OBJECTIVE: To establish size ranges of normal fetal kidneys by ultrasonogram during pregnancy. METHODS: The A-P diameter and length of each of 450 kidneys in 225 consecutive fetuses between 19 and 41 weeks of gestation were measured on sonogram from March to August 2001 in Samsung Medical Center. Gestational ages were determined by last menstrual period and Crown-Rump Lengths of early stage of pregnancy. Abnormal fetuses, twins, offspring of diabetic mothers, and fetuses with renal pelvic dilatation of 5 mm or greater were excluded to avoid any questionable measurements. RESULTS: The results showed normal distribution and results were similar to previous reports. There was a strong correlation between fetal renal size and gestational age, but no significant difference between right and left renal sizes in fetuses. Average A-P diameter and renal lengths were significantly different when compared across the range of gestational ages (p<.001). CONCLUSION: As long as we know, this was the first report of size of the normal fetal kidney sonographically during pregnancy in Korea. We think that these results can be used to detect abnormality of fetal kidney and to estimate uncertain gestational age.
Crown-Rump Length ; Dilatation ; Fetus ; Gestational Age ; Humans ; Kidney* ; Korea ; Mothers ; Pregnancy ; Ultrasonography*

The primitive erythroblasts in 21 cases of embryonic hearts from 4 to 9 weeks of gestation were studied with a light microscope. The nuclear diameter, the motosis, and the loss of nuclei of the primitive erythoblasts were analyzed quantitatively. The results obtained were as follows. 1. At 4 weeks of gestation, the blood cells consisted of proerythroblasts, along with basophilic polychromatophilic primitive erythroblasts. The nuclear diameter ranged from 3.20 µm to 9.20 µm, but the main range was from 4.20 µm to 6.00 µm. It was revealed that 9.50% had diameter of more than 6 µm. 2. At the fist half of the 7 week gestation when hepatic hemopoiesis developed, the blood cells consisted of basophilic, polychromatophilic, and eosinophilic erythroblasts. Cells of more than 6 µm in nuclear diameter were about 1.10% and thereafter gradually disappeared. The range of the nuclear diameters was from 2.60 µm to 7.00 µm, while a range from 3.40 µm to 5.20 µm wqs the main. The proportion of cells less than 4 µm in nuclear diameter was 39.58% and thereafter rapidly increased. 3. From the second half of 7 weeks to 9 weeks of gestation, the erythrocytes originating from hepatic hemopoiesis increasingly replaced the circulating primitive erythroblasts, which became mature during this time. The erythrocytes showed 72.88% at 9 weeks of gestation. The proportions of cells less than 4 µm in nuclear diameter in the first and second haIves of 8 weeks and 9 weeks were 52.73%, 80.02%, and 89.09%, which represented the rapid destruction of nuclei. 4. Mitosis in the primitive erythroblasts occurred principally up to the early 6th weeks, and very weakly at 8 weeks. 5. As the crown-rump length increased, the average nuclear diameter decreased very significantly (P<0.01, y=-0.2811X + 0.3171). The results suggest that distrilbution of the nuclear diameter, the maturity, the rate of nuclear loss, and the mitotic figure offer credible data for estimating embryonic age.
Basophils ; Blood Cells ; Crown-Rump Length ; Embryonic Structures* ; Eosinophils ; Erythroblasts* ; Erythrocytes ; Heart ; Humans* ; Mitosis ; Pregnancy

OBJECTIVES: To evaluate whether the day of delivery for women with regular menstrual history was predicted best from the last menstrual period (LMP), crown rump length (CRL) and or biparietal diameter (BPD). METHODS: All of 561 women had estimated the day of delivery by LMP, CRL in the first trimester (In case of 217 women, it was available) and BPD in the second trimester. The accuracy of each method in predicting the day of delivery was determined. Those who were delivered after the spontaneous onset of labor were included. Differences among these methods were evaluated with nonparametric tests. RESULTS: The percentage of women who delivered within 3 days of the estimated day of delivery was 254(45.3%) and 216(38.5%) of the women with pregnancies by BPD and LMP, respectively. And within 7days of the estimated day were 408(72.7%), 390(69.5%) of the women from BPD and the LMP. In the women, the BPD estimate was significantly better predictor within the 7days of the day of delivery than LMP estimate (p=0.027). Compared to LMP estimate, CRL and BPD estimates seemed to be advanced the day of delivery about 2.6 days in CRL, and 0.9 days in BPD (p=0.004, p=0.034). But we could not find any advantage of the CRL measurement in first trimester than single BPD measurement in the second trimester for the predictor of the day of delivery. CONCLUSIONS: When the difference between the methods in predicting the day of delivery was less than 7 days, the BPD measurement was better than the last menstrual period.
Biometry* ; Crown-Rump Length ; Female ; Humans ; Pregnancy ; Pregnancy Trimester, First ; Pregnancy Trimester, Second ; Ultrasonography

The anterior process of the malleus (process of Folius) in the middle ear develops through an intramembranous ossification center that appears in the human embryo of 26.5 mm crown-rump length at a caudomedial position in relation to Meckel's cartilage. We present one case of an ossicular anomaly considered to consist of an abnormality of the anterior process and manubrium mallei (malleus handle). In this case, a thick bony bar was found extending from the neck of the malleus and abnormally developed an anterior process of the malleus to the posterior bony wall or the tympanic bone. In the anterior part, a thick bony bar was also found in the anterior bony wall connecting with the malleus neck and the anterior process of malleus, which was abnormally developed by fibrous tissue. The manubrium mallei and the umbo were not identified and the anterior process of the malleus was recognized as an abnormally developed bony fragment. On the basis of these findings, the bony bar was assumed to represent an abnormally developed mesenchyme bone (os goniale), which later developed into the anterior process of the malleus.
Cartilage ; Crown-Rump Length ; Ear, Middle ; Embryonic Structures ; Hearing Loss, Conductive* ; Humans ; Malleus ; Manubrium ; Mesoderm ; Neck

OBJECTIVE: To investigate the importance of transvaginal ultrasonographic findings of spontaneous abortion and the relation of transvaginal ultrasonographic finding and the karyotype of abortus. MATERIALS AND METHODS: Transvaginal sonography was undergone to 48 subjects with spontaneous abortion in their early pregnancies who had visited Ewha Womans University Mokdong Hospital, from March 1996 to June 1999. A chromosome analysis of their aborted products was done. RESULTS: The frequency of chromosome abnormalities of abortus was 47.9%. Among the chromosomal abnormalities, trisomy was 31.2%(simple trisomy 27.0%, double trisomy 4.2%), monosomy X 8.4%, poliploidy 8.4%(tripoidy 4.2%, tetraploidy 4.2%). The average maternal age for trisomy was 30.2+/-4.9, and their past number of spontaneous abortions was 1.0+/-0.9, with trisomy 16 most frequent with 23.0%. In the case with trisomy 5, 22, and double trisomy, the average maternal age was increased with 38.0, 36.0+/-2.8, 35.5+/-5.0, respectively. However, no significant relevance could be found. The average maternal age for polyploidy was 30.5+/-3.7, and their past number of spontaneous abortions was 1.0+/-2.0. No significant relevance could be found compared with normal karyotypes. The average maternal age for monosomy X was 27.5+/-1.7, which is lower than the average maternal age for normal karyotypes, but not significantly so. The mean number of past abortions was no different with 1.0+/-0.8. No significant relevance could be found between ultrasonographic findings and chromosomal abnormalities. The measured/expected crown-rump length ratio of the aborted group was smaller than those of the control group. CONCLUSION: Serial ultrasonographic findings in early pregnancies help to diagnose spontaneous abortion, but not efficient to diagnose chromosomal abnormalities in the aborted group.
Abortion, Spontaneous ; Chromosome Aberrations* ; Crown-Rump Length ; Female ; Humans ; Karyotype ; Maternal Age ; Polyploidy ; Pregnancy ; Tetraploidy ; Trisomy ; Turner Syndrome

Morphological characteristics of human embryos of Carnegie stage 17 were described. The crown rump length of these embryos were 11.7-13.6mm. These embryos were characterized externally by ventrally directed nasal pits, 6 distinct auricular hillocks, finger rays in the hand plate, digital plate at the lower limb bud, herniation of a part of midgut through umbilical cord, and internally by the partial fusion of ventral and dorsal pancreas, prominent nasal sac which is not open to primitive oral cavity, formation of segmental and some subsegmental bronchial buds, branching of metanephrotic pelvis, crescent-shaped lens cavity, and imminent semicircular ducts.
Crown-Rump Length ; Embryonic Structures* ; Fingers ; Hand ; Humans* ; Lower Extremity ; Mouth ; Pancreas ; Pelvis ; Semicircular Ducts ; Umbilical Cord

The aim of the present cross-sectional study is to define the reference range for the nuchal translucency (NT) measurements in normal Korean fetuses between 10 and 14 weeks' gestation. The nuchal translucency was measured prospectively in 202 chromosomally normal singletons of women attending our antenatal clinic or prenatal diagnostic center by 177 transabdominal sonography (88%) and by 25 transvaginal sonography (12%) if difficulty was encountered with transabdominal sonography. The NT measurement was expressed as the median and 5th, 95th centiles according to crown-rump length (CRL) measurements by ultrasound. Mean multiple of median (MoM) and the 95th centile of MoM values of the NT measurements with CRL in 10 mm intervals were also calculated. NT measurements increased significantly with CRL[NT (mm)=0.481647+0.020142xCRL (mm)]. A NT measurement greater than 2.5 mm was found in 4% of normal fetuses, but this proportion increased form 0% at 10-11 weeks, to 3.8, 8.8, 11.5% at 12, 13, 14 weeks, respectively. The present study provides normative data on the fetal NT thickness in a Korean population, which may improve the performance of NT screening for chromosomal abnormalities in the first trimester.
Chromosome Aberrations ; Cross-Sectional Studies ; Crown-Rump Length ; Female ; Fetus* ; Humans ; Mass Screening ; Nuchal Translucency Measurement* ; Pregnancy ; Pregnancy Trimester, First ; Prospective Studies ; Reference Values ; Ultrasonography

BACKGROUND: Trisomy 16 in mice is considered to be an animal model for Down's syndrome in human. We studied the morphologic characteristics of the heart and the edema, and their significance to the teratogenesis in this animal model. METHODS: A total of 30 dams were sacrificed to bear 125 (61.9%) normal fetuses 35 (17.3%) abnormal fetuses and 42 (20.8%) resorptions. Cytogenetic study and morphological examination were performed using microdissection agar-mount sectioning histologic examination and scanning electron microscope. RESULTS: The crown-rump length was significantly shorter in abnormal (trisomic fetuses) than the normal (eusomic) fetuses. Trisomic fetuses showed massive edema at the back from the vertex to the lumbar area. Four-chamber view section of the agar-mount and histologic section showed a common atrioventricular valve bridging the left and the right atrioventricular junction. Scanning electron microscopic examination on atrioventricular valves showed three types of atrioventricular valves:five cases with common atrioventricular orifice, three cases with partitioned atrioventricular orifice and two cases with atresia of the right atrioventricular orifice. CONCLUSION: This study confirmed the presence of massive edema and cardiac anomalies in the mouse with trisomy 16. But there was morphologic diversity of cardiac anomaly in this model.
Animals ; Crown-Rump Length ; Cytogenetics ; Down Syndrome ; Edema* ; Endocardial Cushion Defects ; Fetus* ; Heart ; Humans ; Hydrops Fetalis ; Mice ; Microdissection ; Models, Animal ; Pathology* ; Teratogenesis ; Trisomy*

OBJECTIVE: Nuchal translucency (NT) is the most powerful screening tool for Down syndrome and congenital cardiac anomaly, therefore strict guidelines were established to get accurate NT values. However, to stick to the guideline in all pregnant women is time-consuming and superfluous in majority of low risk population. We undertook this study to investigate whether the simplified protocol enables to select low risk group and is effective in them even if we skip the suggested NT measurement. METHODS: NT and crown-rump length (CRL) were measured prospectively. First, CRL was measured in the ordinary view that was mid-sagittal section of fetus in neutral position, and NT was measured at the same frozen screen (first measured value, 1MV). Then, NT was measured again according to the Fetal Medicine Foundation (FMF) guideline (second measured value, 2MV). RESULTS: There was good correlation between 1MV and 2MV in each case (r = 0.83, P < 0.001). All of the NT values over the 95th percentile in 2MV also belonged to over the 95th percentile in 1MV. NT value of 2 mm in 1MV could be used as a cut-off to obtain over the 95th percentile 2MV by receiver operating characteristic curve (sensitivity 100%, specificity 80.5%). The proportion of 1MV > or = 2 mm was only 23.8% of all cases, namely we had only to measure 2MV in 23.8% patients. Every 95th percentile or more 2MV could be detected with this simplified protocol. CONCLUSION: If NT is less than 2 mm at ordinary CRL view, we may skip suggested NT measurement according to FMF guideline.
Crown-Rump Length ; Down Syndrome ; Female ; Fetus ; Humans ; Mass Screening ; Nuchal Translucency Measurement ; Pregnant Women ; Prospective Studies ; ROC Curve ; Sensitivity and Specificity

The development and differentiation of cells in the spinal ganglion were studied by electron microscopy in human fetuses ranging from 12 mm to 260 mm crown rump length. At 12 mm embryo the primitive neuroblasts which had a single process, contained a large numbers of free ribosome and mitochondria but very little rough endoplasmic reticulum. At 30 mm fetus, the primitive spinal ganglion consisted of bipolar neuroblasts, satellite cells and undifferentiated cells. Spindle-shaped bipolar neuroblasts formed spinal ganglion of loosely grouped cells at 50 mm fetus. Two neuroblast cell types, a small cell contained large clumps of rough endoplasmic reticulum at periphery, could be distinguished. At 80 mm fetus, the spinal ganglion constituted of bipolar neuroblast with apparently random distribution of small and large neurons with processes, together with satellite cells and blood vessels. The presences of a large numbers of neurotubules in the Golgi-central region were one of the first sign of further maturation of the neuroblast. During next prenatal stage from 120 mm on fetus, the ganglion cells were large and contained much rough endoplasmic reticulum, neurotubules and extensive Golgi complex. A large number of neuroblasts became transformed into unipolar cells from 180 mm to 260 mm feuts. Nissl bodies appeared during this stage. The ganglion-satellite cell boundary became complicated with increasing age, then enlarging in parallel with the increase in volume of the nerve cell. During next prenatal stage up to 180 mm fetus, the unipolar ganglion cell increased in number and size, and the cytoplsm contained all intracytoplasmic structures which were also found in mature spinal ganglion except for large pigment granules.
Blood Vessels ; Crown-Rump Length ; Embryonic Structures ; Endoplasmic Reticulum, Rough ; Fetus* ; Ganglia, Spinal* ; Ganglion Cysts ; Golgi Apparatus ; Humans* ; Microscopy, Electron ; Mitochondria ; Neurons ; Nissl Bodies ; Ribosomes