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 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

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 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

To investigate predictable ultrasonographic findings of early abortion. To investigate objective rules for the screening of abortion Ultrasonographic examination of 111 early pregnancies between the sixth and ninth week in women who had regular 28 day menstrual cycles was performed. Ultrasonographic measurements of the gestational sac. Crown rump length and fetal heart rate were performed using a linear array real time transducer with doppler ultrasonogram. All measurements of 17 early abortions were compared to those of 94 normal pregnancies. Most of early aborted pregnanices were classified correctly by disciminant analysis with G-SAC and CRL (GSAC=0.5 CRL+15. Sensitivity 76.5%, specificity 96.8%). With the addition of FHR, 94.1 of early abortions could be predicted. In conclusion, ultrasonographic findings of early intrauterine growth retardation. Small gestational sac and bradycardia can be predictable signs suggestive of poor prognosis of early pregnancies.
Bradycardia ; Crown-Rump Length ; Female ; Fetal Growth Retardation ; Gestational Sac ; Heart Rate, Fetal ; Humans ; Mass Screening ; Menstrual Cycle ; Pregnancy ; Prognosis ; Sensitivity and Specificity ; Transducers ; Ultrasonography

OBJECTIVE: Fetal heart rate in embryos(6-8 gestational weeks) have been significantly related to fetal outcome, but have rarely been studied. We attempted to identify fetal heart rate during 6-8 gestational weeks. Our purpose was to determine the lower limit of the heart rate associated with a favorable outcome and to evaluate the prognosis for those embryos with slow heart rates in early period. METHODS: We prospectively studied 798 singleton pregnancies between Jul. 1997-Dec. 1999 visiting our hospital. Gestational age was calculated from the beginning of the last menstrual period in the case of regular cycle and was confirmed by the crown-rump length. Other cases were measured by crown-rump length or mean gestational sac diameter. Color doppler sonography was used to calculate the fetal heart rate in beats per minute as the mean of 3 waves. RESULTS: Mean fetal heart rate (+/-SD) were 114.08+/-15.40 bpm for group 1, 126.49+/-18.78 for group 2, 139.83+/-19.92 for group 3, and 149.58+/-23.34 for group 4(p<0.001). Prognosis in the first trimester improved as heart rate increased to 100 bpm in group 1 and 120 bpm in group 2. In group 3 and 4, most of fetus with heart rates below 110 bpm died. CONCLUSIONS: The fetal heart rate during 6-8 gestational weeks is associated with fetal outcome at the end of the first trimester and we can identify the fetuses that are in risk.
Crown-Rump Length ; Embryonic Structures ; Female ; Fetal Heart* ; Fetus ; Gestational Age ; Gestational Sac ; Heart Rate ; Heart Rate, Fetal* ; Humans ; Pregnancy ; Pregnancy Trimester, First ; Pregnancy* ; Prognosis ; Prospective Studies ; Ultrasonography*

In the embryonic heart, the primitive atrium is considered to receive the bilateral sinus horns including the upper terminal of the inferior vena cava (IVC). To reveal topographical anatomy of the embryonic venous pole of the heart, we examined horizontal serial paraffin sections of 15 human embryos with crown-rump length 9-31 mm, corresponding to a gestational age of 6-7 weeks or Carnegie stage 14-16. The IVC was often fixed to the developing right pulmonary vein by a mesentery-like fibrous tissue. Rather than the terminal portion of the future superior vena cava, the IVC contributed to form a right-sided atrial lumen at the stage. The sinus venosus or its left horn communicated with the IVC in earlier specimens, but in later specimens, the left atrium extended caudally to separate the sinus and IVC. In contrast, the right atrium consistently extended far caudally, even below the sinus horn, along the IVC. A small (or large) attachment between the left (or right) atrium and IVC in adult hearts seemed to be derived from the left (or right) sinus valve. This hypothesis did not contradict with the incorporation theory of the sinus valves into the atrial wall. Variations in topographical anatomy around the IVC, especially of the sinus valves, might not always depend on the stages but partly in individual differences.
Adult ; Animals ; Crown-Rump Length ; Embryonic Structures* ; Gestational Age ; Heart ; Heart Atria* ; Horns ; Humans ; Individuality ; Paraffin ; Pulmonary Veins ; Vena Cava, Inferior* ; Vena Cava, Superior

The crown-rump length(CRL) remains the most accurate parameter used for gestational dating. We aimed to establish the early fetal growth with CRL range in Korean women. The CRL of 48 singleton pregnancies which resulted from in vitro fertilization and e mbryo transfer(IVF-ET) at SNUH were assessed two to six times in the first trimester by trans-vaginal ultrasonography. All women included in this study went on to deliver norma l infa-nts at 37 completed weeks or after weighing over 2.5 kg. And we also studied the r elationship between CRL(in millimeters) and gestational age(in days), and found that the fo llowing second-order polynomial might be applied either to expect CRL using the menstr ual gestational age, or to estimate gestational age using measured CRL(r2=0.980, p=0.000 1). CRL=0.0175(GA)2-1.049(GA)+19.17 GA=7.5593(CRL-3.45)1/2+29.97 Finally we compared our data with some of published articles which assessed CRL in spontaneous and induced pregnancies. In conclusion, this study establish the early fetal growth with CRL range in Korean women on the basis of exact ovulation timing using high resolution transvaginal ultrasonography. And these data will be of great use in the evaluation of fetal growth in the first trimester.
Crown-Rump Length* ; Embryo Transfer* ; Embryonic Structures* ; Female ; Fertilization in Vitro* ; Fetal Development ; Gestational Age ; Humans ; Ovulation ; Pregnancy ; Pregnancy Trimester, First* ; Ultrasonography