Determinants of visual evoked potentials in preterm infants

The latency and amplitude of N1, the first negative peak of single flash visual evoked cortical potentials (VEP) were evaluated in 86 preterm infants (25-34 weeks of gestation), investigated during the first day of life. All infants were regarded stable at the time of investigation and none had experienced severe asphyxia. Both the VEP latency and amplitude were inversely related to gestational age. When latency was corrected for age it was longer in boys than in girls. Age corrected VEP amplitude was inversely related to head circumference, umbilical cord pH and EEG activity. There was no difference between VEP parameters in asymmetrically growth retardated infants compared to those with normal growth. Administration of dexamethasone to the mother before delivery, mode of delivery, presence of hyaline membrane disease, mode of assisted ventilation or imminent development of periintraventricular haemorrhage did not affect the VEP.     

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.     

Anthropometric assessment of nutritional status in newborn infants. Discriminative value of mid arm circumference and of skinfold thickness

74 appropriate-for-gestational age (AGA) and 22 small-for-gestational age (SGA) caucasian infants were studied for anthropometric parameters: mid arm circumference (MAC), triceps and subscapular skinfold thickness (TSKF and SSKF) recorded at 15 and 60 s, chest circumference (cc), head circumference, birth weight and length.MAC is highly correlated with birth weight either in AGA (r = 0.936; P < 0.001) or in SGA infants (r = 0.860; P < 0.001). MAC is also correlated with gestational age in AGA (r = 0.850; P < 0.001) and SGA infants (r = 0.76; P < 0.001). Similar correlations were found between TSKF, SSKF and birth weight or gestational age. Arm muscle and fat areas are also positively correlated with birth weight and gestational age, in AGA and SGA infants.A multiple regression analysis of our data allowed a classification of the best discriminant anthropometric parameters between AGA and SGA infants. MAC, SSKF15, SSKF60 and chest circumference were selected. An equation was established in AGA infants with these four parameters giving a predictive gestational age: gestational age (weeks) = 1.216 MAC (cm)?3.588 SSKF15 (mm)+0.263 CC (cm) + 17.9.The ratio of predicted gestational age to the real gestational age was 1.0 ± 0.044 in AGA versus 0.896 ± 0.034 in SGA infants.Our data suggest that MAC and SSKF provide a simple measure of body composition of neonates and a useful tool for determining the degree of maturity of a newborn independent of birth weight.     

大于胎龄儿脐血脂联素水平测定及其临床意义

目的探讨大于胎龄儿(LGA)血脂联素水平变化及其对新生儿的影响。方法研究对象为LGA和适于胎龄儿(AGA)各30例。应用酶联免疫吸附法(ELISA)测定脐血和产妇血脂联素水平,用免疫比浊法测定三酰甘油(TG)、总胆固醇(TCH)、低密度脂蛋白胆固醇(LDL-c)、高密度脂蛋白胆固醇(HDL-c)水平,并分析脐血脂联素水平与母血脂联素、新生儿性别、出生体质量、体质量指数(BMI)、胎盘重量和血脂水平的相关性。结果1.LGA脐血浆脂联素水平低于AGA,差异有非常显著性(P<0.01);LGA血TG、TCH、LDL-c、HDL-c水平与AGA比较差异均无显著性(Pa>0.05)。2.LGA血浆脂联素水平与新生儿出生体质量、BMI、胎盘重量、脐血TG水平均呈显著负相关(r=-0.848,-0.785,-0.835 Pa<0.001),与母血脂联素水平、新生儿身长、孕前和分娩时产妇体质量及其BMI、其他脐血脂成分无相关性(Pa>0.05)。3.LGA男婴和女婴脐血浆脂联素、血脂各成分水平比较差异均无显著性(Pa>0.05)。结论血脂联素水平变化与LGA的发生有关,测定脐血脂联素水平有助于判断LGA的发展趋势。     

多中心大于胎龄儿新生儿期死亡原因及风险的病例对照研究

目的探讨大于胎龄儿（LGA）新生儿期死亡原因及死亡风险。方法病例对照研究。《中国新生儿死亡原因多中心调查》数据库包括39家三级医院新生儿科胎龄≥24周的所有死亡病例数据，以数据库中的LGA为病例组（单胎出生，晚期早产儿或足月儿），分别以数据库中全部适于胎龄儿（AGA）和配对的AGA（1∶1）为对照组（匹配条件：单胎、胎龄、性别、来源医院），比较LGA和AGA新生儿期死亡原因。通过整体人群中LGA和AGA活产婴儿比例，估计整体人群LGA死亡风险。采集母亲因素、围生期因素、新生儿因素和死亡原因。根据WHO ICD-PM分类标准分为11类新生儿期死亡原因。结果2016年7月1日至2019年6月30日数据库中新生儿期死亡的LGA和AGA分别为126和1 183例。LGA组新生儿除出生体重、母亲妊娠期糖尿病患病率外均与匹配AGA组差异无统计学意义。多因素回归分析，矫正出生体重和妊娠期糖尿病因素，LGA组早期新生儿死亡风险较匹配AGA组增加1.94倍（OR=2.938，95%CI: 1.346~6.416,P=0.007）。LGA的主要死亡原因排序为先天性疾病（29.4%）、围产期窒息（21.4%）、呼吸系统疾病和心血管疾病（14.3%）、重症感染（11.9%）。LGA组新生儿全因死亡风险与匹配AGA组差异无统计学意义，LGA组死于重症感染（N6：细菌性败血症,细菌脑膜炎，肺炎，病毒感染等）的风险低于匹配AGA组（OR=0.541，95%CI：0.320~0.912，P=0.019）。结论国内三级医院晚期早产儿和足月单胎LGA的主要死亡原因构成及其比例与AGA相比总体一致，LGA并不增加新生儿期的死亡风险，且死于重症感染风险低于AGA。     

多中心大于胎龄儿新生儿期死亡原因及风险的病例对照研究

目的探讨大于胎龄儿（LGA）新生儿期死亡原因及死亡风险。方法病例对照研究。《中国新生儿死亡原因多中心调查》数据库包括39家三级医院新生儿科胎龄≥24周的所有死亡病例数据,以数据库中的LGA为病例组（单胎出生,晚期早产儿或足月儿）,分别以数据库中全部适于胎龄儿（AGA）和配对的AGA（1∶1）为对照组（匹配条件：单胎、胎龄、性别、来源医院）,比较LGA和AGA新生儿期死亡原因。通过整体人群中LGA和AGA活产婴儿比例,估计整体人群LGA死亡风险。采集母亲因素、围生期因素、新生儿因素和死亡原因。根据WHO ICD-PM分类标准分为11类新生儿期死亡原因。结果2016年7月1日至2019年6月30日数据库中新生儿期死亡的LGA和AGA分别为126和1 183例。LGA组新生儿除出生体重、母亲妊娠期糖尿病患病率外均与匹配AGA组差异无统计学意义。多因素回归分析,矫正出生体重和妊娠期糖尿病因素,LGA组早期新生儿死亡风险较匹配AGA组增加1.94倍（OR=2.938,95%CI: 1.346~6.416,P=0.007）。LGA的主要死亡原因排序为先天性疾病（29.4%）、围产期窒息（21.4%）、呼吸系统疾病和心血管疾病（14.3%）、重症感染（11.9%）。LGA组新生儿全因死亡风险与匹配AGA组差异无统计学意义,LGA组死于重症感染（N6：细菌性败血症,细菌脑膜炎,肺炎,病毒感染等）的风险低于匹配AGA组（OR=0.541,95%CI：0.320~0.912,P=0.019）。结论国内三级医院晚期早产儿和足月单胎LGA的主要死亡原因构成及其比例与AGA相比总体一致,LGA并不增加新生儿期的死亡风险,且死于重症感染风险低于AGA。     

Disproportionate alterations in body composition of large for gestational age neonates

OBJECTIVE: The objective was to compare dual-energy x-ray absorptiometry-measured body composition between large (LGA) and appropriate (AGA) birth weight for gestational age neonates.Study design: LGA term infants (n = 47) with birth weights > or =4000 g were compared with 47 gestational age-matched AGA infants; 11 LGA infants were born to mothers with gestational (9) or pregestational diabetes (2). Dual-energy x-ray absorptiometry scans were performed at 1.8 +/- 1.0 days after birth. RESULTS: Body weight and length were the dominant predictors of body composition in LGA and AGA neonates. However, LGA neonates had significantly (P <.001, all comparisons) higher absolute amounts of total body fat, lean body mass, and bone mineral content and had significantly (P <.001, all comparisons) higher proportions of total body fat and bone mineral content but lower lean body mass as a percent of body weight. The changes for total body fat and lean body mass as a percent of body weight were greatest (P <.001) in LGA infants whose mothers had impaired glucose tolerance. CONCLUSION: LGA neonates have higher body fat and lower lean body mass than AGA infants. Impaired maternal glucose tolerance exaggerated these body composition changes.     

Leptin, insulin, and glucose serum levels in large-for-gestational-age infants of diabetic and non-diabetic mothers

BACKGROUND: It has been suggested that hyperleptinemia could be caused by hyperinsulinemia in infants of diabetic mothers (IDMs). AIM: To compare leptin, insulin, and glucose levels in large-for-gestational-age (LGA) and appropriate-for-gestational-age (AGA) infants. Methods: A cross-sectional study was conducted in IDMs, infants of non-diabetic mothers (INDM) and AGA infants. RESULTS: Seventy-seven newborns were studied (11 IDM, 16 INDM, and 50 AGA infants). Leptin levels were significantly higher in LGA infants than in the AGA group and a trend for higher levels in IDM than NIDM was observed. Insulin levels and insulin resistance were significantly higher in IDMs. Glucose levels were lower in both groups of LGA infants. CONCLUSIONS: We found insulin resistance, hyperinsulinism and hyperleptinemia in IDMs, and the trend of higher leptin levels in IDMs than INDMs shows that leptin could be related to insulin resistance in these infants.     

脐血脂联素、瘦素水平与胎儿发育的相关性

目的 探讨脐血脂联素、瘦素水平与胎儿生长发育的关系.方法 选择2006年10月至2007年10月在我院产科出生的新生儿86例,根据不同出生体质量分为小于胎龄儿(SGA)组16例,适于胎龄儿(AGA)组41例,大于胎龄儿(LGA)组29例.胎儿娩出后立即断脐留脐血20ml,采用放射免疫分析法测定血清脂联素、瘦素水平,同时检测其血脂水平,测量新生儿生长参数,计算体质量指数(BMI).结果 (1)3组脐血瘦素和脂联素水平差异有统计学意义(P<0.001),LGA组明显高于AGA及SAG组(P<0.01);(2)脐血瘦素水平与体质量、胎龄、头围、身长、足长及胎盘重量呈正相关(P<0.01),脐血脂联素水平与出生体质量、头围、足长、BMI水平呈正相关(P<0.05).(3)脐血瘦素与脂联素水平呈显著正相关(P<0.01).(4)3组血脂水平比较差异无统计学意义;脐血脂联素、瘦素水平与血脂各指标间无明显相关性(P>0.05).结论 瘦素与脂联素在胎儿宫内生长和发育过程中起重要的调节作用.     

Longitudinal investigation of the relationship between breast milk leptin levels and growth in breast-fed infants

BACKGROUND: It has been shown that leptin is present in breast milk and human mammary epithelial cells are able to synthesize leptin. It has been suggested that leptin in human milk might be involved in the regulation of postnatal nutrition and growth. AIMS: To investigate whether there is a relationship between leptin levels in human milk and weight gain in the postnatal period and to compare variations of milk-borne maternal leptin concentrations for small for gestational age (SGA), large for gestational age (LGA) and appropriate for gestational age (AGA) infants. INFANTS AND METHODS: Forty-seven healthy lactating women aged from 17-38 years and their infants were included in the study. The infants were separated into three groups according to birth weight as SGA (n = 11), LGA (n = 14) and AGA (n = 22). All infants were fed with breast milk during the study period. Anthropometric measurements were performed on the 15th day of life and at 1, 2, and 3 months of age, and the body mass index (BMI) of the infants' mothers was calculated. Breast milk leptin levels were analyzed by radioimmunoassay. RESULTS: Breast milk leptin levels were found reduced in the SGA group and increased in the LGA group compared to the AGA group at 15 days of life (13.4 +/- 2.2, 28.5 +/- 4.4 and 18.4 +/- 2 ng/ml, respectively; p <0.05). At 1 month of age, leptin levels in breast milk were significantly lower in the LGA group than in the AGA group (15.5 +/- 4.9, 19.4 +/- 1.7 ng/ml, respectively; p<0.05). There was no difference among the three groups at 2 and 3 months of age (p>0.05). There was a positive correlation between birth Weight and breast milk leptin levels on the 15th day (r = 0.47, p = 0.001). A negative correlation was found between weight gain during the first 15 days and 1 month of life and breast milk leptin levels on the 15th day (r = -0.44, p = 0.002; r = -0.40, p = 0.005, respectively). No relationship could be determined between breast milk leptin levels and BMI of the mothers. CONCLUSION: Maternal milk of SGA, LGA and AGA infants had different leptin levels, especially during the first month of life. More rapid growth was shown in the SGA infants during the first postnatal 15 days compared to AGA and LGA infants, and human milk leptin levels were significantly reduced in the SGA group. However, LGA infants gained more weight during the second 15 days of life and breast milk leptin levels were dramatically decreased in LGA and increased in SGA infants at the end of first month of life. These findings suggest that the presence of leptin in breast milk might have a significant role in growth, appetite and regulation of nutrition in infancy, especially during the early lactation period, and the production of leptin in breast tissue by human mammary epithelial cells might be regulated physiologically according to necessity and state of the infant.     

骨钙素、Ⅰ型前胶原羧基端前肽、胰岛素样生长因子-1及其相关激素与胎儿骨发育的关系

目的 探讨骨钙素(OC)、Ⅰ型前胶原羧基端前肽(PICP) 及胰岛素样生长因子.1(IGF.1)等激素水平与胎儿骨生长发育的关系.方法 选择本院2008年10月-2009年10月收治的新生儿80例.男41例,女39例;胎龄28～42周.根据不同出生体质量分为小于胎龄(SGA)儿组22例,适于胎龄(AGA)儿组36例及大于胎龄(LGA)儿组(22例).胎儿娩出后,胎盘娩出前抽取其脐静脉血6 mL,采用放射免疫分析法测定其血清OC、IGF.1及甲状旁腺激素水平,酶联免疫吸附法检测其脐血PICP水平;同时检测其血钙、磷、ALP水平,测量新生儿生长参数,计算体质量指数(BMI).结果 1.脐血OC水平在SGA儿组、AGA儿组、LGA儿组间比较差异有统计学意义(P=0.000),LGA儿组显著高于AGA儿及SAG儿组(P＜0.01,0.001);脐血OC水平与出生体质量、头围、BMI呈正相关(Pa＜0.05),与身长无明显相关性(P＞0.05).2.LGA儿组脐血IGF.1水平显著高于AGA儿及SAG儿组,3组间比较有统计学差异(P=0.002);脐血IGF.1水平与出生体质量、头围、BMI水平均呈正相关(Pa＜0.05),与身长无明显相关性(P＞0.05).3.AGA儿组、LGA儿组脐血PICP水平明显高于SGA儿组,但3组间无统计学差异(P=0.070).脐血PICP、PTH水平与生长参数各指标水平均无直线相关关系(Pa＞0.05),偏相关分析脐血PICP与出生体质量、头围、BMI均呈正相关(r=0.239、0.250、0.306,Pa<0.05).4.脐血OC水平与PICP、IGF.1水平均呈正相关(Pa＜0.05),OC、PICP与PTH、ALP水平之间均无明显相关(Pa＞0.05).5.3组脐血钙、血磷、ALP水平均无统计学差异(Pa＞0.05).结论 SGA儿低血清OC、PICP水平与骨形成活动下降相关,脐血OC、PICP及IGF.1可作为评价胎儿骨骼生长发育的临床指标之一.     

Association between serum leptin and anthropometric parameters at birth and at 15th day of life in infants born asymmetrically small for gestational age

The aim of this study was to investigate changes in skinfold measurements taken at three sites, mid-arm circumference and umbilical circumference during the first 15 days of life; and to evaluate relationships between anthropometric measurements and umbilical cord blood serum leptin levels in infants born small for gestational age (SGA) and appropriate for gestational age (AGA) infants. Of 50 newborn infants, 25 were SGA and 25 were AGA. Neonates' weight, mid-arm circumference (MAC), umbilical circumference (UC), and triceps, subscapular and periumbilical skinfold thicknesses were measured (Holtain callipers) immediately after delivery. Anthropometric parameters were measured again at 15th days of age. At birth, mean birth weight, mean skinfold thickness, MAC and UC measurements in the AGA group were significantly higher than those of the SGA group. These differences were also found on the 15th day. Birth weight correlated with all skinfold thicknesses, MAC and UC at birth. Weight at 15th day of life correlated with skinfold thicknesses, MAC and UC at 15th day of life. Cord blood leptin level was significantly lower in the SGA than in the AGA infants. This difference continued on the 15th day. When cord blood leptin level was compared with that of the 15th day, we found that leptin levels in the cord blood were significantly higher. There were significantly positive correlations between leptin levels and birth weight and skinfold thicknesses when the infants were all grouped together. When the newborns were grouped according to birth weight, there were positive correlations between cord blood serum leptin levels and these parameters in the AGA group, but no correlation in the SGA group. At the 15th day of life serum leptin levels correlated with weight, subscapular and triceps skinfold thickness in the AGA group, but only with triceps skinfold thickness in the SGA group.     

The relationship between intrauterine and postnatal growth on the subsequent psychomotor development of very low birthweight (VLBW) infants

ABSTRACT. The aim of this study was to demonstrate the relationship between intrauterine and postnatal growth and subsequent neurological and intellectual development of very low birth weight (VLBW) infants. The effect of intrauterine growth was assessed by comparing the developmental outcomes of the 131 appropriate weight for gestational age (AGA) infants with the 33 small for gestational age (SGA) infants. No significant differences were found between the two groups with respect to head circumference, neurological, intellectual or sensory handicap rates. The mean General Quotient (GQ) at the last clinic assessment for the AGA infants was 101.2 and 97.2 for the SGA infants. The effect of extra-uterine growth on subsequent development was assessed in the AGA and SGA infants separately, at the time of discharge and again at 12 months. The 31 AGA infants who failed to grow adequately in the nursery had more neonatal risk factors than the 100 AGA infants who continued to grow adequately after birth. This early postnatal growth failure was not predictive of developmental outcome. At 12 months of age, 26 infants (20%) who were initially appropriately grown at birth were failing to thrive. These infants had sustained more chronic diseases and caretaking disorders in the first year of life than their appropriately grown counterparts. They also had lower GQ and head circumference measurements (p<.05). The SGA infants who exhibited “catch up'’growth between birth and term had larger head circumference measurements at 1 year than those with persistent growth failure. Growth assessment at 12 months of age was not predictive of developmental outcome in SGA infants. We failed to show a relationship between intrauterine growth of VLBW infants and their subsequent development. AGA infants whose weights had dropped to the 3rd percentile by 12 months of age had a poorer outcome than their appropriately grown counterparts. Furthermore, early postnatal growth failure before term had no additional effects if catch up growth occurred thereafter. In the SGA group neither failure to reach the 3rd percentile by term or 12 months affected outcome.     

Cord prealbumin values in newborn infants: effect of prenatal steroids, pulmonary maturity, and size for dates

We assessed cord prealbumin concentrations in 214 appropriate for gestational age newborn infants, 21 small for gestational age infants, and 27 large for gestational age infants to establish normal values and to assess the effect of intrauterine growth, prenatal steroids, and pulmonary maturity on prealbumin levels. Cord prealbumin values were significantly correlated with increasing gestational age (r = 0.33; P less than 0.001) and birth weight (r = 0.40, P less than 0.001) in the AGA neonates. Neonates born before 37 weeks gestation had significantly lower prealbumin levels than those born at term (P less than 0.001). The SGA infants had significantly lower levels than age-matched AGA controls (P less than 0.01), and LGA infants had significantly higher levels than age-matched AGA controls (P less than 0.001). In preterm infants, those with exposure to prenatal steroids (betamethasone or premature rupture of membranes) had significantly higher prealbumin values than control infants of comparable age and weight (P less than 0.001). Infants without respiratory distress syndrome had higher levels than those of comparable age and weight with hyaline membrane disease (P less than 0.05). This study demonstrates that a correlation of gestational age and birth weight exists with cord prealbumin levels, and that the large variability at each gestational age may be accounted for in part by appropriateness of size for dates, prenatal steroid exposure, and pulmonary maturity.     

脐血脂联素、瘦素水平与胎儿发育的相关性

目的 探讨脐血脂联素、瘦素水平与胎儿生长发育的关系.方法 选择2006年10月至2007年10月在我院产科出生的新生儿86例,根据不同出生体质量分为小于胎龄儿(SGA)组16例,适于胎龄儿(AGA)组41例,大于胎龄儿(LGA)组29例.胎儿娩出后立即断脐留脐血20ml,采用放射免疫分析法测定血清脂联素、瘦素水平,同时检测其血脂水平,测量新生儿生长参数,计算体质量指数(BMI).结果 (1)3组脐血瘦素和脂联素水平差异有统计学意义(P<0.001),LGA组明显高于AGA及SAG组(P<0.01);(2)脐血瘦素水平与体质量、胎龄、头围、身长、足长及胎盘重量呈正相关(P<0.01),脐血脂联素水平与出生体质量、头围、足长、BMI水平呈正相关(P<0.05).(3)脐血瘦素与脂联素水平呈显著正相关(P<0.01).(4)3组血脂水平比较差异无统计学意义;脐血脂联素、瘦素水平与血脂各指标间无明显相关性(P>0.05).结论 瘦素与脂联素在胎儿宫内生长和发育过程中起重要的调节作用.     

Differential effects of intrauterine and postnatal brain growth failure in infants of very low birth weight

We investigated the contribution of brain growth failure to outcome in infants of very low birth weight (VLBW; less than 1.5 kg) who were appropriate for gestational age (AGA; n = 379) or small for gestational age (SGA; n = 102). Growth was assessed at birth, term, and 8 and 20 months' corrected age and results of a Bayley Mental Developmental Index (MDI) and neurologic examination were evaluated at 20 months of age. Both groups had similar 20-month MDI scores (93 vs 90) and similar rates of neurologic impairment (14% vs 10%). More SGA infants (25%) than AGA infants (14%) had a subnormal head circumference at 8 months' corrected age, indicating failure to catch up in head growth. Subnormal head size at 8 months predicted the 20-month MDI score for both groups. However, multivariate analysis indicated that, whereas subnormal 8-month head size was directly associated with the MDI score in AGA children, in SGA children 8-month head size was not significantly related to the MDI score when neonatal illness, neurologic impairment, socioeconomic status, and race were controlled for. We conclude that in AGA VLBW infants, subnormal head size at 8 months results from major neonatal illness and has adverse later effects. In SGA infants, subnormal head size at 8 months has many causes, including growth retardation in utero, which may not have an adverse effect on outcome; if subnormal head size is superimposed with neonatal illness, a poorer outcome is likely.     

84例早产适于胎龄儿第一年体格追赶生长纵向评估

目的：分析早产适于胎龄儿1岁以内的追赶生长特点,探讨其追赶生长规律。方法：选择84名胎龄28～36周的早产适于胎龄儿（男44例,女40例）作为研究对象,对其0～12月内的体重、身长及头围分别按实际月龄足月儿生长标准和纠正月龄标准进行Z评分评估并分析。结果：早产适于胎龄儿1岁内体重、身长和头围均出现追赶性生长,且增长最快的阶段均在实际月龄0～3月,体重追赶速度优于身长追赶速度。结论：生后前3个月是早产适于胎龄儿的快速生长期;体重与身长的变化存在不平衡性。     

Growth of low-birth-weight infants

Growth in weight, length, and head circumference were compared among 3 different groups of infants. These measurements for each group were also compared to those presumed representative for the average fetus and infant of corresponding gestational age. A graph was prepared to show curves of fetal growth in the 3 parameters for the last trimester of pregnancy and through the 1st year of life after the equivalent age of "term" has been reached. The composite curves of the 3 groups were compared from the time of birth with no correction for gestational age. Since 1962 all low birthweight infants admitted to the Premature Center of the University of Oregon Medical School have been measured longitudinally for weight, length, and head circumference. 3 weight gestation groups were selected for study: Group A, very premature with weight appropriate for gestational age, gestation 27-29 weeks, birth weight .95-1.30 kg; Group B, moderately premature, with weight appropriate for gestational age, gestation 31-33 weeks, birth weight 1.40-2.00 kg; and Group C, full term, but severely underweight for gestational age, 38 weeks or more, birth weight less than 2.00 kg. Weight was obtained from an automatic Toledo balance scale, accurate to 10 gm. The babies were weighed prior to the morning feeding. Since measurements could not be made at precisely the same age for all infants after discharge from the hospital, derived measurements for appropriate intervals of time were extrapolated from the curves of growth of each infant. For estimation of fetal growth in weight, length, and head circumference, data were obtained from measurements reported in the literature for infants of known gestational age. After a 2-week lag, the curves for weightand length of Groups A and B paralleled those for standard fetuses and infants thoughout the 1st year of life. The curves were at a lower level with the curve of the most immature group (A) being reduced the most. Head circumference, after a 2-week lag, regained and followed the projectedcurve, suggesting a temporary acceleration in the growth of the head. This was in contrast to growth in length. Growth in Group C, after a lesser interruption following birth, also paralleled the mean curves of full-sized infants, but at a level substantially below them as well as those forthe Groups A and B. The curve for head growth in Group C gradually approached that of full-sized infants, but the significant disparity in head size from the normal-sized infant at birth was only partly reduced by the end of the 1st year. From the data it appears that little, if any, of the retardation in weight and length that may be suffered in the fetal or neonatal period is made up during the 1st year of life if the infant's age is corrected to term.     

Growth Dynamics of Low-birth-weight infants

ABSTRACT. The growth of weight, length and head circumference of 65 appropriate for gestational age (AGA) preterm infants and 85 full term controls has been studied longitudinally, with emphasis on growth velocity in the perinatal period. In comparison growth patterns of 51 small for gestational age (SGA) preterm infants have been analysed with respect to catch-up growth in relation to feeding practices. Weight gain of the AGA preterm infants is retarded until the corrected age of two months; their length remains below that of full term controls up to 21 months on average. Head circumference growth however is similar to intrauterine standards and from term agrees with that of the full term controls. Growth velocity is very high in the perinatal period and in the first months after term and decreases rapidly thereafter.