Fetal Ultrasound Measurements Research Articles

Ultrasound fetal measurements and pregnancy associated glycoprotein secretion in early pregnancy in cattle recipients carrying somatic clones

Somatic cloning in the bovine species leads to high levels of fetal losses which occur throughout pregnancy. These losses are most often associated with fetal overgrowth, a syndrome known as large offspring syndrome (LOS), and excessive maternal plasma pregnancy serum protein 60 (PSP60), a protein similar to a pregnancy-associated glycoprotein of 67kDa (PAG I67) produced by the bovine placenta. Predicting the outcome of pregnancies initiated from cloned embryos has become an important issue both to prevent potential harm to the mother because of excessive fetal size at birth and also to get a better understanding of the relationships between growth, differentiation and placental functions in developing cloned fetuses. Here, we report on a systematic analysis of fetal and placental development in the first trimester of pregnancy performed by ultrasonographic imaging and by measurement of the maternal concentrations of pregnancy associated glycoproteins (PAGS), using four different radioimmunoassays (RIA) (two homologous RIA systems with PSP60 and PAG I67; two heterologous RIA systems with PAG I67 as standard and tracer, and antisera anti-caprine PAGs). We showed that crown-rump length (CRL) in clones appeared smaller than controls at 35, 50 and 62 days (P<0.05). At 62 days of pregnancy, CRL in cloned fetuses that died before 90 days was smaller compared to the other cloned fetuses (P<0.05) whereas the width of the fetal sack and the biparietal diameter (BPD) was larger in fetuses that developed LOS in late gestation (P<0.05). Maternal PAGs concentrations were statistically different between controls and all clone recipients as early as Day 34, suggesting early abnormal placental glycoprotein synthesis for clone pregnancies regardless of pregnancy outcome. This work provides a practical, non-invasive tool to follow up clone pregnancies and suggests that primary growth retardation and abnormal placental function precedes excessive fetal and placental growth at later stages of pregnancy.

Analysis of Z‐score distribution for the quality control of fetal ultrasound measurements at 20–24 weeks

To develop and evaluate the feasibility of Z-score distribution-based quality assessment for fetal biometry at 20-24 gestational weeks. Four sonographers measured fetal biparietal diameter, head circumference, abdominal circumference and femur length in unselected pregnancies undergoing routine sonography at 20-24 weeks in our center between June 2001 and January 2004. All measurements were transformed into Z-scores. Distributions of Z-scores were compared with the expected standard normal distribution based on mean, SD and the Kolmogorov-Smirnov test. Modelling was performed to assess the sensitivity, specificity and Youden's index (sensitivity + specificity - 1) of each sonographer, reflecting their ability to detect fetuses with abnormal biometry in our population. A total of 5241 ultrasound examinations were included. None of the Z-score distributions could be considered similar to the standard normal distribution: means of Z-scores ranged from -0.604 to 0.73 and the SD ranged from 0.726 to 0.896. Sensitivity and specificity ranged from 25.31% to 68.67% and 93.44% to 100%, respectively; Youden's index ranged from 0.25 to 0.69. Analysis of Z-score distribution can be used to assess the quality of fetal measurements. Several indices can be extracted from this analysis in order to improve quality assessment of fetal biometry measured by ultrasound.

Preterm birth in rural Malawi: high incidence in ultrasound-dated population

Preterm birth is the major cause of neonatal death, and has an incidence in industrialized countries of 7%. We have found a high incidence (25-30%) previously in a population of anaemic, pregnant women in southern Malawi, studied with ultrasound dating. Cohort study of 512 unselected pregnant women in rural communities in Malawi. All had ultrasound fetal measurements before 24 weeks. 20.3% of women delivered before 37 completed weeks of pregnancy. Babies born before 37 completed weeks but after 32 weeks (16%) were twice as likely to die as babies born at term (6.9 versus 3.4%) but this difference did not achieve statistical significance. For those born between 24 and 33 weeks gestation (4.4%) there was a highly significant increase in perinatal mortality (75%) (p <0 .000001). This population has a very high rate of preterm birth, which is probably infection-related. It may be representative of many rural populations in sub-Saharan Africa. Tackling the problem of neonatal mortality in low income countries will require effective methods to prevent preterm birth.

Ultrasound biometry of Arabian fetuses

Objective To establish fetal ultrasound biometry charts for Arabian fetuses between 14 and 40 weeks of gestation. Method Cross-sectional fetal ultrasound data of normal singleton pregnancies, which had been performed over a period of 7 years, were retrieved. Only pregnant Arab women with certain last menstrual period dates and/or early ultrasound examinations were included. Each fetus contributed to only one set of data. Normal ranges for biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) were established. The mean and 5th and 95th percentiles at 18th, 28th, and 36 weeks of gestation were compared with similar ranges of published data from pregnancies of American and Anglo-Saxon population. Results Fetal ultrasound biometry has been established for our local population. Comparing our data with Western population emphasizes the presence of significant variation in fetal morphometric measurements, particularly in the later weeks of gestation and at the extremes of the range of fetal size. Conclusion The clinical significance of this variation differs according to the primary objective of ultrasound fetal measurements. For estimation of fetal age, usually by head and femur measurements in early gestation, ethnic variation seems to have limited significance. Whereas for estimation of fetal growth and/or weight in the third trimester, based on abdominal circumference, the use of given points, e.g., 10th or 5th percentile derived from other population charts, has the potential of either over- or underdiagnosis of IUGR fetuses. The adoption of locally developed charts is recommended.

A systematic review of the ultrasound estimation of fetal weight

The range and use of ultrasound fetal measurements have gradually been extended. Measurements have been combined to estimate fetal weight by mathematically based non-linear regression analysis or physically based volumetric methods. Fetal weight estimation is inaccurate, with poor sensitivity for prediction of fetal compromise. Several authors have shown the unacceptable level of intra- and interobserver variability in fetal measurement and the impact of errors on growth assessment. The aims of this study were to review the available methods and possible sources of inaccuracy. Four databases were searched for studies comparing ultrasound estimated fetal weight (EFW) with birth weight. Studies meeting the inclusion criteria evaluated 11 different methods. Errors were graphically summarized. No consistently superior method has emerged. Volumetric methods provide some theoretical advantages. Random errors are large and must be reduced if clinical errors are to be avoided. The accuracy of EFW is compromised by large intra- and interobserver variability. Efforts must be made to minimize this variability if EFW is to be clinically useful. This may be achieved through averaging of multiple measurements, improvements in image quality, uniform calibration of equipment, careful design and refinement of measurement methods, acknowledgment that there is a long learning curve, and regular audit of measurement quality. Further work to improve the universal validity and accuracy of fetal weight estimation formulae is also required.

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

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

Prediction of successful induction of labor at term: role of clinical history, digital examination, ultrasound assessment of the cervix, and fetal fibronectin assay

Objective The purpose of this study was to evaluate whether biochemical (fetal fibronectin assay) or biophysical (cervical assessment by transvaginal ultrasound) tests may have more value than digital examination in predicting successful induction of labor at term. Study design The study enrolled prospectively 134 women undergoing labor induction at term caused by several obstetric conditions. All participants submitted to digital examination, fetal fibronectin assay, and transvaginal ultrasound for measurement of the cervical length and detection of funneling. The performance of each test in predicting delivery within 24 hours of labor induction was evaluated. Cox multiple regression analysis was performed to identify, among clinical and laboratory tests, which variables were independently associated with the duration of the latent phase and with the total duration of induced labor. Results The likelihood ratios for positive results (predicting that delivery would occur within 24 hours) were 6.61 (95% CI, 1.7-25.8) for a positive obstetric history (previous vaginal delivery), 2.61 (95% CI, 1.6-4.3) for a “favorable” digital examination, 1.41 (95% CI, 0.9-2.2) for a positive fetal fibronectin test, 1.61 (95% CI, 0.9-3.0) for cervical length, and 2.20 (95% CI, 1.1-4.4) for the presence of funneling at transvaginal ultrasound. The likelihood ratios for negative results were 1.81 (1.3-2.5) for obstetric history, 4.34 (2.5-7.7) for digital examination, 1.41 (0.9-2.1) for fetal fibronectin, 1.29 (1.0-1.7) for cervical length, and 1.48 (1.1-2.0) for funneling. On multiple regression, the only variables independently associated with the duration of the latent phase and with the total duration of induced labor were obstetric history and digital examination. Conclusion Only obstetric history and digital examination predicted accurately vaginal delivery within 24 hours and were independently associated with labor duration. Fetal fibronectin and ultrasound measurements failed to predict accurately the outcome of induced labor.

MSP003 Presence of multi-drug efflux pump gene adeB in clinical isolates of Acinetobacter baumannii

To date many studies have been published about predicting parturition by ultrasonographic fetal measurements in the bitch. Given that accuracy in such prediction is a key point for clinicians and breeders, formulas to calculate the whelping date were mainly obtained from small and medium sized dogs, which means poor accuracy when applied to large or giant breeds.Based on the evidence that ethnicity significantly affects fetal biometry in humans, this study aimed at developing a breed-specific linear regression model for estimating parturition date in the German shepherd dog. For this purpose, serial ultrasonographic measurements of the inner chorionic cavity diameter (ICC) and the fetal biparietal diameter (BP) were collected in 40 pregnant German shepherd bitches. The quality of the regression models for estimating parturition date was further verified in 22 other pregnant German shepherd bitches. Accuracy related to the prediction of parturition date was higher than previously reported: 94.5% and 91.7% within ±2 days interval based on ICC and BP measurements, respectively. Additional investigation was performed on the effects of maternal weight, age and litter size in relation to fetal biometry and to accuracy of parturition estimation. Moreover, the study included a comparison between hormonal and fetal ultrasound (ICC and BP) measurements connected to the estimation of whelping date.We suggest that specific equations from a single breed are likely to offer excellent accuracy, comparable to that of periovulatory progesteronemia, in parturition prediction and to avoid morphological variables present in dogs of different breeds even with the same size/weight.

Nasal bone length throughout gestation: normal ranges based on 3537 fetal ultrasound measurements.

To establish normal ranges for nasal bone length measurements throughout gestation and to compare measurements in two subsets of patients of different race (African-American vs. Caucasian) to determine whether a different normal range should be used in these populations. Normal nasal bone length reference ranges were generated using prenatal measurements by a standardized technique in 3537 fetuses. The nasal bone lengths were found to correlate positively with advancing gestation (R(2) = 0.77, second-order polynomial). No statistical difference was found between African-American and Caucasian subjects. These reference ranges may prove to be useful in prenatal screening and diagnosis of syndromes known to be associated with nasal hypoplasia. Different normal ranges for African-American and Caucasian women are not required.

Infants thinner at birth exhibit smaller kidneys for their size in late gestation in a sample of fetuses with appropriate growth.

Fetal ultrasound measurements were employed to investigate the relationship between weight and ponderal index at birth and kidney size during the second (23 weeks) and third (32 weeks) trimesters of pregnancy in a sample of 25 normally growing fetuses. Kidney volume and kidney volume / fetal weight ratio at 32 weeks are significantly and positively related to both weight and ponderal index at birth, controlling for sex, gestational age at birth, and day of ultrasound measurement. A second-degree polynomial relationship approximates the predictability of kidney volume fetal weight ratio at 23 weeks to that at 32 weeks, demonstrating shifting growth rates in fetal organ and body growth relationships during midgestation. Sex and parental size are suggested as contributing to these patterns. Females have a surge in renal growth between 23 and 32 weeks to catch up to earlier growing males, and maternal weight significantly predicts incremental growth in kidney volume and the kidney volume / fetal weight ratio at 32 weeks of gestation. The observation that fetuses relatively thin at birth have relatively smaller kidneys for their size in late gestation suggests that the influence of maternal weight on birth outcome may act through organ growth.

Is statural growth predictable in utero? Follow-up from the second trimester of gestation to the 8th year of life.

It is well known that birth weight is related to later childhood growth and adult height. It can therefore be hypothesized that this relationship exists also for fetal size before birth. To verify whether a child's final height can be predicted by sonographic biometry in utero. We evaluated in 116 healthy children both ultrasound measurements in utero and postnatal measurements at a mean age of 6.0 +/- 1.4 years. The following fetal ultrasound measurements were obtained: crown-rump length in the first trimester; biparietal diameter, head circumference and femur length in the second and third trimester. Midparental height of the children was correlated both with crown-rump length in the first trimester and with femur length (FL) in the second and third trimester. Predicted adult height was correlated both with FL in the second and third trimester, while present height of the child was correlated with FL only at the third trimester. FL showed a close relationship with postnatal measurements. For the extreme values of FL, it seems possible to make quite an accurate prediction of the limits of future height. We can reasonably speculate, therefore, that the basis for the future growth of the child can be found in utero.

Careful ultrasound fetal measurements fail to demonstrate “intrinsic” biological variability in the third trimester allowing accurate estimation of gestational age

Careful ultrasound fetal measurements fail to demonstrate “intrinsic” biological variability in the third trimester allowing accurate estimation of gestational age

Fetal brain development of twins assessed in utero by ultrasound: implications for schizophrenia

There is evidence that some forms of schizophrenia are due to alterations of in utero brain development. Given the concordance rate for schizophrenia in monozygotic twins is approx. 45%, it is not clear how a shared genetic predisposition for schizophrenia and a shared in utero environment might selectively lead to schizophrenia in one but not the other twin in a monozygotic wwin pair. This study was undertaken to test the hypothesis that there is a difference in brain development between twins in a monozygotic twin pair that may contribute to the observed concordance rates for schizophrenia. Fetal ultrasound measures of brain (biparietal diameter, head circumference, ventricular width) and body size (femur length, abdominal circumference) obtained during the second trimester of fetal development were retrospectively analyzed in 41 monozygotic and 103 dizygotic twin pairs. In monozygotic twin pairs, there was a significant difference in measures of biparietal diameter, head circumference, and ventricular width, as well as in femur length and abdominal circumference, between twins. There was a similar difference in dizygotic twin pairs. These results indicate that in monozygotic twins, brain development is not identical. This difference in brain development may contribute to the observed concordance rates in monozygotic twins with schizophrenia.

Maternal body mass, proportional weight gain, and fetal growth in parous women.

This study is designed to examine the impact of maternal body mass index (BMI), proportional weight gain, and other variables on fetal growth. From a 10% random sample of 5722 Norwegian and Swedish para one and two women (n = 561), three hundred and sixty-nine women for whom prepregnant weight and height were recorded and for whom four fetal ultrasound measurements were taken at 17, 25, 33, and 37 weeks of gestation, were divided into low, average, and high body mass index groups (weight/height2). Fetal growth rate (mm/day) was determined by taking the mean of three measurements of the sagital and transverse diameters of the fetal abdomen (MAD) in each of three study time periods: weeks 17 to 25, first period; weeks 25 to 33, second period; weeks 33 to 37, third period. Proportional weight gain (kilograms gained within a specific time period/prepregnant weight) was measured in those same intervals. Fetal growth rate was significantly slower in the first and second periods, and significantly faster in the third time period for women with a low BMI, compared with those of average BMI. Fetal growth also significantly increased with increases in proportional weight gain in the second and third periods, but not in the first. Fetal growth appears to be independently associated with maternal BMI and proportional maternal weight gain.

Ultrasound Fetal Measurements — Part 456 or “How was it for You?”

Ultrasound Fetal Measurements — Part 456 or “How was it for You?”

Fetal Growth in Women Using Low-Dose Aspirin for the Prevention of Preeclampsia: Effect of Maternal Size

We wanted to determine whether low-dose aspirin has an effect on birthweight in a low-risk population and to evaluate the interaction between aspirin and maternal risk factors in relationship to their effect on birthweight. We also wanted to determine the specific fetal ultrasound measurements affected by low-dose aspirin and the gestational age at which this effect becomes apparent.The women studied were derived from a population of 606 nulliparous women who participated in a randomized trial of low dose aspirin to reduce the incidence of preeclampsia. This analysis included only women who remained normotensive and delivered live horn singletons at term. There were 254 women in the group randomized to 60 mg of aspirin daily from 24 weeks onward, and 248 who received a daily placebo.The mean birthweight was 3,353 g in the aspirin versus 3,282 g in the control group, a difference of 71 g (P = 0.08). In a regression analysis controlling for race, height, weight, smoking, and infant sex, the use of aspirin w...

Ultrasound diagnosis of fetal macrosomia.

Macrosomic infants and their mothers are at increased risk for intrapartum injury and perinatal morbidity and mortality. This study investigates the effectiveness of individual ultrasound fetal measurements, ponderal indices and estimated fetal weight in the identification of macrosomia in 732 pregnant patients who underwent ultrasound examination within 7 days of delivery. All the indices evaluated were compared for accuracy in predicting birth weight. Statistical comparison revealed that estimated fetal weight predicted macrosomia better than single ultrasound parameters and ponderal indices. The formulae tested yielded an accuracy of 94% and a positive predictive value of 90%. Abdominal diameter and abdominal circumference values above the 90th centile correctly predicted macrosomia in 82% and 72% of cases, respectively. Fetal length showed a sensitivity of 61% with a predictive positive test of 41%. Femur length-to-abdominal circumference ratio detected macrosomia with a sensitivity of 80% and an accuracy of 82%. The other single ultrasound parameters and ponderal indices were significantly less indicative of macrosomia. The combined use of four indices (growth profile) did not improve the effectiveness of ultrasound in detecting fetal macrosomia. We conclude that the optimal prediction of fetal macrosomia is obtained from mathematical formulae for fetal weight estimation, based on several fetal measurement parameters and adjusted for different gestational periods.

Improved Care for Rh-Isoimmunized Patients in Saudi Arabia

ABSTRACT Although the number of patients with Rh isoimmunization in pregnancy has been decreasing in recent years, this category of patients contributes significantly to the perinatal mortality in ...

The use of clinical, biochemical, and ultrasound parameters for the diagnosis of intrauterine growth retardation.

Fifty-four pregnant patients referred for nonstress testing with findings suggestive of intrauterine growth retardation (IUGR) were followed with serial biochemical determinations and ultrasound evaluations. Confirmation of IUGR was made in 18 of the neonates based on body weights below the 10th percentile. Stepwise discriminate function analysis was used to determine the factors most predictive of IUGR among several clinical, biochemical, and ultrasound parameters as well as their combinations. Only the determinations closest to the time of delivery were used in analysis. The presence of abnormal fetal ultrasound measurements had the highest predictive value. Prepregnancy weight improved the prediction slightly with a proportion of correct predictions increasing from 70 to 74%. Only the extremes of prepregnancy weight altered the prediction made on the basis of ultrasound. In contrast, no significant predictive value was demonstrated for weight gain, heavy cigarette smoking, hypertension, serum estriol, human placental lactogen, alpha-fetoprotein, or a decrease in amniotic fluid volume, either singly or in combination with other variables.

Growth retardation in preterm infants.

This paper combines earlier results on the relation between birthweight and gestational age, and the relation between fetal weight and ultrasound measurements of the fetal biparietal diameter (BPD) and mean abdominal diameter (AD) to investigate whether preterm infants (viewed as a group) are smaller than unborn fetuses of the same gestational age. The birthweight distribution for each sex at 223 and 258 days gestation was derived from the birthweight-for-gestational age charts based on 3888 newborn infants. The sex-specific intrauterine weight distribution was estimated from ultrasound measurement of the fetal BPD and AD performed on randomly selected fetuses of gestational age 223 and 258 days. The birthweights were lower than the intrauterine weights, especially early in pregnancy and for female infants. Thus, the 10th birthweight centile for girls at day 223 corresponds to the 4th centile of the 'true' intrauterine weight, and the 'true' intrauterine 10th centile corresponds to the 25th centile birthweight at day 223.