Proportionality Changes in the First Year of Life; the Influence of Weight for Gestational Age at Birth

ABSTRACT. Data on 55 small-for-gestational age (SGA), 56 average-for-gestational age (AGA) and 55 large-for-gestational age (LGA) infants whose growth had been monitored regularly from birth to 12 months are presented. SGA head-chest ratios were high at birth; but by 6 months they were very similar to AGA ratios, with values just below unity. Head-length ratios showed a steady decrement; SGA infants having the highest and LGA infants the lowest values at all ages. Chest-length ratios showed little change up to 6 months, with a steady decrease thereafter. Stem-stature ratios showed a similar pattern; and were confined within a narrow margin from 6 months onwards. These changes seem to be target orientated. We suggest the goal is that proportionality which enables the infant to attain the upright stature; and thus to sit, stand and walk at the appropriate time.     

杭州地区不同出生体质量小儿早期体格生长水平调查

目的 通过不同出生体质量小儿早期体格生长水平的调查、分析与比较，了解小于胎龄儿（SGA）、大于胎龄儿（LGA）和适于胎龄儿（AGA）生命早期生长发育的规律。方法 通过新生儿筛查中心，对浙江省杭州地区2000、2004、2005年出生的38898名新生儿进行调查，随机对其中794名新生儿进行随访，获得当地测量的该年龄时段体质量、身高的体检资料，并计算BMI及Z值。结果 2000、2004、2005年SGA的发生率为1．5％、2．0％和2．3％，LGA的发生率为4．7％、5．2％和4．2％。12～30月龄LGA组体质量、身长和BMI值均为3组之最，其次是AGA组，SGA组处于最低水平。72～78月龄LGA组体质量仍处于领先水平，SGA组身高、BMI追赶上余2组。结论 宫内生长与儿童早期生长密切相关，应针对不同出生体质量儿合理喂养，进行早期生长监测和干预。     

Small and growth-restricted babies: drawing the distinction

The terms “small for gestational age” and “intrauterine growth restriction” have been used interchangeably to denote an in utero growth-restricted neonate. However, the two terms are not synonymous; not all small babies are growth restricted and not all growth-restricted ones are small. Research evidence, extending back to the middle of the last century, reveals that the number of growth-restricted babies who escape attention is not negligible and that the postnatal outcome of these babies is not uneventful. This paper highlights this issue and further discusses the available diagnostic tools for the identification of in utero-restricted neonates, that is, clinical assessment, anthropometric indices and obstetric ultrasound. Each of these tools has strengths and limitations, but, if combined, each could complement the other and help differentiate well-grown babies from those who are growth restricted.

Conclusion: Identification of growth-restricted neonates is feasible through the integrated use of diagnostic tools.     

Breastfeeding and intelligence of preschool children

AIM: To investigate whether breastfeeding during infancy is a determinant of intelligence at 3.5 y. METHODS: Five hundred and fifty European children enrolled at birth in the Auckland Birthweight Collaborative Study were assessed at 3.5 y of age. Approximately half were small for gestational age (SGA < or =10th percentile) at birth and half were appropriate for gestational age (AGA >10th percentile). Duration of breastfeeding was recorded at maternal interview, and the intelligence of children was assessed using the Stanford Binet Intelligence Scale. Regression analysis was used to calculate estimates of difference in intelligence scores between breastfeeding groups for the total sample and the group of SGA children. Analyses of the total sample were weighted to account for the disproportionate sampling of SGA children. RESULTS: Breastfeeding was not significantly related to intelligence scores in the total sample despite a trend for longer periods of breastfeeding to be associated with higher intelligence scores. However, in the SGA group, breastfeeding was significantly related to IQ at 3.5 y. Small for gestational age children who were breastfed for longer than 12 mo had adjusted scores 6.0 points higher than those who were not breastfed (p=0.06). CONCLUSION: Breastfeeding may be particularly important for the cognitive development of preschool children born small for gestational age.     

早产儿与足月新生儿血清脂联素水平比较

目的探讨早产对血清脂联素水平的影响及早产成为成人期2型糖尿病、心血管疾病发生的重要危险因素可能机制。方法 采用放射免疫分析法,测定30例正常足月新生儿和21例早产儿血清脂联素水平结果早产儿血清脂联素水平(34.29±7.24)mg/L,正常足月新生儿血清脂联素水平(62。47±28.33)mg/L,早产儿血清脂联素水平显著低于足月新生儿(P<0.001);血清脂联素水平与胎龄(r-0.386 P<0.005)、出生体质量(r=0.432 P<0.005)均呈显著正相关 结论 早产儿具有较低血清脂联素水平;胎儿宫内发育不良引起早产或低出生体质量,进而降低其血清脂联素水平,可能是该群体日后发生2型糖尿病、动脉粥样硬化、代谢综合征的重要危险因素     

Human milk mineral intake and serum concentrations of calcium and phosphorus in newborn term infants: influence of intrauterine growth restriction

A prospective case-control study was performed to test the hypothesis that the milk Ca and P contents of term, small-for-gestational-age (SGA) newborns' mothers differs from that of term, adequate-for-gestational-age (AGA) newborns' mothers. We studied 71 pairs of mothers and newborns, divided into two groups: I (control): 41 pairs of mothers and term AGA newborns and II (study): 30 pairs of mothers and term SGA newborns. This latter group was subdivided according to type (symmetric: birthweight, length and head circumference <10th percentile; asymmetric: birthweight <10th percentile) and severity (P3 - P3 - 相似文献   

Bone Mineral Content in Preterm Infants at Age 4 to 16

Using photon absorptiometry the forearm bone mineral content (BMC) was determined in 75 children aged 4 to 16, who all had a low birth weight. Forty-five of them were born preterm AGA (27 boys, 18 girls, mean weight 1580 g; range 920-2060 g) and 30 preterm SGA (17 boys, 13 girls, mean weight 1510; range 940-2130 g). The results were compared with a control group of children of the same age, and analyses of covariance with age, height and weight as the covariant factors were performed. The BMC, weight and height did not differ between the children born AGA or SGA. Irrespective of AGA or SGA, the BMC was significantly decreased in boys but the difference was less pronounced and less significant when height and weight were used as covariant factors. Boys who had been born preterm had a less BMC than the control boys for their age but the were also somewhat shorter and lighter than expected with regard to their age.     

Ponderal index as a predictor of neonatal morbidity in small for gestational age infants

Seventy four consecutively born small for gestational age infants (birth weight<10th centile) were classified into two groups based on the nutritional status at birth as determined by the ponderal index (weight gm/length cm³×100). All the infants had a ponderal index below the 50th centile. The disproportionately grown infants (52·7%) (PI<3rd centile) were more frequently affected by birth asphyxia, polycythemia and hypothermia than their more proportionately grown (47·3%) (PI>10th centile) counterparts. Thus the identification of disproportionately grown small-for-gestational age infants, which constitute a high risk group among the small-for-gestational age infants, is important at birth.     

Children born small for gestational age are not at special risk for preschool emotion and behaviour problems

Despite the wealth of literature examining long term outcomes of preterm low birthweight children, few studies have directly assessed the developmental impact of being born full term but small for gestational age (SGA). We aim to determine whether (i) being SGA increases preschool behavioural problems and (ii) other risk factors operate differently in SGA and appropriate for gestational age (AGA) controls. 550 New Zealand European mothers and their 3.5 year old children participated in this study. All children were born at full term (>37 weeks' gestation) and approximately half were SGA (≤sex specific 10th percentile for gestation) the remainder were AGA controls. Extensive data were collected at the child's birth, 1 year and 3.5 years. Behavioural problems were measured when children were 3.5 years, using the Strengths and Difficulties Questionnaire (SDQ). Multiple regression analyses were used to examine the associations between risk factors and behavioural problems; statistical weighting was used for analyses of the total study group. There was no significant difference in behavioural problems between SGA and AGA groups. In the total sample the significant predictors of behavioural problems included: mothers' school leaving age; smoking during pregnancy; maternal alcohol use during pregnancy; and absence of the father. Predictors of behavioural problems were found to be the same for SGA and AGA groups. These results do not support the view that SGA is a risk for behavioural preschool difficulties or that SGA children are sensitised to risks known to be associated with such difficulties in the preschool years.     

Development and behaviour of low-birthweight term infants at 8 years in northeast Brazil: a longitudinal study

Aim: To investigate the development and behaviour of low-birthweight (LBW) term infants compared with matched term infants of appropriate birthweight (ABW).

Methods: Two parallel cohorts of LBW infants (1500-2499 g) and ABW controls (3000-3499 g) were enrolled at birth in northeast Brazil. At 8 y, 164 children were assessed using clinical and psychological tests.

Results: The LBW group had lower IQ scores than ABW children on the Weschler Intelligence Scale for Children; differences were larger on the performance (5 points, p = 0.04) than the verbal scale (3 points, p = 0.11). LBW children had poorer dynamic balance (p = 0.03) and eye-hand coordination (p = 0.02), but better selective attention (p = 0.02). Hyperactivity and conduct problems were common in both groups, but fewer LBW children had peer problems (p = 0.04). After controlling for social background, IQ was not significantly associated with birthweight (p = 0.10). Significant determinants were maternal education, home stimulation and type of school attended. The effect of birthweight on coordination and selective attention remained significant. Birth head circumference and growth in head size in the first 6 mo had independent effects on IQ.

Conclusion: After controlling for social background, LBW term infants did not differ from ABW infants in cognition at school age. Head circumference at birth and 6 mo was a better predictor than birthweight of IQ.     

Modelling of Reference Values for Size at Birth

ABSTRACT. Data from the Swedish Medical Birth Registration, 1977–1981 were used to apply methods of constructing reference standards for size at birth. Using clinical information a 'healthy' sub-population was extracted. The conditional distributions of birthweight (BW) and birth-length (BL) for each week of Gestational age, and the conditional distribution of birthweight given birthlength were modelled using truncated Normal distributions, after making use of Box-Cox power transformations. Spline functions were then used in conjunction with a multiplicative method to obtain appropriate percentage point curves. Examples of this analysis are given.     

Prediction of early tolerance to enteral feeding by measurement of superior mesenteric artery blood flow velocity: appropriate- versus small-for-gestational-age preterm infants

AIM: To evaluate whether serial Doppler measurements of superior mesenteric artery blood flow velocity could predict early tolerance to enteral feeding in preterm infants. METHODS: In a prospective study, 54 healthy preterm neonates were assigned to one of the following groups: neonates with birthweight appropriate for gestational age (group 1), neonates small for gestational age without (group 2) and with prenatal haemodynamic disturbances (group 3). We studied Doppler blood flow velocity and resistance index before and after the first feed. RESULTS: Contrary to patients of group 3, infants in groups 1 and 2 showed a significant increase in blood flow velocity and a significant decrease in resistance index from the preprandial values after the first feed. At each postprandial time, we found significant differences in all velocity and resistance measurements between patients of group 3 and patients of both groups 1 and 2. In all patients, we found that the value of mean velocity measured 30 min after the first feed was the most predictive of early feed tolerance, with 95% sensitivity and 94% specificity when mean velocity >0.38 m/s. CONCLUSION: Small-for-gestational-age preterm infants with prenatal haemodynamic disturbances have an unusual intestinal haemodynamic response to the first feed. In the whole group of preterm infants, the value of mean velocity measured 30 min after the first feed is a good tool for the clinician in predicting early enteral feeding.     

Intrauterine growth retardation and brainstem auditory-evoked response in preterm infants

Intrauterine growth retardation is frequently associated with intrauterine undernutrition, and can deleteriously affect brain function. Twenty-eight premature small for gestational age infants were compared with 28 premature appropriate for gestational age infants to determine whether intrauterine growth retardation was associated with abnormalities in the auditory pathway in the early neonatal period. The auditory pathway was studied between 4-18 wk of life by analysis of brainstem auditory-evoked potentials elicited by a 10/s 75 decibel above normal adult hearing level (dB nHL) click stimulus presented at the infants' ears. Peak latencies of components I, III and V, and interpeak latencies I-III, III-V and I-V, yielded no statistically significant differences between groups. The present study indicates that intrauterine growth-retarded premature infants may not have abnormalities of brainstem auditory-evoked response in the early neonatal period.