volumetrics, biometrics, apparent diffusion coefficients (ADC), 1H-MRS-metabolites, and oxygenation of the fetal brain. Risk of bias was assessed using Newcastle-Ottawa Scale (NOS). A meta-analysis was conducted on variables when reported in at least three studies, calculating the mean difference (MD) with a 95% confidence interval (CI).

RESULTS

Twenty-nine studies were included after three-phase screening, 13 used the FGR consensus definition according to the Delphi procedure. Total brain volume and cerebellar volume were significantly reduced in FGR fetuses (n = 183; 74) when compared to AGA fetuses (n = 283; 166) with a MD of -30.84 cm3 (p < 0.01) and - 2.24 cm3 (p < 0.01). ADC values in the frontal white matter (FWM), occipital white matter (OWM), temporal white matter (TWM), thalami, centrum semiovale (CSO), basal ganglia, pons and cerebellum, significantly lower in growth restricted fetuses (-0.07 × 10-3 mm2/s (p < 0.01); -0.06 × 10-3 mm2/s (p < 0.01); -0.07 × 10-3 mm2/s (p < 0.01); -0.10 × 10-3 mm2/s (p < 0.01); -0.06 × 10-3 mm2/s (p < 0.01); -0.07 × 10-3 mm2/s (p < 0.01); -0.07 × 10-3 mm2/s (p < 0.01); -0.02 × 10-3 mm2/s (p < 0.01); respectively). 1H-MRS showed reduced levels of N-acetyl aspartate (NAA): Choline (Cho) and NAA: Creatine(CR) levels in the frontal lobe and central brain tissue, whilst contradictive findings concerning Cho: Cr and Inositol(Ino): Cho ratios were found. Two studies investigated the cerebral hemodynamic changes in FGR fetuses showing no difference in fractional moving blood volume, similar venous blood oxygenation in the superior sagittal sinus and no difference in T2* in the fetal brain.

DISCUSSION

MRI provides additional information on fetal brain development in a growth restricted population. Smaller total brain and cerebellar volumes and lower ADC values in the FWM, OWM, TWM, thalami, CSO, basal ganglia, pons and cerebellum have been observed in FGR. These conclusions are drawn on relatively small sample sizes with high heterogeneity resulting from diverse study populations and MRI techniques. Furthermore, how these findings correlate to long-term neurocognitive abnormalities associated with FGR remains to be elucidated. A large cohort study comparing brain maturation, myelination, metabolic and hemodynamic status between brain-sparing FGR fetuses to healthy age-matched controls is needed.

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

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Frontal lobe development in fetuses with growth restriction by using ultrasound: a case-control study

BACKGROUND

Fetal growth restriction (FGR) occurs in up to 10% of pregnancies and is a leading cause of perinatal mortality and neonatal morbidity. Three-dimensional ultrasonography of intracranial structure volume revealed significant differences between fetuses with FGR and appropriate for gestational age (AGA) fetuses. We aimed to compare the frontal lobe development between fetuses with FGR and appropriately grown fetuses and evaluate the impact of fetal circulatory redistribution (FCR) on frontal lobe development in fetuses with FGR.

METHODS

We performed a case-control study at our institution from August 2020 to April 2021. The frontal antero-posterior diameter (FAPD) and occipito-frontal diameter (OFD) were measured on the trans-ventricle view and we calculated the Z-scores for FAPD and OFD standardized for gestational age (GA) and transverse cerebellar diameter (TCD) by performing a standard regression analysis followed by weighted regression of absolute residual values in appropriately grown fetuses. We calculated the FAPD/OFD ratio as 100 × FAPD/OFD and FAPD/HC (head circumference) as 100 × FAPD/HC. To compare intracranial parameters, we randomly selected a control group of appropriately grown fetuses matched with the FGR group at the time of ultrasonography. We performed between-group comparisons of the FAPD Z-score, OFD Z-score, FAPD/OFD ratio and FAPD/HC. Similarly, we compared intracranial parameters between fetuses with FGR with and without FCR.

RESULTS

FAPD/OFD ratio was curvilinear related to all the independent variables (GA, BPD, FL, and TCD). Compared with appropriately grown fetuses, fetuses with FGR showed a significantly lower FAPD/OFD ratio, FAPD Z-score, and FAPD/HC. There was no significant difference in the FAPD Z-score, FAPD/OFD ratio, and FAPD/HC between FGR fetuses with and without FCR.

CONCLUSIONS

The FAPD/OFD ratio varied during pregnancy, with a mild reduction before and a mild increase after about 33 gestational weeks. Fetuses with FGR showed reduced frontal lobe growth; moreover, fetal frontal lobe development disorders were not significantly different in fetuses with FCR.

TRIAL REGISTRATION

Date: 09-27-2017; Number: [2017]239.

Taurine supplementation improves hippocampal metabolism in immature rats with intrauterine growth restriction (IUGR) through protecting neurons and reducing gliosis

Taurine as an essential amino acid in the brain could play an important role in protecting the fetal brain of intrauterine growth restriction (IUGR). The hippocampus with IUGR showed neural metabolic disorder and structure changed that affected memory and learning ability. This study was aimed to identify the effect of taurine supplementation on the metabolism alterations and cellular composition changes of the hippocampus in IUGR immature rats. Metabolite concentrations were determined by magnetic resonance spectroscopy (MRS) in the hippocampus of juvenile rats with IUGR following taurine supplementation with antenatal or postnatal supply. The composition of neural cells in the hippocampus was observed by immunohistochemical staining (IHC) and western blotting (WB). Antenatal taurine supplementation increased the ratios of N-acetylaspartate (NAA) /creatine (Cr) and glutamate (Glu) /Cr of the hippocampus in the IUGR immature rats, but reduced the ratios of choline (Cho) /Cr and myoinositol (mI) /Cr. At the same time, the protein expression of NeuN in the IUGR rats was increased through intrauterine taurine supplementation, and the GFAP expression was reduced. Especially the effect of antenatal taurine was better than postpartum. Furthermore, there existed a positive correlation between the NAA/Cr ratio and the NeuN protein expression (R = 0.496 p < 0.001 IHC; R = 0.568 p < 0.001 WB), the same results existed in the relationship between the mI/Cr ratio and the GFAP protein expression (R = 0.338 p = 0.019 IHC; R = 0.440 p = 0.002 WB). Prenatal taurine supplementation can better improve hippocampal neuronal metabolism by increasing NAA / Cr ratio related to the number of neurons and reducing Cho / Cr ratio related to the number of glial cells.

Deficient neural encoding of speech sounds in term neonates born after fetal growth restriction

Infants born after fetal growth restriction (FGR)-an obstetric condition defined as the failure to achieve the genetic growth potential-are prone to neurodevelopmental delays, with language being one of the major affected areas. Yet, while verbal comprehension and expressive language impairments have been observed in FGR infants, children and even adults, specific related impairments at birth, such as in the ability to encode the sounds of speech, necessary for language acquisition, remain to be disclosed. Here, we used the frequency-following response (FFR), a brain potential correlate of the neural phase locking to complex auditory stimuli, to explore the encoding of speech sounds in FGR neonates. Fifty-three neonates born with FGR and 48 controls born with weight adequate-for-gestational age (AGA) were recruited. The FFR was recorded to the consonant-vowel stimulus (/da/) during sleep and quantified as the spectral amplitude to the fundamental frequency of the syllable and its signal-to-noise ratio (SNR). The outcome was available in 45 AGA and 51 FGR neonates, yielding no differences for spectral amplitudes. However, SNR was strongly attenuated in the FGR group compared to the AGA group at the vowel region of the stimulus. These findings suggest that FGR population present a deficit in the neural pitch tracking of speech sounds already present at birth. Our results pave the way for future research on the potential clinical use of the FFR in this population, so that if confirmed, a disrupted FFR recorded at birth may help deriving FGR neonates at risk for postnatal follow-ups.

Fetal neurosonography detects differences in cortical development and corpus callosum in late-onset small fetuses

OBJECTIVE

To explore whether neurosonography can detect differences in cortical development and corpus callosal length in late-onset small fetuses subclassified into small-for-gestational age (SGA) or growth restricted (FGR).

METHODS

This was a prospective cohort study in singleton pregnancies, including normally grown fetuses (birth weight between the 10^th and 90^th centiles) and late-onset small fetuses (estimated fetal weight < 10^th centile, diagnosed after 32 weeks of gestation and confirmed by birth weight < 10^th centile). Small fetuses were subclassified into SGA (birth weight between the 3^rd and 9^th centiles and normal fetoplacental Doppler) and FGR (birth weight < 3^rd centile and/or abnormal cerebroplacental ratio and/or abnormal uterine artery Doppler). Neurosonography was performed at 33 ± 1 weeks of gestation to assess the depth of the insula, Sylvian fissure and parieto-occipital sulcus in the axial views and corpus callosal length in the midsagittal plane. Measurements were performed offline using Alma Workstation software and were adjusted by biparietal diameter or cephalic index. Linear regression analysis was used to assess the association between the neurosonographic variables and study group, adjusting for confounding factors such as gender, gestational age at neurosonography, nulliparity and pre-eclampsia.

RESULTS

In total, 318 fetuses were included, of which 97 were normally grown and 221 were late-onset small fetuses that were further subdivided into late-onset SGA (n = 67) or late-onset FGR (n = 154). Compared to controls, both SGA and FGR cases showed significantly increased insular depth adjusted for biparietal diameter (median (interquartile range), controls 0.329 (0.312-0.342) vs SGA 0.339 (0.321-0.347) vs FGR 0.336 (0.325-0.349); P = 0.006). A linear tendency to reduced Sylvian fissure depth adjusted for biparietal diameter was also observed across the study groups (mean ± SD, controls 0.148 ± 0.021 vs SGA 0.142 ± 0.025 vs FGR 0.139 ± 0.022; P = 0.003). However, differences were significant only between the FGR and control groups. Corpus callosal length adjusted for cephalic index was significantly reduced in FGR cases compared with both controls and SGA cases, while there was no difference between SGA cases and controls (median (interquartile range), controls 0.500 (0.478-0.531) vs SGA 0.502 (0.487-0.526) vs FGR 0.475 (0.447-0.508); P = 0.005). No differences were found in parieto-occipital sulcus depth between the three study groups.

CONCLUSION

Neurosonography seems to be a sensitive tool to detect subtle structural differences in brain development in late-onset small fetuses. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Neurodevelopment of infant with late fetal growth restriction

Late fetal growth restriction has increasingly gain interest. Differently from early fetal growth restriction, the severity of this condition and the impact on perinatal mortality and morbidity is less severe. Nevertheless, there is some evidence to suggest that fetuses exposed to growth restriction late in pregnancy are at increased risk of neurological dysfunction and behavioral impairment. The aim of our review was to discuss the available evidence on the neurodevelopmental outcome in fetuses exposed to growth restriction late in pregnancy. Cerebral blood flow redistribution, a Doppler hallmark of late fetal growth restriction, has been associated with this increased risk, although there are still some controversies. Currently, most of the available studies are heterogeneous and do not distinguish between early and late fetal growth restriction when evaluating the long-term outcome, thus, making the correlation between late fetal growth restriction and neurological dysfunction difficult to interpret. The available evidence suggests that fetuses exposed to late growth restriction are at increased risk of neurological dysfunction and behavioral impairment. The presence of the cerebral blood flow redistribution seems to be associated with adverse neurodevelopmental outcome, however, from the present literature the causality cannot be ascertained.

FIGO (international Federation of Gynecology and obstetrics) initiative on fetal growth: best practice advice for screening, diagnosis, and management of fetal growth restriction

Fetal growth restriction (FGR) is defined as the failure of the fetus to meet its growth potential due to a pathological factor, most commonly placental dysfunction. Worldwide, FGR is a leading cause of stillbirth, neonatal mortality, and short- and long-term morbidity. Ongoing advances in clinical care, especially in definitions, diagnosis, and management of FGR, require efforts to effectively translate these changes to the wide range of obstetric care providers. This article highlights agreements based on current research in the diagnosis and management of FGR, and the areas that need more research to provide further clarification of recommendations. The purpose of this article is to provide a comprehensive summary of available evidence along with practical recommendations concerning the care of pregnancies at risk of or complicated by FGR, with the overall goal to decrease the risk of stillbirth and neonatal mortality and morbidity associated with this condition. To achieve these goals, FIGO (the International Federation of Gynecology and Obstetrics) brought together international experts to review and summarize current knowledge of FGR. This summary is directed at multiple stakeholders, including healthcare providers, healthcare delivery organizations and providers, FIGO member societies, and professional organizations. Recognizing the variation in the resources and expertise available for the management of FGR in different countries or regions, this article attempts to take into consideration the unique aspects of antenatal care in low-resource settings (labelled “LRS” in the recommendations). This was achieved by collaboration with authors and FIGO member societies from low-resource settings such as India, Sub-Saharan Africa, the Middle East, and Latin America.

Blood myo-inositol concentrations in preterm and term infants

OBJECTIVE

To describe relationship between cord blood (representing fetal) myo-inositol concentrations and gestational age (GA) and to determine trends of blood concentrations in enterally and parenterally fed infants from birth to 70 days of age.

DESIGN/METHODS

Samples were collected in 281 fed or unfed infants born in 2005 and 2006. Myo-inositol concentrations were displayed in scatter plots and analyzed with linear regression models of natural log-transformed values.

RESULTS

In 441 samples obtained from 281 infants, myo-inositol concentrations varied from nondetectable to 1494 μmol/L. Cord myo-inositol concentrations decreased an estimated 11.9% per week increase in GA. Postnatal myo-inositol concentrations decreased an estimated 14.3% per week increase in postmenstrual age (PMA) and were higher for enterally fed infants compared to unfed infants (51% increase for fed vs. unfed infants).

CONCLUSIONS

Fetal myo-inositol concentrations decreased with increasing GA. Postnatal concentrations decreased with increasing PMA and were higher among enterally fed than unfed infants.

Prognostic value of diffusion-weighted magnetic resonance imaging of brain in fetal growth restriction: results of prospective multicenter study

OBJECTIVE

To measure prospectively apparent diffusion coefficient (ADC) values between 28 and 32 weeks of gestation in different cerebral territories of fetuses with estimated fetal weight (EFW) ≤ 5^th centile, and analyze their association with adverse perinatal outcome.

METHODS

This was a prospective study involving six tertiary-level perinatal centers. In the period 22 November 2016 to 11 September 2017, we included singleton, small-for-gestational-age (SGA) fetuses with EFW ≤ 5^th percentile, between 28 and 32 weeks of gestation, regardless of the umbilical artery Doppler and maternal uterine artery Doppler findings. A fetal magnetic resonance imaging (MRI) examination with diffusion-weighted sequences (DWI) was performed within 14 days following inclusion and before 32 weeks. ADC values were calculated in the frontal and occipital white matter, basal ganglia and cerebellar hemispheres. An ultrasound examination was performed within 1 week prior to the MRI examination. The primary outcome was a composite measure of adverse perinatal outcome, defined as any of the following: perinatal death; admission to neonatal intensive care unit with mechanical ventilation > 48 h; necrotizing enterocolitis; Grade III-IV intraventricular hemorrhage; periventricular leukomalacia. A univariate comparison of median ADC values in all cerebral territories between fetuses with and those without adverse perinatal outcome was performed. The association between ADC values and adverse perinatal outcome was then analyzed using multilevel logistic regression models to adjust for other common prognostic factors for growth-restricted fetuses.

RESULTS

MRI was performed in 64 patients, of whom five were excluded owing to fetal movement artifacts on DWI and two were excluded for termination of pregnancy with no link to fetal growth restriction (FGR). One intrauterine death occurred secondary to severe FGR. Among the 56 liveborn neonates, delivered at a mean ± SD gestational age of 33.6 ± 3.0 weeks, with a mean birth weight of 1441 ± 566 g, four neonatal deaths occurred. In addition, two neonates required prolonged mechanical ventilation, one of whom also developed necrotizing enterocolitis. Overall, therefore, seven out of 57 (12.3%) cases had an adverse perinatal outcome (95% CI, 3.8-20.8%). The ADC values in the frontal region were significantly lower in the group with adverse perinatal outcome vs those in the group with favorable outcome (mean values of both hemispheres, 1.68 vs 1.78 × 10^-3  mm² /s; P = 0.04). No significant difference in ADC values was observed between the two groups in any other cerebral territory. A cut-off value of 1.70 × 10^-3  mm² /s was associated with a sensitivity of 57% (95% CI, 18-90%), a specificity of 78% (95% CI, 63-88%), a positive predictive value of 27% (95% CI, 8-55%) and a negative predictive value of 93% (95% CI, 80-98%) for the prediction of adverse perinatal outcome. A mean frontal ADC value < 1.70 × 10^-3  mm² /s was not associated significantly with an increased risk of adverse perinatal outcome, either in the univariate analysis (P = 0.07), or when adjusting for gestational age at MRI and fetal sex (odds ratio (OR), 6.06 (95% CI, 0.9-37.1), P = 0.051) or for umbilical artery Doppler (OR, 6.08 (95% CI, 0.89-41.44)).

CONCLUSION

This first prospective, multicenter, cohort study using DWI in the setting of SGA found lower ADC values in the frontal white-matter territory in fetuses with, compared with those without, adverse perinatal outcome. To determine the prognostic value of these changes, further standardized evaluation of the neurodevelopment of children born with growth restriction is required. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Effects of maternal stress and nutrient restriction during gestation on offspring neuroanatomy in humans

Cognitive and mental health are major determinants of quality of life, allowing integration into society at all ages. Human epidemiological and animal studies indicate that in addition to genetic factors and lifestyle, prenatal environmental influences may program neuropsychiatric disorders in later life. While several human studies have examined the effects of prenatal stress and nutrient restriction on brain function and mental health in later life, potentially mediating effects of prenatal stress and nutrient restriction on offspring neuroanatomy in humans have been studied only in recent years. Based on neuroimaging and anatomical data, we comprehensively review the studies in this emerging field. We relate prenatal environmental influences to neuroanatomical abnormalities in the offspring, measured in utero and throughout life. We also assess the relationship between neuroanatomical abnormalities and cognitive and mental disorders. Timing- and gender-specific effects are considered, if reported. Our review provides evidence for adverse effects of an unfavorable prenatal environment on structural brain development that may contribute to the risk for cognitive, behavioral and mental health problems throughout life.

Society for Maternal-Fetal Medicine Consult Series #52: Diagnosis and management of fetal growth restriction: (Replaces Clinical Guideline Number 3, April 2012)

Fetal growth restriction can result from a variety of maternal, fetal, and placental conditions. It occurs in up to 10% of pregnancies and is a leading cause of infant morbidity and mortality. This complex obstetrical problem has disparate published diagnostic criteria, relatively low detection rates, and limited preventative and treatment options. The purpose of this Consult is to outline an evidence-based, standardized approach for the prenatal diagnosis and management of fetal growth restriction. The recommendations of the Society for Maternal-Fetal Medicine are as follows: (1) we recommend that fetal growth restriction be defined as an ultrasonographic estimated fetal weight or abdominal circumference below the 10th percentile for gestational age (GRADE 1B); (2) we recommend the use of population-based fetal growth references (such as Hadlock) in determining fetal weight percentiles (GRADE 1B); (3) we recommend against the use of low-molecular-weight heparin for the sole indication of prevention of recurrent fetal growth restriction (GRADE 1B); (4) we recommend against the use of sildenafil or activity restriction for in utero treatment of fetal growth restriction (GRADE 1B); (5) we recommend that a detailed obstetrical ultrasound examination (current procedural terminology code 76811) be performed with early-onset fetal growth restriction (<32 weeks of gestation) (GRADE 1B); (6) we recommend that women be offered fetal diagnostic testing, including chromosomal microarray analysis, when fetal growth restriction is detected and a fetal malformation, polyhydramnios, or both are also present regardless of gestational age (GRADE 1B); (7) we recommend that pregnant women be offered prenatal diagnostic testing with chromosomal microarray analysis when unexplained isolated fetal growth restriction is diagnosed at <32 weeks of gestation (GRADE 1C); (8) we recommend against screening for toxoplasmosis, rubella, or herpes in pregnancies with fetal growth restriction in the absence of other risk factors and recommend polymerase chain reaction for cytomegalovirus in women with unexplained fetal growth restriction who elect diagnostic testing with amniocentesis (GRADE 1C); (9) we recommend that once fetal growth restriction is diagnosed, serial umbilical artery Doppler assessment should be performed to assess for deterioration (GRADE 1C); (10) with decreased end-diastolic velocity (ie, flow ratios greater than the 95th percentile) or in pregnancies with severe fetal growth restriction (estimated fetal weight less than the third percentile), we suggest weekly umbilical artery Doppler evaluation (GRADE 2C); (11) we recommend Doppler assessment up to 2-3 times per week when umbilical artery absent end-diastolic velocity is detected (GRADE 1C); (12) in the setting of reversed end-diastolic velocity, we suggest hospitalization, administration of antenatal corticosteroids, heightened surveillance with cardiotocography at least 1-2 times per day, and consideration of delivery depending on the entire clinical picture and results of additional evaluation of fetal well-being (GRADE 2C); (13) we suggest that Doppler assessment of the ductus venosus, middle cerebral artery, or uterine artery not be used for routine clinical management of early- or late-onset fetal growth restriction (GRADE 2B); (14) we suggest weekly cardiotocography testing after viability for fetal growth restriction without absent/reversed end-diastolic velocity and that the frequency be increased when fetal growth restriction is complicated by absent/reversed end-diastolic velocity or other comorbidities or risk factors (GRADE 2C); (15) we recommend delivery at 37 weeks of gestation in pregnancies with fetal growth restriction and an umbilical artery Doppler waveform with decreased diastolic flow but without absent/reversed end-diastolic velocity or with severe fetal growth restriction with estimated fetal weight less than the third percentile (GRADE 1B); (16) we recommend delivery at 33-34 weeks of gestation for pregnancies with fetal growth restriction and absent end-diastolic velocity (GRADE 1B); (17) we recommend delivery at 30-32 weeks of gestation for pregnancies with fetal growth restriction and reversed end-diastolic velocity (GRADE 1B); (18) we suggest delivery at 38-39 weeks of gestation with fetal growth restriction when the estimated fetal weight is between the 3rd and 10th percentile and the umbilical artery Doppler is normal (GRADE 2C); (19) we suggest that for pregnancies with fetal growth restriction complicated by absent/reversed end-diastolic velocity, cesarean delivery should be considered based on the entire clinical scenario (GRADE 2C); (20) we recommend the use of antenatal corticosteroids if delivery is anticipated before 33 6/7 weeks of gestation or for pregnancies between 34 0/7 and 36 6/7 weeks of gestation in women without contraindications who are at risk of preterm delivery within 7 days and who have not received a prior course of antenatal corticosteroids (GRADE 1A); and (21) we recommend intrapartum magnesium sulfate for fetal and neonatal neuroprotection for women with pregnancies that are <32 weeks of gestation (GRADE 1A).

Apparent diffusion coefficient of different areas of brain in foetuses with intrauterine growth restriction

Purpose

This study aimed to compare the apparent diffusion coefficient (ADC) values of different brain areas between two groups of intrauterine growth restricted (IUGR) foetuses and control cases.

Material and methods

A total of 38 foetuses with IUGR and 18 normal control foetuses with similar gestational age were compared using a 3T magnetic resonance scanner. IUGR cases included 23 foetuses with clinical severity signs (group A) and 15 foetuses without clinical severity signs (group B). ADC values were measured in different brain regions and compared among groups. Foetuses with structural brain abnormalities were excluded from the study.

Results

All foetuses had normal foetal structural brain anatomy. Head circumference (HC) < 5% was more common in IUGR group A compared to IUGR group B (56.5% vs. 13.3%, p < 0.0001). In comparison to the normal group, the ADC values in IUGR foetuses were significantly lower in cerebellar hemispheres (CH) (1.239 vs. 1.280.5 × 10^-3 mm²/s, p = 0.045), thalami (1.205 vs. 1.285 × 10^-3 mm²/s, p = 0.031) and caudate nucleus (CN) (1.319 vs. 1.394 × 10^-3 mm²/s, p = 0.04). However, there were no significant differences in ADC values between IUGR subtypes. Among all brain regions, pons had the lowest ADC values.

Conclusions

ADC values of thalami, CN, and CH were significantly lower in IUGR than control foetuses, while there was no significant difference among IUGR groups. Further studies are needed to evaluate the prognostic value of ADC changes in IUGR foetuses.

Delayed neonatal visual evoked potentials are associated to asymmetric growth pattern in twins

OBJECTIVES

To study the association between intrauterine growth and visual pathways maturation by neonatal visual evoked potentials (VEPs) in twins, in view of a possible prognostic role.

METHODS

Seventy-four twin neonates from 37 pregnancies were selected based on gestational age of more than 30 weeks and uneventful perinatal clinical course. Flash VEPs were recorded at the same postmenstrual age in each twin pair. The association between P2 latency and anthropometric variables at birth was analyzed by comparison within each twin pair and regarding each variable as ordered difference between the two twins.

RESULTS

Analysis of differences within each twin pair highlighted that inter-twin difference in P2 latency was significantly related to difference in ponderal index (PI) (p = 0.048). Expressing the difference in latency as a categorical binary variable, the correlation was significant for both difference in PI, (median difference = -0.36, 95% CI -0.54 to -0.14, p = 0.001) and difference in body mass index (BMI), (median difference = -1.06, 95% CI -1.74 to -0.29, p = 0.006).

CONCLUSIONS

Lower values of PI and BMI differences are associated to delayed VEP latency in twin pairs.

SIGNIFICANCE

VEP latency suggests reduced myelination of visual pathways when difference in growth pattern occurs in twins.

Premature placental aging in term small-for-gestational-age and growth-restricted fetuses

OBJECTIVE

To perform a comprehensive assessment of the placental aging process in small term fetuses classified as being small-for-gestational age (SGA) or having fetal growth restriction (FGR) through analysis of senescence and apoptosis markers.

METHODS

This was a prospective nested case-control study of singleton pregnancies delivered at term, including 21 control pregnancies with normally grown fetuses and 36 with a small fetus classified as SGA (birth weight between the 3^rd and 9^th percentiles and normal fetoplacental Doppler; n = 18) or FGR (birth weight < 3^rd percentile and/or abnormal cerebroplacental ratio and/or uterine artery Doppler; n = 18). Telomerase activity, telomere length (quantified by comparing the amount of amplification product for the telomere sequence (T) to that of a single copy of the gene 36B4 (S)) and RNA expression of senescence (Sirtuins 1, 3 and 6) and apoptosis (p53, p21, BAX and Caspases 3 and 9) markers (analyzed using the 2^-ΔΔCt method) were determined in placental samples collected at birth and compared between the three groups.

RESULTS

Compared to pregnancies with a normally grown fetus, both SGA and FGR pregnancies presented signs of accelerated placental aging, including lower telomerase activity (mean ± SD, 12.8 ± 6.6% in controls vs 7.98 ± 4.2% in SGA vs 7.79 ± 4.6% in FGR; P = 0.008), shorter telomeres (mean ± SD T/S ratio, 1.20 ± 0.6 in controls vs 1.08 ± 0.9 in SGA vs 0.66 ± 0.5 in FGR; P = 0.047) and reduced Sirtuin-1 RNA expression (mean ± SD 2^-ΔΔCt , 1.55 ± 0.8 in controls vs 0.91 ± 0.8 in SGA vs 0.63 ± 0.5 in FGR; P = 0.001) together with increased p53 RNA expression (median (interquartile range) 2^-ΔΔCt , 1.07 (0.3-3.3) in controls vs 5.39 (0.6-15) in SGA vs 3.75 (0.9-7.8) in FGR; P = 0.040). FGR cases presented signs of apoptosis, with increased Caspase-3 RNA levels (median (interquartile range) 2^-ΔΔCt , 0.94 (0.7-1.7) in controls vs 3.98 (0.9-31) in FGR; P = 0.031) and Caspase-9 RNA levels (median (interquartile range) 2^-ΔΔCt , 1.21 (0.6-4.0) in controls vs 3.87 (1.5-9.0) in FGR; P = 0.037) compared with controls. In addition, Sirtuin-1 RNA expression, telomerase activity, telomere length and Caspase-3 activity showed significant linear trends across groups as severity of the condition increased.

CONCLUSIONS

Accelerated placental aging was observed in both clinical forms of late-onset fetal smallness (SGA and FGR), supporting a common pathophysiology and challenging the concept of SGA fetuses being constitutionally small. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Association of Fetal Growth Restriction With Neurocognitive Function After Repeated Antenatal Betamethasone Treatment vs Placebo: Secondary Analysis of the ACTORDS Randomized Clinical Trial

Importance

Repeated doses of antenatal betamethasone are recommended for women at less than 32 weeks' gestation with ongoing risk of preterm birth. However, concern that this therapy may be associated with adverse neurocognitive effects in children with fetal growth restriction (FGR) remains.

Objective

To determine the influence of FGR on the effects of repeated doses of antenatal betamethasone on neurocognitive function in midchildhood.

Design, Setting, and Participants

This preplanned secondary analysis of data from the multicenter Australasian Collaborative Trial of Repeat Doses of Corticosteroids (ACTORDS) included women at less than 32 weeks' gestation with ongoing risk of preterm birth (<32 weeks) at least 7 days after an initial course of antenatal corticosteroids who were treated at 23 hospitals across Australia and New Zealand from April 1, 1998, through July 20, 2004. Participants were randomized to intramuscular betamethasone or saline placebo; treatment could be repeated weekly if the woman was judged to be at continued risk of preterm birth. All surviving children were invited to a midchildhood outcome study. Data for this study were collected from October 27, 2006, through March 18, 2011, and analyzed from June 1 through 30, 2018.

Interventions

At 6 to 8 years of corrected age, children were assessed by a pediatrician and psychologist for neurosensory and cognitive function, and parents completed standardized questionnaires.

Main Outcomes and Measures

The prespecified primary outcomes were survival free of any disability and death or survival with moderate to severe disability.

Results

Of 1059 eligible children, 988 (55.0% male; mean [SD] age at follow-up, 7.5 [1.1] years) were assessed at midchildhood. The FGR rate was 139 of 493 children (28.2%) in the repeated betamethasone treatment group and 122 of 495 (24.6%) in the placebo group (P = .20). Primary outcome rates were similar between treatment groups for the FGR and non-FGR subgroups, with no evidence of an interaction effect for survival free of any disability (FGR group, 108 of 144 [75.0%] for repeated betamethasone treatment vs 91 of 126 [72.2%] for placebo groups [odds ratio [OR], 1.1; 95% CI, 0.6-1.9]; non-FGR group, 267 of 335 [79.7%] for repeated betamethasone vs 283 of 358 [79.0%] for placebo groups [OR, 1.0; 95% CI, 0.7-1.5]; P = .77) and death or moderate to severe disability (FGR group, 21 of 144 [14.6%] for repeated betamethasone treatment vs 20 of 126 [15.9%] for placebo groups [OR, 0.9; 95% CI, 0.4-1.9]; non-FGR group, 29 of 335 [8.6%] for repeated betamethasone vs 36 of 358 [10.0%] for placebo [OR, 0.8; 95% CI, 0.4-1.3]; P = .84).

Conclusions and Relevance

In this study, repeated antenatal betamethasone treatment compared with placebo was not associated with adverse effects on neurocognitive function at 6 to 8 years of age, even in the presence of FGR. Physicians should use repeated doses of antenatal corticosteroids when indicated before preterm birth, regardless of FGR, in view of the associated neonatal benefits and absence of later adverse effects.

Trial Registration

anzctr.org.au Identifier: ACTRN12606000318583.

Fetal brain development at 25-39 weeks gestational age: A preliminary study using intravoxel incoherent motion diffusion-weighted imaging

BACKGROUND

The fetal brain developmental changes of water diffusivity and perfusion has not been extensively explored.

PURPOSE/HYPOTHESIS

To evaluate the fetal brain developmental changes of water diffusivity and perfusion using intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI).

STUDY TYPE

Prospective.

POPULATION

Seventy-nine normal singleton fetuses were scanned without sedation of healthy pregnant women.

FIELD STRENGTH/SEQUENCE

5 T MRI/T₁ /₂ -weighted image and IVIM-DWI.

ASSESSMENT

Pure diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) values were calculated in the frontal (FWM), temporal (TWM), parietal (PWM), and occipital white matter (OWM) as well as cerebellar hemisphere (CH), basal ganglia region (BGR), thalamus (TH), and pons using an IVIM model.

STATISTICAL TESTS

One-way analysis of variable (ANOVA) followed by Bonferroni post-hoc multiple comparison was employed to reveal the difference of IVIM parameters among the investigated brain regions. The linear and the nonlinear polynomial regression analyses were utilized to reveal the correlation between gestational age (GA) and IVIM parameters.

RESULTS

There were significant differences in both D (F(7,623) = 96.64, P = 0.000) and f values (F(7,623) = 2.361, P = 0.0219), but not D* values among the varied brain regions. D values from TWM (r²  = 0.1402, P = 0.0002), PWM (r²  = 0.2245, P = 0.0002), OWM (r²  = 0.2519, P = 0.0002), CH (r²  = 0.2245, P = 0.0002), BGR (r²  = 0.3393, P = 0.0001), TH (r²  = 0.1259, P = 0.0001), and D* value from pons (r²  = 0.2206, P = 0.0002) were significantly correlated with GA using linear regression analysis. Quadratic regression analysis led to results similar to those using the linear regression model.

DATA CONCLUSION

IVIM-DWI parameters may indicate fetal brain developmental alterations but the conclusion is far from reached due to the not as high-powered correlation between IVIM parameters and GA.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;50:899-909.

Fetal neurology: Principles and practice with a life-course perspective

Clinical service, educational, and research components of a fetal/neonatal neurology program are anchored by the disciplines of developmental origins of health and disease and life-course science as programmatic principles. Prenatal participation provides perspectives on maternal, fetal, and placental contributions to health or disease for fetal and subsequent neonatal neurology consultations. This program also provides an early-life diagnostic perspective for neurologic specialties concerned with brain health and disease throughout childhood and adulthood. Animal models and birth cohort studies have demonstrated how the science of epigenetics helps to understand gene-environment interactions to better predict brain health or disease. Fetal neurology consultations provide important diagnostic contributions during critical or sensitive periods of brain development when future neurotherapeutic interventions will maximize adaptive neuroplasticity. Age-specific normative neuroinformatics databases that employ computer-based strategies to integrate clinical/demographic, neuroimaging, neurophysiologic, and genetic datasets will more accurately identify either symptomatic patients or those at risk for brain disorders who would benefit from preventive, rescue, or reparative treatment choices throughout the life span.

Diffusion-weighted magnetic resonance imaging of the fetal brain in intrauterine growth restriction

OBJECTIVE

Diffusion-weighted magnetic resonance imaging (DWI) is a sensitive method for assessing brain maturation and detecting brain lesions, providing apparent diffusion coefficient (ADC) values as a measure of water diffusion. Abnormal ADC values are seen in ischemic brain lesions, such as those associated with acute or chronic hypoxia. The aim of this study was to assess whether ADC values in the fetal brain were different in fetuses with severe intrauterine growth restriction (IUGR) compared with normal controls.

METHODS

Brain magnetic resonance imaging (MRI) with single-shot axial DWI (b = 0 and b = 700 s/mm² ) was performed in 30 fetuses with severe IUGR (estimated fetal weight < 3^rd centile with absent or reversed umbilical artery Doppler flow) and in 24 normal controls of similar gestational age. Brain morphology and biometry were analyzed. ADC values were measured in frontal and occipital white matter, centrum semiovale, thalami, cerebellar hemisphere and pons. Frontal-occipital and frontal-cerebellar ADC ratios were calculated, and values were compared between IUGR fetuses and controls.

RESULTS

There was no difference in gestational age at MRI between IUGR and control fetuses (IUGR, 30.2 ± 1.6 weeks vs controls, 30.7 ± 1.4 weeks). Fetal brain morphology and signals were normal in all fetuses. Brain dimensions (supratentorial ± infratentorial) were decreased (Z-score, < -2) in 20 (66.7%) IUGR fetuses. Compared with controls, IUGR fetuses had significantly lower ADC values in frontal white matter (1.97 ± 0.23 vs 2.17 ± 0.22 × 10^-3 mm² /s; P < 0.0001), thalami (1.04 ± 0.15 vs 1.13 ± 0.10 ×10^-3 mm² /s; P = 0.0002), centrum semiovale (1.86 ± 0.22 vs 1.97 ± 0.23 ×10^-3 mm² /s; P = 0.01) and pons (0.85 ± 0.19 vs 0.94 ± 0.12 ×10^-3 mm² /s; P = 0.043). IUGR fetuses had a lower frontal-occipital ADC ratio than did normal fetuses (1.00 ± 0.11 vs 1.08 ± 0.05; P = 0.003).

CONCLUSIONS

ADC values in IUGR fetuses were significantly lower than in normal controls in the frontal white matter, thalami, centrum semiovale and pons, suggesting abnormal maturation in these regions. However, the prognostic value of these ADC changes is still unknown. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Volumetric MRI study of the intrauterine growth restriction fetal brain

OBJECTIVES

Intrauterine growth restriction (IUGR) is a pathologic fetal condition known to affect the fetal brain regionally and associated with future neurodevelopmental abnormalities. This study employed MRI to assess in utero regional brain volume changes in IUGR fetuses compared to controls.

METHODS

Retrospectively, using MRI images of fetuses at 30-34 weeks gestational age, a total of 8 brain regions-supratentorial brain and cavity, cerebral hemispheres, temporal lobes and cerebellum-were measured for volume in 13 fetuses with IUGR due to placental insufficiency and in 21 controls. Volumes and their ratios were assessed for difference using regression models. Reliability was assessed by intraclass correlation coefficients (ICC) between two observers.

RESULTS

In both groups, all structures increase in absolute volume during that gestation period, and the rate of cerebellar growth is higher compared to that of supratentorial structures. All structures' absolute volumes were significantly smaller for the IUGR group. Cerebellar to supratentorial ratios were found to be significantly smaller (P < 0.05) for IUGR compared to controls. No other significant ratio differences were found. ICC showed excellent agreement.

CONCLUSIONS

The cerebellar to supratentorial volume ratio is affected in IUGR fetuses. Additional research is needed to assess this as a radiologic marker in relation to long-term outcome.

KEY POINTS

• IUGR is a pathologic fetal condition affecting the brain • IUGR is associated with long-term neurodevelopmental abnormalities; fetal characterization is needed • This study aimed to evaluate regional brain volume differences in IUGR • Cerebellar to supratentorial volume ratios were smaller in IUGR fetuses • This finding may play a role in long-term development of IUGR fetuses.

Motor and cortico-striatal-thalamic connectivity alterations in intrauterine growth restriction

BACKGROUND

Intrauterine growth restriction is associated with short- and long-term neurodevelopmental problems. Structural brain changes underlying these alterations have been described with the use of different magnetic resonance-based methods that include changes in whole structural brain networks. However, evaluation of specific brain circuits and its correlation with related functions has not been investigated in intrauterine growth restriction.

OBJECTIVES

In this study, we aimed to investigate differences in tractography-related metrics in cortico-striatal-thalamic and motor networks in intrauterine growth restricted children and whether these parameters were related with their specific function in order to explore its potential use as an imaging biomarker of altered neurodevelopment.

METHODS

We included a group of 24 intrauterine growth restriction subjects and 27 control subjects that were scanned at 1 year old; we acquired T1-weighted and 30 directions diffusion magnetic resonance images. Each subject brain was segmented in 93 regions with the use of anatomical automatic labeling atlas, and deterministic tractography was performed. Brain regions included in motor and cortico-striatal-thalamic networks were defined based in functional and anatomic criteria. Within the streamlines that resulted from the whole brain tractography, those belonging to each specific circuit were selected and tractography-related metrics that included number of streamlines, fractional anisotropy, and integrity were calculated for each network. We evaluated differences between both groups and further explored the correlation of these parameters with the results of socioemotional, cognitive, and motor scales from Bayley Scale at 2 years of age.

RESULTS

Reduced fractional anisotropy (cortico-striatal-thalamic, 0.319 ± 0.018 vs 0.315 ± 0.015; P = .010; motor, 0.322 ± 0.019 vs 0.319 ± 0.020; P = .019) and integrity cortico-striatal-thalamic (0.407 ± 0.040 vs 0.399 ± 0.034; P = .018; motor, 0.417 ± 0.044 vs 0.409 ± 0.046; P = .016) in both networks were observed in the intrauterine growth restriction group, with no differences in number of streamlines. More importantly, strong specific correlation was found between tractography-related metrics and its relative function in both networks in intrauterine growth restricted children. Motor network metrics were correlated specifically with motor scale results (fractional anisotropy: rho = 0.857; integrity: rho = 0.740); cortico-striatal-thalamic network metrics were correlated with cognitive (fractional anisotropy: rho = 0.793; integrity, rho = 0.762) and socioemotional scale (fractional anisotropy: rho = 0.850; integrity: rho = 0.877).

CONCLUSIONS

These results support the existence of altered brain connectivity in intrauterine growth restriction demonstrated by altered connectivity in motor and cortico-striatal-thalamic networks, with reduced fractional anisotropy and integrity. The specific correlation between tractography-related metrics and neurodevelopmental outcomes in intrauterine growth restriction shows the potential to use this approach to develop imaging biomarkers to predict specific neurodevelopmental outcome in infants who are at risk because of intrauterine growth restriction and other prenatal diseases.

Region-specific reductions in brain apparent diffusion coefficient in cytomegalovirus-infected fetuses

OBJECTIVE

To evaluate the effects of cytomegalovirus (CMV) infection on apparent diffusion coefficient (ADC) values of the fetal brain in utero.

METHODS

In this retrospective analysis we compared 58 fetal head magnetic resonance imaging (fhMRI) scans of PCR-verified CMV-infected fetuses, obtained in 2008-2012, with those of a normal control group of 36 gestational age (GA)-matched uninfected fetuses scanned between 2006 and 2012. Estimated GA at infection ranged from 1 to 32 weeks, and fhMRI was performed at 24 to 38 weeks. The frontal, parietal, temporal and occipital lobes (mainly white matter), basal ganglia, thalamus, pons and cerebellum were analyzed by assessing ADC values. Two pregnancies were terminated and postmortem confirmation was available in these cases.

RESULTS

ADC values of CMV-infected fetuses correlated significantly and negatively with GA in all brain regions except the basal ganglia. The cerebellum had the greatest reduction (r = -0.52, P < 0.0001). Maternal age correlated positively with ADC in the frontal lobe (P < 0.05). GA at infection and overt pathological changes did not affect ADC significantly. Compared with non-infected fetuses, ADC values of affected fetuses were significantly reduced in the frontal (P < 0.0001), parietal (P < 0.0001), occipital (P = 0.0005) and temporal (P = 0.001) lobes and thalamus (P = 0.006).

CONCLUSION

CMV infection of the fetal brain results in a highly significant, region-dependent reduction of ADC values in the frontal, parietal, occipital and temporal lobes and thalamus, probably reflecting hypercellularity and inclusion bodies in damaged areas. Further studies are needed to determine if reduction in ADC values may serve as a prognostic factor in CMV-infected fetuses. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Respiratory sinus arrhythmia in growth restricted fetuses with normal Doppler hemodynamic indices

BACKGROUND

The autonomic behavior of growth-restricted fetuses at different evolving hemodynamic stages has not been fully elicited.

AIM

To analyze the respiratory sinus arrhythmia (RSA) of growth-restricted fetuses that despite this severe condition show normal Doppler hemodynamics.

SUBJECTS

10 growth-restricted fetuses (FGR group) with normal arterial pulsatility indices (umbilical, uterine, middle cerebral, ductus venosus and aortic isthmus), and 10 healthy fetuses (Control group), 32-37weeks of gestation.

METHOD

B-mode ultrasound images for visualizing fetal breathing movements (FBM) or breathing akinesis (FBA), and the simultaneous RR-interval time series from maternal abdominal ECG recordings were obtained. The root-mean-square of successive differences of RR-intervals (RMSSD) was considered as a RSA-related parameter among the instantaneous amplitude of the high-frequency component (AMPHF) and its corresponding instantaneous frequency (IFHF), both computed by using empirical mode decomposition. Mean fetal heart-periods and RSA-related parameters were assessed during episodes of FBM and FBA in 30s length windows.

RESULTS

FGR and Control groups presented RSA-related fluctuations during FBM and FBA. Also, both groups showed significant higher (p<0.001) values for the mean heart-period, RMSSD and AMPHF during FBM. No-significant differences (p>0.05) were found for the IFHF regardless of breathing activity (FBM vs. FBA).

CONCLUSION

Growth-restricted fetuses without evident hemodynamic compromise exhibit a preserved autonomic cardiovascular regulation, characterized by higher values of RSA and mean heart-period in the presence of FBM. This physiological response reflects a compensatory strategy that may contribute to preserve blood flow redistribution to vital organs.

Early functional and morphological brain disturbances in late-onset intrauterine growth restriction

AIMS

To determine whether the brain disturbances develop in late-onset intrauterine growth restriction (IUGR) before blood flow redistribution towards the fetal brain (detected by Doppler measurements in the middle cerebral artery and umbilical artery). Further, to evaluate predictive values of Doppler arterial indices and umbilical cord blood gases and pH for early functional and/or morphological brain disturbances in late-onset IUGR.

STUDY DESIGN

This cohort study included 60 singleton term pregnancies with placental insufficiency caused late-onset IUGR (IUGR occurring after 34 gestational weeks). Umbilical artery resistance index (URI), middle cerebral artery resistance index (CRI), and cerebroumbilical (C/U) ratio (CRI/URI) were monitored once weekly. Umbilical blood cord samples (arterial and venous) were collected for the analysis of pO2, pCO2 and pH. Morphological neurological outcome was evaluated by cranial ultrasound (cUS), whereas functional neurological outcome by Amiel-Tison Neurological Assessment at Term (ATNAT).

RESULTS

50 fetuses had C/U ratio>1, and 10 had C/U ratio≤1; among these 10 fetuses, 9 had abnormal neonatal cUS findings and all 10 had non-optimal ATNAT. However, the total number of abnormal neurological findings was much higher. 32 neonates had abnormal cUS (53.37%), and 42 (70.00%) had non-optimal ATNAT. Furthermore, Doppler indices had higher predictive validity for early brain disturbances than umbilical cord blood gases and pH. C/U ratio had the highest predictive validity with threshold for adverse neurological outcome at value 1.13 (ROC analysis), i.e., 1.18 (party machine learning algorithm).

CONCLUSION

Adverse neurological outcome at average values of C/U ratios>1 confirmed that early functional and/or structural brain disturbances in late-onset IUGR develop even before activation of fetal cardiovascular compensatory mechanisms, i.e., before Doppler signs of blood flow redistribution between the fetal brain and the placenta.

Factors Influencing Neurodevelopment after Cardiac Surgery during Infancy

Short- and long-term neurodevelopmental (ND) disabilities with negative impact on psychosocial and academic performance, quality of life, and independence in adulthood are known to be the most common sequelae for surviving children after surgery for congenital heart disease (CHD). This article reviews influences and risk factors for ND impairment. For a long time, the search for independent risk factors was focused on the perioperative period and modalities of cardiopulmonary bypass (CPB). CPB operations to ensure intraoperative vital organ perfusion and oxygen supply with or without circulatory arrest or regional cerebral perfusion bear specific risks. Examples of such risks are embolization, deep hypothermia, flow rate, hemodilution, blood gas management, postoperative hyperthermia, systemic inflammatory response, and capillary leak syndrome. However, influences of these procedure-specific risk factors on ND outcome have not been found as strong as expected. Furthermore, modifications have not been found to support the effectiveness of the currently used neuroprotective strategies. Postoperative factors, such as need for extracorporal membrane oxygenation or assist device support and duration of hospital stay, significantly influence ND parameters. On the other hand, the so-called "innate," less modifiable patient-specific risk factors have been found to exert significant influences on ND outcomes. Examples are type and severity of CHD, genetic or syndromic abnormalities, as well as prematurity and low birth weight. Structural and hemodynamic characteristics of different CHDs are assumed to result in impaired brain growth and delayed maturation with respect to the white matter. Beginning in the fetal period, this so-called "encephalopathy of CHD" is suggested a major innate risk factor for pre-, peri-, and postoperative additional hypoxic or ischemic brain injury and subsequent ND impairment. Furthermore, MRI studies on brain volume, structure, and function in adolescents have been found correlated with cognitive, motor, and executive dysfunctions. Finally, family and environmental factors independently moderate against ND outcomes. In conclusion, the different mediating factors may exert independent effects on ND and interactive influences. Implications for the future comprise modifying clinical risk factors, such as perioperative cerebral oxygen delivery, conducting brain MRI studies in correlation to ND outcomes, and extending psychosocial interventions leading to adequate resilience.

Does fetal growth restriction lead to increased brain injury as detected by neonatal cranial ultrasound in premature infants?

AIM

Intra-uterine growth restriction (IUGR) is an important cause for prematurity as well as a significant risk factor for neurodevelopmental deficits. In this study, we aimed to examine the association between IUGR and early brain injury on neonatal cranial ultrasound in preterm infants.

METHODS

This retrospective cohort study examined the relationship between IUGR and neonatal cranial ultrasound findings in preterm infants <32 weeks gestation with IUGR, compared with gestation and year of birth-matched appropriately grown infants, in a tertiary level neonatal unit. Primary outcome was incidence and severity of intraventricular haemorrhage (IVH), periventricular leucomalacia (PVL) and hydrocephalus detected by cranial ultrasound in the neonatal period.

RESULTS

A total of 153 IUGR and 306 non-IUGR preterm infants <32 weeks were included. The rates of IVH (21.6% vs. 23.9%), severe IVH (3.9% vs. 4.6%), PVL (8.4% vs. 9.4%), cystic PVL (2.6% vs. 0%) and hydrocephalus (0.7% vs. 0.3%) were similar in the two groups. Composite outcome of death and severe brain injury (severe IVH, cystic PVL and hydrocephalus) was greater (20.2% vs. 9.1%, P = 0.001) in IUGR infants.

CONCLUSION

IUGR did not lead to increased neonatal brain injury on cranial ultrasound but was associated with increased mortality. Advanced neonatal neuroimaging techniques may be necessary to estimate risk and to provide prognostic information of adverse neurological outcomes in this vulnerable population.

Association of brain metabolism with sulcation and corpus callosum development assessed by MRI in late-onset small fetuses

OBJECTIVE

We sought to determine the relationship between fetal brain metabolism and microstructure expressed by brain sulcation, and corpus callosum (CC) development assessed by fetal brain magnetic resonance (MR) imaging and proton MR spectroscopy ((1)H-MRS).

STUDY DESIGN

A total of 119 fetuses, 64 that were small for gestational age (estimated fetal weight <10th centile and normal umbilical artery Doppler) and 55 controls underwent a 3T MR imaging/(1)H-MRS exam at 37 weeks. Anatomical T2-weighted images were obtained in the 3 orthogonal planes and long echo time (TE) (1)H-MRS acquired from the frontal lobe. Head biometrics, cortical fissure depths (insula, Sylvian, parietooccipital, cingulate, and calcarine), and CC area and biometries were blindly performed by manual and semiautomated delineation using Analyze software and corrected creating ratios for biparietal diameter and frontooccipital diameter, respectively, for group comparison. Spectroscopic data were processed using LCModel software and analyzed as metabolic ratios of N-acetylaspartate (NAA) to choline (Cho), Cho to creatine (Cr), and myo-inositol (Ino) to Cho. Differences between cases and controls were assessed. To test for the association between metabolic ratios and microstructural parameters, bivariate correlation analyses were performed.

RESULTS

Spectroscopic findings showed decreased NAA/Cho and increased Cho/Cr ratios in small fetuses. They also presented smaller head biometrics, shorter and smaller CC, and greater insular and cingulate depths. Frontal lobe NAA/Cho significantly correlated with biparietal diameter (r = 0.268; P = .021), head circumference (r = 0.259; P = .026), CC length (r = 0.265; P = .026), CC area (r = 0.317; P = .007), and the area of 6 from the 7 CC subdivisions. It did not correlate with any of the cortical sulcation parameters evaluated. None of the other metabolic ratios presented significant correlations with cortical development or CC parameters.

CONCLUSION

Frontal lobe NAA/Cho levels-which are considered a surrogate marker of neuronal activity-show a strong association with CC development. These results suggest that both metabolic and callosal alterations may be part of the same process of impaired brain development associated with intrauterine growth restriction.

Neurodevelopment in children with intrauterine growth restriction: adverse effects and interventions

Intrauterine growth restriction (IUGR) is associated with higher rates of fetal, perinatal, and neonatal morbidity and mortality. The consequences of IUGR include short-term metabolic, hematological and thermal disturbances that lead to metabolic syndrome in children and adults. Additionally, IUGR severely affects short- and long-term fetal brain development and brain function (including motor, cognitive and executive function) and neurobehavior, especially neuropsychology. This review details the adverse effects of IUGR on fetal brain development and discusses intervention strategies.

Neurosonographic assessment of the corpus callosum as imaging biomarker of abnormal neurodevelopment in late-onset fetal growth restriction

OBJECTIVE

To explore corpus callosum (CC) developmental differences by ultrasound in late-onset small fetuses compared with adequate for gestational age (AGA) controls.

STUDY DESIGN

Ninety four small (estimated fetal weight <10th centile) and 71 AGA fetuses were included. Small fetuses were further subdivided into fetal growth restriction (IUGR, n = 64) and small for gestational age (SGA, n = 30) based on poor perinatal outcome factors, that is, birth weight <3rd centile and/or abnormal cerebroplacental ratio and/or uterine artery Doppler. The entire cohort was scanned to assess CC by transvaginal neurosonography obtaining axial, coronal and midsagittal images. CC length, thickness, total area and the areas after a subdivision in 7 portions were evaluated by semiautomatic software. Furthermore, the weekly average growth of the CC in each study group was calculated and compared.

RESULTS

Small fetuses showed significantly shorter (small fetuses: 0.49 vs. AGA: 0.52; p < 0.01) and smaller CC (1.83 vs. 2.03; p < 0.01) with smaller splenium (0.47 vs. 0.55; p < 0.01) compared to controls. The CC growth rate was also reduced when compared to controls. Changes were more prominent in small fetuses with abnormal cerebroplacental Doppler suggesting fetal growth restriction.

CONCLUSIONS

Neurosonographic assessment of CC showed significantly altered callosal development, suggesting in-utero brain reorganization in small fetuses. This data support the potential value of CC assessment by US to monitor brain development in fetuses at risk.

Brain morphometry and cognition in young adults born small for gestational age at term

OBJECTIVES

To examine brain volumes and cortical surface area and thickness and to relate these brain measures to cognitive function in young adults born small for gestational age (SGA) at term compared with non-SGA control patients.

STUDY DESIGN

This population-based follow-up study at age 20 years included 58 term-born SGA (birth weight <10th percentile, mean: 2915 g) and 81 non-SGA controls (birth weight ≥ 10th percentile, mean: 3707 g). Brain volumes and cortical surface area and thickness were investigated with magnetic resonance imaging, which was successfully obtained in 47 SGA patients and 61 control patients. Cognitive function was assessed using the Wechsler Adult Intelligence Scale, 3rd edition. A subgroup analysis was performed in the SGA group among subjects diagnosed with fetal growth restriction (FGR) based on repeated fetal ultrasound measurements.

RESULTS

The SGA group showed regional reductions in cortical surface area, particularly in the frontal, parietal, and temporal lobes. Total brain volume, cortical gray matter, cerebral white matter, and putamen volumes were reduced in the SGA group compared with control patients, but there were no differences in specific subcortical brain structure volumes when correcting for intracranial volume. Reductions were most pronounced among SGA subjects with FGR. No associations were found between brain measures and IQ measures in either group.

CONCLUSION

Young adults born SGA at term show a global reduction in brain volume as well as regional reductions in cortical surface area. We speculate whether these reductions may be confined to those exposed to FGR. None of the brain measures correlated with cognition.

Balancing the risks of stillbirth and neonatal death in the early preterm small-for-gestational-age fetus

OBJECTIVE

Timing of delivery for the early preterm small-for-gestational-age (SGA) fetus remains unknown. Our aim was to estimate the risk of stillbirth in the early preterm SGA fetus compared with the risk of neonatal death.

STUDY DESIGN

We performed a retrospective cohort study of singleton pregnancies that underwent second-trimester anatomy ultrasound (excluding fetal anomalies, aneuploidy, and pregnancies with incomplete neonatal follow-up data). SGA was defined as birthweight <10th percentile by the Alexander standard. Life-table analysis was used to calculate the cumulative risks of stillbirth per 10,000 ongoing SGA pregnancies and of neonatal death per 10,000 SGA live births for 2-week gestational age strata in the early preterm period (24-33 weeks 6 days of gestation). We further examined the composite risk of expectant management and then compared the risk of expectant management with the risk of immediate delivery.

RESULTS

Of 76,453 singleton pregnancies, 7036 SGA pregnancies that met inclusion criteria were ongoing at 24 weeks of gestation; there were 64 stillbirths, 226 live births, and 18 neonatal deaths from 24-33 weeks 6 days of gestation. As the risk of stillbirth increases with advancing gestational age, the risk of neonatal death falls, until the 32-33 weeks 6 days of gestation stratum. The relative risk of expectant management compared with immediate delivery remains <1 for each gestational age strata.

CONCLUSION

Our findings suggest that the balance between the competing risks of stillbirth and neonatal death for the early preterm SGA fetus occurs at 32-33 weeks 6 days of gestation. These data can be useful when delivery timing remains uncertain.

Proton Magnetic Resonance Spectroscopy Assessment of Fetal Brain Metabolism in Late-Onset ‘Small for Gestational Age' versus ‘Intrauterine Growth Restriction' Fetuses

Objectives: We used magnetic resonance spectroscopy (MRS) to evaluate brain metabolic differences in small fetuses near term as compared to appropriate for gestational age (AGA) fetuses. Study Design: 71 term small fetuses (estimated fetal weight <10th centile for gestational age with normal umbilical artery Doppler sonography) were subclassified as late intrauterine growth restriction (IUGR) (n = 50) or small for gestational age (SGA) (n = 21), and compared with 65 AGA fetuses. IUGR was defined by either abnormal middle cerebral artery, abnormal uterine artery Doppler sonography or estimated fetal weight <3rd centile. All participants underwent brain magnetic resonance imaging at 37 weeks of gestation, and single-voxel magnetic resonance spectra were obtained from the frontal lobe on a 3-tesla scanner. N-acetylaspartate (NAA)/choline (Cho), NAA/creatine (Cr) and Cho/Cr ratios were calculated and compared between cases and controls. The association of the metabolic ratios with the study groups was tested. Results: After MRS processing and applying quality control criteria, 31 spectra from late-onset IUGR, 11 from SGA and 30 from AGA fetuses were selected for further analysis. Both SGA and late-onset IUGR fetuses showed significantly reduced NAA/Cho levels when compared to AGA fetuses. This decrease followed a linear trend across the three clinical groups that were considered. Conclusions: Both SGA and late-onset IUGR fetuses showed differences in MRS brain metabolic ratios. The findings suggest that despite near-normal perinatal outcomes, SGA fetuses are not constitutionally small and may represent a form of growth disorder that needs to be clarified.

Assessment of apparent diffusion coefficient of normal fetal brain development from gestational age week 24 up to term age: a preliminary study

OBJECTIVES

This study was designed to investigate the feasibility of apparent diffusion coefficient (ADC) values in evaluating normal fetal brain development from gestational week 24 up to term age.

METHODS

Diffusion-weighted imaging (DWI) was performed on 40 normal fetuses (with normal results on sonography and normal fetal MRI results), with two b-values of 0 and 600 s/mm² in the three (x, y, z) orthogonal axes. Ten regions of interest (ROIs) were manually placed symmetrically in the bilateral frontal white matter (FWM), occipital white matter (OWM), thalamus (THAL), basal ganglia (BG), and cerebellar hemispheres (CH). ADC values of the ten ROIs in all subjects were measured by two radiologists independently. One-way ANOVA was used to calculate the differences among the five regions in the fetal brain and linear regression analysis was used to evaluate the correlation between ADC values and gestational age (GA). p < 0.05 was considered significantly different.

RESULTS

Mean GA was 31.3 ± 3.9 (range 24-41) weeks. The overall mean ADC values (× 10⁻⁶ mm²/s) of the fetuses were 1,800 ± 214 (FWM), 1,400 ± 100 (BG), 1,300 ± 126 (THAL), 1,700 ± 133 (OWM) and 1,400 ± 155 (CH), respectively. The ADC value of BG was not significantly different from those of THAL and CH, while the other four ROIs had significant differences with each other. The ADC values of BG, THAL, OWM and CH had strong negative correlations with increasing GA (R were -0.568, -0.716, -0.830 and -0.700, respectively, all p < 0.01), OWM declined fastest with GA, followed by CH and THAL, the slowest being BG. The ADC value of FWM had no significant change with GA (p = 0.366).

CONCLUSIONS

The measurement of ADC values is feasible to evaluate fetal brain development with high reliability and reproducibility.

Myoinositol: a new marker of intrauterine growth restriction?

Inositol is a cyclic sugar alcohol which occurs naturally in a variety of stereoisomers, the most common of which is myo-inositol. Inositol phosphoglycan molecules have been isolated from mammalian tissues and are a major component of the intracellular mediators of insulin action. The fetus with intrauterine growth retardation (IUGR) activates a series of adaptive mechanisms to increase the chances for survival, such as a saving of glucose to ensure nutrition of the vital organs, with a consequent reduction in insulin secretion. It can be hypothesized that the reduced production of fetal insulin leads to an excretion of inositol from the intracellular to the extracellular compartment, with a consequent increase of the metabolite in plasma and urine and a decrease inside the cells. Recently, reports suggesting that the increase in extracellular myo-inositol may be a valid marker of an altered glucose metabolism during fetal development in IUGR have been published.

Brainstem and cerebellar differences and their association with neurobehavior in term small-for-gestational-age fetuses assessed by fetal MRI

OBJECTIVE

We tested the hypothesis whether small-for-gestational-age (SGA) fetuses have different brain stem and cerebellar morphometry when compared with appropriate-for-gestational-age (AGA) fetuses and whether the differences in these structures were associated with their neonatal neurobehavior.

STUDY DESIGN

Magnetic resonance imaging was performed on 51 SGA fetuses and 47 AGA fetuses at 37 weeks' gestation. Pontine width, medullar width, vermian width and height, cerebellar primary fissure's depth, and cerebellar volume were measured and corrected by biparietal diameter and cerebellar volume by total intracranial volume. Ratios were compared between cases and control subjects. The association between morphometric differences and neurobehavioral outcome in SGAs was tested.

RESULTS

Brainstem and cerebellar ratios were significantly larger in SGA fetuses: pontine width, SGA 0.143 ± 0.01 vs AGA 0.135 ± 0.01 (P < .01); medullar width, SGA 0.088 ± 0.01 vs AGA 0.083 ± 0.01 (P = .03); vermian width, SGA 0.181 ± 0.03 vs AGA 0.162 ± 0.02 (P < .01); vermian height, SGA 0.235 ± 0.03 vs AGA 0.222 ± 0.01 (P < .01); cerebellar volume, SGA 0.042 ± 0.01 vs AGA 0.038 ± 0.00 (P = .04); with deeper cerebellar primary fissure in SGAs, SGA 0.041 ± 0.01 vs AGA 0.035 ± 0.01 (P = .01). Medullar, cerebellar biometries, and volumetry were significantly associated with different Neonatal Behavioral Assessment Scale cluster scores in SGA infants.

CONCLUSION

Brain stem and cerebellar morphometric measurements are significantly different in term SGA fetuses, which are associated significantly with their neurobehavioral outcome. This finding supports the existence of brain microstructural changes in SGA fetuses and lays the basis for potential image biomarkers to detect fetuses who are at risk.

Second- and third-trimester biochemical and ultrasound markers predictive of ischemic placental disease

Ischemic placental disease is a recently coined term that describes the vascular insufficiency now believed to be an important etiologic factor in preeclampsia, intrauterine fetal growth restriction, and placental abruption. Given the increased risk for poor maternal and fetal outcomes, early prediction and prevention of this disorder is of significant clinical interest for many. In this article, we review the second- and third-trimester serum and ultrasound markers predictive of ischemic placental disease. Limited first-trimester data is also presented. While current studies report a statistical association between marker levels and various adverse perinatal outcomes, the observed diagnostic accuracy is below the threshold required for clinical utility. An exception to this generalization is uterine artery Doppler for the prediction of early-onset preeclampsia. Metabolomics is a relatively new analytic platform that holds promise as a first-trimester marker for the prediction of both early- and late-onset preeclampsia.

Pathways of neuronal and cognitive development in children born small-for-gestational age or late preterm

OBJECTIVE

To assess the effects of late small-for-gestational-age (SGA) birth and late prematurity on cognitive outcomes and structural changes in the central nervous system at primary school age, using a novel approach to examine changes in neuronal integrity of the retina.

METHODS

We conducted a cross-sectional study of 347 children aged 6-13 years, including in the analysis only infants born after 34 weeks' gestation. We recorded all perinatal outcomes through a survey of parents. Neuronal damage was evaluated using optical coherence tomography of the retina. In a subgroup of 112 children aged 6-8 years, visuospatial perception was evaluated with the Children's Bender Visual Motor Gestalt Test.

RESULTS

The proportions of SGA and late preterm children were 11.8 and 6.3%, respectively. Prematurity and SGA were simultaneously present in five children. When compared with controls, SGA children showed significantly lower than average retinal nerve fiber layer (RNFL) thickness (94.1 vs 98.8 μm; P = 0.007) and an increased percentage of abnormal Bender scores (27.3 vs 6.2%; P = 0.017) (odds ratio 5.6 (95% CI, 1.2-26.8)). These differences increased when late SGA infants with a birth weight below the 3(rd) percentile were compared with SGA infants with a birth weight between the 3(rd) and 10(th) percentiles and with controls, for RNFL thickness (92.5 vs 94.6 and 98.8 μm, respectively; P = 0.021) and abnormal Bender tests (33.3 vs 25.0 and 6.2%, respectively; P = 0.036). However, no differences were found in retinal structure and visuomotor performance between late preterm and term infants.

CONCLUSIONS

These data suggest that late SGA and late prematurity induce a distinct neuronal pattern of structural changes that persist at school age. Late-onset SGA infants are at increased risk for axonal loss in the retina and present specific visuomotor difficulties.

Long-term functional outcomes and correlation with regional brain connectivity by MRI diffusion tractography metrics in a near-term rabbit model of intrauterine growth restriction

BACKGROUND

Intrauterine growth restriction (IUGR) affects 5-10% of all newborns and is associated with increased risk of memory, attention and anxiety problems in late childhood and adolescence. The neurostructural correlates of long-term abnormal neurodevelopment associated with IUGR are unknown. Thus, the aim of this study was to provide a comprehensive description of the long-term functional and neurostructural correlates of abnormal neurodevelopment associated with IUGR in a near-term rabbit model (delivered at 30 days of gestation) and evaluate the development of quantitative imaging biomarkers of abnormal neurodevelopment based on diffusion magnetic resonance imaging (MRI) parameters and connectivity.

METHODOLOGY

At +70 postnatal days, 10 cases and 11 controls were functionally evaluated with the Open Field Behavioral Test which evaluates anxiety and attention and the Object Recognition Task that evaluates short-term memory and attention. Subsequently, brains were collected, fixed and a high resolution MRI was performed. Differences in diffusion parameters were analyzed by means of voxel-based and connectivity analysis measuring the number of fibers reconstructed within anxiety, attention and short-term memory networks over the total fibers.

PRINCIPAL FINDINGS

The results of the neurobehavioral and cognitive assessment showed a significant higher degree of anxiety, attention and memory problems in cases compared to controls in most of the variables explored. Voxel-based analysis (VBA) revealed significant differences between groups in multiple brain regions mainly in grey matter structures, whereas connectivity analysis demonstrated lower ratios of fibers within the networks in cases, reaching the statistical significance only in the left hemisphere for both networks. Finally, VBA and connectivity results were also correlated with functional outcome.

CONCLUSIONS

The rabbit model used reproduced long-term functional impairments and their neurostructural correlates of abnormal neurodevelopment associated with IUGR. The description of the pattern of microstructural changes underlying functional defects may help to develop biomarkers based in diffusion MRI and connectivity analysis.

Differences in cortical development assessed by fetal MRI in late-onset intrauterine growth restriction

OBJECTIVE

The objective of the study was to evaluate cortical development parameters by magnetic resonance imaging (MRI) in late-onset intrauterine growth-restricted (IUGR) fetuses and normally grown fetuses.

STUDY DESIGN

A total of 52 IUGR and 50 control fetuses were imaged using a 3T MRI scanner at 37 weeks of gestational age. T2 half-Fourier acquisition single-shot turbo spin-echo anatomical acquisitions were obtained in 3 planes. Cortical sulcation (fissures depth corrected by biparietal diameter), brain volumetry, and asymmetry indices were assessed by means of manual delineation and compared between cases and controls.

RESULTS

Late-onset IUGR fetuses had significantly deeper measurements in the left insula (late-onset IUGR: 0.293 vs control: 0.267; P = .02) and right insula (0.379 vs 0.318; P < .01) and the left cingulate fissure (0.096 vs 0.087; P = .03) and significantly lower intracranial (441.25 cm(3) vs 515.82 cm(3); P < .01), brain (276.47 cm(3) vs 312.07 cm(3); P < .01), and left opercular volumes (2.52 cm(3) vs 3.02 cm(3); P < .01). IUGR fetuses showed significantly higher right insular asymmetry indices.

CONCLUSION

Late-onset IUGR fetuses had a different pattern of cortical development assessed by MRI, supporting the existence of in utero brain reorganization. Cortical development could be useful to define fetal brain imaging-phenotypes characteristic of IUGR.

Neurodevelopmental outcome of full-term small-for-gestational-age infants with normal placental function

OBJECTIVE

To evaluate the 2-year neurodevelopmental outcome of full-term, small-for-gestational-age (SGA) newborns with normal placental function, according to current criteria based on umbilical artery Doppler findings.

METHODS

A cohort of consecutive full-term, SGA newborns with normal prenatal umbilical artery Doppler was compared with a group of full-term, appropriate-for-gestational-age (AGA) infants sampled from our general neonatal population. Neurodevelopmental outcome was evaluated at 24 months' corrected age using the Bayley Scales of Infant and Toddler Development, 3(rd) Edition (Bayley-III), which evaluates cognitive, language, motor, social-emotional and adaptive competencies. The effect of the study group on each domain was adjusted with MANCOVA and logistic regression for gestational age at delivery, socioeconomic status, gender, tobacco smoking and breastfeeding.

RESULTS

A total of 223 infants (112 SGA and 111 AGA) were included. The groups differed significantly with respect to socioeconomic status and gestational age at delivery. All studied neurodevelopmental domains were poorer in the SGA group, reaching significance for the cognitive (92.9 vs 100.2, adjusted P = 0.027), language (94.7 vs 101, adjusted P = 0.025), motor (94.2 vs 100, adjusted P = 0.027) and adaptive (89.2 vs 96.5, adjusted P = 0.012) scores. Likewise, the SGA group had a higher risk of low scores in language (odds ratio (OR) = 2.63; adjusted P = 0.045) and adaptive (OR = 2.72; adjusted P = 0.009) domains.

CONCLUSIONS

Compared with normal-sized babies, full-term SGA infants, without placental insufficiency defined according to currently used criteria, have lower 2-year neurodevelopmental scores. These data challenge the concept that SGA fetuses with normal umbilical artery Doppler are 'constitutionally small' but otherwise completely normal.

Automatic quantitative MRI texture analysis in small-for-gestational-age fetuses discriminates abnormal neonatal neurobehavior

Background

We tested the hypothesis whether texture analysis (TA) from MR images could identify patterns associated with an abnormal neurobehavior in small for gestational age (SGA) neonates.

Methods

Ultrasound and MRI were performed on 91 SGA fetuses at 37 weeks of GA. Frontal lobe, basal ganglia, mesencephalon and cerebellum were delineated from fetal MRIs. SGA neonates underwent NBAS test and were classified as abnormal if ≥1 area was <5^th centile and as normal if all areas were >5^th centile. Textural features associated with neurodevelopment were selected and machine learning was used to model a predictive algorithm.

Results

Of the 91 SGA neonates, 49 were classified as normal and 42 as abnormal. The accuracies to predict an abnormal neurobehavior based on TA were 95.12% for frontal lobe, 95.56% for basal ganglia, 93.18% for mesencephalon and 83.33% for cerebellum.

Conclusions

Fetal brain MRI textural patterns were associated with neonatal neurodevelopment. Brain MRI TA could be a useful tool to predict abnormal neurodevelopment in SGA.

Neurodevelopment after fetal growth restriction

Fetal growth restriction (FGR) can emerge as a complication of placental dysfunction and increases the risk for neurodevelopmental delay. Marked elevations of umbilical artery (UA) Doppler resistance that set the stage for cardiovascular and biophysical deterioration with subsequent preterm birth characterize early-onset FGR. Minimal, or absent UA Doppler abnormalities and isolated cerebral Doppler changes with subtle deterioration and a high risk for unanticipated term stillbirth are characteristic for late-onset FGR. Nutritional deficiency manifested in lagging head growth is the most powerful predictor of developmental delay in all forms of FGR. Extremes of blood flow resistance and cardiovascular deterioration, prematurity and intracranial hemorrhage increase the risks for psychomotor delay and cerebral palsy. In late-onset FGR, regional cerebral vascular redistribution correlates with abnormal behavioral domains. Irrespective of the phenotype of FGR, prenatal tests that provide precise and independent stratification of risks for adverse neurodevelopment have yet to be determined.

Childhood cognitive development after fetal growth restriction

OBJECTIVE

To examine the relationship between prenatal umbilical artery (UA) and internal carotid artery (ICA) Doppler findings and cognitive development at 3 and 6 years in low-birth-weight children.

METHODS

This was a study of 209 low-birth-weight (< 10(th) centile) children born after 28 gestational weeks with UA resistance index (RI) measured within 2 weeks before delivery. Children with normal UA- and ICA-RI were defined as small-for-gestational age (SGA) and those with abnormal UA or ICA Doppler findings as having fetal growth restriction (FGR). Cognitive ability at 3 and 6 years' corrected age was assessed using the fourth edition of the Stanford-Binet Intelligence Scale (SBIS) and compared between SGA and FGR groups. An SBIS score < 85 was considered to indicate delayed development.

RESULTS

The median gestational age at diagnosis of abnormal fetal growth was 36.6 (range, 28-41) weeks. There were 87 (41.6%) children classified as having FGR and 122 (58.4%) as SGA. The mean global SBIS score at 3 years was 109.4 (SD, 22.8) and at 6 years it was 110.5 (SD, 13.9). Overall, 22 (10.5%) children had delayed development at 3 years. Total SBIS scores and individual domain scores did not differ between FGR and SGA groups at 3 or 6 years and similar proportions in each group had delayed development.

CONCLUSION

Abnormal prenatal UA and ICA Doppler findings are not associated with lower developmental scores in low-birth-weight children delivered in the third trimester of pregnancy.