Respiratory distress syndrome in infants with impaired intrauterine growth

The recently introduced intrauterine growth curve, based on ultrasonically estimated foetal weights, was retrospectively applied to an inborn population of 883 infants bom before 33 gestational weeks at the University Hospital of Lund, during 1985–94. The estimation of birthweight deviation resulted in 630 (71.3%) infants with a birthweight appropriate for gestational age (AGA), 244 (27.6%) infants with a birthweight small for gestational age (SGA) and 9(1.1%) infants with a birthweight large for gestational age. Birthweight deviation was associated with an increased mortality [odds ratio (OR) adjusted for gestational age 1.29 per SD (12%) change in birthweight for gestational age, 95% CI: 1.10–1.50; p = 0.002]. At gestational age 25–28 weeks, SGA-infants had an increased incidence of respiratory distress syndrome (RDS) as compared to AGA-infants (OR adjusted for gestational age: 1.98,95% CI: 1.12–3.52; p = 0.019). At gestational age 29–32 weeks, SGA-infants had a lower incidence of RDS as compared to AGA-infants (OR adjusted for gestational age: OR 0.52,95% CI: 0.34–0.80; p = 0.003). After adjustment for confounding variables, infants born at gestational age 25–28 weeks from mothers with pre-eclampsia, appeared to be a high-risk group for RDS, whereas at the age of 29–32 gestational weeks, negative birthweight deviation had a protective effect against RDS. Antenatal corticosteroid administration appeared to have a less beneficial effect on mortality, RDS and cerebral haemorrhage in infants born SGA vs in those born AGA.     

Intrauterine growth restriction and postnatal steroid treatment effects on insulin sensitivity in preterm neonates

OBJECTIVES: To study whether intrauterine growth restriction (IUGR) is associated with decreased sensitivity to the main fetal growth factor, insulin, and the effect of glucocorticoid therapy on insulin sensitivity in preterm infants. STUDY DESIGN: Newborn infants with a birth weight (BW) of< 1500 g were classified as appropriate for gestational age ([AGA], BW within +/- 1 SD, n = 10), or small for gestational age ([SGA], BW <-2 SD, n = 13); 5 AGA infants and 8 SGA infants received systemic steroids. An abbreviated modified minimal model test was performed, consisting of sequential blood samples for glucose and insulin assays, and intravenous infusions of 0.3 g/kg glucose and 0.02 U/kg regular human insulin. The insulin sensitivity index (S(I)) was calculated using a computer program. RESULTS: The basal insulin/glucose ratio (I/G) and S(I) did not differ between the AGA and SGA groups. Steroids did not influence the I/G nor the S(I) of AGA infants (10.2 +/- 6.7 vs 8.2 +/- 2.3), but decreased the S(I) in the SGA group (12.2 +/- 5.1 vs 5.3 +/- 2.7, P <.05). CONCLUSIONS: Insulin sensitivity of neonates can be measured by the modified minimal model. IUGR is not associated with impaired fetal glucose tolerance. Early neonatal steroid treatment decreases insulin sensitivity in SGA infants, which may contribute to their risk of having hyperglycemia.     

System A amino acid transporter activity in human placental microvillous membrane vesicles in relation to various anthropometric measurements in appropriate and small for gestational age babies.

Fetal growth and development is dependent on the transfer of amino acids from maternal to fetal blood across the microvillous plasma membrane (MVM) and basal plasma membrane of placental syncytiotrophoblast. The aim of this study was to determine the relationship of system A amino acid transporter (SysA) activity in MVM to a variety of measurements of size at birth in a group of term small for gestational age (SGA) babies and in a group of appropriate for gestational age (AGA) babies. Mean SysA activities (nmol/mg vesicle protein/30 s +/- SEM) were: SGA, 0.027 +/- 0.004 (n = 25) and AGA, 0.045 +/- 0.005 (n = 24); p = 0.006. Spearman rank correlations were calculated for SGA (n = 19-25) and AGA (n = 21-24) groups for SysA activity against the following anthropometric measurements: abdominal circumference, birth weight, length, midarm circumference (MAC), head circumference, midarm circumference:head circumference ratio, placental weight (PW), placental ratio (placental weight:birth weight), birth weight:length ratio, Ponderal index (birth weight/length3) and triceps and subscapular skin-fold thicknesses (tsft and ssft). In SGA babies, SysA activity was positively correlated (p < 0.05) with subscapular skin-fold thicknesses (r = 0.48), triceps skin-fold thicknesses (r = 0.42), PW (r = 0.42), and placental ratio (r = 0.46). In AGA babies, the only significant correlation was an inverse one with placental ratio (r = -0.50). These data suggest there are differences in the relationship between placental SysA activity and fetal proportion in term AGA compared with SGA babies.     

Growth and catch-up growth of Australian infants of low birthweight

The growth of 90 infants of low birthweight (1500-2499 g) has been studied longitudinally from birth to 2 years of age. Seventy-five per cent of those infants were of birthweight that was appropriate-for-gestational age (AGA) and of mean gestational age 33.6 weeks (boys) and 34.5 weeks (girls). Twenty-four per cent were small-for-gestational age (SGA) and of mean gestational age 39.4 weeks (boys) and 38.5 weeks (girls). The data showed that, when gestational age was considered, the growth of AGA infants was similar to that of full-term infants of normal birthweight; SGA infants displayed accelerated growth ('catch-up'), particularly in the first months of life with upward percentile crossing from below the 5th toward the 50th. These results provide further evidence of the need to consider gestational age and whether AGA or SGA when assessing the growth of low birthweight infants.     

Birthweight and stature, body mass index and fat distribution of 14-year-old Polish adolescents

OBJECTIVES: The relationships between intra-uterine growth retardation and stature, relative weight and fat distribution at adolescence have not been comprehensively established. The aim of this report is to assess the effect of low birthweight on stature, relative weight and fat distribution in 14-year-old boys and girls from Wroclaw, Poland. METHODOLOGY: Cross-sectional measurements of 1197 boys and 819 post-menarcheal girls aged 13.50-14.49 years were performed during medical examinations in 1997. Stature, body mass index (BMI; kg/m2), waist-to-hip ratio (WHR) and waist-to-thigh ratio (WTR) were used in the present study. A cut-off value of the 10th percentile of birthweight for particular gestational weeks was used in order to define subjects born small for gestational age (SGA) or appropriate for gestational age (AGA). Two-way ANOVA was used to evaluate the effect of birthweight on anthropometric variables of 14-year-old adolescents, allowing for socioeconomic status (determined by the level of the mother's education). RESULTS: Birthweight affected stature in boys and girls (P < 0.001), BMI in boys (P < 0.05) and WHR and WTR in girls (P < 0.001 and P < 0.05, respectively). At the age of 14 years, both SGA boys and girls were shorter than their AGA peers. The SGA boys had lower BMI, whereas SGA girls accumulated more centralized fat compared with their AGA counterparts. CONCLUSION: Fetal growth retardation has a long-lasting adverse effect on later physical growth. Polish SGA children do not catch up with their peers in terms of stature by adolescence. Moreover, central fat distribution, as observed among SGA girls, constitutes a significant risk for several adult degenerative diseases.     

Growth and catch-up growth of Australian infants of low birthweight

Abstract The growth of 90 infants of low birthweight (1500–2499 g) has been studied longitudinally from birth to 2 years of age. Seventy-five per cent of those infants were of birthweight that was appropriate-for-gestational age (AGA) and of mean gestational age 33.6 weeks (boys) and 34.5 weeks (girls). Twenty-four per cent were small-for-gestational age (SGA) and of mean gestational age 39.4 weeks (boys) and 38.5 weeks (girls). The data showed that, when gestational age was considered, the growth of AGA infants was similar to that of full-term infants of normal birthweight; SGA infants displayed accelerated growth ('catch-up'), particularly in the first months of life with upward percentile crossing from below the 5th toward the 50th. These results provide further evidence of the need to consider gestational age and whether AGA or SGA when assessing the growth of low birthweight infants.     

Effect of breastfeeding on cognitive development of infants born small for gestational age

Breastfeeding during infancy appears to result in enhanced cognitive development during childhood, but it is not known whether breastfeeding should be encouraged for infants born small for gestational age (SGA) whose growth might otherwise benefit from nutritional supplementation. To address this issue, duration of exclusive breastfeeding and cognitive development were evaluated prospectively for 220 term children born SGA and 299 term children born appropriate for gestational age (AGA). Cognitive development was assessed using the Bayley Scale of Infant Development at 13 mo and Wechsler Preschool and Primary Scales of Intelligence at 5 y of age. Infants born SGA were given supplemental foods significantly earlier than those born AGA. Growth of infants born SGA was not related to early nutritional supplementation. The salutary effect of exclusive breastfeeding on cognitive development was greater for children born SGA than for those born AGA. Based on a linear association between duration of exclusive breastfeeding and intelligence quotient (IQ), children born SGA and exclusively breastfed for 24 wk were predicted to have an 11-point IQ advantage over those breastfed for 12 wk, as opposed to a 3-point advantage for children born AGA with similar durations of breastfeeding. The IQ distribution of children born SGA and exclusively breastfed for more than 12 wk was not different from that of all children born AGA.

Conclusion : Duration of exclusive breastfeeding has a significant impact on cognitive development without compromising growth among children born SGA. These data suggest that mothers should breastfeed exclusively for 24 wk to enhance cognitive development.     

早产小于胎龄儿生长代谢的临床研究

目的 探讨早产小于胎龄儿（SGA）与适于胎龄儿（AGA）在住院期间生长代谢的差异,为临床对早产SGA进行营养干预提供依据。方法 1 370例早产儿纳入研究,根据胎龄与出生体重的关系分为SGA组（675例）与AGA组（695例）,比较两组早产儿住院期间的一般情况、体格增长及血生化指标等情况。结果 SGA组住院天数长于AGA组（P < 0.05）。与AGA组相比,SGA组出院体重、出院体重Z评分及出院身长均较低,宫外生长迟缓发生率较高（P < 0.05）,头围增长速率大于AGA组。与AGA组相比,SGA组达全肠内喂养时间及需肠外营养时间均较长（P < 0.05）。SGA组入院时白蛋白、前白蛋白、血清磷、出院前总胆汁酸高于AGA组,白蛋白低于AGA组（P < 0.05）。SGA组窒息、新生儿呼吸窘迫综合征、心肌损伤、喂养不耐受、肺炎、败血症、低血糖、低甲状腺素血症的发生率高于AGA组（P < 0.05）。结论 早产SGA住院期间体格发育明显落后于AGA,宫外生长迟缓发生率较高,更易出现并发症。     

Growth and development are similar in VLBW children born appropriate and small for gestational age: an interim report on 97 preschool children

AIM: To investigate growth and development in a cohort of children born with very low birth weight (VLBW) treated at a single tertiary neonatal unit. METHODS: We studied 97 children born between January 1995 and July 1997 with BW <1,500 g. At follow-up (mean age 3.7 years) anthropometric data and data on neurological status, motor, speech and language development were collected. Small for gestational age (SGA) was defined as weight and/or length at birth <10th percentile; shortness at follow-up was defined as height <10th percentile. RESULTS: Comparison was made between the appropriate for gestational age (AGA) (n = 46) and SGA (n = 51) groups. At follow-up, 23 AGA and 35 SGA children were short, had a smaller head circumference (-1.9 vs -0.8 SDS), were lighter at birth (BW -1.3 vs -0.7 SDS), and had a higher rate of broncho-pulmonary dysplasia (BPD) (28 vs 12); no differences in neonatal characteristics or neurological status were evident. A higher frequency of motor delay occurred in the 'short' group. Short children also had a smaller head circumference (HC) (-1.6 vs -0.7). Short SGA children had a higher frequency of BPD, smaller HC (-2.1 vs -1.0), and a slightly higher proportion of suspicious neurological findings, motor delay, and speech and language delay (n.s.). CONCLUSIONS: Preterm VLBW infants, whether AGA or SGA at birth, face the risk of being short at preschool age. Height outcome is probably influenced by postnatal factors. Our data also suggest that short stature is associated with developmental difficulties in this population.     

Growth of 519 Small for Gestational Age Infants during the First Two Years of Life

ABSTRACT. The physical growth of 519 small for gestational age infants (SGA), with a birth weight below the 10th percentile on our own growth curve, born in the region of University Central Hospital of Turku during the period June 1,1981-May 31, 1982, was studied. The study population consists of 4 517 term, appropriate for gestational age (AGA) infants, 488 term SGA infants, 320 preterm AGA infants and 31 preterm SGA infants. The degree of intrauterine growth retardation (IUGR) seemed to have an effect on physical growth in term SGA infants. Those term SGA infants with a low Ponderal Index (PI) (type II) were taller and had a larger head circumference at the age of 24 months than term SGA infants with adequate PI (type I). Among the preterm SGA infants the degree of IUGR seemed to have no effect on later growth. Smoking is still one of the main risk factors associated with poor intrauterine growth. In this study we also found that smoking has an effect on later growth; the children of smoking mothers were smaller than those of non-smoking mothers in the AGA group. Among the SGA infants the infants of non-smoking mothers were bigger than those of smoking mothers. This difference could be explained by other factors associated with SGA. We found that in spite of the catch-up growth during the first months, 26% of the severely SGA infants (birth weight below the 2.5th percentile) still had a weight below the 2.5th percentile at the age of 24 months.     

Placental size of small-for-gestational-age infants at term

Placental size was compared between appropriate-for-gestational age (AGA) and small-for-gestational age (SGA) infants born at term. Placental weight, chorionic plate area and villous surface area were significantly reduced in the SGA infants. Although the ratio of placental weight to birth weight was similar in the AGA and SGA infants, the latter had significantly underweight placentas for their head circumference and crown-heel length. The ratios of placental weight to assessed brain weight and villous surface area to assessed brain weight were also significantly reduced in the SGA infants. It is concluded that the study SGA infants had both absolutely and relatively small placentas.     

The contribution of preterm birth and intrauterine growth restriction to childhood undernutrition in Tanzania

Objectives were to examine the growth patterns of preterm and growth‐restricted infants and to evaluate the associations of prematurity and intrauterine growth restriction (IUGR) with risk of stunting, wasting and underweight. Data from a cohort of HIV‐negative pregnant women–infant pairs were collected prospectively in Tanzania. Small for gestational age [SGA, birthweight (BW) <10th percentile] was used as proxy for IUGR. Anthropometry was measured monthly until 18 months. Length‐for‐age (LAZ), weight‐for‐length (WLZ), and weight‐for‐age (WAZ) z‐scores were calculated using the 2006 World Health Organization (WHO) Child Growth Standards. Stunting, wasting and underweight were defined as binary outcomes using a cut‐off of z‐scores. Multivariate Cox proportional hazard models were used to assess the associations between preterm and SGA to time to stunting, wasting and underweight. The study included 6664 singletons. Preterm and appropriate for gestational age (AGA) infants had slightly better nutritional status than term‐SGA infants and despite some catch‐up growth, preterm‐SGA infants had the poorest nutritional status. The gap in LAZ and WAZ z‐scores among the groups remained similar throughout the follow‐up. Compared with term‐AGA babies, relative risk (RR) of stunting among preterm‐AGA babies was 2.13 (95% confidence interval (CI) 1.93–2.36), RR among term‐SGA was 2.21 (95% CI 2.02–2.41) and the highest risk was among the babies who were both preterm and SGA (RR = 7.58, 95% CI 5.41–10.64). Similar magnitude of RR of underweight was observed among the three groups. Preterm and SGA infants should be closely monitored for growth failure. Intervention to reduce preterm and SGA birth may lower risk of undernutrition in resource‐limited settings.     

Catch-up growth in appropriate- or small-for-gestational age preterm infants

The aim was to evaluate postnatal growth of preterm infants in childhood and to determine factors that have an effect on catch-up growth (CUG). Ninety-six (42F, 54M) preterm born children with a gestational age of 32.6+/-2.9 weeks and birth weight of 1815+/-668 g were evaluated at age 4.7+/-1.1 years. Preterm children with birth weight and/or length below 10th percentile were accepted as small-for-gestational age (SGA) and those above as appropriate-for-gestational age (AGA). Height SDS was similar (-0.5+/-1.0) in preterm AGA and SGA children. Both groups had low body mass index (BMI) SDS (-0.6+/-1.4 and -1.0+/-1.5, respectively). Of the preterm SGA children, 65.8% showed a CUG in height and 3.8% catch- down growth. These rates were 24.6% and 33.5% in preterm AGA children. CUG in height was best explained by birth length and mother's height and CUG in weight by birth weight and mother's weight. In conclusion, although most of the preterm SGA children show CUG, they reach a compromised height in childhood. A number of preterm AGA children show a catch-down growth.     

Changes in circulating levels of adiponectin and leptin in children during the first two years of life

AIM: Adiponectin, leptin and insulin play an important role in the control of growth and glyco-metabolic homeostasis both during pre- and post-natal life. In order to find out markers indicative of post-natal growth, we evaluated circulating levels of these growth factors in full term small for gestational age (SGA) children, during the first 2 years of life, correlating them with the auxological parameters. METHODS: Fourteen SGA (8 males and 6 females) and 16 AGA (appropriate for gestional age) infants (7 males and 9 females) have been included in this study, recording length, weight, body mass index (BMI), adiponectin, leptin and insulin levels at birth. In SGA subjects, these biochemical and clinical parameters have also been evaluated at the first and at the second year of age. RESULTS: AGA and SGA adiponectin and insulin levels at birth did not show statistically significant differences, while leptin concentrations were significantly (P=0.011) lower in SGA children (median 418.49, range 157.68-903.67 pg/mL) in comparison with AGA ones (median 811.71, range 312.50-3085.95 pg/mL). CONCLUSIONS: In conclusion, at birth adiponectin and insulin levels do not differ between AGA and SGA subjects while leptin concentrations are significantly lower in SGA infants and positively correlated to the birthweight.     

Die neurologische und kognitive Entwicklung zu klein geborener Kinder

This article aims to provide an overview on the neurological and cognitive outcome of children who were “born too small”. We will discuss the neurodevelopmental prognosis of term born small for gestational age children, and for children born prematurely (appropriate and small for gestational age). The various underlying causes responsible for intrauterine growth retardation (IUGR) and significance for neurodevelopmental outcome will be discussed briefly. Neurodevelopmental outcome of term born children with IUGR due to intrauterine malnutrition and outcome of preterm born small for gestational age (SGA) as well as preterm born appropriate for gestational age (AGA) children will then be discussed in more detail. Children with IUGR represent a heterogeneous group regarding the underlying cause that is responsible for the growth retardation. Neurodevelopmental prognosis very much depends on the specific underlying cause. IUGR caused by intrauterine malnutrition is not necessarily associated with neurodevelopmental problems. However, results of several studies suggest that in term born children with IUGR mild neuromotor problems and lower full scale IQ is more frequent when compared with term born appropriate for gestational age children. Prematurely born children are at high risk for neurodevelopmental impairment. There is no difference in frequency of disabling impairments between AGA and SGA preterm children. However, in preterms with IUGR there seems to be a higher frequency of mild neuromotor problems and cognitive function seems to be poorer than in appropriate for gestational age preterms.     

Bone ultrasound velocity of infants born small for gestational age

BACKGROUND: Quantitative ultrasound is increasingly used to assess bone status. Bone speed of sound (SOS), a biophysical property of bone, has been used to predict bone breakability. While decreased bone mineral content and delayed epiphyseal growth have been reported in small for gestational age (SGA) infants, there are no data on bone SOS in this group of infants. OBJECTIVE: To test the hypothesis that SGA infants have lower bone SOS than appropriate for gestational age (AGA) infants. METHODS: Bone SOS was measured within the first 96 hours of life at the right tibial midshaft in 22 singleton SGA infants. We compared these data with data obtained in 73 AGA controls. We used the Omnisense instrument which measures axially transmitted SOS. Infants ranged in gestational age (GA) from 25 to 42 weeks and in birth weight (BW) from 500 to 2,585 g. Statistical analyses included paired t-tests between the actual value obtained in every child and the theoretical, computed average normal value for GA, BW, or knee-sole length (KSL) based on our curves for AGA singletons. A p value < 0.05 was considered significant. RESULTS: Bone SOS measured in SGA infants was higher than the predicted computed average SOS of AGA singletons with significant differences in all of the parameters studied. CONCLUSIONS: Contrary to our hypothesis, SGA infants have higher bone SOS than AGA controls. Since bone mineral density is reported to be low in these infants, we speculate that intrauterine growth restriction may affect bone mineral density and bone protein matrix in opposite directions.     

Catch up growth and pancreatic function in growth retarded neonates.

To test the hypothesis that relative pancreatic dysfunction is a determinant of catch up growth in small for gestational age (SGA) babies, 47 such babies (median gestation 38 weeks; range 27-41) and 41 appropriate for gestational age (AGA) babies matched for sex, race, and gestational age were recruited. Anthropometry was performed within 48 hours of birth and at 6 months. Faecal chymotrypsin activities were measured at 0-2 days, 14 days, 6 weeks and 6 months. At 6 months 30 SGA infants and 25 AGA infants were remeasured. In each group, median stool chymotrypsin activities doubled between 0-2 days and 6 months (9.0-25.5 IU/g SGA group; 11.6-25.3 IU/g AGA group). SGA babies had significantly lower chymotrypsin activities at 14 days (10.9 U/g) than AGA babies (15.5 U/g). In the SGA group faecal chymotrypsin activities at 0-2 days were strongly correlated with both catch up weight and with catch up length when corrected for the effects of birthweight. These data show that impaired pancreatic exocrine function at birth is associated with severe intrauterine malnutrition and with impaired catch up growth during the first 6 months of life.     

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.     

Gestational age assessment in Japanese low birthweight infants

We evaluated the validity of the Ballard scoring system for assessing gestational age in Japanese low birthweight infants. Infants included in this study were 116 neonates who were admitted to seven hospitals in Hokkaido. Gestational ages of all infants were prenatally established by ultrasonographic measurement of the crown-rump length performed between 8 and 12 weeks of gestation (clinical age). Of these, 74 infants were appropriate for gestational age (AGA) and the remaining were small for gestational age (SGA). Mean birthweight was 1703 g and 34% (39/116) were <1500 g. The correlation coefficient for the total population was 0.93 (P < 0.001). Although mean Ballard age tended to overestimate clinical age, mean differences between Ballard age and clinical age did not exceed 0.6 weeks. Agreement within 2 weeks among all infants was 86.2%. Percentages of agreement within 2 weeks did not differ to a statistically significant degree between AGA and SGA. These results indicate that the Ballard method is of value in assessing gestational age in Japanese low birthweight infants.     

Metabolic consequences of intrauterine growth retardation in very low birthweight infants

By the combination of energy and macronutrient balances, continuous open circuit computerized indirect calorimetry, and anthropometry, we have compared small for gestational age (SGA) and appropriate for gestational age (AGA) very low birthweight infants with respect to metabolizable energy intake (mean +/- SE: 125.9 +/- 2.5 versus 130.4 +/- 3.5 kcal/kg X day), energy expenditure (67.4 +/- 1.3 versus 62.6 +/- 0.9 kcal/kg X day), storage of energy and macronutrients and growth. Fourteen studies in six SGA infants (gestational age, 33.1 +/- 0.3 weeks; birthweight, 1120 +/- 30 g) and 22 studies in 13 AGA infants (gestational age, 29.3 +/- 0.4 weeks; birthweight, 1155 +/- 40 g) were performed. The SGA infants had a lower absorption of fat (68.7 +/- 3.2 versus 79.7 +/- 1.7%) and protein (69.1 +/- 3.2 versus 83.4 +/- 1.5%) and hence increased (P less than 0.001) energy loss in excreta (29.9 +/- 2.8 versus 18.2 +/- 1.5 kcal/kg X day). The significant hypermetabolism of SGA infants by 4.8 kcal/kg X day was associated with an increased fat oxidation. Despite lower energy storage, SGA infants were gaining weight (19.4 +/- 0.9 g/kg X day), length (1.25 +/- 0.14 cm/week), and head circumference (1.16 +/- 0.9 cm/week) at higher rates than the AGA group. The energy storage per g weight gain was lower (P less than 0.001) in the SGA group (3.0 +/- 0.14 versus 4.26 +/- 0.26 kcal) reflecting higher water, lower fat (22.2 +/- 1.8 versus 33.8 +/- 2.5%; P less than 0.001) and lower protein (7.7 +/- 0.5 versus 12.5 +/- 0.8%; P less than 0.001) contents of weight gain in the SGA group.