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1.
In 219 normal pregnancies between 28 and 42 weeks the relationships of different ultrasound measurements of the fetal head and the fetal body to the gestational age were determined in order to improve the accurate diagnosis of fetal maturity during the last trimester of pregnancy. With the A and B ultrasound apparatus of Kretz, the biparietal diameter was determined by the A mode, the fronto occipital plane and the largest abdominal diamter were determined by the B scan. The following ultrasound measurements were taken: the two horizontal and transverse diameters, the circumferences and the planes. The abdominal measurements showed a higher rate of growth, compared to the cranial measurements a lesser rate of growth retardation and a higher variation of the normals. The correlation of the abdominal measurements with the gestational age was worse than that of the cranial measurements. Wth the exception of the biparietal diameter in the A mode, the mean diameters of the cranial and abdominal measurements gave better results than the single diameters. Circumference and surface measurements showed no advantages. The best results were obtained by combined fetal head and body measurements using the summation of the biparietal diameter in the A mode and the mean abdominal diameter in the B scan.  相似文献   

2.
OBJECTIVE: To construct nomograms of the size of the fetal orbit and lens during gestation. SUBJECTS: The study group included 349 normal pregnant women at 14-36 weeks' gestation. METHODS: Routine biometric measurements were obtained in all the participants; these included biparietal diameter, head and abdominal circumferences, measurements of the long bones and the diameters of the fetal orbit and lens. The orbital and lens circumference measurements were also related to gestational ages. RESULTS: A linear growth function was observed between gestational age (GA) and orbital diameter (r = 0.94; p < 0.00001; y = -0.66 + 0.5 x GA), orbital circumference (r = 0.94; p < 0.00001; y = -2.1 + 1.5 x GA) and orbital area (r = 0.94; p < 0.00001; y = -98.1 + 8.3 x GA). Significant correlation was also found between femoral length (FL) and orbital diameter (r = 0.95; p < 0.00001; y = 3.3 + 1.9 x FL), orbital circumference (r = 0.95; p < 0.00001; y = 10.3 + 5.9 x FL) and orbital area (r = 0.93; p < 0.00001; y = -28.2 + 32.2 x FL). A linear growth function was observed between orbital circumference and biparietal diameter (r = 0.94; p < 0.00001) and head circumference (r = 0.95; p < 0.00001). A linear growth function was also observed between gestational age and the diameter of the lens (r = 0.89; p < 0.00001; y = 0.88 + 1.4 x GA) the circumference of the lens (r = 0.89; p < 0.00001; y = 2.78 + 0.4 x GA) and the area of the lens (r = 0.89; p < 0.00001; y = -7.95 + 1.0 x GA). The correlation was found between the ratios of the diameters, circumferences and areas of the lens and the orbit. CONCLUSIONS: These results provide normative data of the growth of the fetal orbit and lens and may aid future studies relating to fetal eye anomalies.  相似文献   

3.
OBJECTIVES: To establish normative data for the width of the fetal cavum septi pellucidi at various gestational ages. SUBJECTS AND METHODS: A total of 608 consecutive fetuses between 19 and 42 gestational weeks were included in this prospective study. The largest width of the cavum septi pellucidi was measured by two-dimensional ultrasound. Piecewise regression analysis was used to study the relationships between the width of the fetal cavum septi pellucidi, gestational age and biparietal diameter. RESULTS: The fetal cavum septi pellucidi width increased gradually between 19 and 27 weeks of gestation and then plateaued between 28 weeks and term. Regression analysis revealed significant associations between cavum septi pellucidi width and gestational age, and cavum septi pellucidi width and biparietal diameter. CONCLUSIONS: The present study provides normative data for fetal cavum septi pellucidi width and useful information about the development of the midline brain structure in the fetus.  相似文献   

4.
OBJECTIVE: Fetal growth rates determined on the basis of findings at two separate sonographic examinations can be used to detect growth abnormalities. This article determines the relationship between the length of the interval between examinations and the associated variability in measured fetal growth rates. MATERIALS AND METHODS: We analyzed 1479 fetal measurements of the biparietal diameter, average abdominal diameter, and femur length from 539 normal pregnancies. Mean growth rates were computed as functions of gestational age. The standard deviation of the growth rate was computed as a function of the interval between examinations. RESULTS: The standard deviation of fetal growth rates is relatively constant when the interval between examinations is 8-10 weeks or more, but increases substantially when the interval is fewer than 6 weeks. CONCLUSION: From a purely statistical point of view, the optimal interval for assessment of fetal growth rates is 8-10 weeks or more. Shorter intervals, however, usually are mandated by the clinical situation. Correction factors can be used to determine the standard deviations and associated confidence intervals for fetal growth measured over a period of fewer than 10 weeks.  相似文献   

5.
OBJECTIVE: We sought to construct an ultrasonography-based growth curve in a Chinese population. STUDY DESIGN: Routine ultrasonographic examination was performed in 5496 normal pregnancies (>95% first births) in five obstetric ultrasonography laboratories in Central-South China from January 1, 1992, to December 31, 1993. RESULTS: All the fetal growth measures increased with gestational age, whereas the ratios either decreased or remained constant across gestation. Biparietal diameter and cerebral hemispheric width were higher at early gestational ages, whereas femur length, thoracic circumference, and abdominal circumference were lower at later gestational ages in our study than in previous studies. The ratio of lateral ventricular width/cerebral hemispheric width was lower at an early gestational age but higher in later gestational ages in our study. CONCLUSIONS: A different standard of ultrasonography-based fetal growth is needed for different populations. The ultrasonography-based growth curve constructed in this large Chinese population provides an additional tool for the evaluation of fetal growth and development.  相似文献   

6.
BACKGROUND: The crown-rump length is conventionally used to determine the age of human abortuses. However, it is not reliable as it is dependent on the positioning of the conceptus. We compared this with the biparietal diameter and foot length for determining the gestational age. METHODS: Different measurements, commonly used to assess gestational age, were measured in 146 human abortuses for which an accurate obstetric history could not be elicited. Measurements taken were crown-rump length, biparietal diameter and foot length. These were correlated with the observations at antenatal examinations before finalizing the approximate age. RESULTS: Multiple regression analysis of the data indicated that of the three measurements, the biparietal diameter was the most reliable for determining foetal gestational age between 8 and 26 weeks. The age determined with the biparietal diameter correlated well with that of abortuses with an accurate obstetric history. CONCLUSION: The biparietal diameter of a human foetus may be used to determine its age if the obstetric history regarding the period of gestation is vague or not available.  相似文献   

7.
Sonographic growth curves of 47 normal triplet pregnancies were compared with those of 71 uncomplicated twin gestations. Starting from the 25th week, the biparietal diameter in triplets was found to lag progressively compared with that of twins, reaching a mean difference of 2 weeks at 36 weeks gestation. Similarly, a significant difference was found between the femur length and head to abdomen circumference ratio growth curves of triplets and twins. It is concluded that as pregnancy continues from the 25th to the 36th gestational week, there is a significant delay in the growth patterns of normal triplet pregnancies compared with twin gestations.  相似文献   

8.
OBJECTIVE: This study was designed to determine the range of normal fetal nasal width by ultrasonography, which may be beneficial for detection of trisomy 21 and other chromosomal abnormalities. We hypothesize that a wide, saddle-shaped nose, which is one of the clinical neonatal anatomic features of trisomy 21, can be diagnosed prenatally. STUDY DESIGN: Fetal nasal width diameter was measured on 782 normal white fetuses by ultrasonography. Gestational ages ranged from 13.8 to 40.4 weeks. Mean and SD of fetal width diameter was calculated weekly by gestational age to establish normal values. RESULTS: The fetal nasal width increased as a function of gestational age, showing a polynomial curve during pregnancy (r = 0.912, p = 0.002). With use of mean +/- 1 SD as a cutoff value, the results showed a sensitivity of 80% with a specificity of 67% and a positive predictive value of 2.2% with a negative predictive value of 99.7% for the diagnosis of trisomy 21. CONCLUSION: The fetal nasal width diameter may be used as a biometric measurement and may be useful to identify trisomy 21 or other chromosomal abnormalities in conjunction with other already defined parameters used in a genetic ultrasonographic screen.  相似文献   

9.
In early pregnancy, ultrasonic scanning is valuable if the patient's menstrual history is unreliable or if uterine size is less than expected. The crown-rump length of the embryo can be measured from the sixth week of gestation, and pulsation of the heart detected from the seventh. The crown-rump length of the early embryo gives precise information about maturity. Somewhat later in pregnancy, fetal maturity and growth rate can be assessed accurately by measurement of the biparietal diameter. The head circumference and the fetal upper abdominal circumference together give the head-abdomen ratio, which can be helpful in assessing fetal nutrition. The abdominal circumference also may be used to predict fetal weight.  相似文献   

10.
It is known that different genes are expressed during ontogeny; however, it is unclear how variation in that expression is associated with changes in growth patterns. The objective of this study is to assess how genetic variation in fetal morphology changes with ontogeny in baboons. Longitudinal measures of the head and femur (60 to 180 days gestation) were available for 892 pregnancies. We used a genetic model that allowed both the genetic and environmental variances (sigma 2G and sigma 2E) to change with age and estimated genetic and environmental correlations (rho G and rho E) between measurements at different ages. The results indicate a significant increase in the genetic variance for biparietal diameter and femur length but not for head circumference and fronto-occipital diameter. The rho G estimates for all measures decreased as the age between measures increased from 0 to 120 days, indicating that different groups of genes are expressed early in gestation and late in gestation. The rho E estimates dropped rapidly from 1 to 0 for all measures, indicating temporally localized environmental influences on fetal growth. Thus fetal morphometrics are significantly heritable and those genes that influence them show age-specific expression during ontogeny.  相似文献   

11.
Our objective was to construct a nomogram of the fetal lingual size early pregnancy and to assess the size of the tongue in abnormal fetuses. The lingual width was measured by using transvaginal ultrasonography in 80 normal fetuses at 13 and 18 weeks' gestation. In addition the tongue was measured in 22 fetuses at these gestational ages who had an abnormal karyotype or oro-facial malformations. A linear relationship was found between the lingual width and gestational age in normal fetuses. The lingual size was within the normal range in cases of trisomy 13, trisomy 21 and Turner syndrome. A small tongue was observed in fetuses with micrognathia. Correlation between lingual width and gestational age was observed in early pregnancy. The relationship between the size of the tongue and oro-facial malformation needs further evaluation.  相似文献   

12.
In a synoptic schema are presented the percentiles curves of the biparietal diameter, the sum of the sagittal and transversal thoracic diameter and the fetal weight (Lubchenco modif.). To attain the percentiles curves of the ultrasonic parameters we applied 5400 mensurations of the biparietal diameter and 1300 mensurations of the thorax. In the diagram are published the percentiles P 10, P 25, P 50, P 75, P 90. It is possible to diagnose a divergence between the cephalic and thoracic growth (dystrophia, hypertrophia) and estimate the gestation weeks.  相似文献   

13.
OBJECTIVE: To evaluate the umbilical and uterine arterial Doppler flow velocity waveform systolic to diastolic (S/D) ratios performed at 24-30 weeks gestation for predicting fetal growth retardation (IUGR). METHODS: A prospective double blind study was conducted in 118 cases of high risk singleton pregnant women. The umbilical and uterine arterial S/D ratios were measured at 24-30 gestational weeks and the pregnancy outcomes were followed up. RESULTS: The prevalence of IUGR in our study population was 16.9%. At 24-30 weeks gestation, the S/D ratio of both umbilical artery and uterine artery in IUGR pregnant women were significantly higher than those in normal pregnant women, while the fetal biometric measurements were normal in all the 118 cases. The sensitivity, specificity and positive predictive value of umbilical arterial S/D ratio to predict IUGR were 80.0%, 83.7% and 50.0% with a Kappa index of 0.51 at 24-30 weeks gestation. With lower sensitivity, specificity, positive predictive value and Kappa index (40.0%, 84.5%, 34.8% and 0.23 respectively), the uterine arterial S/D ratio had less predictive value. CONCLUSIONS: The umbilical arterial Doppler flow velocity waveform S/D ratio may be an earlier predictor for screening of IUGR at 24-30 weeks gestation in high risk pregnant women with normal fetal biometric measurements.  相似文献   

14.
A dataset of 64 pregnancies conceived by artificial reproductive techniques was studied to assess the accuracy of second-trimester dating formulae when these were applied in routine ultrasound clinics in different centers. Dating formulae for biparietal diameter (BPD) and femur length (FL) were derived for a gestational age range of 14-23 weeks. The best fit curves represented linear equations: gestational age (days) = 44.2 + 2 x BPD; and gestational age (days) = 67.4 + 2.3 x FL. Twelve published formulae for biparietal diameter and femur length were reviewed and systematic and random errors were calculated for these formulae when they were applied to second-trimester scan measurements in precisely dated pregnancies. Overall, published dating formulae performed well in predicting gestational age. The 95% confidence interval was 8.3 days for biparietal diameter and 10.2 days for femur length. The study confirms the accuracy of ultrasound dating in routine ultrasound clinics and supports the use of ultrasound measurement alone in preference to menstrual history for dating pregnancy.  相似文献   

15.
OBJECTIVE: Most of the routine ultrasound screening in our institution consists of early transvaginal examinations at 14-17 weeks. Complete fetal echocardiography is performed in every case. However, normal values for most fetal cardiac structures at this stage of gestation are not available. Our aim was to construct normal ranges for fetal cardiac structures, derived from cross-sectional echocardiography, at 14-40 weeks of gestation. DESIGN: A prospective study was performed. The study group consisted of 637 pregnant women referred for a routine sonographic examination. Women with abnormal prenatal or postnatal outcome were not included in the study. Transvaginal examinations were used for 14-17 weeks of gestation. More advanced pregnancies were examined transabdominally. RESULTS: We constructed normal ranges for the left and right end-diastolic transverse ventricular diameters (n = 637), left/right ventricular ratio (n = 637), aortic root diameter (n = 637), pulmonary artery diameter (n = 637), aortic/pulmonary ratio (n = 490), left and right transverse atrial diameters (n = 201) and left/right atrial ratio (n = 201). CONCLUSIONS: The results provide the examiner with normal ranges for fetal cardiac structures for the early transvaginal examination. The continuity of all curves from 14 to 40 weeks of gestation allows follow-up of any specific fetus to term.  相似文献   

16.
OBJECTIVE: To test the usefulness of the fetal transverse cerebellar diameter/abdominal circumference (TCD/AC) ratio in predicting known small-for-gestational-age (SGA) infants. METHOD: The relationship between fetal TCD and AC throughout the second half of pregnancy was investigated in 635 well-dated, normal pregnancies and examined with regard to gestational age and infant birth weight percentiles. RESULTS: One hundred eighteen (19%) fetuses were excluded due to inadequate visualization of the fetal cerebellum. A strong correlation was noted between gestational age determined by the last menstrual period and both fetal TCD (r2 = 0.91338) and AC (r2 = 0.89361) in fetuses with birth weights between the 10th and 90th percentiles (n = 407; mean 14.4, S.D. 1.2). Although the TCD/AC ratio showed a poor correlation with gestational age (r2 = 0.15788), a slight increase was noted during gestation. A TCD/AC ratio greater than 15.5 was present in 80% of SGA infants when measurements were performed within 1 week of delivery. CONCLUSION: Fetal TCD/AC ratio as a gestational age-independent method could improve diagnostic sensitivity and specificity in the early detection of fetal growth abnormalities.  相似文献   

17.
Assessment of gestational age is one of the most important aims of ultrasonography in obstetrics. As pregnancy progresses, influences of factors which makes the growth of the fetuses different, cumulates. It has been revealed that the earlier in pregnancy ultrasound examination was performed, the better precision in the assessment of gestational age was obtained. The best precision is encountered when Crown-rump length is measured between 7-9 weeks of gestation. Until the end of the half of pregnancy, biparietal measurement allows for better assessment of gestational age than the date of the last menstrual period. As pregnancy progresses the variability of the measurements increases, reaching 7 week variation at term. The aim of this study is the assessment of fetal sacral length ultrasonographic measurements in the calculation of gestational age. The investigated group consists of 453 pregnant women between 16-41 weeks of physiological gestation.  相似文献   

18.
OBJECTIVE: Our purpose was to examine the impact of gestational age and fetal growth restriction on fetal and neonatal mortality rates in the postterm pregnancy. STUDY DESIGN: All deliveries occurring in Sweden between Jan. 1, 1987, and Dec. 31, 1992, were evaluated for participation in this study. Data were derived from the National Swedish Medical Birth Registry. Pregnancies were selected for inclusion in the study on the basis of the following criteria: (1) singleton pregnancy, (2) reliable dates, (3) gestational age > or = 40 weeks, and (4) maternal age 15 to 44 years. Fetal growth restriction was defined as birth weight <2 SD below the mean for gestational age. A total of 181,524 pregnancies met the inclusion criteria and formed the study population. Fetal and neonatal mortalities at 40 weeks' gestation were used as reference levels. Logistic regression analysis was used to estimate the independent effects of gestational age and fetal growth restriction on fetal and neonatal mortality rates. RESULTS: A significant rise in the odds ratio for fetal death was detected from 41 weeks' gestation and on (odds ratios 1.5, 1.8, and 2.9 at 41, 42, and 43 weeks, respectively). Odds ratios for neonatal mortality did not demonstrate a significant gestational age dependency. Fetal growth restriction was associated with significantly higher odds ratios for both fetal and neonatal mortality rates at every gestational age examined (with odds ratios ranging from 7.1 to 10.0 for fetal death and from 3.4 to 9.4 for neonatal death). CONCLUSIONS: Postterm pregnancies have long been considered to be at high risk for adverse perinatal outcome. This study documents a small but significant increase in fetal mortality in accurately dated pregnancies that extend beyond 41 weeks of gestation. This study also demonstrates that fetal growth restriction is independently associated with increased perinatal mortality in these pregnancies.  相似文献   

19.
OBJECTIVE: To evaluate the screening utility of early transvaginal measurement of the transverse cerebellar diameter for identification of Down syndrome fetuses. METHOD: Measurements of the transverse cerebellar diameter were obtained by transvaginal sonography between 11 and 16 weeks of gestation in 544 fetuses with a normal karyotype and in 37 Down syndrome fetuses. RESULTS: The transverse cerebellar diameter was found to show a fairly constant increment of values throughout the period evaluated with a linear relationship to the gestational age. The measurements obtained in Down syndrome fetuses are within the normal range for gestational age. CONCLUSION: The transverse cerebellar diameter cannot be considered a useful tool in the detection of Down syndrome in early pregnancy.  相似文献   

20.
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