Correlation between fetal gastric size and amniotic fluid volume

PURPOSE: Since abnormal conditions of the fetal digestive tract may alter both amniotic fluid volume and fetal gastric volume, we sought to determine whether amniotic fluid volume is correlated with fetal gastric volume in normal pregnancy. METHODS: A total of 280 fetal gastric size measurements were made prospectively from routine sonographic examinations of women with normal singleton pregnancies between 16 and 42 weeks of gestation. The fetal stomach was defined as the largest area including the pyloric site on transverse or oblique real-time sonographic scans. Gastric volume was calculated according to the formula for a prolate ellipsoid. The amniotic fluid index (AFI) was used for the evaluation of amniotic fluid volume. RESULTS: Both fetal gastric volume and AFI were significantly correlated with gestational age (R2= 0.422 and R2= 0.128, respectively). Only a weak correlation was found between gastric volume and AFI (R2= 0.036, p <0.001). On multivariate linear regression analysis adjusting for gestational age and fetal biometric measurements, gastric volume was not an independent and significant predictor of AFI. CONCLUSIONS: Although sonographically determined fetal gastric volume measurements appear to be useful in the assessment of fetal digestive tract anomalies, fetal gastric volume has no clinically significant effect on the amniotic fluid volume in normal pregnancy.     

Growth of the fetal gall bladder in normal pregnancies.

Our objective was to obtain dimensions of the fetal gall bladder as a basis, for further studies and to establish normative data to assess deviations in growth. The study group included 183 normal pregnant women from 13 to 40 weeks' gestation. Routine biometric measurements were obtained on all fetuses, including biparietal diameter, head and abdominal circumferences and measurements of the long bones and the two diameters of the fetal gull bladder. The gall bladder area and circumference were calculated for each gestational age.A linear growth function was observed across the gestational age and a first-degree correlation was found to exist between gestational age and both the longitudinal (r = 0.77067; p < 0.00001; y = -0.41060 + 0.0907 x gestational age) and transverse (r = 0.602; p < 0.00001; y = 0.58567 + 0.01925 x gestational age) diameters of the fetal gall bladder. A significant correlation was also found between gull bladder area and gestational age (r = 0.6878; p < 0.00001), biparietal diameter (r = 0.72768; p < 0.00001), abdominal circumference (r = 0.71363; p < 0.00001) and femoral length (r = 0.72190; p < 0.00001). In addition, a significant correlation was found between gall bladder circumference and gestational age (r = 0.76181; p < 0.00001), biparietal diameter (r = 0.80039; p < 0.00001), abdominal circumference (r = 0.78030; p < 0.00001) and femoral length (r = 0.79694; p < 0.00001).These results provide normative data of the fetal gall bladder in various dimensions and across gestational age. In addition, the data offer the potential for prenatal diagnosis of additional lesions in the extrahepatic biliary duct system.     

Evaluation of pulsatility index nomograms based on fetal biometry in small for gestational age fetuses.

Reference limits for the PI from the umbilical, middle cerebral, and renal arteries were constructed using BPD, AC, FL, and transverse cerebellar diameter as independent variables and their efficacy tested in a population of SGA fetuses. Therefore, 153 normal fetuses and 90 SGA fetuses with established dates between 20 and 40 weeks of gestation were considered. Normal fetuses showed a linear negative relationship between the PI from all the vessels investigated and all the biometric parameters considered. Although the BPD related better with the PI from the umbilical artery (r = 0.646) and the renal artery (r = 0.765) and the transverse cerebellar diameter related better with middle cerebral artery PI values (r = 0.510), no evident differences in fitting were found among the variables tested. In SGA fetuses the nomograms on BPD, AC, and FL significantly underestimated PI values in all the vessels studied when compared to the nomograms based on gestational age, while a similar ability in identifying abnormal PI values was found for nomograms based on gestational age and transverse cerebellar diameter. These newly developed nomograms based on transverse cerebellar diameter may prove useful in the evaluation of Doppler indices of fetuses with uncertain gestational age.     

Fetal transverse cerebellar diameter measurements in normal and reduced fetal growth.

OBJECTIVES: To establish the increase in fetal transverse cerebellar diameter (TCD) relative to gestational age during normal and restricted fetal growth; to determine the significance of TCD and TCD/AC relationship in predicting fetal outcome as expressed by perinatal mortality. DESIGN: A retrospective cross-sectional study. SUBJECTS: Three hundred and sixty normally developing fetuses between 17 and 34 weeks of gestation and 73 growth-restricted fetuses between 24 and 34 weeks of gestation. METHODS: Ultrasonographic measurements included head circumference (mm), abdominal circumference (mm) and transverse cerebellar diameter (mm). A gestational age-related normal reference chart was produced for TCD. RESULTS: Statistically significant relationships between transverse cerebellar diameter and gestational age, abdominal circumference and head circumference were found. The normal fetal TCD exhibited a more than twofold increase in size during the second half of pregnancy. Twenty-six per cent of the small-for-gestational age (SGA) fetuses displayed a reduced TCD and 82% of the SGA fetuses demonstrated raised TCD/AC values. No statistically significant difference in perinatal mortality or birth weight was found between the subsets of growth-restricted fetuses with reduced or normal TCD; or between the subsets with normal or raised TCD/AC values. CONCLUSIONS: In the normally developing fetus the TCD increases with advancing gestational age. Increased TCD/AC values are suspicious of fetal growth restriction. The perinatal mortality in growth-restricted fetuses with a small cerebellum is increased twofold over that of other fetuses.     

The fetal cerebellar vermis: anatomy and biometric assessment using volume contrast imaging in the C-plane (VCI-C).

OBJECTIVES: To describe the normal appearance and study the biometry of the fetal cerebellar vermis by three-dimensional (3D) volume contrast imaging in the coronal (C-) plane (VCI-C). METHODS: A total of 203 normally developed fetuses were examined prospectively at 18-33 weeks' gestation. At the level of the view used to measure the transverse cerebellar diameter (TCD), a VCI-C plane was displayed to examine, using a transabdominal probe, the fetal mid-saggital vermis. The volumes acquired were stored for later review and measurement of the anteroposterior (AP) diameter, craniocaudal (CC) diameter and surface area of the cerebellar vermis. Each dataset was evaluated by two independent observers. Measurements as a function of gestational age (GA), biparietal diameter (BPD), head circumference (HC) and TCD were expressed by regression equations. Interobserver variability was evaluated. Nomograms were produced. In order to validate the use of VCI in fetal biometry, datasets from 57 patients were selected arbitrarily for comparison of their VCI-C measurements with those from mid-sagittal sections of a stored 3D multiplanar examination. Intraclass correlation was used to evaluate the agreement between these measurements. RESULTS: The mean maternal age was 32 years. We were able to measure mid-sagittal CC diameter, mid-sagittal AP diameter and cerebellar vermis surface area in all fetuses. Interobserver variability analysis showed no significant differences between the two observers (P > 0.05). Measurements of the cerebellar vermis (AP diameter, CC diameter and surface area) correlated linearly with GA, BPD, HC and TCD (r > or = 0.82, P < 0.0001). CC and AP diameters estimated from the mid-sagittal section of the multiplanar measurements were significantly correlated with VCI-C measurements (r = 0.96, P < 0.00001 and r = 0.95, P < 0.00001, respectively). CONCLUSIONS: VCI-C is a valuable tool, allowing intrauterine assessment of the normal appearance of the fetal cerebellar vermis. The nomograms developed in this study should enable accurate evaluation of the cerebellar vermis.     

Nomogram of Wharton's jelly as depicted in the sonographic cross section of the umbilical cord.

OBJECTIVES: To generate a nomogram for the sonographic measurement of Wharton's jelly area (WJA) during gestation and to investigate whether WJA is related to fetal biometric parameters. METHOD: The sonographic cross-sectional area of the umbilical cord and of its vessels was measured in 659 fetuses between 15 and 42 weeks of gestation. The WJA was calculated by subtracting the vascular area from the umbilical cord area. The conventional biometric parameters were measured and correlated with the WJA. Polynomial regression analysis was utilized for statistical purposes. RESULTS: The WJA increased as a function of gestational age (r = 0.63, P < 0.001). The regression equation for the mean WJA (y) according to gestational age (x) was y = -114.7 + 4.142x - 0.01x2 and for the standard deviation (y') was y' = -7.567 + 1.319x. There was a strong correlation between the WJA and the umbilical cord area (r = 0.97, P < 0.001). A significant correlation was also found between the WJA and fetal biometric parameters before 32 weeks of gestation (WJA and biparietal diameter: r = 0.82, P < 0.001; WJA and abdominal circumference: r = 0.79, P < 0.001; WJA and femur length: r = 0.81, P < 0.001) while after 32 weeks of gestation no correlations were found between WJA and fetal anthropometric parameters. CONCLUSION: A nomogram for the WJA has been generated. The WJA increases as a function of gestational age and it is correlated with fetal size up to 32 weeks of gestation.     

正常胎儿眼球横径、周长、截面积及眼距的超声研究与临床价值

【目的】探讨超声方法观察胎儿眼球横径、周长、截面积及眼距的生长规律及其与孕周的相关性。【方法】从接受胎儿超声系统筛查和常规产前超声检查的孕龄13～40周胎儿中选取符合条件的2988例进入样本库,在常规检查后对其胎儿眼球横径、周长、截面积及眼距进行测量,按孕龄分组,并进行相关统计学处理。【结果】胎儿眼球横径、周长、截面积及眼距在13～40周中随孕龄增加而增长,与孕周呈线性相关（r=0．87～0．92,均P〈0．01）;左、右眼球横径、周长及截面积在各孕周间无明显统计学差异（P〉0．05）。【结论】胎儿眼球横径、周长、截面积与孕龄呈正相关,超声检查为评价胎儿眼部发育情况提供了一种简便实用的方法。胎儿眼距正常参考值的确立,有助于检查出胎儿眼距过宽或过窄。     

Fetal transabdominal biometry at 11-14 weeks of gestation.

OBJECTIVE: To establish comprehensive transabdominal ultrasonographic reference ranges for viable normal singleton human fetuses at 11-14 weeks' gestation. METHODS: Single transabdominal ultrasound measurements were taken once per pregnancy at a gestational age of between 11+0 and 14+0 weeks (crown-rump length, 45-84 mm), in viable singleton fetuses with nuchal translucency < or = 3 mm and without detectable structural anomalies, using four standard planes: (i) biparietal diameter (BPD) and fronto-occipital diameter (FOD) resulting in head circumference (HC), anterior horn (Va), posterior horn (Vp), and hemisphere (HEM); (ii) transcerebellar diameter (TCD) and cisterna magna (CM); (iii) abdominal anteroposterior (AAP) and abdominal transverse diameter (ATD) resulting in abdominal circumference (AC); and (iv) femur length (FL). The respective ratios Va/HEM, Vp/HEM, HC/AC, BPD/FL, BPD/FOD, FL/CRL, FL/BPD and FL/AC and the estimated weight were derived. Reference ranges were constructed and the mean and 5th and 95th centiles were plotted against gestation. RESULTS: There was a general increase in biometric parameters with gestation. The ratios for the ventricles vs. hemisphere and BPD/FL ratio decreased while the BPD/FOD and HC/AC ratios remained constant. Analysis of the reference range for BPD/FL was performed in both 167 and 664 fetuses and the results showed almost the identical type of equation, indicating a high degree of accuracy for the growth charts. CONCLUSIONS: We have established comprehensive reference ranges for first-trimester fetal biometry by transabdominal sonography. These charts may have a role in the diagnosis of early onset symmetrical or asymmetrical growth restriction and in the interpretation of measurements in chromosomally abnormal fetuses, and they may help in the detection of skeletal dysplasias or acrania/anencephaly.     

胎儿腹部囊性包块的产前超声诊断与鉴别诊断

目的 探讨胎儿腹部囊性包块的声像特征,提高超声对胎儿腹部囊性包块的诊断及鉴别诊断价值.方法 收集2010年1月至2012年12月间我院产前超声检查发现胎儿腹部囊性包块并有随访结果的病例192例,分析不同孕周、不同来源囊性包块的声像特征、发生部位及动态变化,对照产后结果进行分析.结果 产前超声诊断与产后结果符合175例,其中肝脏来源10例,胆道来源8例,肠道来源39例,肾实质来源32例,泌尿系梗阻来源41例,生殖系统来源38例,其他来源7例;超声诊断符合率为91.1％ （175/192）.首次超声检查发现包块的时间主要集中于18～ 32周之间,中位孕周为25周.18周以前以巨膀胱多见,晚孕期以卵巢囊肿、低位消化道梗阻和输尿管扩张为主.产前超声误诊17例,误诊率为8.9％.产前超声对肠道来源的囊性包块误诊率较高,为5.7％,对生殖系统及其他来源误诊率较低,均为0.5％.结论 超声依据胎儿腹部囊性包块的发生部位、形态、内部回声、血流情况、与周围器官的毗邻关系、与孕周的关系等情况判断囊性包块的来源,对胎儿的评估有重要的临床指导意义.     

产前超声诊断胎儿消化道闭锁

目的 探讨产前超声诊断胎儿消化道闭锁的临床价值。方法 回顾性分析22胎消化道闭锁胎儿的产前超声图像及尸体解剖资料。结果 22胎产后尸体解剖共发现24处消化道闭锁(2胎同时合并食管及肛门闭锁),产前超声检出食管闭锁3处、十二指肠闭锁4处、空回肠闭锁3处、肛门闭锁3处,检出率为54.17%;漏诊食管闭锁4处、幽门闭锁1处、肛门闭锁6处。结论 产前超声诊断胎儿消化道闭锁方法简便,加强动态观察尤其是晚孕期复查与全面系统检查可减少漏诊。     

Nomogram of maxillary bone length in normal pregnancies.

OBJECTIVE: The aim of this study was to define normal ultrasonographic growth of the fetal maxillary bone throughout pregnancy as a basis for further studies and as normative data for assessing deviations in growth. METHODS: A prospective cross-sectional study was performed. Consecutive routine biometric measurements and fetal organ scans were obtained from patients undergoing elective fetal anatomic surveys. Special attention was paid to the profile view of the fetal face, and the maxillary bone was identified and measured. RESULTS: Three hundred twenty-seven fetuses between 13 and 40 weeks' gestation were scanned. The maxillary bone is seen as a rodlike structure; it is a part of the facial skeleton that allows the opening and closing of the pharynx. A linear growth function was observed across gestational age (GA), and first-degree correlation was found to exist between GA and the maxillary bone (r = .645; P < .0001; y = 7.78 + 0.18 x GA). Significant correlation was also found between the maxillary bone and biparietal diameter (BPD) (r = 0.652; P > .0001; y = 8.36 + 0.66 x BPD), head circumference (HC) (r = .645; P < .0001; y = 8.39 + 0.18 x HC), femoral bone length (FBL) (r = .640; P < .0001; y = 9.28 + 0.7 x FBL), and abdominal circumference (AC) (r = .640; P < .0001; y = 8.91 + 0.17 x AC). CONCLUSIONS: Normative data for ultrasonographic measurements of the fetal maxillary bone throughout pregnancy are provided. These data potentially allow the prenatal diagnosis of abnormal maxillary bone length.     

Diameter of the normal fetal thymus on ultrasound.

OBJECTIVE: To present the normative data of the transverse diameter of the developing fetal thymus. METHODS: In this prospective study, the maximum transverse diameter of the thymus was measured by one sonologist in 376 normal fetuses between 19 and 38 weeks of gestation. We assessed the relationship of the transverse thymic diameter with gestational age (GA), biparietal diameter, femur length and abdominal circumference using general linear regression modeling. The predicted mean and 95% reference range of thymic diameter at each GA were calculated from the regression equation. RESULTS: Measurements of the transverse diameter were possible in 352 of the 376 (94%) fetuses. The transverse diameter of the fetal thymus increased with increasing GA and fetal size parameters in a linear manner. The regression equation for transverse diameter of the thymus as a function of GA was: thymic diameter (cm) = 0.15 x GA (weeks) - 1.59 (r(2) = 0.86, P < 0.001). CONCLUSION: The transverse diameter of the fetal thymus is easy to measure; this study presents normative data.     

产前超声诊断先天性消化道梗阻

目的 探讨产前超声诊断先天性消化道梗阻的价值.方法 对46例先天性消化道梗阻的产前超声诊断资料进行回顾性分析.结果 46例中,食道闭锁1例,幽门狭窄或闭锁7例,十二指肠狭窄或闭锁18例,小肠狭窄或闭锁6例,结肠闭锁3例,肛门闭锁9例,先天性巨结肠2例,均经引产解剖或产后手术证实.结论 产前超声检查可直接显示消化道扩张的部位和程度,并由此作出消化道梗阻的定位定性诊断,是先天性消化道梗阻重要的诊断方法.     

Nomograms of the axial fetal cerebellar hemisphere circumference and area throughout gestation.

OBJECTIVE: The widely applied transcerebellar diameter (TCD) obtained at axial cranial imaging, measures the distance between the lateral aspects of the cerebellum and incorporates the width of the cerebellar vermis. Our objective was to create reference ranges of axial fetal cerebellar hemisphere circumference (CHC) and area (CHA), independent of the cerebellar vermis, throughout gestation. METHODS: This cross-sectional study involved pregnant patients between 14 and 41 weeks of gestation. Inclusion criteria consisted of well-established dates (confirmed by early ultrasound), non-anomalous singleton fetuses and intact amniotic membranes. Sonographic measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL), TCD, and estimated fetal weight (EFW). Values of axial fetal CHC and CHA were each calculated as the mean of three separate measurements. The 5th, 50th and 95th centiles were estimated at each week of gestational age (GA) by least-squares regression for the mean and standard deviation (SD) of the CHC and CHA as functions of GA. r2 and associated P-values for the relationships of CHC and CHA with other sonographic biometric measurements were calculated. RESULTS: The study included 651 consecutive patients. All attempts at obtaining axial fetal CHC and CHA were successful. Mean maternal age was 27.3+/-6.7 years, median gravidity was 1 (range 1-16), and median parity was 1 (range 0-6). Mean CHC (cm) throughout gestation was modeled as -2.091+0.2563xGA (weeks) (SD=-0.075+0.0164xGA), and mean CHA (cm2) was modeled as 0.245-0.0765xGA+0.00506xGA2 (SD=1.167-0.1565xGA+0.006785xGA(2)-0.00008028xGA3). Fetal axial CHC and CHA correlated significantly and strongly with BPD, HC, AC, HL, FL, TCD and EFW (all R2 values were >or=0.95, and all P-values were <0.001). CONCLUSION: Nomograms of axial fetal cerebellar hemisphere circumference and area throughout gestation, independent of the cerebellar vermis, have been provided.     

Sex-specific antenatal reference growth charts for uncomplicated singleton pregnancies at 15-40 weeks of gestation.

OBJECTIVE: Female fetuses, on average, weigh less than male fetuses at all gestational ages. The purpose of this study was to compare female and male fetuses in terms of intrauterine ultrasound growth measurements and to develop gestational-age-related charts based on a computerized perinatal database. METHODS: This was a retrospective study of unselected women in the second and third trimesters of pregnancy, who had a normal scan at 10-14 weeks. Data analysis was performed using measurements obtained from a mixed-race population of 4234 women, who underwent 5198 ultrasound examinations. The scans were performed by four trained sonographers, according to a standardized protocol. Routine measurements included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). The main end-points were sex- and race-specific differences in fetal biometry, which were also used to estimate fetal weight. RESULTS: The base-line demographic characteristics and risk factors were comparable in female and male fetuses. Significant differences in fetal BPD, HC, AC and estimated fetal weight, but not FL, were seen between male and female fetuses. Centile charts for each of these variables were constructed for both male and female fetuses. CONCLUSIONS: This study suggests that small but consistent sex-related differences in prenatal BPD, HC and AC measurements are established by as early as 15 weeks of gestation. The use of sex-specific nomograms may improve the prenatal assessment of fetal growth as well as the diagnosis of structural abnormalities.     

Nomograms of sonographic measurements throughout gestation of the fetal hard palate width, length and area.

OBJECTIVE: To assess the feasibility of sonographic depiction of the fetal hard palate and secondarily to create nomograms throughout gestation of its sonographic width, length and area. METHODS: This was a cross-sectional study of pregnant patients between 15 and 41 weeks' gestation. Inclusion criteria consisted of well-established dates (confirmed by early ultrasound), and singleton, non-anomalous fetuses. Sonographic measurements obtained included biparietal diameter, head circumference, abdominal circumference and femur length. Fetal hard palate measurements included maximum width, maximum length and the calculated area. Tables were prepared depicting the estimated mean +/- SD and 5(th), 50(th) and 95(th) centiles at each gestational week between 15 and 41 weeks. Pearson's correlation coefficient and associated P-values for the relationships between fetal hard palate measurements and other sonographic measurements and coefficients of variation for each of the fetal hard palate measurements were calculated. RESULTS: The study included 602 consecutive patients. The mean maternal age was 28.7 +/- 6.3 years, with median gravidity of 2 (range, 1-12) and parity 1 (range, 0-8). All attempts at obtaining fetal hard palate ultrasound measurements were successful. Mean fetal hard palate width (cm) = -0.73579345 + 0.11370432 x GA - 0.00083919 x GA(2) and SD = -0.017842055 + 0.005142475 x GA, where GA is gestational age in weeks. Mean fetal hard palate length (cm) = -0.82020463 + 0.11767777 x GA - 0.00092801 x GA(2) and SD = -0.043064317 + 0.006378869 x GA. Mean fetal hard palate area (cm(2)) = -2.40090641 + 0.17136556 x GA + 0.00097308 x GA(2) and SD = -0.603647741 + 0.040740282 x GA. Sonographic measurements of the fetal hard palate width, length and area correlated significantly and strongly with gestational age (all P < 0.001) and significantly but less strongly with femur length (P = 0.004). CONCLUSION: The fetal hard palate may be depicted sonographically with relative ease between 15 and 41 weeks' gestation and measurements of the fetal hard palate width, length and area correlate well with gestational age, biparietal diameter, abdominal circumference, sonographic estimated fetal weight, and femur length.     

三维超声体积自动测量技术对胎儿肺体积的研究

目的：探讨正常孕中晚期胎儿肺体积随孕周、胎儿体重的变化规律,以及超声肺重比（UFLB）对胎儿肺发育不良（PH）的诊断价值。方法：超声检查315例正常胎儿和28例PH高危胎儿,应用三维超声体积自动测量（VOCAL）技术测量胎儿肺体积,采用二维超声测得的生物参数经Hadlock方程系统获得胎儿质量,计算得到胎儿UFLB,随访胎儿产后及引产结果,并与产前诊断结果作对照。结果：正常胎儿肺体积与胎儿质量（r=0.97,P<0.05）的相关性高于胎儿肺体积与孕周（r=0.93,P<0.05）的相关性。28例PH高危胎儿中,2例因羊水过少未能获得满意的三维图像,PH高危胎儿应用VOCAL技术获得肺体积的成功率为92.90%。在成功获得肺体积的26例胎儿中,应用UFLB诊断胎儿PH的敏感度为89.47%,特异度为85.71%,阳性预测值为94.44%,阴性预测值为75.00%,诊断准确率为88.46%。结论：正常胎儿的肺体积随孕周、胎儿体重的增加而增大,应用UFLB可以较准确的诊断PH。     

Biometrical threshold of biparietal diameter for certain fetal sex assignment by ultrasound.

OBJECTIVES: The aim of this study was to establish the biometric threshold of biparietal diameter (BPD), assumed to be an independent variable of gestational age, at which 100% accuracy in the assessment of fetal sex by ultrasonography is achievable. METHODS: Transvaginal and/or transabdominal sonography was used for detecting the 'sagittal sign' as a marker of fetal sex in 385 fetuses with BPD between 18 and 29 mm. The results of ultrasound examination were compared with sex at birth or with karyotype obtained from amniotic fluid cells or chorionic villus sampling. RESULTS: Fetal sex assignment was feasible in 337 of 385 cases (87.5%). Of the 312 fetuses with known fetal sex outcome, 164 were males and 148 were females. An accuracy rate of 100% was achieved when a BPD of > or = 23 mm was obtained. CONCLUSION: This study provides important information about the earliest stage of fetal development, expressed in terms of BPD, at which a diagnosis of fetal sex can be made with 100% accuracy.     

Revisiting first-trimester fetal biometry.

INTRODUCTION: Although advances in ultrasound have facilitated the diagnosis of fetal abnormalities in the first trimester, fetal biometry at this stage of pregnancy remains underused in prenatal diagnosis. We hypothesized that charts which directly correlate measurements to crown-rump length (CRL) could be more accurate than those based on gestational age (GA) derived from CRL measurement. The aim of this study was to construct CRL-based biometric charts. METHODS: Measurements of biparietal diameter (BPD), head circumference (HC) and abdominal circumference (AC) were prospectively collected from 939 normal singleton fetuses. Charts and predictive equations were constructed from data obtained from pregnancies in which the CRL was between 45 and 84 mm and for which the outcome was normal. RESULTS: Measurements of BPD, HC and AC from 880 fetuses who met the criteria were correlated with CRL and used to construct charts and predictive equations. The standard error of estimates using CRL was significantly lower than that using GA in all cases. DISCUSSION: First-trimester growth charts and predictive equations based on CRL instead of GA are more accurate. They might have a role in quality control of first-trimester ultrasound examination and may help in the diagnosis of fetal conditions that involve early growth abnormalities.     

胎儿超声心动图检查定量11~17周正常胎儿主动脉和肺动脉内径Z-评分的初步研究

目的探讨早孕期（11^＋0周~13^＋6周）和中孕早期（14^＋0周~17^＋6周）胎儿主动脉内径（AO）与肺动脉内径（PA）与胎儿生物学生长参数的相关性,初步建立早孕期和中孕早期胎儿AO与PA的正常参考值范围及Z-评分方程,并评价方程的有效性。 方法随机选取孕周（GA）为（11^＋0周~17^＋6周）正常单胎胎儿270例,将成功显示左、右心室流出道切面的245例胎儿纳入研究,获得胎儿顶臀径（CRL）、双顶径（BPD）、股骨长径（FL）、孕周（GA）等生物学生长参数。在胎儿左、右心室流出道切面测量收缩末期AO及PA,以GA、BPD和FL作为独立自变量,AO及PA作为因变量,建立AO、PA的正常参考值范围,并对每个参数的绝对残差（SD）进行加权回归,建立Z-评分方程。 结果采用简单的线性回归模型,可以很好地描述AO和PA与非心脏生物特征参数（BPD、FL、GA）的关系。AO、PA与GA、BPD、FL均呈显著线性相关（GA与AO：r=0.9276,GA与PA：r=0.9271,BPD与AO：r=0.9551,BPD与PA：r=0.9558,FL与AO：r=0.9462,FL与PA：r=0.9483,均<0.001）,其中与BPD的相关性最强。 结论正常早孕期及中孕早期胎儿的AO、PA随着孕周的增加而增长,本研究初步建立了正常胎儿早孕期及中孕早期AO、PA的参考范围及其Z-评分方程。为早孕期及中孕早期评估胎儿大血管生长提供精确的参考标准,在早期筛查或诊断胎儿先天性心脏畸形方面具有潜在的应用价值。