Neonatal Growth Assessment Scores Research Articles

The relationship of newborn adiposity to fetal growth outcome based on birth weight or the modified neonatal growth assessment score

Objectives: (1) Develop reference ranges of neonatal adiposity using air displacement plethysmography. (2) Use new reference ranges for neonatal adiposity to compare two different methods of evaluating neonatal nutritional status. Methods: Three hundred and twenty-four normal neonates (35–41 weeks post-menstrual age) had body fat (%BF) and total fat mass (FM, g) measured using air displacement plethysmography shortly after delivery. Results were stratified for 92 of these neonates with corresponding fetal biometry using two methods for classifying nutritional status: (1) population-based weight percentiles; and (2) a modified neonatal growth assessment score (m3NGAS51). Results: At the 50th percentile, %BF varied from 7.7% (35 weeks) to 11.8% (41 weeks), while the corresponding 50th percentiles for total FM were 186–436 g. Among the subset of 92 neonates, no significant differences in adiposity were found between small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA) groups using population-based weight standards. Classification of the same neonates using m3NGAS51 showed significant differences in mean %BF between corresponding groups. Conclusions: Population-based weight criteria for neonatal nutritional status can lead to misclassifications on the basis of adiposity. A neonatal growth assessment score, that considers the growth potential of several anatomic parameters, appears to more effectively classify under- and over-nourished newborns.

OP20.04: The relationship of newborn adiposity to neonatal growth outcome based on birth weight or the neonatal growth assessment score

OP20.04: The relationship of newborn adiposity to neonatal growth outcome based on birth weight or the neonatal growth assessment score

Individualized growth assessment of fetal thigh circumference using three‐dimensional ultrasonography

To develop individualized growth assessment (IGA) standards for upper (ThC(u)) and middle (ThC(m)) fetal thigh circumferences using three-dimensional ultrasonography. A prospective, longitudinal sonographic study of 30 fetuses was performed beginning at 18 weeks' menstrual age. Second-trimester sonographic parameters were measured from three-dimensional volume data to establish IGA standards. Normal infant growth outcomes were confirmed using modified Neonatal Growth Assessment Scores (m(3)NGAS(51)). ThC(u) and ThC(m) were studied in more detail. Rossavik growth model specification procedures, based on the slopes of the second-trimester growth curves, were developed for both ThC(u) and ThC(m). Third-trimester growth trajectories and birth measurements were subsequently predicted for these parameters. Percentage deviations during the third trimester and percentage differences at actual birth age were used to compare observed and predicted measurements. The 95% ranges for Growth Potential Realization Index (GPRI) values for both types of thigh circumference were determined. Values for m(3)NGAS(51) using GPRI(ThC(u)), GPRI(ThC(m)) and GPRI(ThC(o)) (original method) were compared. The 30 newborns had no postnatal evidence of abnormal growth. Two examiners demonstrated a satisfactory measurement bias of mean +/- SD 2.1 +/- 3.6 (95% limits of agreement,-4.9 to 9.1)% for ThC(m) and 3.3 +/- 4.1 (95% limits of agreement,-4.8 to 11.4)% for ThC(u). Rossavik functions fitted parameter trajectories well, with mean R(2) values of 99.5 +/- 0.4% for ThC(u) and 99.6 +/- 0.3% for ThC(m). By fixing coefficients k at their mean values, their respective fits did not change, and the variabilities of coefficients c and s were significantly reduced. For ThC(u), coefficient c was significantly related to the second-trimester slope (R(2)=98.6%), as was s to c(R(2)=91.0%). For ThC(m), coefficient c was significantly related to the second-trimester slope (R(2)=98.6%), as was s to c(R(2)=85.6%). Third-trimester growth trajectories, derived from second-trimester slopes for individual fetuses, had third-trimester deviations of 0.07 +/- 3.7% for ThC(u) and-0.04 +/- 3.7% for ThC(m). Percentage differences at birth age were 16.8 +/- 10.2% for ThC(u) and 8.9 +/- 9.5% for ThC(m). With correction for systematic overestimations, the mean GPRI values were 103.7 (95% range, 90-121)% for ThC(u) and 101.6 (95% range, 88-118)% for ThC(m). Corresponding mean +/- SD m(3)NGAS(51) values, using GPRI(ThC(u)), GPRI(ThC(m)) and GPRI(ThC(o)), were 203 +/- 11%, 201 +/- 10% and 200 +/- 9%, respectively. Fetal thigh circumference can be measured reliably and evaluated using standard IGA methods. Both ThC(u) and ThC(m) give similar results in the third trimester but neonatal thigh circumference predictions are improved by using ThC(m). Corresponding GPRI(ThC(m)) values are closer to the ideal value of 100% and can be used in m(3)NGAS(51) calculations for assessment of neonatal growth outcome.

Individualized growth assessment of fetal soft tissue using fractional thigh volume

The main goals of this study were to introduce fractional thigh volume (TVol) as a new soft tissue parameter for fetal growth evaluation, define its relationship to menstrual age, and develop individualized fetal growth standards based on Rossavik growth models. A prospective, longitudinal study of 22 fetuses was conducted with conventional biometry and TVol measurements by three-dimensional ultrasonography. Infant growth outcomes were determined from modified neonatal growth assessment scores. Rossavik functions (P = c(t)k+s(t)) were used to fit complete datasets to examine relationships between TVol and model coefficients. Second-trimester models were subsequently specified from the linear slopes of growth curves before 28.0 menstrual weeks with each fetus acting as its own control. Third-trimester trajectories and birth measurements were predicted for standard growth parameters and TVol. Observed and predicted measurements were compared using percent deviations and growth potential realization index values. Four additional infants, with serial prenatal scans and postnatal evidence of intrauterine growth restriction (IUGR), were also evaluated. All 22 fetuses had no evidence of growth abnormalities after delivery. Accelerated soft tissue deposition occurred in the fetal thigh by 28 menstrual weeks. A mean TVol start point of 9.0 +/- 1.4 menstrual weeks was consistent with embryological studies of thigh development. Rossavik functions fitted all TVol trajectories well (mean R2 = 0.998 +/- 0.002). By fixing the coefficient k at its mean value (2.976), the fit did not change and the variabilities of coefficients c and s were reduced. The mean percent deviation between observed and predicted third-trimester TVol measurements was -0.048 +/- 7.5%. Relatively early pathological deviations were observed for TVol in all four fetuses with IUGR; in these cases the abdominal circumference was abnormal in only one fetus and thigh circumference in none. Individualized growth assessment can be used to accurately predict TVol during the third trimester of pregnancy and at birth. Expected growth trajectories, from second-trimester data, do not rely on population-based standards because each fetus serves as its own control. This new parameter may allow earlier detection and improved monitoring of fetal soft tissue abnormalities such as IUGR.

Individualized growth assessment: evaluation of growth using each fetus as its own control

In Individualized Growth Assessment, each fetus serves as its own control. Rossavik growth models [P = c{t} k + s{t}] for the 5 anatomical parameters of the Prenatal Growth Profile are specified from 2nd trimester measurements obtained from a given fetus. These growth models are used to determine expected 3rd trimester growth trajectories and to predict birth characteristics. Actual measurements obtained in the 3 rd trimester and at birth are compared to expected measurements by calculation of Percent Deviation and Growth Potential Realization Index values, parameters proportional to the difference between measured and expected average growth rates in the 3rd trimester. Prenatal Growth Assessment Scores and modified Neonatal Growth Assessment Scores, calculated from Percent Deviation and Growth Potential Realization Index values for the 5 anatomical parameters, respectively, can be used to detect growth abnormalities manifesting themselves differently in different individuals. Individualized Growth Assessment methods have effectively identified growth abnormalities in fetuses and neonates except in prenatal cases where only a change in soft tissue has occurred.

Identification of Macrosomic, Normal and Intrauterine Growth Retarded Neonates Using the Modified Neonatal Growth Assessment Score

Objective: Separation of Macrosomic, normal and intrauterine growth retarded (IUGR) neonates using the modified Neonatal Growth Assessment Score (NGAS). Methods: A sample of 23 neonates with evidence of growth acceleration and 74 neonates classified as normal or IUGR in a previous study was used in this investigation. The prenatal growth of all neonates had been studied longitudinally with ultrasound. From the data collected, Rossavik models describing the growth trajectories of head circumference (HC), abdominal circumference (AC), thigh circumference (ThC), femur diaphysis length, head cube (A) and abdominal cube (B) were specified. These models were used to predict birth weight (WT), crown-heel length (CHL), HC, AC and ThC at birth. Actual birth measurements of WT, CHL, HC, AC and ThC were evaluated using age-specific normal size curves and compared to predicted measurements by means of the growth potential realization index (GPRI). GPRI values were evaluated by comparison to previously established normal ranges and used to calculate Neonatal Growth Assessment Scores (NGAS₅). NGAS₅ values, together with assessments of anatomical measurements and GPRI values, were used to establish macrosomic, normal and IUGR groups. Principal components analysis was applied to the sets of GPRI values available for each neonate to provide a principal component score for separating macrosomic and normal neonates (m₂NGAS₅₁) or one to separate macrosomic, normal and IUGR neonates (m₃NGAS₅₁) using linear discriminant analysis. The groups identified by these multivariate methods were compared to the original classification and their characteristics evaluated. Results: The m₂NGAS₅₁ and a boundary value of 207.5% separated macrosomic and normal neonates with an accuracy of 97.3%. The m₃NGAS₅₁ and boundary values of 210.0 and 182.5% separated macrosomic, normal and IUGR neonates with an accuracy of 96.9%. No single GPRI value or anatomical measurement could achieve these levels of accuracy. All normal infants were AGA but only 45.5% of the IUGR group were SGA and only 60.9% of the macrosomic group were LGA. Thirteen different types of IUGR and eleven different types of macrosomia were identified based on GPRI values. Conclusion: The modified NGAS accurately separates macrosomic, normal and IUGR neonates although growth abnormalities are expressed in different ways in different individuals.

P197: Fractional thigh volume: a new soft tissue parameter for fetal growth assessment

Previous attempts to quantify fetal soft tissue by conventional sonography have been difficult. Fractional thigh volume measurements, obtained by three-dimensional ultrasonography (3DUS) were evaluated for this purpose, using Individualized Growth Assessment (IGA). Longitudinal sonographic studies of normal fetuses were performed to obtain standard biometry and fractional thigh volumes. Fractional thigh volumes were based on 50 percent of the femoral diaphysis length. Start points, the theoretical age at which an anatomical parameter can first be identified, were calculated from linear functions relating the cube root of fractional limb volume to menstrual age prior to 28.5 weeks'. Regression analysis was used to fit Rossavik functions (P = c(t) k + s(t), where P is the anatomic parameter, t is menstrual minus start point, and c, k, s are model coefficients) to individual growth trajectory data. Rossavik models specified from the linear slopes of growth curves before 28.5 weeks were used to predict TVol during the third trimester and at birth. Neonatal growth status was determined from anatomic measurements and 3DUS within 48 hours of delivery. 22 fetuses (14 females, 8 males) were prospectively studied between 17.4 and 39.3 weeks, menstrual age. The mean birthweight was 3296 ± 253 (SD) grams. All neonates had normal modified Neonatal Growth Assessment Scores. The mean start point (9.0 ± 1.4 weeks') was consistent with completion of thigh development at 8.5 weeks', determined from embryological studies. Rossavik models fit the TVol trajectories very well (mean R2 = 99.8 ± 0.2). By fixing the k coefficient at its mean (2.976), the fit did not change and the variabilities of coefficients c and s were reduced. The mean percent deviation between observed and predicted TVol measurements was − 0.048 ± 7.5% (n = 72) during the third trimester. Neonatal TVol measurements in 12 infants, corrected for systematic error (− 16.7%) led to an averaged signed deviation of − 1.8 ± 9.2% from predicted values. IGA standards for fractional thigh volume provide a new approach for characterizing soft tissue growth. Normal growth trajectories and neonatal soft tissue volume can be accurately predicted from growth models specified by fractional thigh volume data obtained before 28.5 menstrual weeks. The normal variability for these predicted TVol measurements is about one-third of what has been reported for fetal thigh circumference. This parameter may allow earlier detection and improved monitoring of fetuses with soft tissue abnormalities such as IUGR and macrosomia.

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.

Prenatal prediction of neonatal growth status in twins using individualized growth assessment.

To determine if the growth status at birth of twins can be predicted in the third trimester using the Prenatal Growth Assessment Score (PGAS). The growth of 40 twin fetuses were studied with ultrasound from 14 weeks until delivery. Measurements of the head circumference (HC), abdominal circumference (AC), thigh circumference (ThC), femur diaphysis length (FDL), head cube (A), and abdominal cube (B) were made at 2 to 3 week intervals. Rossavik growth models for these parameters were determined from second trimester measurements. These models were used to define expected third trimester growth curves and birth characteristics. Comparisons of expected and actual third trimester measurements were used to calculate PGAS values after various time points (PGASAt) and after the last time point (PGASAT). Similar comparisons after birth were used to determine Growth Potential Realization Index (GPRI) values for HC, AC, ThC, weight (WT), and crown-heel length (CHL), with and without correction for decreased soft tissue deposition. These two sets of GPRI values were used to calculate two sets of Neonatal Growth Assessment Scores (NGASS, NGASTw). Using NGASS and NGASTw (as well as GPRI values in some cases), the twin neonates were classified as Normal (N), Decreased Soft Tissue Deposition, (DSTD), Intrauterine Growth Retardation (IUGR) and Macrosomia (M). At birth 22/40 (55%) were classified as N, 9/40 (22.5%) as DSTD, 6/40 (15.0%) as IUGR, and 3/40 (7.5%) as M. All -PGASAT values in the N group were greater than -0.40% with one exception (-PGASAT = -0.43%). All PGASAt values were above this same boundary except for one fetus. No differences were seen between the N and DSTD groups [mean -PGASAT (range): N, -0.12% (0% to -0.34%); DSTD, -0.10% (0% to -0.30%)]. The IUGR group had 4 fetuses with -PGASAT values between -0.65% and 2.79% and two with values of 0.0% and -0.12%. Growth retardation in the latter two was limited to a decrease in thigh soft tissue deposition. -PGASAt values in the first 4 fetuses were below -0.40% 1.6 to 9.5 weeks before delivery (mean: 6.1 weeks). Fetuses in group M had +PGASAT values of 0.0%, +1.8%, and +1.2%. PGASAt values were above +0.40% at 3.6 and 9.8 weeks before delivery in the latter two fetuses. These results support the concept that PGASAT and PGASAt values outside +/- 0.40% indicate either IUGR or macrosomia. Almost all fetuses with growth problems in the third trimester can be detected, on average, 6 weeks before delivery unless the growth abnormality is limited to decreased soft tissue deposition.

Prenatal prediction of neonatal growth status in twins using individualized growth assessment

Objective To determine if the growth status at birth of twins can be predicted in the third trimester using the Prenatal Growth Assessment Score (PGAS). Methods The growth of 40 twin fetuses were studied with ultrasound from 14 weeks until delivery. Measurements of the head circumference (HC), abdominal circumference (AC), thigh circumference (ThC), femur diaphysis length (FDL), head cube (A), and abdominal cube (B) were made at 2 to 3 week intervals. Rossavik growth models for these parameters were determined from second trimester measurements. These models were used to define expected third trimester growth curves and birth characteristics. Comparisons of expected and actual third trimester measurements were used to calculate PGAS values after various time points (PGASAt) and after the last time point (PGASAT). Similar comparisons after birth were used to determine Growth Potential Realization Index (GPRI) values for HC, AC, ThC, weight (WT), and crown-heel length (CHL), with and without correction for decreased soft tissue deposition. These two sets of GPRI values were used to calculate two sets of Neonatal Growth Assessment Scores (NGASS, NGASTw). Using NGASS and NGASTw (as well as GPRI values in some cases), the twin neonates were classified as Normal (N), Decreased Soft Tissue Deposition, (DSTD), Intrauterine Growth Retardation (IUGR), and Macrosomia (M). Results At birth 22/40 (55%) were classified as N, 9/40 (22.5%) as DSTD, 6/40 (15.0%) as IUGR, and 3/40 (7.5%) as M. All −PGASAT values in the N group were greater than −0.40% with one exception (−PGASAT = −0.43%). All PGASAt values were above this same boundary except for one fetus. No differences were seen between the N and DSTD groups [mean −PGASAT (range): N, −0.12% (0% to −0.34%); DSTD, −0.10% (0% to −0.30%)]. The IUGR group had 4 fetuses with −PGASAT values between −0.65% and 2.79% and two with values of 0.0% and −0.12%. Growth retardation in the latter two was limited to a decrease in thigh soft tissue deposition. −PGASAt values in the first 4 fetus were below −0.40% 1.6 to 9.5 weeks before delivery (mean: 6.1 weeks). Fetuses in group M had +PGASAT values of 0.0%, +1.8%, and +1.2%. PGASAt values were above +0.40% at 3.6 and 9.8 weeks before delivery in the latter two fetuses. Conclusions These results support the concept that PGASAT and PGASAt values outside ± 0.40% indicate either IUGR or macrosomia. Almost all fetuses with growth problems in the third trimester can be detected, on average, 6 weeks before delivery unless the growth abnormality is limited to decreased soft tissue deposition. © 1996 John Wiley & Sons, Inc.

Modified neonatal growth assessment score: a multivariate approach to the detection of intrauterine growth retardation in the neonate.

The objective of this investigation was the development of a modified Neonatal Growth Assessment Score (mNGAS) for use in the evaluation of neonatal growth status. The growth of 74 fetuses at risk for intrauterine growth retardation (IUGR) was followed longitudinally, beginning in the first or early second trimester. Rossavik growth models derived from data obtained in the second trimester were used to predict the weight (WT), crown-heel length (CHL) and head (HC), abdominal (AC) and thigh circumferences (ThC) at birth, which were then actually measured within 24 h after delivery. These measurements were compared to age-specific size curves and used to calculate sets of five growth potential index (GPRIi) values, which in turn were used to calculate five-variable Neonatal Growth Assessment Scores (NGAS5). Neonates were initially classified as normal or IUGR on the basis of NGAS5, GPRIi, and anatomic measurements. A final classification based on principal component analysis and linear discriminant analysis was carried out. The score obtained using the first principal component function was defined to be mNGAS51. The effectiveness of mNGASij values, determined from 1-4 GPRIi values, in separating normal and IUGR neonates was also evaluated. Neonates initially considered to be normal had very few abnormal GPRI values or anatomic measurements, whereas the frequency of these abnormalities in IUGR neonates was significantly increased. However, no single anatomic variable was 100% normal in the normal neonates and 100% abnormal in IUGR neonates. Only 40% of IUGR neonates were small for gestational age. Classification of these neonates using principal component analysis and linear discriminant analysis was essentially the same (98.6%) as that made initially after reclassification of two IUGR neonates as normal. The characteristics of the initial and final normal and IUGR groups were very similar and the mNGAS51 was strongly correlated with the NGAS5 in the IUGR group. The effectiveness of mNGASij in separating normal and IUGR neonates increased with the number of GPRIi values included and the types used. GPRIThC and GPRIWT were the most important, followed by GPRIAC. GPRICHL and GPRIHC were much less important and in some cases detrimental. These findings support the concepts of a decrease in soft tissue mass as the initial step in the development of IUGR and the protection of head growth (brain-sparing). The characteristics of mNGAS51, particularly its comprehensiveness, its independence of differences in growth potential, its weighting of GPRIi values according to their importance in the detection of IUGR and its ability to detect different manifestations of IUGR in different individuals, indicate that this should be a most effective parameter for separating normal and IUGR neonates.

Evaluation of Perinatal Outcome Using Individualized Growth Assessment: Comparison With Conventional Methods

To evaluate individualized growth assessment using the Rossavik growth model for detection of growth-retarded neonates with poor perinatal outcomes. Rossavik growth models derived from second-trimester ultrasound measurements were used to predict birth characteristics of 154 singleton neonates. 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 and the 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 admission, and maternal complications), using NGAS, were compared with those by the traditional birth weight-for-gestational age method and the ponderal index, respectively. Of the 154 fetuses studied, 120 had normal growth outcomes at birth; 18 showed evidence of intrauterine growth retardation; and 16 had macrosomia, based on NGAS. According to birth weight-for-gestational age classification, 32 fetuses were small for gestational age; 118 were appropriate for gestational age; and only 4 were large for gestational age. According to the ponderal index, 55 fetuses had growth retardation, 99 showed appropriate growth and there was no macrosomia. There was a significant increase in mechanical deliveries in cases of growth-retarded neonates, determined using the NGAS classification, when compared with events related to normally grown or macrosomic neonates. However, there were no significant differences in mechanical deliveries among the groups by birth weight classification or ponderal index. Both birth weight classification and NGAS classification showed a significant increase in the low Apgar score, abnormal FHR patterns, and neonatal acidosis in infants classified as growth retarded when compared with appropriately grown or macrosomic infants. However, there were no significant differences in the low Apgar score, abnormal FHR patterns, and neonatal acidosis between growth-retarded and appropriately grown infants when they had been so classified by ponderal index. Three growth category classification methods failed to reveal significant differences in meconium staining of amniotic fluid, neonatal intensive care unit admission, and maternal complications among the groups. We do cast doubt on the usefulness of the ponderal index for detection of growth-retarded neonates with poor perinatal outcomes, and individualized growth assessment seems to perform at least as well as the traditional birth weight-for-gestational age method.

Evaluation of triplet growth status at birth using individualized growth assessment: Comparison with conventional methods and development of a new classification system

A new growth classification system for triplets based on individual growth curve standards provides new information on the growth status of triplets at birth. OBJECTIVES. The objectives of this study were to characterize growth outcome at birth in triplet pregnancies using Individualized Growth Assessment methods, and to compare these results to conventional methods of growth outcome evaluation. STUDY DESIGN. Rossavik growth models derived from second-trimester ultrasound measurements were used to predict the birth characteristics of 21 triplet neonates. Actual measurements of weight, head, abdominal, and thigh circumferences at birth were compared to population standards and to predicted values, the latter by calculation of Growth Potential Realization Index (GPRI) values. GPRI values were calculated using singleton (measurement procedure correction) and triplet (measurement procedure correction+decreased soft tissue deposition) correction factors (SCF, TCF). Neonatal Growth Assessment Scores (NGAS) were calculated using both sets of GPRI values. RESULTS. Three types of triplet neonates were identified. Group I (33.3%) were normal with both types of NGAS values, had very few abnormal GPRI values or anatomic measurements, and were all appropriate for gestational age. Group III (14.3%) were abnormal with both types of NGAS values, most GPRI values were abnormal, and all were small for gestational age. Group II (52.4%) had abnormal NGAS values when calculated from GPRI values determined with SCF and normal NGAS values when calculated from GPRI values determined with TCF. All but one was AGA. Almost all GPRIWT and GPRIThC values were abnormal using SCF and normal using TCF. CONCLUSION. Although growth outcome in triplet neonates can be normal (Group I) or intrauterine growth retarded (Group III), the majority are in an intermediate group (Group II) characterized by a decrease in soft tissue mass, which may or may not be pathological.

Detection of intrauterine growth retardation in twins using individualized growth assessment. II. Evaluation of third-trimester growth and prediction of growth outcome at birth.

Second- and third-trimester growth in 34 twin fetuses was evaluated with ultrasonography by measurement of five anatomic parameters. Rossavik growth models, derived from second-trimester measurements, were used to specify expected third-trimester growth curves. Actual measurements were compared to predicted measurements by calculation of the percent deviations. Growth outcome at birth [normal, intrauterine growth retardation (IUGR)] was determined from Neonatal Growth Assessment Scores. Growth in the second trimester was similar in normal and IUGR twins. In the third trimester, abnormal negative deviations were larger and more numerous in IUGR twins. However, there was considerable individual variability and normal twins also had abnormal negative deviations. In IUGR twins, the first appearance of an abnormal negative deviation was quite variable (range: 28.6 weeks to 35.1 weeks), as was the parameter to show such a deviation. Prediction of neonatal outcome was poor using individual anatomic parameters but improved considerably with use of all five parameters. However, some fetuses were misclassified when only the number of abnormal negative deviations was used. The Prenatal Growth Assessment Score (PGAS), determined by both the number and magnitude of abnormal negative deviations, predicted neonatal outcomes with a sensitivity of 100% and specificity of 100%. On average, PGAS values were abnormal 5 weeks before delivery. These results indicate that normal and IUGR twins can be separated, using third-trimester growth patterns, if multiple parameter Individualized Fetal Growth Assessment is employed.

Detection of intrauterine growth retardation in twins using individualized growth assessment: I. Evaluation of growth outcome at birth.

The growth of 17 sets of twins was evaluated at 2 to 3 week intervals from 15 weeks to delivery by measurement of the head circumference, abdominal circumference, and thigh circumference, and estimation of weight. The birth characteristics of these twins were compared to those predicted by Rossavik growth models, derived from second-trimester ultrasound measurements, using the Growth Potential Realization Index (GPRI) and by comparison to population standards. Newborns were classified as normal or intrauterine growth retarded (IUGR) based on their Neonatal Growth Assessment Score, determined from GPRI values. All normal twins had birth weights that were appropriate-for-gestational-age and had few abnormal birth measurements. The birth weight differences between normal twin fetuses were all < 20%. IUGR twins were both small for gestational age (78%) and appropriate-for-gestational-age (22%), and all had 3 or 4 abnormal GPRI values. In only 40% of the cases was the birth-weight difference between a normal and an IUGR twin > 20%. No single anatomic parameter evaluated at birth adequately separated the normal twins from those with IUGR. These results indicate the need for multiple parameter Individualized Growth Assessment in the detection of IUGR in twins.

Neonatal growth assessment score: A new approach to the detection of intrauterine growth retardation in the newborn

To develop an improved means for evaluation of the outcome of fetal growth in utero, a growth study of 37 fetuses at risk for intrauterine growth retardation was undertaken. Intrauterine growth was evaluated with ultrasonography at 2- to 3-week intervals beginning at 15 weeks' gestation. Measurements obtained in the second trimester were used to specify Rossavik growth models for various anatomic parameters. Values for weight, head circumference, abdominal circumference, and thigh circumference at birth were predicted with the use of these models. Growth potential realization index values for these four parameters were calculated from actual and predicted birth measurements. The growth potential realization index values were combined to form a neonatal growth assessment score. With the use of cluster analysis and neonatal growth assessment score values, the 37 infants were separated into 24 group I (neonatal growth assessment score values between 3.7 and 18.6) and 13 group II (neonatal growth assessment score values between 19.4 and 50.0) infants. In group I, 66.7% of the infants had no growth abnormalities; a single abnormality, usually borderline, was found in an additional 20.8% (total = 87.5%). In group II all infants had growth abnormalities (range, 2 to 6) although only 46.2% had birth weights below the 10th percentile. No differences in risk factors (except for the incidence of smoking) or second trimester growth were found in these two groups. The neonatal growth assessment score appears to be a sensitive indicator of third trimester growth retardation, is not affected by differences in growth potential, can separate normal infants from those with evidence of intrauterine growth retardation, and provides a quantitative assessment of growth problems in individual fetuses.