Fetal Biometry Parameters Research Articles

Comparison of Utero-Placental Perfusion Development From First to Second Trimester Between Low-Risk and High-Risk Pre-eclampsia Groups With Aspirin Prophylaxis.

Introduction Pre-eclampsia (PE) is a common diagnosis in pregnancy and affects pregnancies worldwide. Early-onset PE often leads to severe maternal and fetal complications. Prophylactic use of aspirin (150 mg/day) before the 16th week of pregnancy can reduce the risk of PE. This study aimed to investigate the effects of maternal factors on the development of uteroplacental perfusion and fetal biometry from the first to the second trimester in a risk group receiving aspirin prophylaxis compared to a control group without Aspirin. Methods This case-control study included 448 women at high risk for PE (risk group, RG) receiving aspirin prophylaxis and 468 women at low PE risk without aspirin intake (control group, CG). Parameters recorded and considered in the first (T1) and second (T2) trimesters included uterine artery pulsatility multiple of the median (UtAPI MoM), notching at T1 and T2 and fetal biometry parameters at T2. Maternal factors were also captured, and their respective effects were examined. Results UtAPI MoM at T1 and T2 showed a significant positive correlation (r = 0.39, p < 0.001), with UtAPI MoM at T2 significantly higher for notching "yes" at T1. Pre-existing arterial hypertension and UtAPI development demonstrated a significant association (p = 0.006). Women without this risk factor showed a significantly (p < 0.001) greater decline in UtAPI development. The likelihood of notching "yes" at T2 (p < 0.001; OR: 5.80) was increased with higher UtAPI MoM at T1. The mean values (T1 and T2) of UtAPI MoM were significantly higher in the risk group than in the control group. Patients in the risk group exhibited notching at T2 (p < 0.001; OR: 5.64) more often compared to the control group. The 95% CI of the estimated fetal weight for notching "yes" at T1 was below the 50th percentile. Gestational age and head circumference/abdomen circumference (HC/AC) ratio showed a significant negative correlation (p < 0.001; b = -0.01). The control group showed significantly higher estimated fetal weights than the risk group. The HC/AC ratio in the risk group was above the HC/AC ratio in the control group but without proving significance. Conclusions Persistent notching and elevated UtAPI MoMlevels in the second trimester may be risk factors for early-onset PE. Women with pre-existing arterial hypertension, notching and elevated UtAPI MoMvalues ​​in the first and second trimesters require special monitoring during the course of pregnancy.

489 Do fetal biometry parameters> 90th percentile increase the risk of Primary Cesarean Delivery?

489 Do fetal biometry parameters> 90th percentile increase the risk of Primary Cesarean Delivery?

Deep learning for estimation of fetal weight throughout the pregnancy from fetal abdominal ultrasound

Fetal weight is currently estimated from fetal biometry parameters using heuristic mathematical formulas. Fetal biometry requires measurements of the fetal head, abdomen, and femur. However, this examination is prone to inter- and intraobserver variability because of factors, such as the experience of the operator, image quality, maternal characteristics, or fetal movements. Our study tested the hypothesis that a deep learning method can estimate fetal weight based on a video scan of the fetal abdomen and gestational age with similar performance to the full biometry-based estimations provided by clinical experts. This study aimed to develop and test a deep learning method to automatically estimate fetal weight from fetal abdominal ultrasound video scans. A dataset of 900 routine fetal ultrasound examinations was used. Among those examinations, 800 retrospective ultrasound video scans of the fetal abdomen from 700 pregnant women between 15 6/7 and 41 0/7 weeks of gestation were used to train the deep learning model. After the training phase, the model was evaluated on an external prospectively acquired test set of 100 scans from 100 pregnant women between 16 2/7 and 38 0/7 weeks of gestation. The deep learning model was trained to directly estimate fetal weight from ultrasound video scans of the fetal abdomen. The deep learning estimations were compared with manual measurements on the test set made by 6 human readers with varying levels of expertise. Human readers used standard 3 measurements made on the standard planes of the head, abdomen, and femur and heuristic formula to estimate fetal weight. The Bland-Altman analysis, mean absolute percentage error, and intraclass correlation coefficient were used to evaluate the performance and robustness of the deep learning method and were compared with human readers. Bland-Altman analysis did not show systematic deviations between readers and deep learning. The mean and standard deviation of the mean absolute percentage error between 6 human readers and the deep learning approach was 3.75%±2.00%. Excluding junior readers (residents), the mean absolute percentage error between 4 experts and the deep learning approach was 2.59%±1.11%. The intraclass correlation coefficients reflected excellent reliability and varied between 0.9761 and 0.9865. This study reports the use of deep learning to estimate fetal weight using only ultrasound video of the fetal abdomen from fetal biometry scans. Our experiments demonstrated similar performance of human measurements and deep learning on prospectively acquired test data. Deep learning is a promising approach to directly estimate fetal weight using ultrasound video scans of the fetal abdomen.

Placental thickness and its relationship to gestational age and fetal growth parameters in normal singleton pregnancies in the central region of Togo

Introduction: Accurate determination of gestational age (GA) is necessary for qualitative obstetric care, and ultrasound fetal biometry parameters are used when the last menstrual period is not known. The aim of this study was to measure by ultrasound the placental thickness (PT) and correlate it with GA and fetal growth parameters. Population and Methods: This was a descriptive cross-sectional study conducted in the Radiology and Medical Imaging Department of Sokode Regional Hospital. All low-risk pregnancies from the 11th week were included. Excel and R 4.2.2 software were used. A significance level of 5% was established for the statistical tests. Results: A total of 256 pregnancies were recorded. The mean of PT was 29.89 ± 7.42 mm. The mean of PT in the first, second, and third trimesters was 13.50 ± 3.67 mm, 24.61 ± 4.12 mm, and 34.65 ± 4.17 mm, respectively. There was a strong positive linear correlation between PT and GA (r = 0.87, P &lt; 0.00001) and between PT and estimated fetal weight (EFW) (r = 0.80, P &lt; 0.00001). The linear relationship between PT and GA could be expressed by the equation: GA = 0.894*PT-0.103. Similarly, the linear relationship between PT and EFW could be expressed by the equation EFW = 127.314*PT-2563.561. There was a strong linear correlation between PT and parameters such as biparietal diameter (r = 0.88, P &lt; 0.00001), head circumference (r = 0.89, P &lt; 0.00001), and femur length (r = 0.89, P &lt; 0.00001). Conclusions: This study demonstrated a correlation between PT and fetal growth parameters, suggesting that PT can be utilized to monitor fetal growth.

Placental Thickness Measurement by Ultrasonography and Its Correlation with Gestational Age of Fetus in the Manipuri Population.

:Purpose:The study was done to measure the placental thickness (PT) in pregnant women and find its correlation with the gestational age (GA) of the fetus by ultrasonography. Comparisons were also made with the other fetal biometry parameters, and baseline data were generated with respect to the gestational weeks and placental position.Materials and Methods:The study was a cross-sectional one with a sample size of 134 singleton pregnancies. About 11–40 weeks of gestation were studied for the measurement of PT and other fetal parameters. Informed consent was obtained before recording the data on the preformed questionnaire. All measurements were done in mm and during the relaxed phase of the uterus.Results:As per the study, PT (in mm) increases with an increase in GA (in weeks) and almost matches it from 12 to 34 weeks of gestation. PT had a strong correlation with GA (r = 0.966). The correlation was statistically significant, with a P < 0.001.Conclusion:Thus, the estimation of the thickness of the placenta at the cord insertion site by means of ultrasonography is a relatively simple, safe, and cheap modality for accurate estimation of GA, fetal growth, and placental abnormalities and thus can significantly affect the management and outcome of pregnancy.

Impact of adding abdominal circumference to the definition of fetal growth restriction

Fetal growth restriction has traditionally been defined as fetuses with an estimated fetal weight <10th percentile for gestational age. In 2020, the Society for Maternal-Fetal Medicine recommended that the definition be expanded to include either an estimated fetal weight<10th percentile or a fetal abdominal circumference<10th percentile. We sought to determine the impact of adding the criterion abdominal circumference<10th percentile on the rate of diagnosis of fetal growth restriction vs using the criterion estimated fetal weight<10th percentile alone. In addition, we evaluated the definition proposed by Copel and Bahtiyar, estimated fetal weight<10th percentile or abdominal circumference<5th percentile. This was a retrospective, descriptive study from 3 consultative maternal-fetal medicine practices. Biometry was compiled from ultrasound examinations from January 2019 to July 2020. The inclusion criteria were singleton pregnancy, gestational age of ≥24 weeks, presence of fetal cardiac activity, and presence of 4 standard fetal biometry parameters (biparietal diameter, head circumference, abdominal circumference, and femur length). We tabulated the indications for the examinations and the number of examinations meeting several criteria for the diagnosis of fetal growth restriction: Traditional criterion (estimated fetal weight<10th percentile), Copel-Bahtiyar criteria (estimated fetal weight<10th percentile or abdominal circumference<5th percentile), and Society for Maternal-Fetal Medicine criteria (estimated fetal weight<10th percentile or abdominal circumference<10th percentile). During the study period, 20,633 ultrasound examinations met the inclusion criteria. In 62% of examinations, there was ≥1 factor for fetal growth restriction, and in 51% of examinations, there was ≥1 factor for large for gestational age. The rate of estimated fetal weight<10th percentile was 9.7%. The rate of abdominal circumference<5th percentile was 5.7%, and the rate of abdominal circumference<10th percentile was 9.2%. The rate of fetal growth restriction was 9.7% using the traditional definition (estimated fetal weight<10th percentile only). The rate of fetal growth restriction was 10.2% using the Copel-Bahtiyar definition (estimated fetal weight<10th percentile or abdominal circumference<5th percentile), significantly higher than using the traditional definition (P<.001). The rate of fetal growth restriction was 11.6% using the Society for Maternal-Fetal Medicine definition (estimated fetal weight<10th percentile or abdominal circumference<10th percentile), significantly higher than using either the traditional or Copel-Bahtiyar definition (P<.001 for both). Among examinations with an abdominal circumference<10th percentile, 79% also had an estimated fetal weight<10th percentile and was considered fetal growth restriction even without considering abdominal circumference. Adding the criterion abdominal circumference<5th percentile or abdominal circumference<10th percentile to the definition of fetal growth restriction resulted in a statistically significant increase in the rate of diagnosis of fetal growth restriction. However, the absolute increase in the rate was small and was not expected to place a large burden on practice resources.

Estimation of Gestational Age by Ultrasound Measurement of Fetal Transcerebellar Diameter

Introduction: Transcerebellar diameter (TCD) normogram predicts gestational age (GA) with an accuracy of 94% in the third trimester. The study aims to evaluate the application and accuracy of Transcerebellar diameter in determining the GA of the fetus and Its Correlation. Material and Methods: A cross-sectional prospective study conducted to determine the different antenatal ultrasound examinations were performed in 100 normal healthy pregnant with single fetus women having between 25 and 32 weeks of gestation. Results: Mothers mean GA on ultrasound was 28.4 ± 0.75 (27–30.2) weeks. The mean fetal biometry parameters including biparietal diameter (BPD) was 73 ± 2.3 mm (67–80), head circumference (HC) was 264 ± 8.7 mm (237.8–311), abdominal circumference (AC) was 244 ± 8.9 mm (226.6–265.9), femur length (FL) was 55 ± 2.1 mm (49.5–59.6), fetal heart rate was 149 ± 8.5 beats (121–175). The mean transcerebellar (TCD) measurement was 31 ± 1.1 mm. The correlation coefficient between the period of gestation and TCD was found to be 0.99 at 27–30 weeks which was statistically significant (P &lt; 0.001) (r &gt; 0.99). Discussion and Conclusion: From the present study, it was observed that the TCD increases linearly with GA. The correlation between GA and the GA by TCD seems to increase from 28 to 30 weeks. There is a good correlation between GA derived from TCD and from established biometric indices like BPD, HC, AC, and femur length.

Accuracy of sonographic estimation of weight in fetuses with abdominal wall defects.

Accurate estimation of fetal weight is essential in guiding management of fetuses with abdominal wall defects (AWDs), as growth restriction is an important predictor of perinatal morbidity and mortality. Several sonographic formulae are available involving multiple biometric parameters, but abdominal circumference measurements may underestimate weight in fetuses with AWDs. No formula has yet shown superior accuracy. The objectives of this study were to evaluate, in fetuses with gastroschisis and omphalocoele, the accuracy of a sonographic estimated fetal weight (EFW) formula proposed by Siemer and colleagues, specifically for use in fetuses with AWDs compared to the commonly used Hadlock IV formula in estimating fetal weight, and detecting small for gestational age (SGA) fetuses. A retrospective cohort of 113 fetuses with AWDs was identified from an Australian teaching hospital over 13years. Pregnancy data and sonographic fetal biometry parameters were obtained. The accuracy of each formula in predicting birthweight was compared using Bland-Altman limits of agreement, and the intraclass correlation coefficient between EFW and actual birthweight. Performance of each formula in detecting SGA fetuses was determined. The Siemer and Hadlock formulae have similar accuracies for predicting birthweight in fetuses with AWDs. The Hadlock formula has a higher detection rate for SGA<10th centile and<3rd centile compared to the Seimer formula (84% vs 68% and 83% vs 67% respectively), albeit with a higher false-positive rate. There is no clear clinical advantage in using the Siemer formula, which is specifically designed for fetuses with AWDs, over the Hadlock formula to estimate weight in fetuses with AWDs.

Automatic Fetal Biometry Evaluation in Ultrasound Images Using a Deep Learning-Based Approach

Background: The 2D fetal ultrasound biometrics have been extensively used to establish (or confirm) the gestational age of the fetus, estimate its size and weight, and identify growth patterns and abnormalities. Typically, an ultrasound examination is routinely performed between 18 and 22 weeks of pregnancy to evaluate the growth of the fetus by measuring its head, abdomen, and femur. Automatic methods for fetal biometric measurements have been investigated recently to reduce intra- and inter-observer variability and create more accurate and reproducible measurements. Objectives: In this paper, we proposed a deep learning-based approach to calculate fetal biometry parameters automatically. Patients and Methods: The fetal biometry parameters came from the fetal head, abdomen, and femur evaluation. Head circumference (HC) and biparietal diameter (BPD) were related to the fetal head, whereas abdominal circumference (AC) was related to the fetal abdomen and femur length (FL) was related to the fetal femur. Figure 1 shows these parameters in ultrasound images. Our prepared dataset included three parts, as follows: (1) 1334 2D ultrasound images of the fetal head in the standard plane. This dataset was publically available from the automated measurement of fetal head circumference challenge. (2) 158 2D ultrasound images of the fetal abdomen in the standard plane. The dataset was gathered from Alvand Medical Imaging Center, Tehran, Iran, by expert radiologists. (3) 315 2D ultrasound images of the fetal femur in the standard plane. The dataset was gathered from two distinct centers: (i) Alvand Medical Imaging Center, Tehran, Iran, and (ii) Laleh Hospital, Tehran, Iran. We trained and evaluated a novel convolutional network for the segmentation of fetal head and abdomen. The proposed network, called MFP-Unet, was a combination of Unet and feature pyramid network (FPN). The network architecture is depicted in Figure 2. For fetal femur, we had a pre-processing step. We used the superpixel algorithm to remove darker parts of the image, as the femur was typically the brightest part of the US image. Then, we applied an image saliency algorithm to represent the salient features of the image. Finally, MFP-Unet was trained on these pre-processed images to segment the femur. After the segmentation process, image analysis algorithms achieved all of the required measures. An ellipse detection algorithm on the segmented area of the fetal head was to measure the HC and BPD while an ellipse detection algorithm on the segmented area of the fetal abdomen was to measure the AC. Finally, a skeletonization algorithm achieved the femur length. Results: We used the mean absolute difference (MAD) and root mean square error (RMSE) for the measurement errors. The values of MAD and RMSE were 0.23 mm and 0.11 mm for BPD, 0.13 mm and 0.09 mm for HC, 0.17 mm and 0.08 mm for AC, and 0.18 mm and 0.12 mm for FL, respectively. Table 1 shows the results. The correlation between automatic and manual measurements was evaluated by correlation graphs. The R values were 0.97, 0.91, and 0.97 for HC, BPD, and FL, respectively. Conclusion: According to the results, we proposed a robust and useful algorithm for automatic fetal biometry evaluation that could be extended to nuchal translucency (NT) measurement based on the providing dataset.

Ultrasound in labor admission to predict need for emergency cesarean section: a prospective, blinded cohort study

Objective To assess whether assessment with ultrasound could improve the detection of emergency cesarean section (ECS) in laboring women. Methods Women who presented with symptoms of active labor or women in need of labor induction were invited to participate in the study. Women included in the study were evaluated with ultrasonography for fetal biometry and vaginal examinations for Bishop score assessment. The main aim in this study was determining factors associated with ECS due to fetal distress and obstructed labor. Results No fetal biometry variable was associated with ECS due to any indication (fetal distress and obstructed labor combined) in the univariate analysis. In multivariate analyses, biometry variables were adjusted for Bishop score at admission and only abdominal circumference percentile showed a significant association with the odds of ECS due to any indication (OR:1.02, 95% CI: 1.01–1.03). Biparietal diameter and abdominal circumference variables were associated with the odds of ECS due to obstructed labor in both univariate and multivariate analyses (p < .05 for all). However, the predictive accuracy of biparietal diameter percentile (area under the curve (AUC): 0.55, 95% CI: 0.46–0.63) and abdominal circumference percentile (AUC: 0.56, 95% CI: 0.48–0.64) without adjunct variables were poor. Moreover, the addition of fetal biometry parameters to Bishop score did not improve the predictive accuracy of Bishop score. Conclusion Ultrasound assessment at admission, in addition to Bishop score assessment, did not significantly improve the prediction of ECS. Also, the fetal biometry alone had poor predictive capability for ECS. Routine ultrasound assessment at labor admission appears to be ineffective for predicting ECS. Precis Fetal biparietal diameter and abdominal circumference showed an association with emergency cesarean due to obstructed labor but the predictive accuracy of fetal biometry was low. Routine ultrasound examination at admission, in addition to Bishop score assessment, may not useful for assessing the risk of emergency section in unselected populations.

Growth patterns in fetuses with isolated cardiac defects

There is evidence that in fetuses with congenital heart defects (CHDs), head growth is affected. However, scanty data are available on longitudinal growth patterns of other biometric parameters such as abdominal circumference (AC) and femur length (FL). The aim was to evaluate growth patterns in fetuses with isolated CHD diagnosed prenatally in different categories of lesions. Fetuses with isolated CHD seen between 2008 and 2013 at the Fetal Medicine Unit of 2 tertiary referral centers were retrospectively included in the study. CHD was classified into 7 categories. Fetal biometry parameters were assessed at 4 variable time points between 18 and 35weeks' gestation and transformed into Z scores. Linear mixed modeling was performed to analyze repeated measurements and construction of growth models. Two hundred forty-six live births with CHD were analyzed. Linear growth modeling showed a slight decrease in head circumference (HC) in the second half of pregnancy, whereas AC and FL growth were not significantly affected. The model predicted a significantly smaller HC at 36weeks' gestation in fetuses with conotruncal heart defects. Fetuses with CHD showed a modest but significant linear decrease in HC growth, whereas AC and FL growth trajectories remained stable.

Interobserver reliability of sonographic fetal biometry in second trimester maternal serum screening

To examine the interobserver variability for fetal biometry parameters and to investigate whether this variability affects the second-trimester maternal serum screening test (STMSS) results. A total of 60 singleton pregnancies who were scheduled for STMSS were investigated. Two experienced sonographers performed all examinations at the same visit. The risk calclations of screening were performed according to the each operator's biometric measurements separately. Interobserver variability in measurements of fetal biometrics and the effect of this interobserver variability on the screening results were assessed. inter-observer reliability for biparietal diameter (BPD) and femur length (FL) were 0.904 and 0.888 (p < 0.00 1), respectively. interobserver reliability coefficients for trisomy 21, trisomy 13/18, and neural tube defect were 0.887, 0.999, and 0.920 (p < 0.0001), respectively. The present results demonstrate that the interobserver reliability and agreement of ultrasound measurements of fetal biometry in cases of routine prenatal screening are highly reliable.

Single and Serial Fetal Biometry to Detect Preterm and Term Small- and Large-for-Gestational-Age Neonates: A Longitudinal Cohort Study.

ObjectivesTo assess the value of single and serial fetal biometry for the prediction of small- (SGA) and large-for-gestational-age (LGA) neonates delivered preterm or at term.MethodsA cohort study of 3,971 women with singleton pregnancies was conducted from the first trimester until delivery with 3,440 pregnancies (17,334 scans) meeting the following inclusion criteria: 1) delivery of a live neonate after 33 gestational weeks and 2) two or more ultrasound examinations with fetal biometry parameters obtained at ≤36 weeks. Primary outcomes were SGA (<5th centile) and LGA (>95th centile) at birth based on INTERGROWTH-21st gender-specific standards. Fetus-specific estimated fetal weight (EFW) trajectories were calculated by linear mixed-effects models using data up to a fixed gestational age (GA) cutoff (28, 32, or 36 weeks) for fetuses having two or more measurements before the GA cutoff and not already delivered. A screen test positive for single biometry was based on Z-scores of EFW at the last scan before each GA cut-off so that the false positive rate (FPR) was 10%. Similarly, a screen test positive for the longitudinal analysis was based on the projected (extrapolated) EFW at 40 weeks from all available measurements before each cutoff for each fetus.ResultsFetal abdominal and head circumference measurements, as well as birth weights in the Detroit population, matched well to the INTERGROWTH-21st standards, yet this was not the case for biparietal diameter (BPD) and femur length (FL) (up to 9% and 10% discrepancy for mean and confidence intervals, respectively), mainly due to differences in the measurement technique. Single biometry based on EFW at the last scan at ≤32 weeks (GA IQR: 27.4–30.9 weeks) had a sensitivity of 50% and 53% (FPR = 10%) to detect preterm and term SGA and LGA neonates, respectively (AUC of 82% both). For the detection of LGA using data up to 32- and 36-week cutoffs, single biometry analysis had higher sensitivity than longitudinal analysis (52% vs 46% and 62% vs 52%, respectively; both p<0.05). Restricting the analysis to subjects with the last observation taken within two weeks from the cutoff, the sensitivity for detection of LGA, but not SGA, increased to 65% and 72% for single biometry at the 32- and 36-week cutoffs, respectively. SGA screening performance was higher for preterm (<37 weeks) than for term cases (73% vs 46% sensitivity; p<0.05) for single biometry at ≤32 weeks.ConclusionsWhen growth abnormalities are defined based on birth weight, growth velocity (captured in the longitudinal analysis) does not provide additional information when compared to the last measurement for predicting SGA and LGA neonates, with both approaches detecting one-half of the neonates (FPR = 10%) from data collected at ≤32 weeks. Unlike for SGA, LGA detection can be improved if ultrasound scans are scheduled as close as possible to the gestational-age cutoff when a decision regarding the clinical management of the patient needs to be made. Screening performance for SGA is higher for neonates that will be delivered preterm.

Fetal ultrasound biometry for pregnant population in the County of Primorje-Gorski Kotar (Croatia)

Objective. To create curves of three most commonly used biometric parameters for singleton pregnancies from 22 to 41 weeks of gestation in the County of Primorje-Gorski Kotar (Croatia) and to compare results with other studies.Methods. From January 2002 to December 2009, ultrasound examination was performed on fetuses of 1248 pregnant women with uncomplicated pregnancy. Values for biparietal diameter, femur length, and fetal abdominal circumference were measured. Results were compared with studies pertaining to European and North American population. Mean, percentile scale, and Wilcoxon's matched pairs test were used. Regression analysis was applied to analyze data correlation and to determine correlation quotients.Results. Total of 2178 measurements for fetal biometry charts were performed. Established mean and centile values for fetal biometry parameters are reported numerically and graphically. Comparison of obtained values with values of identical fetal biometric parameters of other world populations has revealed statistically significant differences (p < 0.01).Conclusion. Normal fetal biometry charts for population of pregnant women in the northern coastal region of Croatia were constructed. Due to existence of statistically significant differences in ultrasound fetal biometry values among various populations under comparison, construction of own charts and their implementation in routine obstetrical work are justified.

Correlación entre la medición ecográfica del cordón umbilical y la edad gestacional, su relación con la biometría fetal y los resultados perinatales

Aim (a) To evaluate the umbilical cord in normal pregnancies using ultrasonography in the third trimester with a view to obtaining gestational age values according to reference tables. (b) To compare umbilical cord measurements with fetal biometry, length, weight and perinatal outcomes to determine whether this type of correlation exists in our population and whether it could be used to establish values of normality that would help to diagnose abnormalities. Material and methods From Juny 2001 to June 2002 we studied 48 pregnat women that have been controlled by ultrasound from week 28 to 38 of gestation. We just included patients with normal and controlled pregnancies, without any associated pathology. We obtain biparietal diameter, abdominal circumference, femoral long measurement, and umbilical cord diameter through a transversal cut of the umbilical area. Gestational age was obtain by last menstruation and by ultrasound according with biometry. measurement of the umbilical cord was compared with a nomogram of the gestational age (GA) performed by the Obstetric and Gynaecology Department of the Insubria University in Italy. We registered the type of birth the GA at birth, APGAR score length, weight, cephalic diameter, and eventually complications. For calculate the normal umbilical cord area according to the gestational age by last menstruation we use the Raio et al equations to construct the corresponding nomogram. It was apply statistics methods with an alfa of 5%. Results LMP-based gestational age was highly correlated with ultrasound measurements. Theoretical UCA was not correlated with observed UCA. Only 54.2% of UCAs were found to be within the 5th and 95th percentiles (P =0.001), and consequently only two-thirds of the patients were within the parameters of normality. No correlation was found between UCA and gestational age, when attempting to construct a nomogram for our population ( P=.99). No association was found between UCA and fetal biometry parameters. No significant correlation was found with weight, length, head circumference or gestational age at delivery. Apgar score was favorable and stable in all neonates; Apgar score was thus considered a constant and was not correlated with UCA. UCA was significantly lower in women who underwent cesarean section than in those with normal deliveries ( P<.05). Conclusion UCA was not correlated with gestational age, fetal biometry or perinatal outcomes. Values in our population cannot be extrapolated to existing nomograms.

Multivariable analysis of tests for the diagnosis of intrauterine growth restriction.

To describe how data from antenatal fetal ultrasound biometry, amniotic fluid index and umbilical artery Doppler can be appropriately combined using multivariable models and to investigate how the addition of these ultrasound parameters influences the ability to predict intrauterine growth restriction (IUGR). This was a prospective cohort study involving 274 low-risk pregnancies undergoing serial ultrasound examination at predetermined intervals. Standard deviation (Z) scores of the last values for fetal abdominal area (FAA), growth velocity of the FAA, amniotic fluid index (AFI) and umbilical artery Doppler pulsatility index prior to delivery were calculated for 260 fetuses. Customized estimated fetal weight (cEFW) centiles were also calculated using the last EFW before delivery after adjustment for fetal gender, gestational age, birth order and maternal weight, height and ethnic origin. Following delivery the neonatal ponderal index was calculated and centile position obtained. A neonatal ponderal index <25(th) centile served as the main outcome measure for diagnosis of IUGR. Logistic regression analysis was used to delineate the predictive value of the three fetal growth tests FAA, FAA growth velocity and cEFW and the additional values of AFI and pulsatility index of the umbilical artery. The areas under the receiver-operating characteristics (ROC) curves (95% confidence interval) for FAA, FAA growth velocity and cEFW alone were 0.819 (0.748-0.891), 0.784 (0.699-0.869) and 0.74 (0.643-0.837), respectively, in the prediction of a neonatal ponderal index <25(th) centile. The addition of both the AFI and pulsatility index to FAA, FAA growth velocity and cEFW generated small increases in the areas, to 0.831 (0.758-0.904), 0.817 (0.735-0.899) and 0.766 (0.672-0.859), respectively. These improvements in diagnostic prediction were not statistically significant. The addition of AFI and umbilical artery pulsatility index to the fetal biometry parameters did not significantly increase the ROC areas in the study population. The approach applied in this study is useful in the context of hypothesis generation. Further studies using larger data sets and other predictors should be carried out using the analytical techniques outlined in this paper to determine the contribution of various antenatal tests in the prediction of IUGR.