A Comparison of the Mid-Arm Circumference/Head Circumference Ratio and Ponderal Index for the Evaluation of Newborn Infants after Abnormal Intrauterine Growth

ABSTRACT. We studied the accuracy of the ponderal index and the mid-arm circumference/head circumference ratio for detecting newborn infants who were likely to be symptomatic because of aberrant intrauterine growth. Sixty infants were evaluated because of suspected intrauterine growth retardation; both the mean ponderal index and mid-arm circumference/head circumference ratio were significantly lower in the group of 30 symptomatic infants than in the group of 30 asymptomatic infants ( p <0.05). However, the mid-arm circumference/head circumference ratio identified a significantly higher percentage of the symptomatic infants than the ponderal index (80% vs. 47%; p =0.007). An additional 60 infants were evaluated because of suspected abnormal intrauterine growth acceleration. The mean mid-arm circumference/head circumference ratio, but not the ponderal index, was significantly higher in the group of 30 symptomatic infants than in the group of 30 asymptomatic infants ( p <0.005). Again, the mid-arm circumference/head circumference ratio identified a significantly higher percentage of the symptomatic infants than the ponderal index (79% vs. 33%; p <0.001). The mid-arm circumference/head circumference ratio is more accurate than the ponderal index for the evaluation of potentially symptomatic newborn infants who suffered abnormal fetal growth. The ponderal index is not useful for the detection of symptomatic large-for-dates infants.     

Weight to length ratio—a good parameter for determining nutritional status in preterm and full-term newborns

To identify which parameter showed the strongest correlation with neonatal body fat store, when the ratios for assessing both weight-for-length and the mid-arm circumference to head circumference (MAC/HC) were included in the analysis, body anthropometrics and skinfold thickness were measured in 250 full-term and 125 preterm infants. Among the study cases, 66.7% were appropriate for gestational age, 26.7% were small for gestational age and 6.7% were large for gestational age. Sum of the skinfold thickness measured at the midtricepital and subscapular areas correlated well with body anthropometrics, weight/length ratio, body mass index, ponderal index and mid-arm circumference to head circumference ratio. Multiple stepwise regression analysis revealed that the weight/length ratio correlated best with skinfold thickness in both full-term and preterm newborn infants. Therefore, the simple weightllength ratio might be useful for evaluation of the nutritional status of intrauterine growth, and in the prediction of metabolic complications in both full-term and preterm newborns with abnormal intrauterine growth.     

Accuracy of anthropometric measurements in predicting symptomatic SGA and LGA neonates

Mid-arm circumference, mid-arm circumference/head circumference ratio, ponderal index and skinfold thickness at five sites (biceps, triceps, quadriceps, subscapular and flank) were measured in 91 small-for-gestational-age (SGA) and 101 large-for-gestational-age (LGA) neonates to investigate their accuracy in identifying neonates at high risk of complications resulting from disturbed intrauterine growth. Thirty-one of 91 SGA and 19 of 101 LGA neonates who developed hypoglycaemia and/or polycythaemia were regarded as symptomatic. Mean values of all of the anthropometric parameters differed significantly between symptomatic and asymptomatic SGA or LGA neonates. The quadriceps skinfold thickness was the most sensitive index in predicting symptomatic SGA and LGA neonates (sensitivity 0.93 and 0.95, respectively). The mid-arm circumference was also a very sensitive index in predicting symptomatic SGA neonates (sensitivity 0.94) but its specificity was extremely low (0.20). The rest of the parameters showed lower sensitivity than quadriceps skinfold thickness associated with similarly low specificity and validity. The findings of this study indicate that the quadriceps skinfold thickness is the most reliable index for use as a screening test for clinical evaluation of SGA and LGA neonates who are likely to develop complications as a result of disturbed intrauterine nutrition.     

Mid-arm circumference/head circumference ratios for identification of symptomatic LGA, AGA, and SGA newborn infants

Mid-arm circumference/head circumference ratios (MAC/HC) and birth weights obtained in 73 neonates were studied to compare which of these growth measurements could more accurately predict risk of metabolic complications resulting from either acceleration or retardation of fetal growth. The MAC/HC ratio was more sensitive than birth weight in distinguishing symptomatic large for gestational age (LGA) infants who were born to diabetic mothers from other LGA infants who were asymptomatic, and symptomatic from asymptomatic small for gestational age infants. In addition, the MAC/HC ratio identified symptomatic appropriate for gestational age (AGA) infants born to diabetic mothers and AGA infants with signs and symptoms of growth retardation. The MAC/HC is more useful than birth weight in assessing newborn infants at risk for the metabolic complications associated with fetal growth disorders.     

Catch-up growth, muscle and fat accretion, and body proportionality of infants one year after newborn intensive care

We studied catch-up growth, muscle and fat accretion, and body proportionality at 4 and 12 months of age corrected for prematurity in 30 very low birth weight (VLBW) (less than 1500 gm), 30 low birth weight (LBW) (1500 to 2499 gm) and 30 normal birth weight (greater than or equal to 2500 gm) infants who required newborn intensive care. At 4 and 12 months, the VLBW infants had significantly lower mean weight and length (p less than 0.01), but not lower occipitofrontal circumference percentiles, than the LBW and normal birth weight groups, and showed no catch-up weight or length growth between 4 and 12 months. All three groups had significant increases in mean upper mid-arm circumferences, mid-arm muscle circumferences, and arm muscle areas between 4 and 12 months. Mean mid-arm muscle circumferences and arm muscle areas were similar among the three groups at 4 months but became significantly stratified by birth weight groups by 12 months, with VLBW infants having the lowest mean value. In contrast, analysis of fat stores by triceps skin-fold thickness and arm fat area demonstrated no significant increases in any group between 4 and 12 months, except for arm fat area in the LBW group. The VLBW infants had significantly less fat than normal birth weight infants at 4 and 12 months. All three groups had proportional growth at both visits, as assessed by mid-arm circumference/head circumference ratio and weight-length percentile for age. The VLBW infants were significantly lighter for their length than normal birth weight infants. We conclude that VLBW infants have no first-year catch-up growth, remaining smaller than higher birth weight infants, although appropriately proportional. Somatic growth during the first year is due more to muscle than to fat accretion, especially in VLBW infants.     

Standard curves for mid arm circumference and mid-arm/head circumference ratio in newborns

One Thousand singleton neonates, between 28 and 44 weeks of estimated gestational age (EGA) were measured within 48 hours of their birth for upper mid-arm circumference (MAC), head circumference (HC) and birth weight (BW). Regression analysis was used to draw standard curves for MAC versus EGA and mid-arm circumference/head circumference ratio (MAC/HC) versus EGA. Correlation coefficients were 0.961 for MAC versus EGA and 0.889 for MAC/HC versus EGA (p < 0.001). MAC, MAC/HC and HC were also highly correlated with birth weight (p < 0.001). These standard curves make available a discriminating method for evaluation of intra-uterine growth and a noninvasive technique for following somatic protein status in growing preterm infants.     

Mid-arm circumference and mid-arm/head circumference ratios: standard curves for anthropometric assessment of neonatal nutritional status

Two hundred four neonates, 25 to 42 weeks estimated gestational age (EGA), were measured on day 2 or 3 of life for upper mid-arm circumference (MAC) and head circumference. Regression analysis was used to construct standard curves for MAC versus EGA and mid-arm circumference/head circumference ratio (MAC/HC) versus EGA. Correlation coefficients were 0.93 for MAC versus EGA, and 0.84 for MAC/HC versus EGA. MAC, MAC/HC, and head circumference were also highly correlated with birth weight. These measurements may more accurately assess intrauterine growth and body proportionality at birth than weight, length, and head circumference.     

Heterogeneous growth and mental development of intrauterine growth-retarded infants during the first 3 years of life

Postnatal growth and development were studied in two groups of term infants with intrauterine growth retardation (IUGR) and one group of infants with normal birth weight up to 3 years of age (total sample, 205 infants). Infants with IUGR were classified as having low ponderal index (IUGR-LPI) or adequate ponderal index (IUGR-API). At birth, the two groups of infants with IUGR had similar birth weight, but length and head circumference measurements were significantly different. Overall, the IUGR-API infants remained lighter and shorter and had smaller head circumferences up to 30 months of age. The IUGR-LPI infants experienced catch-up growth in weight during the first months, because of greater fat deposition. At 24 months of age, the IUGR-API infants scored below the others on mental items. At 3 years of age the IUGR-API infants had the lowest values on seven of eight developmental measures and on the composite score; at these two time periods, the group with normal birth weight scored the highest, and the IUGR-LPI infants obtained intermediate values. It is concluded that infants with IUGR tend to follow postnatal growth and developmental patterns that are associated with their physical characteristics at birth.     

Exclusive breastfeeding and infant growth studies: reference standards for head circumference, length and mid-arm circumference/head circumference ratio for the first 6 months of life

This paper presents the development of reference standards for head circumference (HC), length and mid-arm circumference/head circumference (MAC/HC) ratio for the evaluation of exclusively breastfed infants. A total of 219 exclusively breastfed term appropriate-for-gestational age (AGA) infants were studied and analysed from 1 June 1995 to 31 May 1997 at the Neonatal Follow-up Clinic, University Teaching Hospital, Benin City, Nigeria. Head circumference and length measurements were recorded for the infants at each postnatal completed month. MAC/HC ratios were also computed for each infant at each completed postnatal month. There was a progressive increase in the mean measurements at the completed months with increasing postnatal age and the differences between the mean measurements of length and head circumference at the 4th and 6th completed months were significant (p < 0.001). The head circumference, length and MAC/HC ratio had significant correlations with postnatal age. The standards represent the regression lines of the anthropometric measurements and MAC/HC ratio on postnatal age with the corresponding 95 per cent confidence limits. The standards identified 95 per cent (for head circumference), 93 per cent (for length) and 94 per cent (for MAC/HC ratio) of exclusively breastfed healthy infants as having normal infant growth for age.     

Fetal growth: relationship with maternal dietary intakes

One hundred urban and 85 rural pregnant women in third trimester were subjected for the studies of dietary intakes and the body size (weight for height ratio index). The intrauterine growth of newborn infants was assessed at birth by weight, crown-heel length and head circumference. The fetal growth improved significantly with increasing maternal caloric and protein intakes. The mean values of weight, crown-heel length and head circumference of newborn infants were significantly higher in mothers receiving more than 2000 kcals and 75g of proteins as compared to the mean values observed for newborns of mothers with dietary caloric and protein intakes less than 1500 kcals and 45.0g respectively in both urban and rural subjects. No significant difference was observed in the growth parameters of newborn infants with further increase in the maternal caloric intake above 2000 kcals. Further the total protein intake influenced the newborn's weight significantly irrespective of the animal protein content.     

Assessment of gestational age: the value of a maturity scoring system for head circumference and mid-arm circumference

Over a 10-month period, 508 newborn infants were studied in three hospitals to develop a simple maturity scoring system for head circumference and mid-arm circumference (MAC). Maturity scores were based on the 95 per cent confidence intervals on the mean measurements of the parameters for gestational age groups. Combined maturity scores had slightly better correlation with gestational age than scores for MAC and head circumference separately. The model had 90 per cent accuracy in estimating gestational age. It is a simple and reliable method, and is recommended for routine use particularly in developing countries.     

Ratio of mid arm circumference to head circumference as a predictor of small for gestational age babies

Birth weight (BW), mid-arm circumference (MAC), head circumference (HC) and MAC/HC ratio were evaluated in 845 term babies within 48 h of birth. MAC/HC ratio of less than 0.28 had a statistically significant sensitivity, specificity and predictive value (p less than 0.001) for identifying term small for gestational age babies. This ratio provides a simple, accurate and cheap way of screening SGA babies. This method may be employed for identification of SGA babies even by paramedical workers at community level. As with any other field index appropriate supervision and standardisation are essential for its usefulness.     

Neonatal body proportionality and body composition after in utero exposure to cocaine and marijuana

The relationship of maternal use of marijuana and cocaine during pregnancy to measures of neonatal body proportionality and body composition was assessed in a multiethnic sample of 1082 newborn infants. Maternal use of marijuana and cocaine during pregnancy was ascertained by self-report and by an enzyme-multiplied immunoassay technique for screening of urine samples obtained prenatally and again post partum. After each substance was analytically controlled for use of the other and for other potentially confounding variables, detection of marijuana metabolites in maternal urine was associated (p less than 0.05) with depressed mean arm muscle circumference and nonfat area of the arm but not with any measure of neonatal fatness. In contrast, detection of cocaine in maternal urine was associated (p less than 0.05) with decrements of subscapular fat folds and of the fat and nonfat areas of the arm. Although both substances were associated with depressed birth weight, there was no decrement of neonatal ponderal index or of the arm circumference/head circumference ratio in association with exposure to either substance. We conclude that both marijuana exposure and cocaine exposure during pregnancy are associated with symmetric intrauterine growth retardation, but that deficits are in differing compartments of intrauterine growth. These findings suggest that marijuana may retard fetal growth through maternal-fetal hypoxia, whereas cocaine may alter nutrient transfer to the fetus and fetal metabolism.     

The relationship between decreased iron stores, serum iron and neonatal hypoglycemia in large-for-date newborn infants

We assessed the relationship between neonatal hypoglycemia and newborn iron status in 15 hypoglycemic, large-for-date newborn infants, 12 of whom were infants of diabetic mothers. These infants had significantly lower mean serum iron concentrations, ferritin concentrations, percent iron-binding saturation and calculated iron stores, and significantly higher mean transferrin concentrations, total iron-binding capacity concentrations and mid-arm circumference:head circumference ratios when compared with either 15 euglycemic large-for-date or 15 euglycemic appropriate-for-date control infants (p less than 0.001 for all comparisons). All hypoglycemic infants had ferritin concentrations below the 5th percentile as compared to 3% of controls (p less than 0.001), and 67% had transferrin concentrations above the 95th percentile (controls: 0%; p less than 0.001). Only the hypoglycemic infants demonstrated a significant negative linear correlation between ferritin and transferrin concentrations (r = -0.83; p less than 0.001). Decreased serum iron concentrations were associated with size at birth (r = -0.60; p = 0.01) and with increased red cell iron (r = -0.60; p = 0.01), implying a redistribution of iron dependent on the degree of fetal hyperglycemia and hyperinsulinemia. Infants with increased red cell iron had more profound neonatal hypoglycemia. These results show a significant association between decreased iron stores and neonatal hypoglycemia in macrosomic newborn infants associated with a significant shift of iron into red blood cells.     

Thigh circumference at birth as the best predictor of low birth weight babies

The present study was undertaken to find out the best simple anthropometric parameter for identifying low birth weight babies (LBW). A total of 1000 newborn babies were subjected to anthropometry within 48 hours of life. Birth weight was significantly correlated (p less than 0.001) with thigh circumference (TC), mid-arm circumference (MAC), chest circumference (CC), length (L) and head circumference (HC). However, the correlation was maximum for TC (r = 0.9201). All anthropometric indicators had a statistically significant sensitivity, specificity and predictive value (p less than 0.001) for identifying less than or equal to 2500 g birth weight babies. However, thigh circumference of less than or equal to 14.5 cm and less than or equal to 13.5 cm had the best sensitivity, specificity and predictive value for identifying babies with birth weight of less than or equal to 2500 g and less than or equal to 2000 g, respectively. TC at birth is a cheap, simple, quick and reliable indicator for predicting LBW babies. It may be used whenever weighing at birth is not feasible.     

The ratio of mid-arm circumference to occipital frontal circumference in Chinese babies: a marker of late gestation growth retardation

The ratio of mid-arm circumference to occipital frontal circumference (MAC/OFC), an index of late gestation growth retardation, was determined in 175 healthy newborn term Chinese babies. The ratio of 0.31 (S.D., 0.02) was significantly higher than in recent data published for Asian, White and Black neonates: whether this is due to differences in measuring techniques or better intra-uterine nutrition remains to be seen. As an initial test of its potential usefulness this ratio was determined in 12 term Chinese babies who showed clinical signs of undernutrition. All but one had a ratio 2S.D. or more below the mean. The MAC/OFC ratio, with its ease of measurement, simplicity and cheapness, is a useful addition to existing methods for assessing late gestation nutritional status.     

Fetal intravenous nutritional supplementation ameliorates the development of embolization-induced growth retardation in sheep

Since decreased transfer of nutrients into the fetus has been documented in many forms of intrauterine growth retardation, we evaluated whether increasing fetal nutrient availability would prevent the development of experimental growth retardation in fetal lambs. Fetuses were separated into three groups: E, animals growth retarded by repetitive uteroplacental embolization (n = 8); ES, animals treated as in E and given fetal femoral venous infusions of 5% glucose and 6.8% amino acids (n = 7); and C, controls (n = 8). The duration and density of embolization were the same in E and ES; initial physical and metabolic characteristics and gestation at delivery were similar in all groups. E birth weight was reduced 26% compared to C (2888 +/- 373 SEM g versus 3880 +/- 277 g, p less than 0.05); fetal/maternal weight ratio was decreased 35% (p less than 0.005) and ponderal index decreased 22% (p less than 0.005). Asymmetric growth retardation was indicated in E by an increased brain/body weight ratio (p less than 0.05). ES fetuses, in contrast, showed no differences from C in birth weight (3601 +/- 190 g) or body proportions. ES were larger than E, with a greater fetal/maternal weight ratio and ponderal index (p less than 0.05 for both). In E and ES, size at birth showed a positive relation to the amount of supplements received. The average daily supplementation rate correlated with the fetal/maternal weight ratio and with the ponderal index (for both r = 0.62, p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Judging fetal growth from body proportions at birth.

Fetal growth velocity from 27 weeks until birth was calculated in 378 infants born after high risk pregnancies from at least three ultrasound measurements of estimated fetal weight and the weight at birth. Anthropometric measurements at birth (weight, head circumference, length, ponderal index and skinfolds), after correction for differences in gestational age, were significantly related to fetal growth velocity. The relation between fetal growth velocity and ponderal index was significant (correlation coefficient = 0.34, P < 0.001). However, the correlations between fetal growth velocity and each of the anthropometric measures disappeared when birth weight relative to gestational age was accounted for. This means that given the birth weight and the gestational age of a newborn infant, body proportions, e.g. ponderal index or skinfold thickness, do not contribute further to the judgment about fetal growth rate.     

Is intrauterine growth retardation a risk factor for child abuse?

A case-control study was conducted to determine whether infants with intrauterine growth retardation are at an increased risk of child abuse. Case children were those who had been born at Yale-New Haven Hospital and were reported to the hospital's child abuse committee because they had been physically abused. For each case, one control child was chosen from the hospital's log of births and matched to the case child by age, gender, race of the mother, method of payment for the hospitalization, and the provider of the child's health care at the time of birth. Infants were defined as having intrauterine growth retardation if they had either a ponderal index or a birth weight that was less than the tenth percentile for gestational age using the Kansas City or Denver growth standards. We identified 117 case-control pairs that met those criteria. The matched odds ratios for each of the four definitions of intrauterine growth retardation were less than one, indicating that infants with intrauterine growth retardation are at a decreased risk of abuse. The matched odds ratio for a low ponderal index according to the Kansas City standard was 0.4 (95% confidence interval 0.19, 0.83). This result was not affected by such possible confounding factors as the mother's age. We conclude that infants with intrauterine growth retardation are not at an increased risk and may be at a decreased risk of physical abuse.     

Distance and velocity standards for head circimference growth before and after term until 18 months--results from a longitudinal study (author's transl)]

Standards for head circumference growth (distance and velocity) from the perinatal period until the age of 18 months have been based on repeated measurements at short intervals (longitudinal) in 60 appropriate for gestational age (AGA) preterm infants of very low fetal age, and 68 full term infants. Moreover the growth of 32 small for gestational age (SGA) preterm infants has been evaluated. Before term the extrauterine head growth curve is similar to that of "intrauterine curves". At term and until the age of 18 months the growth curves of AGA preterm infants agree well with those of the full term controls, without statistically significant differences (p greater than 0.1). If the age is not corrected for prematurity ther is a significant difference between preterm and full term infants until 17 months (p less than 0.05). With decreasing velocity of head circumference growth this difference becomes non-significant at the age of 18 months (p greater than 0.1). Out of the heterogenious group of 32 SGA preterm infants 15 have shown a catch-up growth in head circumference until the third month, whereas 17 infants remained significantly below the growth curve of the AGA. Growth velocity of head circumference, calculated in cm/month, in the last 10 weeks before term is significantly higher (p less 0.025) than later on, with a mean peak of 4.3 cm in the 34th postmentstrual week. After term, the velocity curve of the AGA preterm infants agrees with that of the full term controls. A period of rapid head circumference growth -- a growth spurt -- extends from the 31st postmenstrual week until the 6th month after term. In the following months the velocity curves flatten. If the age is not corrected for prematurity, the peak of the velocity curve becomes flat and spread with a mean growth velocity of 3.0 cm in the first, of 3.4 cm in the second and of 2.5 cm in the third month.