Biometric Charts Research Articles

Fetal Biometric Parameter Reference Charts of a Central Anatolian Turkish Population.

The assessment of fetal biometry using ultrasound provides accurate pregnancy dating and also screening of fetal growth. Fetal biometry, which is common practice in the second and third trimesters of pregnancy, is fetal morphometry, which involves taking measurements of the different anatomical body parts. These fetal dimensions vary on ethnicity. The aim of this study is to demonstrate fetal biometric parameters measurement results of the Central Anatolia Turkish population with detailed percentile tables and graphs to screen fetal growth more accurately. This cross-sectional study was performed on a total of 1132 fetuses (47% girl, and 53% boy) between 15 and 40 weeks of gestation. Biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) measurements are performed in a standardized manner every gestational week. BPD and HC were measured at the level of the thalami on the horizontal plane of the fetal head. HC was measured using the ellipse method. AC measurement was taken at the circular cross-section of the upper fetal abdomen. FL was measured along with the ossified diaphysis of the femur. All measurements were taken in millimeters. Pregnant women's mean age was 27.58 (17-43), and the mean body mass index was 27.68 (15.06-50.78) as demographic data. 38.13% of women had their first, 29.74% had their second, and 32.13% had three or more gestations within our study. Percentile data of fetuses for each parameter (BPD, HC, AC, and FL) and for each week were shown as tables and percentile graphics. Fetal 50th percentile measurements were compared between our study and other studies from different countries. The Kruskal-Wallis test results showed that BPD (p = 0.827), HC (p = 0.808), AC (p = 0.846), and FL (p = 0.725) values have a statistically similar mean in all studies. Hierarchical cluster analysis results showed that our results for BPD, HC, AC, and FL percentile curves have been found closer to Italian population results. However, our results were statistically different from Asian, Nigerian, non-Hispanic American, and Brazilian populations for each of the different parameters. The specialization of fetal biometric charts for a particular population can ensure a more accurate assessment of fetal growth rate. We showed fetal biometric percentile tables and graphics of the Central Anatolian Turkish population in this study. These results may provide a valuable contribution to obstetrical practice.Further studies can be conducted in different regions of Turkiye, thus comparisons could be possible over the country.

Quantitative fetal MRI with diffusion tensor imaging in cases with 'short' corpus callosum.

It has been suggested previously that the presence of Probst bundles (PB) in cases with a short corpus callosum (SCC) on diffusion tensor imaging (DTI) may help to differentiate between corpus callosal (CC) dysplasia and a variant of normal CC development. The objectives of this study were to compare DTI parameters between cases of SCC vs normal CC and between cases of SCC with PB (SCC-PB+) vs SCC without PB (SCC-PB-). This was a retrospective study of patients referred to the Necker Hospital in Paris, France, for magnetic resonance imaging (MRI) evaluation of an apparently isolated SCC detected by sonography between November 2016 and December 2022 (IRB: 00011928). MRI was performed using a 1.5-Tesla Signa system. T2-weighted axial and sagittal sequences of the fetal brain were used to measure the length and thickness of the CC. 16-direction DTI axial brain sequences were performed to identify the presence of PB and to generate quantitative imaging parameters (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) of the entire CC, genu, body and splenium. Cases in which other associated brain abnormalities were detected on MRI were excluded. Cases were matched for fetal gender and gestational age with controls in a 1:3 ratio. Control cases were normal fetuses included in the LUMIERE on the FETUS trial (NCT04142606) that underwent the same DTI evaluation of the brain. Comparisons between SCC and normal CC cases, and between SCC-PB+ and SCC-PB- cases were performed using ANOVA and adjusted for potential confounders using ANCOVA. Twenty-two SCC cases were included and compared with 66 fetuses with a normal CC. In 10/22 (45.5%) cases of SCC, PB were identified. As expected, dimensions of the CC were significantly smaller in SCC compared with normal CC cases (all P < 0.01). In SCC-PB+ vs SCC-PB- cases, FA values were significantly lower in the entire CC (median, 0.21 (range, 0.19-0.24) vs 0.24 (range, 0.22-0.28); P < 0.01), genu (median, 0.21 (range, 0.15-0.29) vs 0.24 (range, 0.17-0.29); P = 0.04), body (median, 0.21 (range, 0.18-0.23) vs 0.23 (range, 0.21-0.27); P = 0.04) and splenium (median, 0.22 (range, 0.16-0.30) vs 0.25 (range, 0.20-0.29); P = 0.03). ADC values were significantly higher in the entire CC, genu and body in SCC-PB+ vs SCC-PB- cases (all P < 0.05). In SCC-PB+ cases, all FA values were significantly lower, and ADC values in the CC body were significantly higher compared with normal CC cases (all P < 0.05). In SCC-PB- cases, there was no significant difference in FA and ADC compared with normal CC cases (all P > 0.05). Fetal DTI evaluation of the CC showed that FA values were significantly lower and ADC values tended to be significantly higher in SCC-PB+ compared with normal CC cases. This may highlight alterations of the white matter microstructure in SCC-PB+. In contrast, isolated SCC-PB- did not demonstrate significant changes in DTI parameters, strengthening the possibility that this is a normal CC variant. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Heterogeneity in defining fetal corpus callosal pathology: systematic review.

Fetal anomalies of the corpus callosum (CC) have been reported in the prenatal imaging literature since 1985, and, especially when isolated, pose challenges for both the patient and fetal medicine specialist. The purpose of this study was to review systematically the literature on prenatally diagnosed abnormalities of the CC, focusing on the terminology used to describe abnormalities other than complete agenesis of the CC, and to assess the heterogeneity of the nomenclature and definitions used. This study was conducted in accordance with the PRISMA statement for reporting systematic reviews. A literature search was performed to identify prospective or retrospective case series or cohort studies, published in English, French, Italian, German or Spanish, reporting fetal imaging findings and describing anomalies of the CC. Quality and risk of bias of the studies were evaluated using the Newcastle-Ottawa scale and a modification of the scale developed by Conde-Agudelo et al. for other fetal imaging studies. The data extracted included the number of patients, the number of different anomalies identified, the descriptive names of the anomalies, and, where applicable, the definitions of the anomalies, the number of cases of each type of anomaly and the biometric charts used. Secondary tests used to confirm the diagnosis, as well as the postnatal or post-termination tests used to ascertain the diagnosis, were also recorded. The search identified 998 records, and, after review of titles and abstracts and full review of 45 papers, 27 studies were included initially in the review, of which 24 were included in the final analysis. These 24 studies had a broad range of quality and risk of bias and represented 1135 cases of CC anomalies, of which 49% were complete agenesis and the remainder were described using the term partial agenesis or nine other terms, of which five had more than one definition. In comparison to the postnatal literature, in the prenatal literature there is much greater heterogeneity in the nomenclature and definition of CC anomalies other than complete agenesis. This heterogeneity and lack of standard definitions in the prenatal literature make it difficult to develop large multicenter pooled cohorts of patients who can be followed in order to develop a better understanding of the genetic associations and neurodevelopmental and psychological outcomes of patients with CC anomalies. As this information is important to improve counseling of these patients, a good first step towards this goal would be to develop a simpler categorization of prenatal CC anomalies that matches better the postnatal literature. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

The study of fetal weight and various fetal parameters during the late gestational period (27-40 weeks) in the Gujarati population by autopsy method

Background: The study of the measurement of various morphometric parameters of the developing fetus is of immense importance to monitor the adequate fetal growth. Various literature regarding the standard reference fetal biometric charts and table for the monitoring of the fetal growth are available which is dependent on different races, demographic characteristics, and nutrition. Objectives: The aim of the present study was to establish a reference range of the fetal weight (FW) and various fetal biometric parameters in the fetuses of the Gujarati population. Materials and Methods: This study was conducted in the Department of Anatomy, B.J. Medical College, Ahmedabad, Gujarat, in collaboration with the Department of Obstetrics and Gynecology of Civil Hospital, Ahmedabad, Gujarat, on 25 fetuses at gestational age from 27 to 40 weeks. The fetuses were studied for various parameters such as FW, crown to rump length (CRL), crown to heel length (CHL), and head circumferences (HC). Results: There was increase in body weight and CRL, CHL, and HC with increasing gestational age. CRL and HC increase at similar rate. CRL and CHL ratio is roughly 2:3. The growth of various parameters was linear. The fetuses of 27–32 weeks of gestational age were found to have mean weight, CRL, and HC to be 1099.42 g, 267, 432.5, and 273.17 mm, respectively, whereas the means of the same parameters for the age group of 33–40 weeks were 2474.61 gm, 321.61, 461.92, and 330.54 mm, respectively. Conclusion: The present study establishes the standard reference values of FW and various fetal biometric parameters such as CRL, CHL, and HC for the Gujarati population for the second trimester of pregnancy. This could be a very useful tool to gynecologist to have a reference for the age estimation during the antenatal examination as well as to pathologists while performing the fetal autopsies.

Ultrasound Assessment of Fetal Biometry in Iranian Normal Pregnancies.

Background:The objective of this study was to provide biometric charts for Iranian fetuses.Methods:One thousand four hundred and twenty-two women enrolled. Four hundred and eighty-four were in the second trimester of pregnancy and 940 were in the third trimester. Data were presented as mean ± standard deviation for continuous variables. Percentiles (5th, 50th, 75th, and 90th) reported.Results:Mean femoral length ranged from 16 to 53 mm in our study in the second trimester and 55–79 mm in the third trimester. Mean biparietal diameter (BPD) for fetuses with in the second trimester was between 14 and 71 and for fetuses in the third trimester was between 74 and 98 mm. Mean abdominal circumference (AC) in our cases with gestational age between 14 and 41 ranged between 86 and 365 mm.Conclusions:We have provided normal reference ranges and percentiles for BPD, AC, femur length, and weight during the second and third trimester of pregnancy in an Iranian population.

Fetal Biometric Charts and Reference Equations for Pregnant Women Living in Port Said and Ismailia Governorates in Egypt.

AIM:To construct new fetal biometric charts and equations for some fetal biometric parameters for women between 12th and 41st weeks living in Ismailia and Port Said Governorates in Egypt.MATERIAL AND METHODS:This cross-sectional study was carried out on 656 Egyptian women (from Ismailia and Port Said governorates) with an uncomplicated pregnancy, and all were sure of their dates. The selected group was between the 12th and 41st weeks of gestation, recruited from the district general hospital in Ismailia and Port Said to measure ultrasonographically biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL), then for each measurement separate regression models were fitted to estimate both the mean and the Standard deviation at each gestational age.RESULTS:New Egyptian charts were reported for BPD, HC, AC, and FL. Reference equations for the dating of pregnancy were presented. The mean of the previous measurements at 12th and 41st weeks were as follows: (23.37, 98.72), (83.05, 336.12), (67.85, 332.57) and (12.50, 74.92) respectively.CONCLUSION:New fetal biometric charts and regression equations for pregnant women living in Port Said & Ismailia governorates in Egypt.

Cross-sectional study of fetal long-bone length in an Iranian population at 17-25weeks of gestation.

To construct improved reference charts for fetal long bones in an Iranian setting and to compare them with previous studies. The present prospective cross-sectional study included singleton fetuses assessed by ultrasonography at 17-25weeks of gestation at the Comprehensive Medical Genetics Center, Shahid Soltani, Shiraz, Iran between May 1, 2012, and February 28, 2014. Exclusion criteria included conditions that could affect fetal growth. Fetal long bones (femur, humerus, tibia, fibula, ulna, and radius) were measured with ultrasonography and biometric charts were produced. Regression models were fitted to estimate bone lengths. The models produced were compared with those from previous studies in other populations. There were 660 singleton fetuses included and 660 femur, 633 humerus, 512 tibia, 498 fibula, 505 ulna, and 498 radius biometric measurements were recorded. The models generated to predict the length of the tibia, fibula, ulna, and radius from the length of the femur and humerus demonstrated a high goodness of fit when the predicted lengths were plotted against the actual lengths. Comparisons of mean lengths with previous studies suggested that long-bone length was affected by maternal ethnicity. The equations generated could be used to predict long-bone length in an Iranian population and ethnicity should be considered when using fetal long-bone length as a prenatal diagnostic tool.

Development of customized fetal growth charts in twins

Twin gestations are at significantly higher risk of fetal growth restriction in comparison with singletons. Using fetal biometric charts customized for obstetrical and parental characteristics may facilitate an accurate assessment of fetal growth. The objective of the study was to construct reference charts for the gestation of fetal biometric parameters stratified by chorionicity and customized for obstetrical and parental characteristics. Fetal biometric measurements obtained from serial ultrasound examinations in uncomplicated twin pregnancies delivering after 36 weeks of gestation were collected by 19 Italian fetal medicine units under the auspices of the Società Italiana di Ecografia Ostetrica e Ginecologica. The measurements acquired in each fetus at each examination included biparietal diameter, head circumference, abdominal circumference, and femur length. Multilevel linear regression models were used to adjust for the serial ultrasonographic measurements obtained and the clustering of each fetus in twin pregnancy. The impact of maternal and paternal characteristics (height, weight, ethnicity), parity, fetal sex, and mode of conception was also considered. Models for each parameter were stratified by fetal chorionicity and compared with our previously constructed growth curves for singletons. The data set included 1781 twin pregnancies (dichorionic, n= 1289; monochorionic diamniotic, n= 492) with 8923 ultrasonographic examinations with a median of 5 (range, 2-8) observations per pregnancy in dichorionic and 6 in (range, 2-11) monochorionic pregnancies. Growth curves of twin pregnancies differed from those of singletons, and differences were more marked in monochorionic twins and during the third trimester. A significant influence of parental characteristics was found. Curves of fetal biometric measurements in twins are influenced by parental characteristics. There is a reduction in the growth rate during the third trimester. The reference limits for gestation constructed in this study may provide a useful tool for a more accurate assessment of fetal growth in twin pregnancies.

P09.11: The assessment of the intergrowth biometric charts in unselected Czech population

P09.11: The assessment of the intergrowth biometric charts in unselected Czech population

The effect of fetal sex on customized fetal growth charts

Objective: To evaluate the effect of fetal sex on singleton pregnancy growth charts customized for parental characteristics, race, and parityMethods: In a multicentric cross-sectional study, 8070 ultrasonographic examinations from low-risk singleton pregnancies between 16 and 40 weeks of gestation were considered. The fetal measurements obtained were biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). Quantile regression was used to examine the impact of fetal sex across the biometric percentiles of the fetal measurements considered together with parents’ height, weight, parity, and race.Results: Fetal gender resulted to be a significant covariate for BDP, HC, and AC with higher values for male fetuses (p ≤ 0.0009). Minimal differences were found among sexes for FL. Parity, maternal race, paternal height and maternal height, and weight resulted significantly related to the fetal biometric parameters considered independently from fetal gender.Conclusion: In this study, we constructed customized biometric growth charts for fetal sex, parental, and obstetrical characteristics using quantile regression. The use of gender-specific charts offers the advantage to define individualized normal ranges of fetal biometric parameters at each specific centile. This approach may improve the antenatal identification of abnormal fetal growth.

Customized Fetal Growth Charts for Parents' Characteristics, Race, and Parity by Quantile Regression Analysis: A Cross-sectional Multicenter Italian Study.

The purpose of this study was to construct fetal biometric charts between 16 and 40 weeks' gestation that were customized for parental characteristics, race, and parity, using quantile regression analysis. In a multicenter cross-sectional study, 8070 sonographic examinations from low-risk pregnancies between 16 and 40 weeks' gestation were analyzed. The fetal measurements obtained were biparietal diameter, head circumference, abdominal circumference, and femur diaphysis length. Quantile regression was used to examine the impact of parental height and weight, parity, and race across biometric percentiles for the fetal measurements considered. Paternal and maternal height were significant covariates for all of the measurements considered (P < .05). Maternal weight significantly influenced head circumference, abdominal circumference, and femur diaphysis length. Parity was significantly associated with biparietal diameter and head circumference. Central African race was associated with head circumference and femur diaphysis length, whereas North African race was only associated with femur diaphysis length. In this study we constructed customized biometric growth charts using quantile regression in a large cohort of low-risk pregnancies. These charts offer the advantage of defining individualized normal ranges of fetal biometric parameters at each specific percentile corrected for parental height and weight, parity, and race. This study supports the importance of including these variables in routine sonographic screening for fetal growth abnormalities.

OC20.02: Prospective assessment of the intergrowth biometric charts in an unselected French nationwide population

OC20.02: Prospective assessment of the intergrowth biometric charts in an unselected French nationwide population

Improving customized fetal biometry by longitudinal modelling

Objective: To develop customized biometric charts to better define abnormal fetal growth.Methods: A total of 1056 singleton fetuses from the Raine Study underwent serial ultrasound biometry (abdominal circumference [AC], head circumference, and femur length) at 18, 24, 28, 34, and 38 weeks’ gestation. Customized biometry trajectories were developed adjusting for epidemiological influences upon fetal biometry using covariates available at 18 weeks gestation. Prediction accuracy (areas under the receiver operating characteristic curve [AUC] and 95% confidence interval [95%CI]) was evaluated by repeated random sub-sampling cross-validation methodology.Results: The model for derived estimated fetal weight (EFW) performed well for EFW less than 10th predicted percentile (AUC = 0.695, 95%CI, 0.692–0.699) and EFW greater than 90th predicted percentile (AUC = 0.705, 95%CI, 0.702–0.708). Fetal AC was also well predicted for growth restriction (AUC = 0.789, 95%CI, 0.784–0.794) and macrosomia (AUC = 0.796, 95%CI, 0.793–0.799). Population-derived, sex-specific charts misclassified 7.9% of small fetuses and 10.7% of large fetuses as normal. Conversely, 9.2% of those classified as abnormally grown by population-derived charts were considered normal by customized charts, potentially leading to complications of unnecessary intervention.Conclusions: Customized fetal biometric charts may offer improved ability for clinicians to detect deviations from optimal fetal growth and influence pregnancy management.

International fetal growth standards: one size fits all

Those working with pregnant women know the situation well: whether a particular unborn baby is judged to be too small will partly depend on the choice of fetal biometric charts used. Some charts can increase the likelihood of finding a fetal measurement below a threshold for smallness by fourfold or more.1 Inconsistent chart use and overestimation of fetal smallness can result in cynicism, confusion, and anxiety for pregnant women and their caregivers at all stages of pregnancy. The stakes are especially high when smallness of biometric measures alone raises a red flag for aneuploidy, other genetic syndromes such as skeletal dysplasia, or fetal developmental abnormalities such as microcephaly.

PF.17 Fetal Biometry Revisited

ObjectiveTo construct fetal biometric charts in the Irish population using methodology recommended by Altman and Chitty with up-to-date ultrasound equipment.Study designThis was a prospective, cross-sectional study involving low-risk women attending...

Establishment of Fetal Biometric Charts Using Quantile Regression Analysis

Fetal growth evaluation is an essential component of pregnancy surveillance. There have been several methods used to construct growth charts. The conventional charts used in current daily practice are based on small numbers and traditional statistical methods. The purpose of this study was to improve fetal biometric charts based on a much larger number of observations with an alternative statistical method: quantile regression analysis. A comparison between the charts is presented. During the 12 years of study, 17,708 sonographic examinations of pregnant women from the north of Israel, between 12 and 42 weeks of pregnancy, were performed. Fetal measurements were obtained by several operators using various equipment and included head circumference, abdominal circumference, and femur length. Growth charts were established based on these measurements. In this study, we constructed biometric growth charts using a large cohort of pregnant women. These charts offer the advantages of specific estimated regression parameters for each specified percentile, thus better defining the normal range. We suggest using these new charts in routine daily obstetric practice.

Biometría placentaria en la predicción de complicaciones de la gestación

The relationship between placental biometry and different complications of pregnancy has been established. However, these measures are complex, time consuming, and they are not a part of U/S examination routine. The objective was to assess the value of placental biometry in the early identification of those pregnancies that will develop pre-eclampsia or fetal growth retardation. A prospective study of an unselected population of 319 in the 20th gestational week was made, measuring the thickness, diameter and area of a placental section. As bibliographical references are scarce, our placental biometric charts are provided. Although there was a tendency to find smaller placentas with these complications (a smaller diameter and section area), the differences were not significant, and the difference was only significant in the in the lowest area in the fetal growth retardation group (p = 0.001; 95% CI, 1.049-3.213). In those cases associated to serious pre-eclampsia and fetal growth retardation under the 5th percentile, the placenta tends to be thicker at 20 weeks, with a lower diameter and section area. However, we could not make any conclusions as the number of cases was too low (4). Uterine artery Doppler is a better predictor. Detailed placentary biometry cannot be incorporated into daily practice, however the measurement of placental thickness has been proposed by some authors as routine, because a large placenta is related to greater perinatal morbidity and mortality.

Revisiting first-trimester fetal biometry.

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. 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. 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. 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.

Can transvaginal fetal biometry be considered a useful tool for early detection of skeletal dysplasias in high-risk patients?

To evaluate the possibility of an early diagnosis of skeletal dysplasias in high-risk patients. A total of 149 consecutive, uncomplicated singleton pregnancies at 9-13 weeks' amenorrhea, with certain menstrual history and regular cycles, were investigated with transvaginal ultrasound to establish the relationship between femur length and menstrual age, biparietal diameter and crown-rump length, using a polynomial regression model. A further eight patients with previous skeletal dysplasias in a total of 13 pregnancies were evaluated with serial examinations every 2 weeks from 10-11 weeks. A significant correlation between femur length and crown-rump length and biparietal diameter was found, whereas none was observed between femur length and menstrual age. Of the five cases with skeletal dysplasias, only two (one with recurrent osteogenesis imperfecta and one with recurrent achondrogenesis) were diagnosed in the first trimester. An early evaluation of fetal morphology in conjunction with the use of biometric charts of femur length against crown-rump length and femur length against biparietal diameter may be crucial for early diagnosis of severe skeletal dysplasias. By contrast, in less severe cases, biometric evaluation appears to be of no value for diagnosis.

FETAL BIOMETRIC RATIOS BY TRANSVAGINAL SONOGRAPHY AS A MARKER FOR ANEUPLOIDIES IN EARLY PREGNANCY

The aim of this study was to obtain by transvaginal sonography in early pregnancy normal biometric charts of some fetal ratios and to evaluate the utility of these ultrasonographic indices as biometric markers for the identification of fetal chromosome abnormalities. The study population included 1054 normal euploid fetuses and 30 fetuses with an abnormal karyotype. We obtained six standard ultrasound measurements by transvaginal sonography at 11-16 weeks' gestation before genetic amniocentesis in patients at risk for genetic disorders. Seven biometric ratios (biparietal diameter/femur length, biparietal diameter/humerus length, head circumference/abdominal circumference, abdominal circumference/femur length, abdominal circumference/humerus length, femur length/foot length, and humerus length/foot length) were calculated and reference curves were plotted. The ratios from aneuploid fetuses showed no differences from reference ranges. Only in trisomy 13 fetuses were abnormal values of head circumference/abdominal circumference, biparietal diameter/humerus length, and biparietal diameter/femur length ratios detected, probably due to the high incidence of microcephaly and central nervous system malformations in these fetuses. The normal values of sonographic ratios obtained by transvaginal sonography in the first and early second trimester of pregnancy cannot generally be considered a useful tool for the detection of chromosomal abnormalities. Only ratios involving cephalic measurements can be used in early pregnancy as screening markers in the detection of trisomy 13 fetuses.