Detection of macrosomia by the individual fetal growth curve assessment method

The value of the Rossavik growth model [P = c(t)k + s(t)] was evaluated in 39 patients with singleton pregnancy who had neonatal weight outcome above the 90th percentile of our birth weight distribution for gestational age. Individual fetal growth curve standards for head and abdominal circumferences, femur diaphysis length, and weight were determined from the data of two scans obtained before 26.1 weeks' gestation and separated by an interval of at least 5 weeks. Projected crown-heel lengths were calculated from projected femur diaphysis length values. Comparisons between actual and predicted birth characteristics were expressed by the Growth Potential Realization Index (GPRI) and Neonatal Growth Assessment Score (NGAS). Excessive growth at birth was seen in almost all cases as indicated by high GPRI for weight and abdominal circumference and abnormal NGAS values. In eight of the 33 patients who delivered after 38 weeks, excessive growth was detected only by comparing birth characteristics to their predicted values at 38 weeks' gestation. Our data suggest that individual growth curve standards may identify several patterns of excessive fetal growth that could represent different pathophysiologic mechanisms, ie, failure to terminate growth after 38 weeks versus a defect in a still unknown growth regulator. The individual fetal growth curve standards method gives additional information and discriminates well between normal and excessive fetal growth.     

Detection of small-for-gestational-age infants with poor perinatal outcomes using individualized growth assessment

OBJECTIVE: Our objective was to evaluate individualized growth assessment using the Rossavik growth model for detection of small-for-gestational-age (SGA) infants with a poor perinatal outcome. METHODS: Rossavik growth models derived from second-trimester ultrasound measurements were used to predict birth characteristics of 47 singleton SGA infants. Individual fetal growth curve standards for head and abdominal circumference, and weight were determined from the data of two scans obtained before 25 weeks' menstrual age and separated by an interval of at least 5 weeks. Comparisons between actual and predicted birth characteristics were expressed by the Growth Potential Realization Index (GPRI) and Neonatal Growth Assessment Score (NGAS). The proportions of perinatal outcomes [mechanical delivery, low Apgar score, abnormal fetal heart rate (FHR) patterns, neonatal acidosis, meconium staining of amniotic fluid, neonatal intensive care unit (NICU) admission and maternal complications] were compared between SGA infants with normal NGAS and those with abnormal NGAS. RESULTS: Of the 47 fetuses studied, 27 had normal growth outcomes at birth and 20 showed evidence of intrauterine growth restriction, based on NGAS. There were significant increases in mechanical deliveries, abnormal FHR patterns and meconium staining of amniotic fluid in cases of growth-restricted neonates, determined using the NGAS classification, when compared with events related to normally grown infants. However, there were no significant differences in low Apgar score, neonatal acidosis, NICU admission and maternal complications between the 2 groups. CONCLUSION: Individualized growth assessment should be useful for detection of SGA infants with poor perinatal outcomes.     

Fetal growth cessation in late pregnancy: its impact on predicted size parameters used to classify small for gestational age neonates

Objective: To evaluate the impact of late 3rd trimester fetal growth cessation on anatomical birth characteristic predictions used in classifying SGA neonates.

Methods: A prospective longitudinal study was performed in 119 pregnancies with normal neonatal growth outcomes. Seven biometric parameters were measured at 3–4 weeks intervals using 3D ultrasonography. Rossavik size models were determined to predict birth characteristics at different ages. Percent Differences (% Diff) were calculated from predicted and measured birth characteristics. Growth Cessation Ages (GCA) were identified when no systematic change in % Diff values occurred after specified prediction ages. Systematic and random prediction errors were compared using different assumptions about the GCA. Predicted and measured size parameters were used to determine six new Growth Potential Realization Index (GPRI) reference ranges. Five were used to sub-classify 34 SGA neonates (weight?<?10th percentile) based on the number of abnormal GPRI values.

Results: Growth cessation ages were 38 weeks for HC, AC, mid-thigh circumference, estimated weight and mid-arm circumference. Crown-heel length GCA was 38.5 weeks. At GCA, birth characteristics had prediction errors that varied from 0.08?±?3.4% to 15.7?±?9.1% and zero % Diff slopes after 38 weeks. Assuming growth to delivery gave increased systematic and random prediction errors as well as positive % Diff slopes after 38 weeks, MA. Seventeen of the SGA neonates had 0 or 1 abnormal GPRI values [Subgroup 1] and 17 others had 2 or more abnormal values [Subgroup 2]. In Subgroup 1, 4/85 (4.7%) of GPRI's were abnormal while in Subgroup 2, 43/85 (50.6%) were abnormal. Use of only one type of GPRI for SGA subclassification resulted in substantial false negative and some false positive rates when compared to subclassification based on all five GPRI values.

Conclusions: Growth cessation occurred at approximately 38 weeks for all six birth characteristics studied. SGA neonates can be separated into normal and growth restricted subgroups based on the frequency of abnormal GPRI values (GPRI Profile Classification).     

Classifying neonatal growth outcomes: use of birth weight,placental evaluation and individualized growth assessment

Objective: To compare neonatal growth outcomes determined by birth weight (BW), placental assessment (Plac Assess) and individualized growth assessment (IGA).

Methods: This retrospective analysis was carried out in 45 selected pregnancies at risk for fetal growth restriction. Serial fetal biometry was carried out in the 2nd and 3rd trimester. First and second trimester placental biomarkers, 2nd trimester uterine artery (Ut A) velocimetry and postnatal placental pathology were evaluated as indicators of placental insufficiency. At delivery, weight (WT), head circumference (HC) and crown–heel length (CHL) were measured. BWs were categorized as large-for-gestational-age (LGA), appropriate-for-gestational-age (AGA) and small-for-gestational age (SGA) (<10th, 10th–90th and >90th percentiles). In these categories, neonatal growth outcomes were classified as growth restricted (GR), normal (NORMAL) or macrosomic (MACRO) based on BW plus Plac Assess (Ut A velocimetry, biomarkers, pathology) or IGA [growth potential realization index profile (WT, HC and CHL)].

Results: There were 6 LGA, 14 AGA and 25 SGA neonates in this sample. All 14 AGA neonates were considered NORMAL by both IGA and BW?+?Plac Assess. All six LGA neonates were classified as MACRO by BW?+?Plac Assess but only four by IGA (the remaining two were NORMAL and high NORMAL). The 25 SGA cases could be divided into five subgroups based on IGA and BW?+?Plac Assess. The largest subgroup (56%) was GR and the next largest (24%) was NORMAL by both classification methods. In the remaining 20%, there was some evidence of GR but IGA and BW?+?Plac Assess were not in complete agreement.

Conclusions: Agreement was good for all three methods in the LGA and AGA groups. The SGA group was heterogeneous but agreement between IGA and BW?+?Plac Assess was 89%. These results, using more sophisticated growth assessment methods, confirm placental insufficiency as a primary cause of growth restriction. Most normal and GR SGA neonates can be identified with conventional anatomical measurements if IGA is used.     

Macrosomia prediction using ultrasound fetal abdominal circumference of 35 centimeters or more

OBJECTIVE: To determine if birth weights greater than 4000 g can be predicted by ultrasound measurements of abdominal circumferences. METHODS: In 1996, 254 newborns delivered at Tampa General Hospital weighed at least 4000 g, 84 of whom had ultrasound examinations within 2 weeks of delivery. Those were compared with 84 neonates with recent ultrasounds who weighed less than 4000 g. Data were abstracted retrospectively from maternal medical records. RESULTS: The best linear predictor of birth weight was ultrasound measurement of abdominal circumference (AC), which had a correlation coefficient of 0.95. An AC measurement of 35 cm or more predicted 93% of macrosomic infants. Among 177 macrosomic infants born vaginally, 23 (13%) had shoulder dystocia. In that group, induction of labor was associated with a greater than three-fold increase in risk of shoulder dystocia (odds ratio [OR] 3.4, 95% confidence interval [CI] 1.4, 8.2; P < .01). Labor augmentation was not associated with increased risk of shoulder dystocia. CONCLUSION: Abdominal circumference measurements were useful in screening for suspected macrosomia. An AC measurement of 35 cm or more identified more than 90% of macrosomic infants who were at risk for shoulder dystocia. Induction of labor in macrosomic patients increased the risk of shoulder dystocia.     

Diagnosis of intrauterine growth retardation by a simple clinical method: measurement of uterine height

Generally there is a tendency to underrate the value of uterine height in the diagnosis of intrauterine growth retardation (IUGR). This fact is probably due to the lack of standard normal values for this measurement. In a group of 298 healthy pregnant women, the 10th, 50th, and 90th percentile were calculated by week of amenorrhea. Uterine height was measured with a nonelastic measuring tape, from the symphysis pubis to the fundus uteri. With the use of these standard values the predictive value of the method was established. Of 44 neonates with low birth weight for gestational age, 38 had a uterine height below the 10th percentile (sensitivity 86%). Six cases of IUGR were not diagnosed by this method. Of 95 neonates with adequate birth weight, 85 had uterine values above the 10th percentile (specificity 90%). Ten (10%) of these were predicted as low birth weight but were born with adequate weight. The uterine height measurement is shown to be a very good method for detecting IUGR. It can be used as a screening test to detect impairment in fetal growth and to make early referral of those pregnancies.     

Fetal abdominal circumference measurements of 35 and 38 cm as predictors of macrosomia. A risk factor for shoulder dystocia

OBJECTIVE: To determine if ultrasound measurements of fetal abdominal circumference (AC) can be used to predict macrosomic infants. STUDY DESIGN: Using a computer database, 1,996 women at > or = 36 weeks' gestation, delivering a singleton infant and having an ultrasound examination within one week of delivery were studied. Fetal AC was evaluated to determine if it was useful in predicting the birth of a macrosomic infant, > 4,000 or > 4,500 g. RESULTS: AC predicted infants > 4,500 g better than those > 4,000 g. Almost all macrosomic infants > 4,500 g had an AC of > or = 35 cm (68/69, or 99%), but many nonmacrosomic infants were also in this group (683). AC of > or = 38 cm occurred in 99 infants, and 37 of the 69 (53.6%) weighing > 4,500 g were identified. Most infants (78%) with AC > or = 38 cm weighed > 4,000 g. CONCLUSION: Fetal AC was very helpful in identifying potential macrosomic infants. If AC was < 35 cm, the risk of infant birth weights > 4,500 g was < 1%. If AC was > or = 38 cm, the risk was 37% (37/99), and > 50% of these infants were identified (37/69, or 53.6%).     

Value of a single early third trimester fetal biometry for the prediction of birth weight deviations in a low risk population

OBJECTIVE: To analyze the value of a single ultrasound biometry examination at the onset of the third trimester of pregnancy for the detection of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) at birth in a low risk population. The aim of this study was to develop a simple and useful method for the detection of growth deviations during pregnancy in primary care (midwife or general practitioner) practices. SETTING: A Dutch primary care midwifery practice. STUDY DESIGN: In an earlier study, we developed parity and sex specific fetal growth charts of abdominal circumference (AC) and head circumference (HC) on the basis of ultrasound data of a low-risk midwifery population in the Netherlands. In the present study, we calculated sensitivity, specificity and predictive values at different cut-off points of AC and HC for the prediction of growth deviations at birth. Patients booked for perinatal care between 1 January 1993 and 31 December 2003 (n=3449) were used for the identification of cut-off points (derivation cohort) and those admitted between 1 January 2004 and 31 December 2005 (n=725) were used to evaluate the performance of these cut-offs in an independent population (validation cohort). For the determination of SGA and macrosomia at birth, we used the recently published Dutch birth weight percentiles. RESULTS: Most promising cut-offs were AC or=75(th) percentile for the prediction of macrosomia (birth weight >or=90(th) percentile). Within the validation cohort these cut-offs performed slightly better than in the derivation cohort. For the prediction of SGA, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 53% (95% CI 49-58%), 81% (95% CI 80-83%), 26% (95% CI 23-29%), and 93% (95% CI 93-94%), respectively. The false positive rate was 74%. For the prediction of macrosomia, the values of these parameters were 64% (95% CI 59-69%), 80% (95% CI 78-81%), 23% (95% CI 20-26%), and 96% (95% CI 95-97%), respectively. Here, false positive rate was 77%. No cut-offs were found that predicted extreme birth weight deviations (or=97.7 percentile) sufficiently well. CONCLUSIONS: In a low risk population, we could predict future growth deviations with a higher sensitivity and in a significant earlier stage (at the onset of the third trimester of pregnancy) than with the use of conventional screening methods (i.e., palpation of the uterus only and fundus-symphysis measurement). Sonographic measurement of fetal abdominal circumference enables to detect more than half of cases of SGA at birth and more than two-thirds of cases of macrosomia with acceptable false-positive rates. We suggest that fetuses with biometry results below the 25(th) percentile or above the 75(th) percentile at the onset of the third trimester of pregnancy should be more intensively investigated in order to distinguish between pathology (e.g., IUGR or macrosomia) and physiology and to decide about the appropriate level of further perinatal care.     

The relative significance of human placental lactogen in the diagnosis of retarded fetal growth.

The purpose of this prospective study was to determine whether serial maternal venous hPL determinations could identify pregnancies resulting in growth-retarded infants from a selected population at presumed high risk for IUGR. Our results demonstrated that mean hPL levels in IUGR outcome pregnancies were significantly lower than normal after 33 weeks' gestation. Mean hPL was also lower in some pregnancies resulting in normal-weight neonates with abnormally low PI or short CHL, suggesting that these neonates, despite normal birth weight achievement, may represent previously unsuspected.     

Accuracy of single ultrasound parameters in detection of fetal growth restriction

The objective of this study was to evaluate the diagnostic accuracy of different single ultrasonographic parameters in predicting intrauterine growth-restricted (IUGR) babies as defined by Ponderal index at birth. Study sample composed of two sets of data from Iran and Australia. The Iranian sample consisted of 296 Iranian women. All the study women received prenatal care and delivered at Fatemieh Hospital in Shahrood, Iran. The data from 219 Australian fetuses were obtained from the ultrasound section at the Wollongong Hospital in Australia. Ultrasonographic measurements of biparietal diameter (BPD), femur length (FL), head circumference (HC), abdominal circumference (AC), amniotic fluid index (AFI), and Doppler from umbilical arteries (S/D ratio) were obtained. Only those pregnancies were included in which the estimated date of delivery (EDD) by LMP (last menstrual period) agreed within 14 days with the estimated date of delivery determined by the initial ultrasound examination. Sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were calculated for single proposed ultrasound parameters in the Iranian and Australian samples. When different variables are compared, with a cut-off point at or below the 10th percentile AC and HC had the highest sensitivities in the Australian sample while AC was the most sensitive parameter for IUGR detection in the Iranian sample. BPD has a reasonably high sensitivity at this threshold. The AFI ratio has the lowest sensitivity in predicting IUGR in the Australian sample. Positive predictive values were low in all of the parameters in both the Iranian and Australian samples. By increasing the cut-off for PI to the 20th percentile, the sensitivity of reduced AC increased in the Australian sample while the sensitivity for an abnormal S/D ratio and reduced AFI to identify IUGR decreased. Our results indicate that reduced AC was the best single parameter in discriminating between IUGR and non-IUGR fetuses with the highest sensitivity among the proposed parameters in the both Iranian and Australian sample. However, the PPV of this parameter is low. This means that a high number of false-positive cases are detected using each parameter, which reduces the usefulness of identification. Other ultrasound obstetrical parameters may also have a reasonable level of sensitivity, however, the PPV of all parameters is low. On the whole, our results show that although the examined ultrasonographic criteria may detect a group of fetuses that need close antepartum surveillance, none of these parameters are appropriate enough to be used in isolation in clinical practice. Using single ultrasound parameters does not have high sensitivity and PPVs in detection of fetal growth restriction. This limits accuracy and utility of these tests in the detection of IUGR fetuses.     

Sonographic diagnosis of IUGR-macrosomia.

Many sonographic methods have been suggested for identification of the fetus with a growth abnormality. Clearly, optimal management depends on early diagnosis. In recent years, advances in sonography have improved the ability to identify abnormal growth patterns and evaluate fetal well-being. When abnormal fetal growth is suspected, a thorough sonographic evaluation should be performed. This evaluation includes measurements of the abdominal circumference, femur length,) BPD, HC, AC, FL, and amniotic fluid volume. If these measurements confirm the suspicion of abnormal fetal growth, careful search for anomalies is mandatory. If there is no evidence of fetal compromise that would warrant delivery, measurements should be repeated in 2-3 weeks to evaluate interval growth. The following conclusions could be drawn from this literature review: 1. Intrauterine growth retardation and macrosomia are multifactorial diseases with varying degrees of severity. It is unlikely that a single sonographic parameter will allow an accurate diagnosis of all cases. 2. The type and degree of growth retardation and macrosomia depend on the intensity and duration of the underlying disease. Thus, an ultrasound assessment performed long before delivery may be of limited value. 3. Most of the sonographic parameters reviewed in this chapter are gestational age dependent. Unfortunately, gestational age is often unknown. Gestational age independent indices such as the amniotic fluid volume, FL/AC ratio, and the rate of fetal growth should be helpful in this situation. 4. The constitutionally small infant whose only problem is low birth weight should not be expected to present with any abnormal indices other than a low EFW. On the other hand, newborns who appear to be malnourished but whose birth weight is at or slightly above the tenth percentile for gestational age, may present with abnormal indirect indices indicating growth retardation (ie, HC/AC, FL/AC, Doppler velocimetry or oligohydramnios) despite a normal estimate of fetal weight. In addition, if the diagnosis of IUGR is made only with the use of birthweight for gestational age criteria, these infants are likely to be misclassified and labelled AGA. However, an abnormal ponderal index would indicate that these neonates are growth retarded. It can be concluded from this review that the use of sonographic measurements for diagnosing IUGR or macrosomia is associated with a high specificity and a somewhat lower sensitivity. Therefore, it would seem that the current ultrasound methods are more useful for excluding the possibility of abnormal fetal growth rather than for confirming it.     

Neonatal transverse cerebellar diameter in normal and growth-restricted infants

OBJECTIVE: To assess the transverse cerebellar diameter (TCD) in preterm and term neonates with normal growth or growth restriction. METHODS: TCD was sonographically measured after birth in 404 neonates born between 23 and 42 weeks of gestation. The study included two groups: Group 1: 334 appropriately grown for gestational age (AGA) neonates (both birthweight (BW) and head circumference (HC) were between the 3rd and 97th centiles), which were subdivided into two subgroups according to the HC measurements. Group 2: 70 small for gestational age (SGA) neonates (BW <3rd centile), were further divided into three subgroups according to HC measurements. RESULTS: In Group 1 of AGA neonates, a linear growth function was observed between the TCD and GA (R = 0.914, P < 0.00001, TCD = 0.279 + 0.142 X GA), and between TCD and HC (R = 0.886, P < 0.00001, TCD = -0.333 + 1.777 X HC). The percentage of neonates with normal TCD (> or =10th centile) was more than 85% of the AGA and asymmetric SGA subgroups, and 60.7% of the microcephalic SGA subgroup (P < 0.02). CONCLUSIONS: This study provides normative data of neonatal TCD across gestational age. TCD measurement via sonography is a new adjunctive criterion for objectively assessing gestational age in infants when a precise determination of gestational age is necessary. This is very important since utility of the TCD is effective for both AGA and asymmetric SGA infants.     

A modified prenatal growth assessment score for the evaluation of fetal growth in the third trimester using single and composite biometric parameters

Objective: To define modified Prenatal Growth Assessment Scores (mPGAS) for single and composite biometric parameters and determine their reference ranges in normal fetuses.

Methods: Nine anatomical parameters (ap) were measured and the weight estimated (EWT_a, EWT_b) in a longitudinal study of 119 fetuses with normal neonatal growth outcomes. Expected third trimester size trajectories, obtained from second trimester Rossavik size models, were used in calculating Percent Deviations (% Dev's) and their age-specific reference ranges in each fetus. The components of individual % Dev's values outside their reference ranges, designated +iapPGAS, -iapPGAS, were averaged to give +apPGAS and ?apPGAS values for the 3rd trimester. The +iapPGAS and ?iapPGAS values for different combinations of ap (c1a (HC, AC, FDL, ThC, EWT_a), c1b (HC, AC, FDL, ThC, EWT_b), c2 (ThC, ArmC, AVol, TVol), c3 (HC, AC, FDL, EWT_a)) were then averaged to give +icPGAS and ?icPGAS values at different time points or at the end of the third trimester (+cPGAS, ?cPGAS). Values for iapPGAS, ic1bPGAS, and ic2PGAS were compared to their respective apPGAS or cPGAS reference ranges.

Results: All mPGAS values had one 95% range boundary at 0.0%. Upper boundaries of 1D +apPGAS values ranged from 0.0% (HC) to +0.49% (ThC) and were +0.06%, +2.3% and +1.8% for EWT, AVol and TVol, respectively. Comparable values for ?apPGAS were 0.0% (BPD, FDL, HDL), to ?0.58% (ArmC), ?0.13% (EWT), ?0.8% (AVol), and 0.0% (TVol). The +cPGAS, 95% reference range upper boundaries varied from +0.36% (c1b) to +0.89% (c2). Comparable values for ?cPGAS lower boundaries were ?0.17% (c1b) to ?0.43% (c2).

Conclusions: The original PGAS concept has now been extended to individual biometric parameters and their combinations. With the standards provided, mPGAS values can now be tested to see if detection of different types of third trimester growth problems is improved.     

Diagnosis of intrauterine growth restriction: comparison of ultrasound parameters

The objective of this study is an attempt to evaluate the best ultrasonic method of diagnosing intrauterine growth restriction (IUGR); a retrospective study of patients with singleton pregnancies who had been scanned at the author's institution within 2 weeks of their delivery was undertaken. Estimated fetal weight, abdominal circumference, head circumference/abdominal circumference ratio, abdominal circumference/femur length ratio, and umbilical artery S/D ratio were compared for accuracy in prediction IUGR in the neonate using both univariant and multivariant statistical analysis. Five hundred one (501) patients were analyzed. One hundred fourteen (114) neonates were classified as IUGR (22.8%). Doppler evaluation of the umbilical artery showed the best sensitivity while both abdominal circumference alone and estimated fetal weight showed similar specificity, positive and negative predictive value, and lowest false-positive and -negative results. Logistic regression analysis confirmed the univariant results and showed that, when used in combination, abdominal circumference and Doppler, or estimated fetal weight and Doppler resulted in the best predictive values. Either estimated fetal weight or abdominal circumference (alone) are accurate predictors of IUGR. Combined with Doppler studies of the umbilical artery either method will provide accurate evaluation of suspected IUGR.     

Sonographic estimates of fetal weight in the intrauterine growth retardation population

The efficacy of different methods of fetal weight estimation using sonographic measurements of the abdominal circumference (AC), biparietal diameter (BPD), and femur length (FL), either alone or in combination, was evaluated in the fetus with intrauterine growth retardation (IUGR). Eighty-one patients, referred with a clinical suspicion of IUGR, were studied. All patients had sonographic measurements within 7 days of delivery. Four regression equations were used to estimate fetal weight: AC (Hadlock), BPD-AC (Shepard), AC-FL (Hadlock), BPD-AC-FL (Hadlock). For the total study group, as well as for the infants who were found to be IUGR at birth, 75% of the estimates of fetal weight using the BPD-AC-FL method were within 10% of the actual birthweight. Nearly comparable results were obtained using the AC-FL method. In the fetus with IUGR, estimates of fetal weight that incorporated the FL correlated best with the actual birthweight.     

Relationship between the sonographic pattern of intrauterine growth restriction and acid-base status at the time of cordocentesis

Objective: To determine whether there is a difference in acid-base status at the time of cordocentesis between fetuses with symmetric and asymmetric intra- uterine growth restriction (IUGR). Study Design: Non-anomalous singleton fetuses with IUGR who underwent fetal blood sampling for rapid karyotype analysis from 1992–1995 were retrospectively identified. Cases with gestational age <24 weeks, abnormal karyotype, or evidence of congenital infection were excluded. Fetuses were divided into two groups based on Head Circumference/ Abdominal Circumference Ratio (HC/AC). The asymmetric-IUGR group had HC/AC ≥95% tile for GA, and the symmetric-IUGR group had HC/AC <95% tile. GA adjusted values of umbilical venous pH, pCO₂, pO₂, HCO3, hemoglobin and reticulocyte count were calculated by subtracting the mean values for GA from the observed and compared between groups. Results: Both symmetric-IUGR (n=7) and asymmetric-IUGR (n=9) had umbilical venous pH and pO₂ levels lower than GA normative values. However, there were no differences between groups for any of the parameters studied. Conclusions: Fetuses with symmetric and asymmetric IUGR due to UPI display a similar degree of acid-base impairment. Received: 20 March 2000 / Accepted: 25 July 2000     

Role of Colour Doppler Indices in the Diagnosis of Intrauterine Growth Retardation in High-Risk Pregnancies

Purpose

Intra uterine growth retardation (IUGR) due to fetoplacental vascular insufficiency is rampant in developing countries like India. Owing to the lack of awareness, antenatal patients often present in their third trimester for their first ultrasound examination. Alterations in the waveforms and Doppler indices of fetal middle cerebral artery (MCA), umbilical artery and bilateral uterine arteries have been extensively described in various studies in the literature. However, the role of each doppler parameter in actually predicting reduced birth weight (for gestational age) in the third trimester is often debatable and frustrating.

Method

A prospective study was done on 100 patients of clinically suspected IUGR/high-risk pregnancies of 31–41 weeks. The cases were followed till delivery; the doppler and grey scale findings were correlated with the birth weight of the baby.

Result

The highest sensitivity was found to be of HC/AC ratio, (84.4 %), the highest specificity of oligohydramnios and Cerebral/Umbilical Pulsatility ratio[C/U ratio] (100 %). The sensitivity of C/U ratio was found to be 68.8 %. Fetal MCA had the lowest sensitivity (7.7 %).

Conclusion

HC/AC ratio is quite sensitive, and oligohydramnios is a highly specific parameter to diagnose IUGR. However, the former has lower specificity, and the latter has very poor sensitivity. The MCA PI alone is not sensitive at all, and should not be used for screening purposes in IUGR patients. Also, C/U ratio is more sensitive than oligohydramnios and more specific than HC/AC ratio and stands out as the best parameter of all to diagnose IUGR in the third trimester.     

Ultrasound prediction of growth abnormalities in fetuses with gastroschisis

Objective.?We seek to determine whether (1) mean abdominal circumference (AC) of fetuses with gastroschisis is smaller than published normative values, (2) diagnosis of AC ≤2.5th percentile is supported by postnatal diagnosis of small-for-gestational age (SGA) and (3) adverse neonatal outcomes are more common in fetuses affected by gastroschisis with a sonographically measured small AC.

Methods.?Retrospective review of pregnancies complicated with gastroschisis between 2000 and 2008. Patient demographics, method of closure, length of stay, use of ventilator support and gastrointestinal complications were compared.

Results.?Seventy-four fetuses were identified with 368 ultrasound observations. Mean AC of fetuses with gastroschisis fell between the 2.5th and 50th percentile for gestational age. Thirty patients had AC measurements ≤2.5th of which 50% were SGA at delivery. Eleven of the 74 fetuses were diagnosed with intrauterine growth restriction (IUGR) and all were SGA. Birth weight was lower in those with a small AC (2104?g vs. 2665?g, p?<?0.001). There were no other differences in outcomes.

Conclusion.?AC values fell within the normal range of normative curves. Fifty percent of fetuses with small AC were SGA at birth. Neonatal outcomes in patients with small AC are similar to those with a normal AC.     

Utility of Head/Abdomen Circumference Ratio in the Evaluation of Severe Early-Onset Intrauterine Growth Restriction

ObjectiveTo determine whether the predominant phenotype of intrauterine growth restriction (IUGR) is symmetric or asymmetric in severe, early-onset disease due to placental insufficiency.MethodsWe conducted a retrospective chart review of high-risk pregnant women with severe, early-onset IUGR who were delivering at < 33+0 weeks’ gestation at Mount Sinai Hospital from 2001 to 2010. Ultrasound images were reviewed for fetal biometry, amniotic fluid volume, and uterine and umbilical Doppler flow studies within seven days of delivery, and the frequency of head circumference/abdominal circumference ratio ≥ 95th percentile for gestation was determined.ResultsSixty-two of 107 pregnancies (58%) with early-onset IUGR had an elevated HC/AC ratio (≥ 95th percentile), which was more than 10-fold greater than the expected proportion (P < 0.001). High rates of severe preeclampsia (53%), abnormal amniotic fluid (70%), and abnormal uterine artery Doppler studies (78%) indicated placental insufficiency.ConclusionFetuses with severe placental IUGR in the second trimester are more likely to have an asymmetric phenotype. This is in contrast to the current belief that asymmetric IUGR is confined to third trimester IUGR.