Measurement Of Fetal Biparietal Diameter Research Articles

Assessment of Transcerebellar Diameter Accuracy in Detection of Gestational Age in Third Trimester in Cases of Intrauterine Growth Restriction

Background: Intrauterine Growth Restriction (IUGR) is defined as decreased fetal birth weight less than 10th percentile as regard to gestational age also diagnosed when there is a delay more than 2 weeks in a serial ultrasound monitoring of fetal gestational age. Objective: The aim of the work was to evaluate accuracy of transcerebellar diameter (TCD) in detection of gestational age in pregnancies with intrauterine growth restriction IUGR. Patients and Methods: Case-Control study was carried out on 52 women with normally progressing pregnancies during the third trimesters, with gestational ages between 27 and 37 weeks of gestation came to outpatient clinic of department of Obstetrics and Gynecology, Zagazig General Hospital and Zagazig University Hospital from June 2019 to March 2020, of them, 26 subjects were normal pregnancies and 26 subjects diagnosed as IUGR in 3rd trimester at gestational age (27week to 37 week). Trans-abdominal ultrasound was performed on all subjects; Fetal TCD was measured using the widest diameter of the cerebellum, measurement of fetal Bi-Parietal Diameter (BPD), Abdominal Circumference (AC), and Femur Length (FL). Results: There was statistically significant difference between gestational age (GA) by Last Menstrual Period (LMP) and sonar parameters at normal group but highest was TCD with P value 0.000 but in IUGR group only TCD, AC and FL were significantly positive correlated with GA; and TCD were highly significant. Conclusions: It could be concluded that the TCD measurement appears to be an accurate predictor of gestational age, even in the third trimester of pregnancy.

Assessment of Transcerebellar Diameter Accuracy in Detection of Gestational Age in Third Trimester in Cases of Intrauterine Growth Restriction

Background: Intrauterine Growth Restriction (IUGR) is defined as decreased fetal birth weight less than 10th percentile as regard to gestational age also diagnosed when there is a delay more than 2 weeks in a serial ultrasound monitoring of fetal gestational age. Objective: The aim of the work was to evaluate accuracy of transcerebellar diameter (TCD) in detection of gestational age in pregnancies with intrauterine growth restriction IUGR. Patients and Methods: Case-Control study was carried out on 52 women with normally progressing pregnancies during the third trimesters, with gestational ages between 27 and 37 weeks of gestation came to outpatient clinic of department of Obstetrics and Gynecology, Zagazig General Hospital and Zagazig University Hospital from June 2019 to March 2020, of them, 26 subjects were normal pregnancies and 26 subjects diagnosed as IUGR in 3rd trimester at gestational age (27week to 37 week). Trans-abdominal ultrasound was performed on all subjects; Fetal TCD was measured using the widest diameter of the cerebellum, measurement of fetal Bi-Parietal Diameter (BPD), Abdominal Circumference (AC), and Femur Length (FL). Results: There was statistically significant difference between gestational age (GA) by Last Menstrual Period (LMP) and sonar parameters at normal group but highest was TCD with P value 0.000 but in IUGR group only TCD, AC and FL were significantly positive correlated with GA; and TCD were highly significant. Conclusions: It could be concluded that the TCD measurement appears to be an accurate predictor of gestational age, even in the third trimester of pregnancy.

Fetal biometry assessment with Intergrowth 21st\u2019s and Salomon\u2019s equations in rural Burkina Faso

BackgroundUltrasound scanning during the 2nd or the 3rd trimester of pregnancy for fetal size disturbances screening is heavily dependent of the choice of the reference chart. This study aimed to assess the agreement of Salomon and the Intergrowth 21st equations in evaluating fetal biometric measurements in a rural area of Burkina Faso, and to measure the effect of changing a reference chart.MethodsData collected in Nazoanga, Burkina Faso, between October 2010 and October 2012, during a clinical trial evaluating the safety and efficacy of several antimalarial treatments in pregnant women were analyzed. We included singleton pregnancies at 16–36 weeks gestation as determined by ultrasound measurements of fetal bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). Expected mean and standard deviation at a given gestational age was computed using equations from Salomon references and using Intergrowth 21st standard. Then, z-scores were calculated and used subsequently to compare Salomon references with Intergrowth 21st standards.ResultsThe analysis included 276 singleton pregnancies.Agreement was poor except for HC: mean difference − 0.01, limits of agreement − 0.60 and 0.59. When AC was used as a surrogate of fetal size, switching from the reference of Salomon to the standards of Intergrowth 21st increased ten times the proportion of fetuses above the 90th percentile: 2.9 and 31.2%, respectively.Mean differences were larger in the third trimester than in the second trimester. However, agreement remained good for HC in both trimesters.Difference in the proportion of AC measurements above the 90th percentile using Salomon and Intergrowth 21st equations was greater in the second trimester (2.6 and 36.3%, respectively) than in the third trimester (3.5 and 19.8%, respectively). The greatest difference between the two charts was observed in the number of FL measurements classified as large in the second trimester (6.8 and 54.2%, using Salomon and Intergrowth 21st equations, respectively).ConclusionThe agreement between Intergrowth 21st and Salomon equations is poor apart from HC. This would imply different clinical decision regarding the management of the pregnancy.

Automatic Detection and Measurement of Fetal Biparietal Diameter and Femur Length —Feasibility on a Portable Ultrasound Device

An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for measurement is identified by the machine, the placement of the measurement calipers is automatically determined by fitting an active contour model to the structure of interest. The fetal biparietal diameter (BPD) and femur length (FL) are then measured automatically. The validation data set contained 167 and 197 B-mode images for BPD and FL measurements, respectively. The images were acquired using 4 different ultrasound scanners, which resulted in varied image quality and gain settings. The mean gestational age (GA) of the fetuses was 19.4 weeks, range 16 to 41 weeks. A measurement success rate of 90% was achieved for both BPD and FL. The correlation coefficients between the manual and automatic measurements were 0.995 (BPD) and 0.967 (FL), mean errors were 0.5 mm (BPD) and -1.7 mm (FL) and error range with 95% confidence interval (CI) were ﹣3.8 - 4.8 mm (BPD) and ﹣11.4 - 8.1 mm (FL). The automatic measurement results were consistent in both high and low gain settings. The intraclass correlation coefficients between manual and automatic measurements were 0.995 (95% CI; 0.981 - 0.999) for BPD in high gain, 1.0 (95% CI; 0.998 - 1.0) for BPD in low gain, 0.998 (95% CI; 0.991 - 0.999) for FL in high gain and 0.999 (95% CI; 0.996 - 1.0) for FL in low gain settings. The method was implemented on a prototype, portable ultrasound machine designed to be used in low- and middle-income countries (LMIC). The overall performance of the method supports our hypothesis that automated methods can be used and are beneficial in a clinical setting.

Role Of Sonological Fetal Cerebellar Measurement In Gestational Age Determination

Sonographic measurement of fetal biparietal diameter is a well accepted predictor of gestational age. However there is a high variability in the calculated gestational age which increases as pregnancy progresses. The estimation of gestational age from individual parameters like the HC, AC, and FL also shows a similar variability. Using all the above parameters this variability can be reduced by 25% to 30 %. There are conditions like oligohydromnios, multiple gestation, breech presentation and intrauterine growth restriction (IUGR) that can alter the shape of the fetal skull which in turn can affect the BPD and increase the variability. The present study is being undertaken to measure the transverse cerebellar diameter (TCD) to validate it as an additional morphological measurement of fetal growth with less variability. The cerebellum and posterior fossa are aligned perpendicular to the plane of maximum extrinsic compression. Hence, they are able to withstand deformation by extrinsic pressure than the parietal bones and can be a more accurate parameter for the determination of gestational age.

Advantages of the population‐based approach to pregnancy dating: results from 23 020 ultrasound examinations

To confirm the results from two previous evaluations of term prediction models, including two sample-based models and one population-based model, in a third population. In a study population of 23,020 second-trimester ultrasound examinations, data were prospectively collected and registered over the period 1988-2009. Three different models for ultrasonically estimated date of delivery were applied to the measurements of fetal biparietal diameter (BPD) and two models were applied to the femur length (FL) measurements; the resulting term estimations were compared with the actual time of delivery. The difference between the actual and the predicted dates of delivery (the median bias) was calculated for each of the models, for three BPD/FL-measurement subgroups and for the study population as a whole. For the population-based model, the median bias was + 0.4 days for the BPD-based predictions and - 0.4 days for the FL-based predictions, and the biases were stable over the inclusion ranges. The biases of the two traditional models varied with the size of the fetus at examination; median biases were - 0.87 and + 2.2 days, respectively, with extremes - 4.2 and + 4.8 days for the BPD-based predictions, and the median bias was + 1.72 days with range - 0.8 to + 4.5 days for FL-based predictions. The disagreement between the two sample-based models was never less than 2 days for the BPD-based predictions. This study confirms the results from previous studies; median biases were negligible with term predictions from the population-based model, while those from the traditional models varied substantially. The biases, which have clinical implications, seem inevitable with the sample-based models, which, even if overall biases were removed, will perform unsatisfactorily.

Post-neonatal Mortality, Morbidity, and Developmental Outcome after Ultrasound-Dated Preterm Birth in Rural Malawi: A Community-Based Cohort Study

Preterm birth is considered to be associated with an estimated 27% of neonatal deaths, the majority in resource-poor countries where rates of prematurity are high. There is no information on medium term outcomes after accurately determined preterm birth in such settings. This community-based stratified cohort study conducted between May-December 2006 in Southern Malawi followed up 840 post-neonatal infants born to mothers who had received antenatal antibiotic prophylaxis/placebo in an attempt to reduce rates of preterm birth (APPLe trial ISRCTN84023116). Gestational age at delivery was based on ultrasound measurement of fetal bi-parietal diameter in early-mid pregnancy. 247 infants born before 37 wk gestation and 593 term infants were assessed at 12, 18, or 24 months. We assessed survival (death), morbidity (reported by carer, admissions, out-patient attendance), growth (weight and height), and development (Ten Question Questionnaire [TQQ] and Malawi Developmental Assessment Tool [MDAT]). Preterm infants were at significantly greater risk of death (hazard ratio 1.79, 95% CI 1.09-2.95). Surviving preterm infants were more likely to be underweight (weight-for-age z score; p<0.001) or wasted (weight-for-length z score; p<0.01) with no effect of gestational age at delivery. Preterm infants more often screened positively for disability on the Ten Question Questionnaire (p = 0.002). They also had higher rates of developmental delay on the MDAT at 18 months (p = 0.009), with gestational age at delivery (p = 0.01) increasing this likelihood. Morbidity-visits to a health centre (93%) and admissions to hospital (22%)-was similar for both groups. During the first 2 years of life, infants who are born preterm in resource poor countries, continue to be at a disadvantage in terms of mortality, growth, and development. In addition to interventions in the immediate neonatal period, a refocus on early childhood is needed to improve outcomes for infants born preterm in low-income settings.

Mortality, morbidity and developmental outcome after ultrasound-dated preterm birth in a rural sub-saharan african setting

AimsWe aimed to assess post neonatal survival, morbidity, growth and development at 12, 18 and 24 months in a community-based sample of infants born after spontaneous preterm delivery in rural...

Accuracy of emergency physicians using ultrasound to determine gestational age in pregnant women

Introduction Rapid and accurate determination of gestational age may be vital to the appropriate care of the critically ill pregnant patient. Before the use of emergency ultrasound, physical examination of fundal height (FH) in the nonverbal patient was considered the quickest method to estimate gestational age. We conducted a prospective, observational study of the performance of bedside sonography to determine gestational age. Methods We enrolled a convenience sample of women in their second or third trimester of pregnancy. Emergency physicians (EPs) made ultrasound measurements of fetal biparietal diameter (BPD) and femur length, followed by a measurement of FH. These measurements were compared with true gestational age (TGA), sonography by an ultrasound technician, and measurement of FH performed by an obstetrician. Main outcome measures were the average time needed to complete measurements; correlation coefficients between EP measurements and those made by an ultrasound technician, an obstetrician, and TGA, and overall accuracy to determine fetal age greater than 24 weeks. Results The average time to complete ultrasound measurements was less than 1 minute. When physician-performed measurements were compared with TGA, the correlation coefficients were 0.947 (0.926-0.968) for BPD, 0.957 (0.941-0.973) for femur length, and 0.712 (0.615-0.809) for FH. When determining fetal viability, EP's overall accuracy was 96% using ultrasound and 80% using FH. Conclusions With brief training, EPs can quickly and accurately determine gestational age using ultrasound, and these estimates may be more accurate than those obtained through physical examination. Emergency physicians should consider using ultrasound in emergent evaluation of pregnant patients who are unable to provide history.

Term prediction with ultrasound: Evaluation of a new dating curve for biparietal diameter measurements

In Norway, routine ultrasound examination with assessment of gestational age was included in the standard antenatal care program in 1985. Until presently, a dating chart introduced in 1983 has been used throughout the country. New national normal values are now developed. The aim of the study was to compare the performance of the two sets of normal values; both are based on measurement of fetal biparietal diameter in the second trimester. We analyzed a cohort of 11,238 singleton deliveries with spontaneous onset of labor. All had reliable last menstrual period and all had a routine ultrasound examination in the second trimester with measurement of fetal biparietal diameter. We calculated the expected day of delivery both according to the old (method A) and the new (method B) reference values. The prediction error (the difference between observed and expected day of delivery) for the last menstrual period method was -0.1 days, for method A -3.5 days, and for method B -0.7 days. The prediction error for method A increased up to 7 days when ultrasound measurements were obtained in gestational week 14-15. The old ultrasound method leads to a systematic underestimation of fetal age, and the prediction error increases notably when the ultrasound measurements are performed in the early second trimester. Gestational age is more precisely assessed with the new reference values.

15th World Congress on Ultrasound in Obstetrics and Gynecology, 25–29 September 2005, Vancouver, Canada: presentations and awards

The 15th World Congress on Ultrasound in Obstetrics and Gynecology was kicked off with a tribute to ISUOG’s founding president and the White Journal’s founding Editor-in-Chief, Professor Stuart Campbell (known by his students as ‘Prof’). Perhaps one of the most well-known figures in the world of obstetric and gynecological ultrasound, Prof’s career has been truly legendary. Under the tutelage of Professor Ian Donald at the Queen Mother’s Hospital in Glasgow, he rose quickly to publish landmark papers on the measurement of fetal biparietal diameter as well as other biometric indices, with the nomograms he published in the

Environmental tobacco smoke exposure among pregnant women: impact on fetal biometry at 20-24 weeks of gestation and newborn child's birth weight.

While there are sufficient data regarding the negative effect of exposure to the constituents of tobacco smoke on newborn infants' birth weights, it is still unclear whether this effect may originate in early pregnancy. The aim of the present study was to evaluate the impact of exposure to tobacco smoke components in early pregnancy (20-24 weeks) on fetal biometry. The study population comprised 183 women consecutively enrolled at 20-24 weeks of pregnancy at the two antenatal care units. Ultrasound biometric measurements of fetal bi-parietal diameter (BPD), abdominal circumference (AC) and femur length (FL) were performed at the time of enrollment. Serum cotinine concentration was determined at 20-24 weeks of gestation by gas chromatography with mass spectrometry detector (GC/MS) to assess environmental tobacco smoke (ETS) exposure during the previous evening and the morning of the same day (blood collection at 1200-1300 h). ETS exposure (passive smoking) was assumed to occur when the level of serum cotinine ranged from 2-10 ng/ml. In a multiple regression model for bi-parietal diameter (BPD), after adjustment for pregnancy duration at the time of ultrasound examination, fetal gender, and maternal pre-pregnancy weight, a statistically significant negative association was found between the BPD and serum cotinine concentration. A similar association was identified for subjects with serum cotinine concentrations below 10 ng/ml (corresponding to passive smoking) (P=0.06). After controlling for pregnancy duration, maternal pre-pregnancy weight and infant's gender, we found that serum cotinine levels at 20-24 weeks of gestation was inversely associated with infant birth weight (P=0.004). For the subjects with serum cotinine levels below 10 ng/ml, a borderline association (P=0.09) with infant birth weight was found. Maternal exposure to tobacco smoke in early pregnancy, as measured by serum cotinine concentrations at 20-24 weeks of gestation, adversely affects fetal BPD. Preventive measures need to be undertaken to encourage pregnant women to stop smoking and avoid passive exposure to tobacco smoke from the very beginning of pregnancy.

Prediction of gestational age by ultrasonic fetometry in llamas ( Lama glama) and alpacas ( Lama pacos)

Fetal biparietal diameter (BPD) and thorax height (TH) were measured by ultrasound during intrauterine growth in pregnant llamas ( Lama glama) and alpacas ( Lama pacos). The goal was to establish representative curves that allows estimation of gestational age (GA) from real-time ultrasonic measurements of these fetal structures at any stage of gestation. Llamas and alpacas were mated under controlled conditions. Ultrasound exams were conducted to determine pregnancy status 1 month later. Measurements of fetal BPD and TH were conducted from the second month of pregnancy until term. Observation and assessment of fetal TH was difficult during the last 3 months of pregnancy, specially in llamas. Regression curves were calculated from the data as a function of GA, with the best fit represented by the following equations: llama GA=(BPD−0.002399)43.02293, r=0.98, P<0.001 ; llama GA=(TH−0.07137)46.94485, r=0.95, P<0.001 ; alpaca GA=(BPD−0.11376)47.23287, r=0.98, P<0.001 ; alpaca GA=(TH−0.36436)52.87663, r=0.96, P<0.001 , where GA was measured in days and BPD and TH in centimeters. Results indicate that ultrasonic measurement of these fetal biometric variables constitute a valuable tool to estimate GA at any stage of pregnancy in these domestic South American camelids.

Early ultrasonographic detection of fetal growth retardation in an ovine model of placental insufficiency

OBJECTIVE: Our aims were as follows: (1) to determine whether fetal growth retardation can be detected noninvasively with ultrasonography in ewes and (2) to establish the time interval between exposure of ewes to environmental stress that causes growth retardation (heat stress) and detection of growth lag for specific fetal body measurements. STUDY DESIGN: Four ewes were exposed to heat stress for 80 days starting at 35 days' gestation. (The duration of pregnancy in sheep is 147 days.) Serial ultrasonographic measurements of fetal biparietal diameter, abdominal circumference, and femur and tibia lengths were obtained beginning at 50 days' gestation. Growth curves were calculated for each parameter and compared with growth curves obtained from 43 normal fetuses. RESULTS: Biparietal diameter measurements deviated significantly from normal starting at 90 days' gestation ( p < 0.05). Abdominal circumference diverged at 70 days' gestation ( p < 0.05), and both femur and tibia length diverged at 80 days ( p < 0.05). The regression lines showed significant differences for all the parameters in both slope ( p < 0.01) and intercept ( p < 0.01). CONCLUSIONS: Fetal growth retardation can be detected noninvasively by ultrasonography after approximately 5 weeks of exposure to heat stress. Fetal growth continues throughout gestation but at a slower rate than normal and according to a pattern similar to that observed in asymmetrically growth-retarded human fetuses. Early detection of stunted fetal growth in an animal model is important for testing intervention strategies in the treatment of fetal growth retardation.

Bias in studies of preterm and postterm delivery due to ultrasound assessment of gestational age.

Ultrasound measurement of fetal dimensions is widely used for estimating gestational age. A little-discussed limitation of this method is that variations in fetal size at a given stage of pregnancy are converted to differences in gestational age. Factors that affect pregnancy duration often affect fetal size also. We explore how the effect of such factors may be biased when gestational age is determined by ultrasound. We selected 3,606 women with singleton pregnancies (1989-1991) who had an early ultrasound measurement of fetal biparietal diameter (BPD) and a good-quality history of last menstrual period (LMP). Using the two measures of gestational age, we estimated risk of preterm and postterm delivery for female babies vs males and for smoking women vs nonsmoking women. There was a 13% excess of preterm delivery among female babies when gestational age was determined by ultrasound, but no excess when gestational age was defined by LMP. For postterm delivery, female babies had a 19% lower risk with ultrasound-defined age, but no deficit with LMP-defined age. We found a similar bias with ultrasound in the analysis of maternal smoking. Thus, factors that reduce fetal size inflate the risk of preterm delivery and deflate the risk of postterm delivery when gestational age is based on ultrasound measurement of the fetus. This bias can distort the relative risk of preterm or postterm delivery by 10-20%.

Sonographic dating of pregnancies among women with menstrual irregularities

In order to study the benefit of sonographic dating, 277 women with irregular periods and 264 women with a scanty last bleeding had gestational age and estimated day of delivery (EDD) estimated from both last menstrual period (LMP) and measurement of fetal Biparietal Diameter (BPD) in the second trimester. For the women with irregular periods, the two estimates differed by more than 7 days for 51.6%, and more than 14 days for 25.6%. Corresponding figures for women with a scanty last bleeding were 44.3% and 21.6%, respectively. In general, the BPD estimates were better than the LMP estimates (P = less than 0.001) in predicting day of delivery, especially when the differences between the estimates exceeded 7 days. For women with irregular periods, post-term pregnancies decreased, from 20.2% according to the LMP estimate to 2.5% according to the BPD estimate. Corresponding figures for women with a scanty last bleeding were 16.7% and 4.5%, respectively. According to the LMP estimate, 64.8% of the women with irregular periods and 69.3% of the women with a scanty last bleeding gave birth within +/- 14 days of EDD. Corresponding figures for the BPD estimate were 83.6% and 88.3%, respectively. The conclusion is that sonographic dating of pregnancies among women with irregular periods and women with a scanty last bleeding substantially improve the accuracy of term prediction.

Growth of fetuses of diabetic mothers

Longitudinal ultrasonographic examinations, with measurements of fetal biparietal diameter and abdominal circumference, were performed in 85 diabetic pregnant women submitted to different treatment protocols. Curves of fetal growth parameters were obtained for each group of patients and for a control group of normal fetuses, applying the function y = k(MA)2.e-a(MA) to the ultrasonographic data. With the use of this function it was possible to demonstrate that there are no significant differences in the pattern of fetal growth when a strict metabolic control is obtained in diabetic pregnant women.

Accuracy of an average ultrasonic laboratory in measurements of fetal biparietal diameter, head circumference and abdominal circumference.

Twenty patients between 14 and 28 gestational weeks were scanned on three occasions during a single day by six operators with different ultrasonic experience (three use a compound scanner and three a real-time equipment). On each occasion every operator had to measure in a "blind" manner the fetal biparietal diameter (BPD), head circumference and abdominal circumference (HC and AC); a coded copy of head and abdominal circumference was subsequently measured by one of the members of the staff. Statistical analysis was carried out on the 1800 measurements, and it was concluded that the accuracy was not dissimilar from that reported by pilot studies. The reproducibility of the parameters studied did not change throughout pregnancy and real-time and compound scanner yielded homogeneous results.

Ultrasonic assessment of fetal head and body sizes in relation to normal and retarded fetal growth

Data on consecutive ultrasonic measurements of fetal biparietal diameter (B.P.D.) and fetal chest area in 303 normal and 84 small-for-dates fetuses are presented. Duration of pregnancy varied from 24 to 41 weeks. A normal curve of the fetal B.P.D., chest area, and head-to-chest ratio was constructed. At 24 weeks mean fetal B.P.D. was 6.29 cm., mean fetal chest area was 24.9 sq. cm., and mean head-to-chest ratio was 1.59. At 41 weeks the mean values were 9.81 cm., 92.4 sq. cm., and 1.05, respectively. In the group of small-for-dates fetuses, a normal head-to-chest ratio was almost always associated with early onset of fetal growth retardation whereas in the majority of fetuses with increased head-to-chest ratios, growth retardation appeared to have started only in the third trimester of pregnancy.

Gray scale measurement of biparietal diameter

Fetal biparietal diameter measurements were obtained simultaneously by gray scale and bistable ultrasonography. The bistable presentation was measured from leading edge to leading edge, while the gray scale presentation was measured from leading point to leading point and middle to middle of the band of echoes defining the fetal head. Statistical analysis of 50 patients demonstrated good reproducibility of the biparietal diameter measurement by each method and intraobserver variation fell well within the acceptable range. In all but one patient differences in measurements between observers and measurement methods were trivial and of no clinical significance. In the patients in whom there was a statistically significant difference, the variability was from 1 to 2 mm with the exception of one patient in whom the variability was about 4 mm.