Crown-rump Length (crown-rump + length)

Distribution by Scientific Domains


Selected Abstracts


Development of olfactory epithelium in the human fetus: Scanning electron microscopic observations

CONGENITAL ANOMALIES, Issue 3 2009
Mitsuhiro Kimura
ABSTRACT Aims:, Human olfactory epithelium becomes functional at birth, but prenatal development remains unclear. In the present study, we aimed to clarify the development of human olfactory epithelium using scanning electron microscopy (SEM). Methods:, The development of human olfactory epithelium was observed in 24 externally normal fetuses, which were formalin-fixed and long-preserved, with a crown-rump length (CRL) of 102,336 mm (gestational week 14,38). The olfactory mucosa in the superior wall of the nasal septum near the choana were dissected and observed under SEM. We examined the number of olfactory vesicles per unit area, diameter of olfactory vesicles, and number and length of cilia on olfactory vesicles. Results:, At circa (ca) CRL 100 mm (ca 14 weeks), olfactory epithelium displayed several olfactory vesicles with 1,2 short cilia per unit area. At ca CRL 150 mm (ca 18 weeks), olfactory vesicles were present in small clusters, and cilia were longer. At CRL lager than 225 mm (ca 26 weeks), olfactory vesicles became located separately from each other, while length and number of cilia per olfactory vesicle were further increased. Conclusion:, The present findings suggest that fetal olfactory epithelium becomes morphologically almost the same as that in adults in late gestation, much later than previously thought. [source]


Development of the pons in human fetuses

CONGENITAL ANOMALIES, Issue 2 2007
Toshihisa Hatta
ABSTRACT Morphometric and histological studies of the pons were performed by light microscopy in 28 cases of externally normal human fetuses ranging from 90 to 246 mm in crown-rump length (CRL) and from 13 to 28 weeks of gestation. The brainstems of fetuses were embedded in celloidin or paraffin, and transverse sections were prepared. The pons was divided into two regions at the most ventral margin of the medial lemniscus at the level of the motor trigeminal nucleus. The relationships between the total dorsoventral length, ventral length, and dorsal length of the pons versus CRL and gestational ages were calculated, and empiric formulas were fitted. It was found that the ventral portion increased in size more rapidly than the dorsal portion. The proportion of the ventral portion in the total dorsoventral length was constitutively higher than that of the dorsal portion in the present range of CRL. In the pontine nuclei, from 235 mm in the CRL, some large cells with rich cytoplasm, pale nuclei, and a distinct nucleolus appeared on the dorsal side of the pyramidal tract. According to Weigert stained preparations, the first myelinated fibers in each motor root of the trigeminal, abducent, and facial nerves were recognized at 130,140 mm in CRL and the medial lemniscus at 230,235 mm. [source]


The pre-natal development and osseous growth of the human cerebellar field

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2003
J.F. Lomholt
Structured Abstract Authors , Lomholt JF, Nolting D, Hansen BF, Stoltze K, Kjęr I Objectives , To describe the pre-natal development of the bones that enclose the cerebellum and part of the brain stem (the neuro-osteological cerebellar field) in the mid-sagittal plane. Design , Radiographic, cephalometric and histologic examination of normal pre-natal human fetuses; 50 normal fetuses, with crown-rump length of 18,227 mm and approximate gestational age from 6 to 26 weeks. Results , The cerebellar field expressed extensive growth during development both sagittally and vertically. Because of changes in shape, the field was displaced in an anterio-caudal direction. Conclusion , In the present study we recorded normal measurements of size, shape and position of the cerebellar field. These standards can be used as references in skeletal analysis of cases with cranial abnormalities and cerebellar malformations. [source]


Low PAPP-A in the first trimester is associated with reduced fetal growth rate prior to gestational week 20

PRENATAL DIAGNOSIS, Issue 6 2010
J. D. Salvig
Abstract Objective To evaluate the association between maternal pregnancy-associated plasma protein-A (PAPP-A) and fetal growth from the first to the second trimester. Methods A prospective cohort study including 8347 pregnant women attending prenatal care at Aarhus University Hospital were conducted. PAPP-A was measured during 8 to 14 gestational weeks. Fetal growth between the two scans in the first and second trimesters was estimated by (GA20, GA12)/Dayscalendar, where GA12 reflects gestational age in days calculated from crown-rump length at a 12-week scan, GA20 reflects gestational age in days calculated from biparietal diameter at a 20-week scan, and Dayscalendar reflects the number of calendar days between the two scans. Results Fetal growth rate from the first to the second trimester was correlated with PAPP-A, with a regression coefficient of 0.009 (95% CI, 0.007,0.012, P < 0.001). PAPP-A below 0.30 MoM was associated with a fetal growth rate below the tenth centile, with an adjusted OR of 2.05 (95% CI, 1.24,3.38). Conclusion Low levels of PAPP-A are associated not only with low birth weight at term but also with slower fetal growth prior to 20 weeks of gestation. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Ethnic variation of fetal nasal bone length between 11,14 weeks' gestation

PRENATAL DIAGNOSIS, Issue 8 2005
Fadi Collado
Abstract Objective We sought to compare the fetal nasal bone length (FNBL) between different ethnic groups at 11,14 weeks' gestation. Methods FNBL and the FNBL/CRL ratio were measured in patients undergoing first trimester ultrasound for nuchal translucency (NT) and the ethnicity of the patient was recorded under four categories: non-Hispanic White, non-Hispanic black, Hispanic, and Chinese. Results Two hundred and one patients were included in the study. Measurement of the FNBL could not be obtained in nine patients (4.5%) and foetal nasal bone was absent in one fetus. Comparing the four groups, non-Hispanic White, non-Hispanic Black, Hispanic, and Asian, there were no statistical differences in crown-rump length (61 ± 14 mm; 68.6 ± 15 mm; 60.2 ± 14 mm; 62.4 ± 8.8 mm, respectively) or the NT (1.3 ± 0.5 mm; 1.25 ± 0.4 mm; 1.35 ± 1 mm; 1.4 ± 0.4 mm, respectively). However, the FNBL (2.9 ± 0.7 mm; 2.5 ± 0.6 mm; 2.5 ± 0.6 mm; 2.2 ± 0.4 mm, respectively, p < 0.01) and the FNBL/CRL ratio (0.049 ± 0.01, 0.045 ± 0.01, 0.043 ± 0.01, 0.037 ± 0.01, respectively, p < 0.01) were both statistically different, when comparing between these groups. Conclusion If the FNBL is to be introduced into first-trimester screening, it should be adjusted for ethnicity. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Nuchal translucency measurement at different crown-rump lengths along the 10- to 14-week period for Down syndrome screening

PRENATAL DIAGNOSIS, Issue 5 2005
Maria A. Zoppi
Abstract Objectives To evaluate the screening accuracy for Down syndrome of nuchal translucency (NT) measurement at different crown-rump length (CRL) subgroups along the 10- to 14-week period. Methods NT was classified ,enlarged' if greater than or equal to 1.5 and 2.0 multiples of the regressed median. Accuracies for Down syndrome (formula = [(TP + TN)/(TP + TN + FP + FN)] × 100, where TP: true positive, TN: true negative, FP: false positive, FN: false negative) were evaluated in four classes of CRL: 38,44 mm, 45,54 mm, 55,70 mm, and 71,84 mm, and compared. Results Of 20 743 fetuses, 20 611 were with no chromosomal abnormalities and 132 were with Down syndrome. Down syndrome fetuses with enlarged NT were 99 (greater than or equal to 1.5 MoM) and 86 (greater than or equal to 2.0 MoM). Sensitivity decreased with gestation, while specificity increased, resulting in increasing likelihood ratios with gestation for each of the CRL groups (8.1, 14.1, 16.3, 17.1 with the use of the 1.5 MoM cut-off, and 13.2, 27.1, 50.1, 84.1 for the 2.0 MoM cut-off). The accuracy increased with gestation (89%, 95%, 95%, 96% with the use of the 1.5 MoM cut-off, and 94%, 97%, 98%, 99% for the 2.0 MoM cut-off, for each of the CRL groups), differences being statistically significant between periods in half of the comparisons. Conclusions Although sensitivity of NT assessment for Down syndrome screening decreased as gestation advanced from the 10th to the 14th week, accuracy showed a remarkable increase. These changes should be taken into account in defining and improving the Down syndrome screening policies. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Effect of Anti-Basic Fibroblast Growth Factor (Anti-bFGF) on In Vitro Embryonic Development in Rat

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2009
E. Unur
Summary In this study, we aimed at the in vitro effects of anti-fibroblast growth factor-2 (anti-FGF-2 or anti-bFGF) on embryo culture in rats. In vitro effects of anti-bFGF on total embryonic development were investigated in 40 rat embryos (which were divided into four groups) (obtained from five pregnant females) at 9.5 days of gestation that were cultured in whole rat serum (WRS), and in WRS+ 2.5, 5, and 10 ,g/ml anti-bFGF. After 48 h of culturing, the embryos from each group were harvested to be analysed morphologically according to a morphological scoring system and biochemically to obtain the embryo protein content. The morphological score, embryo protein content, somite number and crown-rump length of embryos indicated that embryos cultured in WRS+ anti-bFGF had significant embryonic retardation. Mean morphological scores for the embryos grown in WRS, in the presence of 2.5, 5 and 10 ,g anti-FGF-2 were 61.4 ± 1.64, 46.3 ± 8.42, 27 ± 2.58 and13.6 ± 0.96 respectively. These results suggest that bFGF is very important for normal embryonic development and rat anti-bFGF neutralizes bFGF effect. [source]


Expression and Distribution of Intermediate-filament Proteins and Laminin during the Development of the Bovine Müllerian Duct

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2008
R. A.-M.
Summary The expression pattern of several intermediate-filament proteins (vimentin, cytokeratin 8, 18 and19) and the basal lamina component laminin was investigated in the Wolffian and the Müllerian ducts of bovine embryos and fetuses. The material studied comprised sexually undifferentiated stages [crown-rump length (CRL) 0.9 cm/1.0 cm/1.2 cm/1.9 cm/2.5 cm] and female stages (CRL 3.0 cm/4.2 cm/5.1 cm). Laminin could be demonstrated in the basal lamina of the developing Wolffian and Müllerian duct as well as in the stroma surrounding the Müllerian duct. The intermediate-filament protein vimentin was expressed in the mesothelium of the funnel field and in the epithelium of the Müllerian duct in all studied specimens, whereas the epithelial cells of the Wolffian duct only showed vimentin expression from a CRL of 2.2 cm onwards. In the cranial part of the Müllerian ducts only a few cells stained with pan-cytokeratin antibodies, whereas mesothelium and epithelium of the Wolffian duct showed as distinct immunostaining in all investigated stages. Both genital ducts showed no immunostaining with the antibody against cytokeratin 19 at any time of development. We conclude from our immunohistochemical results that the epithelial cells of the Wollfian duct do not contribute cells to the developing Müllerian duct. [source]


The Development of the Metanephric Kidney in the Pig

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005
H. Bragulla
Aims:, The metanephric kidneys of the pig are used as xenotransplants in human medicine. In order for transplants to fit within the host organisms, the subcapsular blastema and blood vessels are crucial for the development of new nephrons to sustain the organ functions. The aim of this study is to obtain data concerning the post-natal development of metanephric nephrons in the porcine kidney. Materials and Methods:, The metanephric kidneys of six porcine fetuses with a crown-rump length ranging from 40 mm to 220 mm of eight piglets aged between 6 to 10 weeks and of three adult pigs were studied. Eight lectins as well as anti-actin and anti-myosin antibodies were used for lectin- and immunohistochemistry to study the subcapsular metanephric blastema, to visualize the blood-urine barrier in the nephrons and collecting tubules, and to study the blood vessels in both the renal cortex and marrow. Results and Conclusions:, A subcapsular metanephric blastema was still present in the kidney of 10-week-old piglets. Dense condensation of mesenchymal cells surrounded the terminal branches of the collecting ducts and showed first signs of mesenchymal-epithelial transformation. Characteristic comma-shaped and s-shaped bodies were found in and underneath the subcapsular blastema. In the fibrous renal capsule of six-week-old piglets, a first faint binding reaction of anti-actin was visible and intensified in the fibrous renal capsule in ten-week-old piglets and in adult pigs. In addition, the smooth-muscle layers of the blood vessels were stained by the anti-actin and anti-myosin antibodies. The lectins showed various affinities to the endothelium of blood vessels and to the epithelial cells lining of the capsules of the metanephric renal corpuscles, the various parts of the renal tubules, as well as the collecting tubules and the renal pelvis. The affinity of the epithelial cells to a specific lectin varies in neighbouring cells, indicating different cell activities or cell cycles. [source]


The Effect of Vascular Endothelial Growth Factor on in vitro Embryonic Heart Development in Rats

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2004
H. Ülger
Summary In vitro effects of vascular endothelial growth factor (VEGF) on heart development and total embryonic growth were investigated in 84 rat embryos (obtained from nine pregnant females) at 9.5 days of gestation that were cultured in whole rat serum (WRS), in <30 kDa + >50 kDa serum fractions [retenate (R)], and in R + VEGF. After 24-h culture, the embryos from each group were harvested and divided into two groups. One group was analysed morphologically and biochemically to obtain embryo protein content, the second group was serially sectioned and examined by light microscopy. Morphological score, embryo protein content, somite number and crown-rump length of embryos indicated that embryos cultured in R had significant embryonic retardation, whereas the addition of VEGF to R increased embryonic growth and development. The morphological scores for WRS, R and R + VEGF were 57.7 ± 0.87, 46.6 ± 1.90 and 52.1 ± 0.97, somite numbers were 26.5 ± 0.47, 20.1 ± 0.63 and 24.4 ± 0.46, crown-rump lengths were 3 ± 0.07, 2.4 ± 0.06 and 2.7 ± 0.06 mm, and embryo protein contents were 160.5 ± 7.41, 98.2 ± 4.81 and 141.1 ± 10.96 ,g per embryo, respectively. The results of histological examination of heart development were similar. The hearts of embryos grown in R were unseptated and tubular. The atrioventricular endocardial cushions were incompletely developed. The addition of VEGF to R improved heart development. There were no gross morphological differences in the cardiac development between embryos grown in WRS and R + VEGF. In both groups, development of the muscular interventricular septum had begun. Development of the atrioventricular cushions was also similar in both groups and had caused narrowing of the atrioventricular canals, but the atrial septation was not observed. [source]


Effects of Subchronic versus Acute in utero Exposure to Dexmedetomidine on Foetal Developments in Rats

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2008
Mohammad Tariq
This study was undertaken to investigate the effects of in utero exposure of dexmedetomidine on foetal development and postnatal behaviour in the offspring. Pregnant Sprague-Dawley rats were chronically treated with dexmedetomidine (0, 5, 10 and 20 µg/kg, subcutaneously) daily from gestation day 7 to day 19. Another group of animals received only a single acute dose of dexmedetomidine (20 µg/kg) on gestational day 19 to mimic a model for systemic analgesia during labour. Administration of dexmedetomidine did not affect the frequency of implantations. Chronic administration of 10 and 20 µg/kg of dexmedetomidine significantly reduced the body weight and crown-rump length of pups, whereas a single acute dose (20 µg/kg) did not affect these parameters. None of the pups exhibited any external malformations or skeletal abnormalities irrespective of treatment assigned. All the pups showed a normal postnatal weight gain during the developmental phase. No significant differences were observed among any of the groups with respect to behavioural performances of offspring in beam balance, grip strength and inclined plane tests as well as motor activity. In conclusion, acute exposure to dexmedetomidine at the anticipated delivery time does not exert any adverse effects on perinatal morphology of pups, their birth weight, crown-rump length, physical growth and postnatal behavioural performances. Since this study was conducted in rats, its clinical relevance in human beings remains to be unclear and warrants further studies. [source]


Magnetic Resonance Microscopy Defines Ethanol-Induced Brain Abnormalities in Prenatal Mice: Effects of Acute Insult on Gestational Day 8

ALCOHOLISM, Issue 6 2009
Scott E. Parnell
Background:, Magnetic resonance microscopy (MRM), magnetic resonance imaging (MRI) at microscopic levels, provides unprecedented opportunities to aid in defining the full spectrum of ethanol's insult to the developing brain. This is the first in a series of reports that, collectively, will provide an MRM-based atlas of developmental stage-dependent structural brain abnormalities in a Fetal Alcohol Spectrum Disorders (FASD) mouse model. The ethanol exposure time and developmental stage examined for this report is gestational day (GD) 8 in mice, when the embryos are at early neurulation stages; stages present in humans early in the fourth week postfertilization. Methods:, For this study, pregnant C57Bl/6J mice were administered an ethanol dosage of 2.8 g/kg intraperitoneally at 8 days, 0 hour and again at 8 days, 4 hours postfertilization. On GD 17, fetuses that were selected for MRM analyses were immersion fixed in a Bouin's/Prohance® solution. Control fetuses from vehicle-treated dams were stage-matched to those that were ethanol-exposed. The fetal mice were scanned ex vivo at 7.0 T and 512 × 512 × 1024 image arrays were acquired using 3-D spin warp encoding. The resulting 29 ,m (isotropic) resolution images were processed using ITK-SNAP, a 3-D segmentation/visualization tool. Linear and volume measurements were determined for selected brain, head, and body regions of each specimen. Comparisons were made between control and treated fetuses, with an emphasis on determining (dis)proportionate changes in specific brain regions. Results:, As compared with controls, the crown-rump lengths of stage-matched ethanol-exposed GD 17 fetuses were significantly reduced, as were brain and whole body volumes. Volume reductions were notable in every brain region examined, with the exception of the pituitary and septal region, and were accompanied by increased ventricular volumes. Disproportionate regional brain volume reductions were most marked on the right side and were significant for the olfactory bulb, hippocampus, and cerebellum; the latter being the most severely affected. Additionally, the septal region and the pituitary were disproportionately large. Linear measures were consistent with those of volume. Other dysmorphologic features noted in the MR scans were choanal stenosis and optic nerve coloboma. Conclusions:, This study demonstrates that exposure to ethanol occurring in mice at stages corresponding to the human fourth week postfertilization results in structural brain abnormalities that are readily identifiable at fetal stages of development. In addition to illustrating the utility of MR microscopy for analysis of an FASD mouse model, this work provides new information that confirms and extends human clinical observations. It also provides a framework for comparison of structural brain abnormalities resulting from ethanol exposure at other developmental stages and dosages. [source]


Nuchal translucency measurement at different crown-rump lengths along the 10- to 14-week period for Down syndrome screening

PRENATAL DIAGNOSIS, Issue 5 2005
Maria A. Zoppi
Abstract Objectives To evaluate the screening accuracy for Down syndrome of nuchal translucency (NT) measurement at different crown-rump length (CRL) subgroups along the 10- to 14-week period. Methods NT was classified ,enlarged' if greater than or equal to 1.5 and 2.0 multiples of the regressed median. Accuracies for Down syndrome (formula = [(TP + TN)/(TP + TN + FP + FN)] × 100, where TP: true positive, TN: true negative, FP: false positive, FN: false negative) were evaluated in four classes of CRL: 38,44 mm, 45,54 mm, 55,70 mm, and 71,84 mm, and compared. Results Of 20 743 fetuses, 20 611 were with no chromosomal abnormalities and 132 were with Down syndrome. Down syndrome fetuses with enlarged NT were 99 (greater than or equal to 1.5 MoM) and 86 (greater than or equal to 2.0 MoM). Sensitivity decreased with gestation, while specificity increased, resulting in increasing likelihood ratios with gestation for each of the CRL groups (8.1, 14.1, 16.3, 17.1 with the use of the 1.5 MoM cut-off, and 13.2, 27.1, 50.1, 84.1 for the 2.0 MoM cut-off). The accuracy increased with gestation (89%, 95%, 95%, 96% with the use of the 1.5 MoM cut-off, and 94%, 97%, 98%, 99% for the 2.0 MoM cut-off, for each of the CRL groups), differences being statistically significant between periods in half of the comparisons. Conclusions Although sensitivity of NT assessment for Down syndrome screening decreased as gestation advanced from the 10th to the 14th week, accuracy showed a remarkable increase. These changes should be taken into account in defining and improving the Down syndrome screening policies. Copyright © 2005 John Wiley & Sons, Ltd. [source]


The Effect of Vascular Endothelial Growth Factor on in vitro Embryonic Heart Development in Rats

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2004
H. Ülger
Summary In vitro effects of vascular endothelial growth factor (VEGF) on heart development and total embryonic growth were investigated in 84 rat embryos (obtained from nine pregnant females) at 9.5 days of gestation that were cultured in whole rat serum (WRS), in <30 kDa + >50 kDa serum fractions [retenate (R)], and in R + VEGF. After 24-h culture, the embryos from each group were harvested and divided into two groups. One group was analysed morphologically and biochemically to obtain embryo protein content, the second group was serially sectioned and examined by light microscopy. Morphological score, embryo protein content, somite number and crown-rump length of embryos indicated that embryos cultured in R had significant embryonic retardation, whereas the addition of VEGF to R increased embryonic growth and development. The morphological scores for WRS, R and R + VEGF were 57.7 ± 0.87, 46.6 ± 1.90 and 52.1 ± 0.97, somite numbers were 26.5 ± 0.47, 20.1 ± 0.63 and 24.4 ± 0.46, crown-rump lengths were 3 ± 0.07, 2.4 ± 0.06 and 2.7 ± 0.06 mm, and embryo protein contents were 160.5 ± 7.41, 98.2 ± 4.81 and 141.1 ± 10.96 ,g per embryo, respectively. The results of histological examination of heart development were similar. The hearts of embryos grown in R were unseptated and tubular. The atrioventricular endocardial cushions were incompletely developed. The addition of VEGF to R improved heart development. There were no gross morphological differences in the cardiac development between embryos grown in WRS and R + VEGF. In both groups, development of the muscular interventricular septum had begun. Development of the atrioventricular cushions was also similar in both groups and had caused narrowing of the atrioventricular canals, but the atrial septation was not observed. [source]