Growth charts of fetal biometry: a longitudinal study

Objective: The aim of this study was to construct reference charts for fetal biometry in Karachi, Pakistan. Methods: This was a prospective longitudinal study involving 1228 women with singleton pregnancies. Biparietal diameter, head circumference, abdominal circumference and femur length were measured repeatedly until delivery. Regression analysis and multilevel modeling was used to construct charts. Results: The mean age of the women in this study was 28.0 years with standard deviation of 4.6. For each gestational age percentiles were calculated and charts were then constructed. Conclusion: Our reference percentiles for fetal biometry measurements are the first of their kind in Karachi, Pakistan. They will not only help us in the diagnosis and management of fetal growth restriction but will provide the basis to develop charts at the national level.     

Longitudinal reference charts for growth of the fetal head, abdomen and femur

OBJECTIVES: The aims of the present study were to establish improved reference charts for growth of the fetal head, abdomen and femur, and to determine the effect of fetal and maternal factors. STUDY DESIGN: This prospective longitudinal study included 650 low-risk pregnancies. Outer-outer biparietal diameter (BPD), head circumference (HC), mean abdominal diameter (MAD), abdominal circumference (AC) and femur length (FL) were measured by ultrasound, and the statistical analysis was based on regression analysis and multilevel modeling. RESULTS: Reference percentiles for the growth of MAD, AC and FL showed continuous growth in gestational week 10-40, while BPD and HC showed a slightly blunted growth toward the end of pregnancy. FL was the only variable that was not influenced by gender. There was a significant negative association between breech presentation and all five biometrical variables, while maternal weight was positively associated with all five variables. Cephalic index significantly influenced BPD and HC. Maternal height had a positive effect on BPD, HC, AC and FL, and parity had a positive effect on MAD and AC, while smoking influenced negatively HC, MAD, and FL. Terms for calculating conditional reference values and customisation for individualised growth assessment are presented. CONCLUSIONS: New reference charts for the growth of fetal head, abdomen and femur are suggested for assessing fetal size and growth, and can be adjusted for maternal and fetal factors to suite individual pregnancies.     

The feasibility of using 5D CNS software in obtaining standard fetal head measurements from volumes acquired by three-dimensional ultrasonography: comparison with two-dimensional ultrasound

Objective: To evaluate the performance of a new software (5D CNS) developed to automatically recognize the axial planes of the fetal brain from three-dimensional volumes and to obtain the basic standard biometric measurements. The accuracy, reproducibility, and time required for analysis of 5D CNS were compared with that of two-dimensional (2D) ultrasound.

Methods: This was a prospective study of 120 uncomplicated singleton pregnancies undergoing routine second trimester examination. For every pregnancy standard biometric measurements including biparietal diameter, head circumference, distal lateral ventricle width, transverse cerebellar diameter and cisterna magna width were obtained using 2D ultrasound and three-dimensional (3D) ultrasound with 5D CNS software. Reliability and agreement of the two techniques were evaluated using intraclass correlation coefficients (ICCs) and proportionate Bland–Altman plots were constructed. The time necessary to complete the measurements with either technique was compared and intraobserver and interobserver agreements of measurements calculated.

Results: In 118/120 (98.3%), 5D CNS successfully reconstructed the axial diagnostic planes and calculated all the basic biometric head and brain measurements. The agreement between the two techniques was high for all the measurements considered (all ICCS?>?0.920). The time necessary to measure the biometric variables considered was significantly shorter with 5D CNS (54 versus 115?s, p?<?0.0001) than with 2D ultrasonography. No significant differences were found in 5D CNS repeated measurements obtained either by the same observer or by two independent observers.

Conclusion: 5D CNS software allows us to obtain reliable biometric measurements of the fetal brain and to reduce the examination time. Its application may improve work-flow efficiency in ultrasonographic practices     

Reference charts and equations of Korean fetal biometry

OBJECTIVE: To construct new reference charts and equations for fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FDL) from Korean fetuses at 12-40 weeks. METHOD: Prospective cross-sectional data obtained in one center for 5 years from a population of pregnant women undergoing ultrasound examination between the 12th and 40th week of gestation. Exclusion criteria comprised all maternal and fetal conditions possibly affecting fetal biometry. No fetuses were excluded on the basis of abnormal biometry. For each measurement, regression models were fitted to estimate both the mean and the standard deviation at each menstrual age. RESULTS: Biometric measurements were obtained for 10 455 fetuses. New charts and reference equations are reported for BPD, HC, AC and FDL. Reference equations are cubic models. CONCLUSION: We present new Korean reference charts and equations for fetal biometry. They can be easily used in obstetric ultrasound studies for the Korean 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 parity

Methods: 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.     

Ultrasonic estimation of fetal weight at term: an evaluation of eight formulae

AIM: To compare the accuracy of eight sonographic formulae for predicting fetal birth weight at term in a multiethnic population. METHODS: Pregnant women at term who were booked for induction of labor or elective cesarean section were included in the study. Eight ultrasonic fetal biometric formulae were used to predict fetal birth weight. RESULTS: A total of 173 patients were included in the study; 53 (30.6%) patients were from the Indian subcontinent, 44 (25.4%) patients were from Africa, 33 (19.1%) patients were from the Arabian Peninsula and 43 (24.9%) were from other ethnic groups. The mean absolute error ranged from a minimum of 0.3% (+/-11.3) for Hadlock (biparietal diameter [BPD], head circumference [HC], abdominal circumference [AC], femur length [FL]) to a maximum of 37.5% (+/-10.0) for Warsof (FL). The correlation of estimated fetal weight with actual birth weight ranged from a minimum of 0.09 with Warsof (FL) to a maximum of 0.77 with Shepard and Warsof (BPD, AC) and Hadlock (BPD, HC, AC, FL). The combination of AC with BPD measurements rather than FL achieves a high level of accuracy. CONCLUSIONS: Shepard (BPD, AC) provides a simple and accurate logarithm for the prediction of fetal weight at term in the studied multiethnic population.     

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.     

A novel reference chart and growth standard of fetal biometry in the Taiwanese population

ObjectiveThe purpose of this study was to establish a new reference chart and growth standards for fetal biometry in Taiwan.Materials and methods2047 singleton pregnancies were enrolled in this study with 15,813 fetal scans between 18 and 40 gestational weeks. A reference chart and normal range for fetal biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) was established by longitudinal quantile regression model. 330 women with comorbidities including gestational hypertension, preeclampsia and gestational diabetes were excluded and 1717 pregnant women were enrolled for the growth standard.ResultsThe new reference values were significantly larger across all gestational ages compared with the prior National Taiwan University reference chart in 1983. Compared with Intergrowth-21st, the BPD was larger at 18–23 weeks, the AC was larger at 18–24 weeks and the FL was larger at 18–36 weeks whereas they were all smaller at 29–40 weeks for the BPD, at 32–40 weeks for the AC and at 38–40 weeks for the FL. A quantile regression equation of biometry was established. BPD, AC, and FL had weekly growth of 2.5, 9.87 and 2.15 mm. Prepregnancy body weight, height, age, and gestational diabetes increased fetal size. Both gestational and chronic hypertension decreased fetal size.ConclusionTo promote maternal-fetal safety, a new reference chart and growth standard for fetal biometry is necessary to measure fetal growth.     

Fetal biometry and fetal weight estimation: JSUM standardization

From the clinical point of view, it is very important to standardize methods of fetal growth evaluation. The standardization committee of fetal measurement of the Japanese Society of Ultrasound in Medicine (JSUM) announced the recommended standard procedure for fetal biometry, calculation of estimated fetal weight (EFW) and their evaluation method. In short, the abdominal circumference (AC) by the ellipse-tracing method should be the standard for the fetal abdominal measurement and the EFW should be calculated by the following formula:

EFW = 1.07 × BPD. + 0.30 × AC × FL,

where BPD is the biparietal diameter and FL the femur length.     

Factors affecting the accuracy of ultrasonographical fetal weight estimation in twin pregnancies

Objective.?To determine the factors affecting the accuracy of ultrasonographic weight estimation in twins.

Methods.?152 sets of twins delivered vaginally, were included. Effects of fetal weights, inter-twin weight discordance, chorionicity, early rupture of membranes, intrauterine growth restriction, and presentations of twins on errors of estimated fetal weights were evaluated. The primary measures of estimated fetal weight accuracy compared were mean-percentage-error and the standart deviation (SD) of percentage errors.

Results.?Mean percentage errors for the first fetus (8.13?±?6.82) and the second fetus (8.07?±?6.88) were similar (p?=?0.64). Random errors of both fetuses were also similar (p?=?0.78). If one of the fetuses had IUGR, the percentage error and also the random error of that fetus would increase significantly. Different presentations and fetal gender combinations were similar for both types of errors of fetal weight estimation. A weak negative lineer relationship was found between the weight of the first fetus and its percentage error (r?=??0.27, p?=?0.04). A similar relation was present between the weight and percentage error of the second fetus (r?=??0.29, p?=?0.03). Percentage errors and also random errors of both fetuses were significantly higher if severe discordance was present between twins (p?=?0.01 and p?=?0.02, respectively).

Conclusions.?IUGR, fetal weights, and inter-twin discordence are the factors affecting the accuracy of weight estimation by ultrasonography.     

The effect of infertility and assisted reproduction on first-trimester placental and fetal development

Our investigation of differences in first-trimester placentation and/or fetal biometry in pregnancies conceived spontaneously compared with those conceived through fertility treatment, and comparing less invasive fertility treatment with in vitro fertilization found no statistically significant difference in first-trimester abnormal placentation or fetal growth between pregnancies conceived spontaneously and those conceived through fertility treatment, or between the in vivo and in vitro subgroups.     

A sinusoidal-like fetal heart-rate pattern in association with fetal sucking--report of 2 cases

A sinusoidal heart-rate pattern (SHR) is usually considered to signify fetal distress. Two cases are reported in which a sinusoidal-like fetal heart-rate pattern was caused by fetal sucking movements as observed by real-time ultrasonography. The patterns observed in these two fetuses were similar to that found in the neonate during suckling.     

New Down syndrome screening algorithm: Ultrasonographic biometry and multiple serum markers combined with maternal age

Objective: We compared the Down syndrome screening efficiency of a new algorithm that combines humerus length measurement and serum analytes versus that of the traditional triple-analyte serum screen. Study Design: Humerus length measurements were obtained prospectively in 1743 midtrimester (14 to 24 weeks) singleton fetuses before genetic amniocentesis. All patients had triple-marker serum screening before amniocentesis. Data on humerus length were expressed as multiples of the median, and were normalized by log transformation. Backward multiple stepwise logistic regression analysis was performed to determine which combination of biometry and serum markers best predicted fetal Down syndrome. The screening efficiency of the traditional triple-analyte algorithm was compared with that of a new multivariate gaussian algorithm that combined biometry and serum markers. Results: There were 31 (1.8%) fetuses with Down syndrome in the study population. In the regression analysis humerus length, human chorionic gonadotropin, α-fetoprotein, and maternal age were significant predictors of Down syndrome, but unconjugated estriol was not. The combined algorithm (humerus length, human chorionic gonadotropin, and α-fetoprotein and age) was superior to the traditional triple screen for Down syndrome detection. The sensitivities at fixed false-positive rates were consistently higher in the combination than in the triple-screen protocol. For example, at a 10% false-positive rate the sensitivities were 65.0% and 52.3%, respectively. Similarly, at a 15% false-positive rate the sensitivities were 73.5% and 55.0%, respectively. Conclusion: A new screening algorithm combining humerus length and serum analytes was superior to the traditional triple screen. Although we used a high-risk population in this study, it is expected that the observed superiority of the combination screen would persist in a population of younger women. The development of a combined biometric and serum analyte screening algorithm for estimating individual odds could represent an advance in prenatal Down syndrome screening. (Am J Obstet Gynecol 1998;179:1627-31.)     

Antenatal treatment of fetal goiter: a therapeutic challenge

Objective. Pre-natal ultrasonography presents an opportunity for in-utero therapy of a fetal goiter. Because of the morbidity associated with a large goiter and the risks of repeated intra-amniotic injections, controversy arose about the precise indications of this mode of treatment. We describe our observations in treating a 22-week-old fetus with a large goiter because of dyshormogenesis, monitored with serial 3D high frequency, high resolution ultrasonography and amniotic hormonal measurements. Fetal hypothyroidism was confirmed by cordocentesis and amniotic hormone levels. After assessment of relevant risk factors and the criteria for in-utero intervention, including goiter volume, amniotic fluid index, polyhydramnios and tracheal compression, we determined that hormonal therapy was warranted. Levothyroxine was injected every 7–10 days, and its efficacy monitored by ultrasound changes and amniotic hormone sampling.

Results. Reduction in goiter volume restored normal neck flexion relieving the pressure on the trachea, polyhydramnios was prevented and amniotic hormone levels were normalised. The infant was euthyroid at birth, however, by age 4 days hypothyroidism was diagnosed, and treatment with l-thyroxine started.

Conclusion. Advances in fetal ultrasonography permit judicious therapy of an enlarging goiter in a hypothyroid fetus, which may contribute to enhancing cognitive development. We discuss the value of amniotic hormone sampling, the objectives and risks of in-utero intervention in the light of recent literature and our own observations.     

Three- and four-dimensional ultrasonography for the structural and functional evaluation of the fetal face

Ultrasonographic examination of the fetal face can provide information that may lead to the diagnosis of anomalies in other organs or systems. Thus, the fetal face represents a "diagnostic window" for fetal diseases and syndromes. Three-dimensional ultrasonography (3DUS) improves the evaluation of anatomic fetal facial anomalies over what is possible by 2-dimensional ultrasonography (2DUS). Four-dimensional ultrasonography (4DUS), by adding the temporal component to the examination, allows visualization of facial expressions that might be useful in the study of fetal behavior and maternal-fetal bonding. In this article, we evaluate the potential of 3D/4DUS for the study of structural and functional development of the fetal face.     

Incidence of fetal macrosomia and birth complications in Chinese immigrant women

OBJECTIVE: To compare rates of fetal macrosomia (birthweight > 4000 g) and birth complications in both Chinese women immigrants and Caucasian women for two time periods: 1992 and 1999-2000. POPULATION: Chinese women immigrants and Caucasian women attending the Royal North Shore Hospital and Hornsby Ku-Ring-Gai Hospital in Sydney's northern health region. METHODS: Data used were extracted from the Northern Suburbs Area Health Service OBSTET database. Significance of trends were assessed using chi2 test. RESULTS: The results show a rise in macrosomic babies born to Chinese immigrants from 4% of total Chinese births in 1992 to 9.8% in 1999-2000 (P = 0.02).There was no significant difference in the rate of macrosomia among Caucasian women with respective rates of 11 and 14% for the same periods. The incidence of post-partum haemorrhage increased significantly in both Chinese immigrants and Caucasian women (P < 0.001). CONCLUSION: Australia has a multicultural population and yet the normal ranges defined for many obstetric investigations do not adjust for ethnicity. The application of values derived from a Caucasian population to other ethnic populations may be inappropriate and conceal important pathologies.     

The comparison of fetal behavior in high risk and normal pregnancies assessed by four dimensional ultrasound

Objective.?We compared fetal behavior (FB) in high risk and normal pregnancies using four dimensional ultrasound (4DUS).

Methods.?For assessment of FB in high risk and normal pregnancies, we used a scoring system of Kurjak's antenatal neurological test (KANET). The newborns were assessed by a postnatal neurological test, Amiel-Tison neurological assessment at term (ATNAT). The scores of KANET in high risk (N?=?116) and in normal pregnancies (N?=?110) were compared. After delivery, the results of KANET from both groups were compared with ATNAT test.

Results.?There was a statistically significant difference between group of high risk and normal pregnancies, for 8 out of 10 parameters in KANET: isolated anteflection of the head, eye blinking, facial expressions, mouth movements, isolated hand movement, hand to face movement, fist and finger movements, general movements. There was no difference for cranial sutures and isolated leg movements. Comparison of KANET and ATNAT showed statistically significant, moderate correlation between the two tests, which means that the neuropediatric exam (ATNAT) confirmed the prenatal 4DUS finding (KANET).

Conclusion.?The difference of FB between the high risk and normal pregnancies was evident. These preliminary results are promising but further studies have to be done before the test could be recommended for wider clinical practice.     

Ultrasonic detection of fetal ascites associated with polyhydramnios

The combination of fetal ascites and polyhydramnios is an uncommon problem that can be detected in utero by sonography. A case is reported where the etiology was found to be generalized cytomegalovirus infection. The differential diagnosis, etiology and diagnostic procedures are discussed.A thorough sonographic study is essential in the diagnosis and evaluation of fetal ascites in utero.     

Defining fetal growth restriction: abdominal circumference as an alternative criterion

Purpose: The purpose of this study is to determine if using abdominal circumference percentile (AC) to define fetal growth restriction (FGR) improves ultrasound at ≥36 weeks as a screening test for small for gestational age (SGA).

Materials and methods: All non-anomalous singletons undergoing ultrasound at a single center at ≥36 weeks during 12/2008–5/2014 were included. FGR was defined as (estimated fetal weight) estimated fetal weight (EFW) and/or abdominal circumference (AC)?Results: There were 1594 ultrasounds. Median (IQR) ultrasound GA was 37.3 (36.6–38.0), days to delivery 10.6 (5.0–18.4), and delivery GA 39.29 (38.6–39.9). EFW <10 had the following characteristics: sensitivity 50.6%, FPR 2.0%, PPV 83.8%, and AUC 0.743. Using AC <10, these were 64.0, 2.9, 81.3, and 0.806, respectively. Using AC or EFW <10, these were 67.5, 3.3, 80.3, and 0.821, respectively; this criterion has the largest AUC (p?Conclusions: AC <10 is more sensitive and has a similar PPV compared with EFW <10 for SGA. Using AC <10 or EFW <10 has the best balance of sensitivity and specificity as a screening test and has a low FPR. AC may be a reasonable alternative criterion to EFW for FGR diagnosis.     

Association between fetal myocardial performance index and fetal heart rate monitoring: a prospective observational cohort study

Objective: To evaluate whether the left myocardial performance index (MPI) changes in association with the fetal heart rate (FHR) tracing during labor.

Study design: Women with term, singleton pregnancies, in labor were recruited to this prospective cohort study. Primary outcome: difference in left MPI between Category of fetal heart rate tracings. Secondary outcomes: differences in left MPI by FHR characteristics. Participants underwent ultrasound examination, during which fetal MPI was measured.

Results: Twenty-four laboring patients were recruited. There were 13 patients with Category I FHR, 11 patients with Category II FHR, and 0 patients with Category III FHR. Demographics were similar between the groups. MPI was not significantly different between fetuses with Category I or Category II FHR (0.67 versus 0.65, p?=?.385). MPI was significantly higher in fetuses with accelerations versus those without (0.71 versus 0.59, p?=?.045). MPI was not significantly different for fetuses with or without decelerations (0.65 versus 0.68, p?=?.350), between deceleration type (0.50 versus 0.64 versus, 0.75, p?=?.421), or between variability type (0.56 versus 0.68, p?=?.113).

Conclusions: MPI of fetuses in term, laboring patients did not vary with differing FHR characteristics except for the presence or absence of accelerations.