NR2F1 regulates regional progenitor dynamics in the mouse neocortex and cortical gyrification in BBSOAS patients.

The relationships between impaired cortical development and consequent malformations in neurodevelopmental disorders, as well as the genes implicated in these processes, are not fully elucidated to date. In this study, we report six novel cases of patients affected by BBSOAS (Boonstra-Bosch-Schaff optic atrophy syndrome), a newly emerging rare neurodevelopmental disorder, caused by loss-of-function mutations of the transcriptional regulator NR2F1. Young patients with NR2F1 haploinsufficiency display mild to moderate intellectual disability and show reproducible polymicrogyria-like brain malformations in the parietal and occipital cortex. Using a recently established BBSOAS mouse model, we found that Nr2f1 regionally controls long-term self-renewal of neural progenitor cells via modulation of cell cycle genes and key cortical development master genes, such as Pax6. In the human fetal cortex, distinct NR2F1 expression levels encompass gyri and sulci and correlate with local degrees of neurogenic activity. In addition, reduced NR2F1 levels in cerebral organoids affect neurogenesis and PAX6 expression. We propose NR2F1 as an area-specific regulator of mouse and human brain morphology and a novel causative gene of abnormal gyrification.

Prenatal stress and the developing brain: Risks for neurodevelopmental disorders.

The prenatal period is increasingly considered as a crucial target for the primary prevention of neurodevelopmental and psychiatric disorders. Understanding their pathophysiological mechanisms remains a great challenge. Our review reveals new insights from prenatal brain development research, involving (epi)genetic research, neuroscience, recent imaging techniques, physical modeling, and computational simulation studies. Studies examining the effect of prenatal exposure to maternal distress on offspring brain development, using brain imaging techniques, reveal effects at birth and up into adulthood. Structural and functional changes are observed in several brain regions including the prefrontal, parietal, and temporal lobes, as well as the cerebellum, hippocampus, and amygdala. Furthermore, alterations are seen in functional connectivity of amygdalar-thalamus networks and in intrinsic brain networks, including default mode and attentional networks. The observed changes underlie offspring behavioral, cognitive, emotional development, and susceptibility to neurodevelopmental and psychiatric disorders. It is concluded that used brain measures have not yet been validated with regard to sensitivity, specificity, accuracy, or robustness in predicting neurodevelopmental and psychiatric disorders. Therefore, more prospective long-term longitudinal follow-up studies starting early in pregnancy should be carried out, in order to examine brain developmental measures as mediators in mediating the link between prenatal stress and offspring behavioral, cognitive, and emotional problems and susceptibility for disorders.

Association of fetal biparietal diameter with mode of delivery and perinatal outcome.

OBJECTIVE: To determine the association between sonographic assessment of fetal biparietal diameter (BPD) and pregnancy outcome. METHODS: This was a retrospective cohort study of pregnancies at 37-42 weeks of gestation which had antepartum sonographic measurement of BPD within 7 days before delivery. Eligibility was limited to singleton pregnancies with neither known structural or chromosomal abnormalities nor prelabor Cesarean delivery (CD). The association of BPD with outcome was analyzed using multivariate logistic regression, receiver-operating characteristics curves and stratification according to BPD quartiles. RESULTS: In total, 3229 women were eligible for analysis, of whom 2483 (76.9%) had a spontaneous vaginal delivery (SVD), 418 (12.9%) underwent operative vaginal delivery (OVD) and 328 (10.2%) underwent CD. The mean BPD in the obstetric intervention groups (OVD and CD) was significantly higher than that in the SVD group (P < 0.001). After adjusting for confounders, increased BPD was an independent risk factor such that higher values of BPD were associated with progressively higher risk of obstetric intervention (adjusted odds ratio, 1.05 for each 1-mm increase in BPD (95% CI, 1.02-1.09)), but no clear cut-off value for obstetric intervention was found. The fourth quartile group (BPD ≥ 97 mm) was associated with a significantly lower SVD rate (P < 0.001) and higher OVD rate (P = 0.04), relative to the first (BPD 88-90 mm) and second (BPD 91-93 mm) quartile groups, with no apparent adverse impact on immediate neonatal outcome. CONCLUSIONS: Increased BPD within the week prior to delivery is an independent risk factor such that higher values of BPD are associated with progressively higher risk of obstetric intervention; however, in our experience, no adverse neonatal outcome resulted from such intervention. Thus, increased BPD should not discourage a trial of vaginal delivery.

Piribedil and Pathological Gambling in six Parkinsonian patients / Piribedil e Jogo Patológico em seis pacientes parkinsonianos

Impulse control disorders (ICD) in Parkinson's disease (PD) have attracted increasing interest. They are characterized by the inability to control the impulse to perform an act that can be detrimental to them or to others. Although dopamine agonists (DA), as a group, have been associated with impulse control disorders (ICD), piribedil has rarely been reported to cause them. Method Case reports of six parkinsonian patients on piribedil presenting pathological gambling (PG). Results All of the patients presented ICD associated with piribedil use. Two of them received this medication as first treatment and four of them who had developed ICDs secondary to other DA that reappeared with piribedil. Conclusion Despite piribedil is commercially available in only a few countries, it should be considered in the differential diagnosis of PG in patients with PD. .

Os distúrbios do controle do impulso (DCI) na doença de Parkinson (DP) têm atraído crescente interesse. Eles são caracterizados pela incapacidade da pessoa em controlar o impulso para realizar um ato que pode ser prejudicial a ela própria ou aos outros. Embora os agonistas dopaminérgicos (AD), como um grupo, têm sido associados com distúrbios do controle do impulso, o piribedil tem sido relatado raramente como causa dos mesmos. Método Relatos de seis casos de pacientes parkinsonianos em uso de piribedil apresentando jogo patológico (JP). Resultados Todos os pacientes apresentaram DCI com o uso do piribedil. Dois deles receberam piribedil como primeiro tratamento e quatro deles que haviam desenvolvido DCI devido a outro AD, reapresentaram o quadro com piribedil. Conclusão Apesar de o piribedil estar disponível comercialmente apenas em alguns países, deveria ser considerado no diagnóstico diferencial de JP em pacientes com DP. .

Biparietal diameter-to-crown-rump length disproportion in first-trimester fetuses with holoprosencephaly.

OBJECTIVES: To determine whether the biparietal diameter measurement is altered in first-trimester fetuses with holoprosencephaly. METHODS: Cases of holoprosencephaly were collected retrospectively from 4 fetal medicine centers, and first-trimester biparietal diameter measurements were reviewed. The diagnosis of holoprosencephaly was established sonographically by the detection of abnormal choroid plexus morphologic characteristics (absent "butterfly" sign) and the identification of a monoventricular cerebral cavity on axial views of the fetal brain. The proportion of fetuses with biparietal diameter measurements below the 5th percentile for crown-rump length was determined. RESULTS: Among 45 cases of holoprosencephaly reviewed, 43 had information on both biparietal diameter and crown-rump length measurements. The biparietal diameter was below the 5th percentile for crown-rump length in 14 (32.6%) fetuses. Chromosomal analysis was available in 41; no statistically significant difference in biparietal diameter measurement between those with associated chromosomal anomalies and those without anomalies was noted. A supplementary analysis using head circumference measurement showed an even greater proportion of fetuses with holoprosencephaly with measurements below the 5th percentile for crown-rump length (18 of 42 [42.9%]). CONCLUSIONS: One-third of first-trimester fetuses with a sonographic diagnosis of holoprosencephaly had a biparietal diameter that was smaller than expected for crown-rump length. In this subset of fetuses, the evaluation of intracranial anatomy for signs of holoprosencephaly may be more difficult to perform due to the smaller size of the brain. Therefore, the detection of a biparietal diameter below the 5th percentile as expected from crown-rump length on the first-trimester scan may be a warning sign of holoprosencephaly and should prompt a detailed examination of the intracranial anatomy.

Fetal nasal bone length during the second trimester of pregnancy in a Turkish population.

OBJECTIVE: To determine the distribution of fetal nasal bone length (NBL) according to gestational age during the second trimester of pregnancy in a Turkish population. STUDY DESIGN: Fetal NBL and other routine biometric measurements were evaluated retrospectively in 2327 fetuses between 15 and 24 weeks of gestation. The measurements were obtained via transabdominal ultrasound. The distribution of fetal NBL between 15 and 24 weeks of gestation was established, and percentiles were calculated. Relationships between fetal NBL and other parameters were assessed using regression analysis. RESULTS: Mean (±standard deviation) fetal NBL ranged from 2.95±0.52 at 15 weeks of gestation to 6.26±0.77mm at 24 weeks of gestation. The fifth percentile for fetal NBL was 2.1mm at 15 weeks of gestation and 5.0mm at 24 weeks of gestation. A significant positive correlation was noted between fetal NBL and gestational age (NBL=gestational age×0.37-2.55; R(2)=0.59; p<0.01) and between fetal NBL and biparietal diameter (BPD) (NBL=BPD×0.11-0.33; R(2)=0.61; p<0.01). CONCLUSION: Fetal NBL is less in Turkish subjects compared with non-Turkish subjects.

Development of the fetal cerebral cortex in the second trimester: assessment with 7T postmortem MR imaging.

BACKGROUND AND PURPOSE: Few investigators have analyzed the fetal cerebral cortex with MR imaging of high magnetic strength. Our purpose was to document the sulcal development and obtain quantitative measurements of the fetal brain in the second trimester. MATERIALS AND METHODS: The brains of 69 fetal specimens, with GA 12-22 weeks, were first scanned on a 7T MR imaging scanner. Then the sequential development of the different fissures and sulci was analyzed, and quantitative measurements of the cerebral cortex were obtained. RESULTS: A new chronology of sulcal development during 12-22 weeks GA was summarized. Before 12 weeks, few sulci were present; by 16 weeks, many sulci were present. The 16th week could be considered the most intensive time point for sulcal emergence. Most sulci, except for the postcentral sulcus and intraparietal sulcus, were present by 22 weeks GA. Measurements of the fetal brains, each with different growth rates, linearly increased with GA, but no sexual dimorphisms or cerebral asymmetries were detected. CONCLUSIONS: The second trimester is the most important phase, during which most sulci are present and can be clearly shown on 7T postmortem MR imaging. It is apparent that the specific time during which neuropathologic features of sulci appear, previously thought to be well understood, should be redefined. Quantitative data provide assistance in the precise understanding of the immature brain. The present results are valuable in anatomic education, research, and assessment of normal brain development in the uterus.

Reference ranges for fetal brain fissure development on 3-dimensional sonography in the multiplanar mode.

OBJECTIVES: To determine reference ranges for measurements of fetal cerebral fissures by 3-dimensional (3D) sonography in the multiplanar mode and to evaluate the reliability and concordance of these measurements. METHODS: A cross-sectional study was conducted on 393 women with normal pregnancies at 22 weeks to 33 weeks 6 days. The distances between the internal bone plate of the fetal calvaria and the sylvian, parieto-occipital, hippocampal, and calcarine fissures were assessed. To obtain the distances for the first 3 fissures, a 3D sweep was made in the axial plane, at the level of the lateral ventricles. To obtain the distance for the calcarine fissure, a coronal sweep was used, at the level of the occipital lobes. To evaluate the correlation between the fissures and gestational age, polynomial regression was performed with adjustments using the coefficient of determination (R(2)). Reliability was determined with intraclass correlation coefficients and concordance with concordance limits. RESULTS: The mean distances ± SD to the sylvian, parieto-occipital, hippocampal, and calcarine fissures were 10.42 ± 2.28, 22.38 ± 3.23, 24.88 ± 4.67, and 21.19 ± 2.73 mm, respectively. These distances correlated with gestational age such that the best fit with the linear equation produced R(2) values of 0.582, 0.627, 0.860, and 0.458 for the sylvian, parieto-occipital, hippocampal, and calcarine fissures. Reliability analyses showed intraobserver and interobserver intraclass correlation coefficients of 0.90 to 0.95 and 0.85 to 0.97. The concordance limits were-1.33 to 1.30 and -2.38 to 2.28 mm for the intraobserver evaluation and -1.60 to 2.57 and -3.51 to 2.73 mm for the interobserver evaluation. CONCLUSIONS: Cerebral fissures can be measured by 3D sonography at 22 to 33 weeks of pregnancy with acceptable reliability and concordance. Reference ranges for this gestational period have thus been described.

Connectomics signatures of prenatal cocaine exposure affected adolescent brains.

Recent in vivo neuroimaging studies revealed that several brain networks are altered in prenatal cocaine exposure (PCE) affected adolescent brains. However, due to a lack of dense and corresponding cortical landmarks across individuals, the systematical alterations of functional connectivities in large-scale brain networks and the alteration of structural brain architecture in PCE affected brain are largely unknown. In this article, we adopted a newly developed data-driven strategy to build a large set of cortical landmarks that are consistent and corresponding across PCE adolescents and their matched controls. Based on these landmarks, we constructed large-scale functional connectomes and applied the well-established approaches of deriving genomics signatures in genome-wide gene expression studies to discover functional connectomics signatures for the characterization of PCE adolescent brains. Results derived from experimental data demonstrated that 10 structurally disrupted landmarks were identified in PCE, and more importantly, the discovered informative functional connectomics signatures among consistent landmarks distinctively differentiate PCE brains from their matched controls.

Developmental expression and distribution of GABA(A) receptor α1-, α3- and ß2-subunits in pig brain.

The principal function of the γ-aminobutyric acid (GABA) system in the adult brain is inhibition; however, in the neonatal brain, GABA provides much of the excitatory drive. As the brain develops, transmembrane chloride gradients change and the inhibitory role of GABA is initiated and continues throughout juvenile and adult life. Previous studies have shown that GABA(A) receptor subunit expression is developmentally regulated, and it is thought that the change in GABA function from excitation to inhibition corresponds to the changeover in expression of 'immature' to 'mature' subunit isoforms. We examined the protein expression pattern and distribution of GABA type A (GABA(A)) receptor α1-, α3- and ß2-subunits in the parietal cortex and hippocampus of the developing piglet brain. Four perinatal ages were studied; 14 days preterm (P-14), 10 days preterm (P-10), day of birth (P0) and at postnatal day 7 (P7). Animals were obtained by either caesarean section or spontaneous birth. Protein expression levels and subunit localization were analysed by Western blotting and immunohistochemistry, respectively. In the cortex and hippocampus, GABA(A) receptor α1-subunit showed greatest expression at P7 when compared to all other age groups (p < 0.05). In contrast, α3 expression in the cortex was elevated in preterm brain, peaking at P0, followed by a significant reduction by P7 (p < 0.05); a similar trend was observed in the hippocampus. GABA(A) receptor ß2-subunit protein expression appeared relatively constant across all time points studied in both the cortex and hippocampus. Immunolabelling of the α1-, α3- and ß2-subunits was observed throughout all cortical layers at every age. GABA(A) receptor α3-subunit appeared to show specific localization to layers V and VI whilst labelling for the ß2-subunit was observed in layer IV. In the hippocampus of all animals, the α1- and ß2-subunits were shown to immunolabel various cells and processes in the dentate gyrus (DG), CA1 and CA3; the α3-subunit was barely observed except at the stratum moleculare of the DG. We report for the first time the ontogenesis of GABA(A) receptor subunits α1, α3 and ß2 in the perinatal pig brain.

Ontogenetic pattern of gyrification in fetuses of cynomolgus monkeys.

The ontogenetic pattern of gyrification and its relationship with cerebral cortical volume were examined in cynomolgus monkey fetuses. T(1)-weighted coronal magnetic resonance (MR) images at 7 T were acquired from the fixed cerebra of three male fetuses, each at embryonic days (EDs) 70 to 150, and the gyrification index (GI) of each slice was estimated. The mean GI was low (1.1-1.2) during EDs 70 to 90, and then increased dramatically on ED 100. The developmental profiles of the rostrocaudal GI distribution revealed that cortical convolution was more frequent in the parietooccipital region than in other regions during EDs 100 to 150, forming an adult-like pattern by ED 150. The mean GI was closely correlated with the volume of cortical gray matter (r=0.9877), and also with the volume of white matter/intermediate zone (r=0.8961). These findings suggest that cortical convolution is correlated with either the maturation of cortical gray matter or the development of white matter bundles. The characteristic GI distribution pattern of catarrhines was formed by ED 150 in correlation with the progressive sulcal infolding in the parietooccipital region of the cerebrum.

Prediction of the date of delivery based on first trimester ultrasound measurements: an independent method from estimated date of conception.

OBJECTIVE: We aimed to develop a population-based nomogram based on 1st trimester ultrasound examination as an independent predictor of the remaining days of pregnancy. METHODS: Fetal measurements were collected in singleton pregnancies undergoing first trimester examination. We prospectively collected actual date of delivery. Predictions of the median interval and key centiles from examination to delivery were computed using crown rump length (CRL), biparietal diameter (BPD), head circumference (HC), and abdominal circumference (AC) measurements. RESULTS: A total of 3738 examinations were included. We computed median and centiles for remaining days of pregnancies from the time of first trimester measurements. The prediction ability of CRL, HC, and BPD was not different but AC yielded worse results. About 90% of the births fell within 14 days of predicted day of delivery, with a median error of 6 days. CONCLUSION: We have developed a method to accurately predict date of delivery from the time of first trimester measurements. It allows monitoring fetal growth and pregnancies at term by considering the duration of pregnancy as a variable rather than a constant.

[Accuracy of ultrasound estimated fetal weight performed by OB-Gyn residents at due date]. / Performance de l'estimation échographique du poids foetal réalisée par les internes de spécialité le jour du terme.

OBJECTIVES: The aim of this study was to evaluate the accuracy of ultrasound fetal weight prediction at due date and to find parameters that may affect this prediction. PATIENTS AND METHODS: We retrospectively studied 201 patients at due date in a university hospital in 2006, the fetal weight estimation being performed by Obstetric-gynecology (OB-Gyn). Estimated fetal weight was calculated with the Hadlock's formula, including biparietal diameter, cephalic circumference, abdominal perimeter and femoral length and was compared with birth weight. RESULTS: The mean birth weight was 3561+/-415 g. The mean absolute weight difference was 261+/-190 g (absolute range: 0 to 1183 g, actual range: -935 to 1183 g). Body mass index>30 kg/m(2) was associated with greater fetal weight inaccuracy (p=0,013). Fetal weight estimation was not influenced by fetal macrosomia, oligoanamnios or maternal weight gain during pregnancy. DISCUSSION AND CONCLUSION: The sonographic estimated fetal weight and birth weight are correlated with a mean absolute percentage error of 7%. However, clinicians should be aware of the risk of inaccuracy in obese women.

[Effects of prenatal exposure to paraquat on the development of amino acid synaptic transmission in mouse cerebral parietal cortex]. / Efectos de la exposición prenatal a paraquat sobre el desarrollo de la transmisión sináptica aminoacídica en la corteza cerebral parietal del ratón.

The effects of prenatal expossure to paraquat (PQ) were studied on postnatal development of mouse parietal cerebral cortex, in particular, the ontogenesis of amino acid synaptic transmission. Pregnant NMRI mice were separated into two groups: the experimental group received 5 doses of 10 mg PQ/kg body weight, between days of gestation (G)12 and G20, whereas the control group received physiological saline solution. Levels of neurotransmitter amino acids: Asp, Glu, Gly, GABA and Tau were determined by HPLC between postnatal (P) days P1 and P30. Between P3 and P15, a significant increment in the levels of excitatory amino acids, Asp and Glu, were observed in mice exposed to PQ, as compared with the control group. With respect to the inhibitory neurotransmitter levels, in the group exposed to PQ, the more important changes were observed in Gly between P1 and P15. In relation to taurine, its levels remained significantly higher between P1 and P7 with respect to the control group. It is important to emphasize that at P30, the levels of all neurotransmitters in the experimental group were significantly lower than those of control. In conclusion, prenatal exposure to PQ caused neurotoxicity in the developing mouse parietal cortex, as shown by the alterations in the basal levels of amino acid neurotransmitters, with the excitatory predominating over inhibitory neurotransmission, throughout the studied developmental period. These alterations could indicate the occurrence of important cortical injuries, such as decrement in some neuronal populations, inadequate formation of intrinsic cortical circuits and alterations in synaptogenic processes.

Exploring cortical subplate evolution using magnetic resonance imaging of the fetal brain.

The subplate is a transient structure essential for normal development of the cortex. We used magnetic resonance imaging of the fetal brain to assess cortical subplate evolution between 20 and 35 weeks gestation. Two-dimensional measures of diameter were obtained for the cortex, subplate and fetal white matter. The subplate was originally seen as a continuous band at early gestations measuring up to 4.5 mm. It became magnetic resonance invisible from approximately 28 weeks initially from the depths of the sulci and then from the tops of the gyri. The disappearance of the subplate was regional, involuting most rapidly in the parietal lobe and remaining prominent in the anterior temporal lobe up to 35 weeks. x

Novel genes differentially expressed in cortical regions during late neurogenesis.

Differential gene expression across the embryonic cerebral cortex is assumed to play a role in the subdivision of the cortex into distinct areas with specific morphology, physiology and function. In a search for genes that may be involved in the cortical regionalization during late neurogenesis in mouse, we performed an extensive in-situ expression analysis at embryonic day (E)16 and E18. The examined candidate genes were selected beforehand by a microarray screen by virtue of their preferential expression in the anlagen of the motor, somatosensory, visual and cingulate cortices or hippocampus. We present new information about graded or regionally enriched expression of 25 genes (nine of which are novel genes) across the mouse embryonic cortex, in progenitor cells as well as in the cortical plate. The established differential expression of most of these genes is persistent at both stages studied, suggesting that their expression is regulated by an intrinsic programme. For some of the genes, the concept of intrinsic regulation is further substantiated by the high similarity of the reported expression patterns at E16 and E18 and published data from earlier stages. Few genes with robust expression in the E16 caudal cortex showed a more restricted pattern at E18, possibly because of their response to extrinsic cues. In addition, several genes appeared to be suitable novel markers for amygdalar and diencephalic nuclei. Taken together, our findings reveal novel molecular partitions of the late mouse cortex that are in accordance with the model of a leading role of intrinsic mechanisms in cortical arealization.

Effects of maternal smoking in pregnancy on prenatal brain development. The Generation R Study.

Nicotine, as has been shown in animal studies, is a neuroteratogen, even in concentrations that do not cause growth retardation. In humans, there is only indirect evidence for negative influences of nicotine on brain development from studies on the association between maternal smoking in pregnancy and behavioural and cognitive development in the offspring. We investigated the associations of maternal smoking in pregnancy with foetal head growth characteristics in 7042 pregnant women. This study was embedded in the Generation R Study, a population-based prospective cohort study from foetal life until adulthood. Maternal smoking was assessed by questionnaires in early, mid- and late pregnancy. Head circumference, biparietal diameter, transcerebellar diameter and atrial width of lateral ventricles were repeatedly measured by ultrasound. When mothers continued to smoke during pregnancy, foetal head circumference showed a growth reduction of 0.13 mm [95% confidence interval (CI): -0.18, -0.09] per week compared to foetuses of mothers who never smoked during pregnancy. Biparietal diameter of foetuses with smoking mothers grew 0.04 mm (95% CI: -0.05, -0.02) less per week than that of foetuses of nonsmoking mothers. Atrial width of lateral ventricle was 0.12 mm (95% CI: -0.22, -0.02) smaller and transcerebellar diameter was 0.08 mm (95% CI: -0.15, -0.00) smaller if mothers smoked, but growth per week of these characteristics was not affected by maternal smoking in pregnancy. In conclusion, continuing to smoke during pregnancy leads to reduced growth of the foetal head. Further research should focus on the causal pathway from prenatal cigarette exposure via brain development to behavioural and cognitive functions.

Development of cerebral sulci and gyri in fetuses of cynomolgus monkeys (Macaca fascicularis).

This study aimed to clarify the development of sulci and gyri on the external surface of the cerebrum of cynomolgus monkeys. Sulcus formation began with the appearance of the lateral fissure on embryonic day (ED) 70, followed by delineations of four cerebral lobes by the emergence of the parietooccipital sulcus, central sulcus, and preoccipital notch on EDs 80-90. The following primary sulci were then visible until ED 120: the superior temporal sulcus on ED 90; the intraparietal sulcus, lunate sulcus, inferior occipital sulcus, and arcuate sulcus on ED 100; and the principle sulcus on ED 110; the occipitotemporal sulcus, anterior middle temporal sulcus, and superior postcentral dimple on ED 120. These sulci demarcated the superior temporal gyrus on ED 90, the precentral gyrus, supramarginal gyrus, and angular gyrus on ED 100, and the inferior and middle temporal gyri, postocentral gyrus, superior parietal lobule, superior, middle and inferior frontal gyri, and inferior occipital gyrus on ED 120. Except for the intermediate and lateral orbitofrontal sulci, the sulci that appeared on ED 130 and thereafter were not related to the gyrus demarcations. Intriguingly, the brain markedly gained weight on EDs 100 and 120, corresponding to the embryonic ages when almost all gyri were visible. The results suggest that a rapid growth of the cerebrum involves convolutions of the gyri by a regular sequence of the sulcus formation in cynomolgus monkeys. This study further provides a standard of reference for normal development in the cerebral cortical morphology of cynomolgus monkeys.

The relation between fetal nasal bone length and biparietal diameter in the Korean population.

OBJECTIVE: To evaluate the relation between fetal nasal bone length (NBL) and biparietal diameter (BPD) at 15-19.9 (20) weeks of gestation by ultrasonography in the Korean population. METHODS: The study population included 1268 Korean women (aged between 19 and 45 years) with a singleton pregnancy who registered at the Maternal Fetal Medicine Unit of Samsung Cheil Hospital between September 2003 and February 2005. Ultrasound measurements of NBL were performed using a strict sagittal plan of the fetal head. Other fetal biometry profiles were conducted before amniocentesis for fetal karyotyping. RESULTS: NBL and fetal biometry profiles were measured successfully in 77.9% (988/1268) of the fetuses. NBL was found to increase linearly as a function of BPD (P < 0.001) with a median NBL of 4.4 mm (range 1.9-7.9). NBL increases through 15-19.9 (20) weeks of gestation were given by the equation NBL (mm) = 0.0836 x BPD (mm) + 1.368 (R2 = 0.1, P < 0.001). CONCLUSIONS: Fetal NBL and BPD are linearly related in the second trimester. Fetal NBL in the Korean population is likely to be shorter than that reported for Caucasians and African-Americans.

First-trimester screening for fetal triploidy at 11 to 14 weeks: a role for fetal biometry.

OBJECTIVE: Intrauterine growth restriction in triploidy has been reported as early as in the first trimester. This study was undertaken to evaluate the ability of first-trimester crown rump length (CRL)-based charts to detect triploid fetuses. MATERIAL AND METHODS: Analysis of fetal biometry in cases of triploidy diagnosed in the first trimester over the last three years. Biometry for abdominal circumference (AC), head circumference (HC) and biparietal diameter (BPD) was analyzed in relation to both gestational age (GA)-based charts and to CRL-based charts. RESULTS: Five cases of fetal triploidy were diagnosed at 11 to 14 weeks. Screening based on nuchal translucency (NT) and maternal age showed a risk > 1/300 in only one of the 5 cases of triploid fetus. In all of these five cases, CRL-based biometry was grossly abnormal, although it was abnormal in only two of these five cases in relation to GA-based charts. CONCLUSION: First-trimester CRL-based biometry charts seem to reflect early asymmetrical growth delay in triploidy more accurately than GA-based charts. CRL-based biometry is likely to improve the early detection of triploid pregnancies without leading to dating error.