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.     

Evaluation of the auxological and metabolic status in prepubertal children born small for gestational age

BACKGROUND: Low birth weight (BW) (<2,500 g) is associated with a high risk of impaired postnatal growth and late metabolic consequences. The aim of this study is to describe the postnatal growth pattern and the metabolic status of children born small for gestational age (SGA) and compare them with premature children born with low (1,500-2,500 g) and very low (<1,500 g) BW. CHILDREN AND METHODS: 104 prepubertal children (47 males and 57 females) aged 3.0 to 8.9 years were divided into four groups according to their birth weight adjusted for gestational age (GA): SGA-premature (SGApr): BW < -2 SD, GA <37 wk (n = 17); SGA-full-term (SGAt): BW < -2 SD, GA >37 wk (n = 29); low birth weight (LBW): BW = 1,500-2,500 g, GA <37 wk (n = 35); very low birth weight (VLBW): BW <1,500 g, GA <37 wk (n = 23). The control group consisted of 27 full-term appropriate for gestational age, prepubertal children matched for age. All children had anthropometric and laboratory measurements. The HOMA model was used to estimate insulin resistance (IR). RESULTS: Weight, height and body mass index (BMI) were significantly lower in the SGA groups -- both term and premature -- (p <0.05) and particularly lower in the VLBW children (p <0.01). At the age of 36 months, 99.6% of SGAt and a smaller percentage of SGApr (88.2%) children achieved catch-up growth. IGF-I and IGFBP-3 levels were lower in the children born SGA, both term and premature, compared to the controls (p <0.05) and especially in those who had catch-up after the age of 6 months (p <0.002). VLBW children aged 6-8.9 years had significantly higher HOMA compared to controls of the same age group (p = 0.005), whereas no evidence of IR was found in the SGA children. None of the children had developed premature adrenarche by the day of examination. CONCLUSIONS: Prepubertal children born SGA and VLBW are thinner and shorter than their age-matched controls. A larger percentage of SGA full-term children achieve catch-up growth than SGA premature children by 3 years of age. SGA children and especially those with late catch-up growth have lower IGF-I levels. Children with VLBW show evidence of IR at age 6-8.9 years. None of the girls showed precocious sexual development by the day of examination.     

Methods of growth assessment for low-birth-weight children

The aim of the study was to establish the trend of physical growth in low-birth-weight (LBW) children, to predict the best method for early diagnosis of growth failure and to make use of biological growth standards for estimation of their postnatal growth. Physical growth of 283 LBW children was longitudinally analysed. The investigated children were divided into 3 groups: group I - AGA preterms, group II - S-f-D infants, group III - SGA preterms. Body weight, length, head circumference and chest circumference were measured at the time of birth and after 1, 2, 3, 6, 9. 12, 18, 24 months of chronological age. In the two groups of preterms (AGA, SGA preterms) chronological age and real values of anthropometric traits were adjusted according to gestational age. For the estimation of growth dynamics, growth velocity indices were calculated. Data basis was statistically analysed (ANOVA, Duncan, Tukey, t-Student tests), and compared with biological standards. Significant differences for physical growth in the 2 groups of preterms according to chronological and gestational age observed (p<0.001; 0.05). It was demonstrated that accelerated growth of preterms in the first months of postnatal life results from the intrauterine growth velocity. The phenomenon of catch-up growth was detected for S-f-D infants. Analysis of physical growth in LBW children showed that not considering gestational age could lead to statistically important mistakes in the estimation of their growth. The method of adjustment of anthropometric traits to gestational age permits the usage of biological standards for the estimation of postnatal physical growth of AGA preterms.     

Serum lipid concentrations and growth characteristics in 12-year-old children born small for gestational age

According to Barker's hypothesis, children born small for gestational age (SGA) are at increased risk for cardiovascular diseases in adulthood. The aim of our study was to determine whether retarded fetal growth is associated with dyslipidemia in childhood and, if so, to find predictive factors in the growth characteristics of SGA children. We studied the serum lipid concentrations of 55 SGA children and their 55 appropriate for gestational age control subjects at the age of 12 y. Growth variables were recorded at birth, 5 y, and 12 y of age. The study group consisted of all full-term SGA children born at our university hospital during a 22-mo period in 1984-1986. Nearly half of the SGA children (47.3%) were in the highest quartile for serum total cholesterol of the appropriate for gestational age children (p = 0.038). In multiple logistic regression analysis, poor catch-up growth in height (odds ratio, 13. 8; 95% confidence interval, 2.0-97.5), female sex (odds ratio, 8.1; 95% confidence interval, 1.3-48.9), and early stage of puberty (odds ratio, 7.5; 95% confidence interval, 1.2-46.5) predicted high cholesterol level in the SGA children. By the age of 5 y, 20 (36.4%) SGA children showed catch-up growth of > or =2 SD scores in height, and 21 (38.2%) SGA children showed catch-up growth of > or =2 SD scores in weight from birth. At the age of 12 y, the SGA children were still significantly shorter (p<0.001) and lighter (p< 0.05) than the appropriate for gestational age children, even though their pubertal development was similarly advanced. In conclusion, to be born SGA has long-term consequences for later growth and may already influence the level of serum total cholesterol before the teens. SGA children with poor catch-up growth in height may be at the highest risk for hypercholesterolemia.     

Variation in size at birth in infants born small for gestational age in Lithuania

The aim of this study was to describe the heterogeneity in body proportions of infants born small for gestational age (SGA), defined by birthweight, and to study the relationship of placental size with neonatal anthropometric measurements. Anthropometry was evaluated in 107 symmetrically and asymmetrically growth-retarded infants born SGA (birthweight <-2 SD) and compared with 181 appropriate-for-gestational age infants (AGA; birthweight and length +/- 2 SD). Study children were born at Kaunas University Hospital during the period from 1 January 1998 to 25 August 2000. Two-thirds of SGA children were light (SGA(W)) and one-third was both light and short (SGA(WL)) for gestational age. Infants in both SGA groups were significantly leaner than AGA children. SGA(WL) infants had significantly larger heads in relation to their length compared with SGA(W) and even AGA children, probably indicating a brain-sparing effect. SGA(WL) children had the lowest mean placental weight, but the highest placental weight to birthweight (PW/BW) ratio. The PW/BW ratio was inversely correlated with most infant measurements; the strongest negative relationship was observed with birthlength and lower leg length. CONCLUSION: There is heterogeneity in children born SGA, defined by birthweight. It is suggested that the two SGA groups represent the continuum of intrauterine growth retardation, with an initial reduction in trophic growth and a subsequent retardation of linear growth. The PW/BW ratio is a strong indicator for impaired prenatal linear growth.     

Longitudinal follow-up of height up to five years of age in infants born preterm small for gestational age; comparison to full-term small for gestational age infants

OBJECTIVE: This aims to conduct a comparative study of the height catch-up rate in preterm small for gestational age (SGA) infants during early childhood by gestational age and identify the factors affecting short stature in comparison to full-term SGA infants. METHODS: 449 SGA infants (214 full-term infants, 73 infants with gestation of less than 32 weeks, and 162 infants with gestation of more than 32 weeks but less than 37 weeks) from 25 institutions in Japan were assessed for catch-up (> or = -2SD) rate in growth by measuring for length/height at 1 year, 3 years and 5 years of age and the risk factors for no catch-up (< -2SD) at 5 years. RESULTS: The overall length/height catch-up rate was 68% at 1 year, 89% at 3 years and 88% at 5 years. The catch-up rate at 3 and 5 years of age in the group with gestation of less than 32 weeks had a rate of 74%, which was significantly less than the other two groups (approximately 90%). A significant factor associated with short stature at 5 years in the group with gestation of less than 32 weeks was the lower length SD score at time of birth, and for preterm infants born more than 32 weeks of gestation and full-term infants, significant factors were the lower maternal height and head circumference at birth. CONCLUSION: SGA infants born less than 32 weeks of gestation had a higher risk of no catch-up and different factors affecting catch-up compared to preterm SGA infants of gestation more than 32 weeks and full-term SGA infants.     

Intrauterine growth retardation: diagnostic and therapeutic approach

Intrauterine growth retardation (IUGR) refers to the fetal growth pattern and assumes that at least 2 intrauterine growth assessments are performed, indicating a low growth velocity in the fetus. The term "small for gestational age" (SGA) does not refer to fetal growth but to the size of the infant at birth. Infants with SGA have a low weight and/or length for their gestational age at birth below the 10(th) percentile or -2 SD. Approximately 3-5% of all newborns are born SGA. The etiology of SGA/IUGR is not known. The majority (80-85%) of infants born SGA catch-up within the normal range by 2 years of age. SGA has also been associated with increased prevalence of hypertension and dyslipidaemia at a relatively young age. Most controlled trials have shown a beneficial effect of GH treatment. The growth response seems to be due to the cumulative dose received, parenteral adjusted height standard deviation score (SDS) and bone age pretreatment, baseline overnight peak of GH and IGF-I levels. During GH treatment, children born SGA show a significant increase in fasting levels of insulin and proinsulin and a decrease in insulin sensitivity. Fasting glucose levels significantly increase. All these effects are reversible upon interruption of treatment. However, fasting insulin concentrations as well as glucosylated hemoglobin must be carefully monitored during GH treatment. Total cholesterol, LDL cholesterol and the atherogenic index significantly decrease during GH treatment. An acceleration of bone maturation with GH treatment has been reported even though a gain in height SDS for bone age is demonstrated.     

Catch-up growth of head circumference of very low birth weight,small for gestational age preterm infants and mental development to adulthood

OBJECTIVE: To examine the influence of postnatal energy quotient (EQ, energy intake/kg body weight per day) on head circumference (HC) growth and mental development of very low birth weight (VLBW), small for gestational age (SGA, <10th percentile) preterm infants. STUDY DESIGN: SGA VLBW preterm infants (n = 46) with primarily symmetric intrauterine growth restriction were compared with 62 appropriate for gestational age (AGA) VLBW preterm infants and 73 term infants from the Bonn Longitudinal study. RESULTS: Twenty-seven of 46 (59%) of the SGA preterm infants showed complete HC catch-up growth by the age of 12 months, but mostly before 6 months after term (HC catch-up group). These infants had significantly higher mean EQs from day 2 to 10 than the group of 19 infants without HC catch-up (EQ, 95 vs 78). Mean EQs correlated significantly with developmental and intelligence quotients (DQ/IQ) from 18 months to 6 years. As adults, the HC of the HC catch-up group was not significantly different from that of the AGA preterm infants, the term infants, and their parents. The group without HC catch-up had smaller HC as adults. CONCLUSIONS: Our data suggest that early postnatal high-energy nutrient intake for SGA preterm infants is needed to promote HC catch-up growth and to prevent negative consequences of undernutrition.     

Growth of premature infants fed own mother's milk supplied with two milk formulas

The purpose of the authors in this article was to evaluate the effects of supplementing maternal milk with two different caloric formulas on the growth of premature newborns until they reached 40 weeks of post-conceptional age. Seventy premature infants weighing < 1750g at birth were randomized: 35 adequate for gestational age (AGA) and 35 small for gestational age received maternal milk and either a special preterm formula or a modified formula. Anthropometric measurements and clinical evaluations were used to determine the nutritional status and the postnatal growth of these infants, who were analyzed in six different moments: at maximum weight loss, at return to birth weight, at definite weight gain, when exclusively fed with formula, at 2000g, and when they reached 40 weeks of post-conceptional age. The AGA premature newborns on preterm formula had greater daily weight gain, cephalic circumference increase and growth. The SGA premature newborns on preterm formula had greater daily weight gain and cephalic circumference increase observed from the third week of life onward. The AGA premature newborns on modified formula had less weight gain and smaller increments in the cephalic circumference. The SGA premature on modified formula had the worst anthropometric results. The preterm formula was more efficient than the modified formula in promoting postnatal growth of AGA and SGA premature infants. We believe that, due to their special characteristics, SGA premature should receive individualized nutritional caloric planning     

Longitudinal follow-up of growth in children born small for gestational age

Postnatal growth was followed in a population-based group of 123 small-for-gestational-age (SGA, birth weight < -2 SD) children (66 boys and 57 girls) to four years of age in order to determine the incidence and time of catch-up growth. Gestational age was determined by ultrasound in gestational weeks 16–17 in all pregnancies, thus eliminating the problem of distinguishing between SGA and preterm infants. Infants with well-defined causes for slow growth rate, i.e. those infants with chromosomal disorders, severe malformations, intrauterine viral infections or cerebral palsy, were excluded. The boys showed an extremely fast weight catch-up, 85% of them reaching weights greater than -2 SD at the age of three months and remaining above this level to the end of the study period. Such a fast catch-up growth was observed in only two-thirds of the girls, but at four years of age 85?4 of the girls were also above -2SD. Length catch-up was more gradual than weight catch-up. Of the boys, 54% had lengths below -2 SD at birth, 26% at 1 year of age, 22% at 2 years of age, 17% at 2.5 years of age and 11% (n= 8) at 4 years of age. Corresponding figures for girls were: 69% at birth, 28%) at 1 year, 15% at 2 years, 12% at 2.5 years and 5%) (n = 3) at 4 years. At 4 years of age, only six boys and three girls remained below -2 SD for both weight and height. We conclude that in Sweden the prognosis for catch-up growth for an SGA child, when children with well-defined causes of growth disturbances are excluded, is very good and it is extremely rare for the child still to have a height below -2 SD by the age of 4 years.     

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。     

Catch-up growth up to ten years of age in children born very preterm or with very low birth weight

Background  

Improved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of these children and aim to identify factors associated with postnatal catch-up growth.     

Catch-up growth of supine length/height of very low birth weight, small for gestational age preterm infants to adulthood

OBJECTIVE: To analyze linear growth of very low birth weight (VLBW), small for gestational age (SGA; < 10th percentile) preterm infants from birth as to catch-up or no catch-up growth. STUDY DESIGN: VLBW SGA preterm infants (n = 46) with primarily symmetric intrauterine growth restriction from the Bonn Longitudinal Study were compared with 62 appropriate for gestational age (AGA) VLBW preterm and 73 term infants and with their parents. RESULTS: Forty-six percent of VLBW SGA (21 of 46) had complete height catch-up by adult age, and most became taller than target height (TH) (15 of 21; 71%). The others did not catch up; most of them remained shorter than TH (18 of 25; 72%) after initial catch-up followed by catch-down growth. Mean adult height z-score was lower than that for birth length. Mean body mass index was similar in the catch-up and no catch-up groups (21.8 and 21.3, respectively) and lower than in the controls (23.2). Approximately 1/2 of the head circumference (HC) catch-up children achieved height catch-up as well. CONCLUSIONS: Height catch-up extended beyond age 6 years, independent of HC growth. We could not predict height catch-down or successful catch-up.     

Breastfeeding and catch-up growth in infants born small for gestational age

Postnatal growth was prospectively measured from birth to 1 y in 54 term infants born small for gestational age (SGA), fed either breast milk or a standard term infant formula. Breastfeeding was associated with a 0.36 and 0.64 standard deviation (SD) increase in weight at 2 weeks and 3 months of age. respectively, which persisted beyond the breastfeeding period (0.64 SD at 1 y). Breastfed infants also showed greater catch-up growth in head circumference [SD score (SDS) 0.53 higher at 3 months], and greater body length gain (SDS 0.68 higher at 6 months). This increased growth was independent of potentially confounding obstetric, social and demographic factors. Our findings suggest that breastfeeding may promote faster growth in infants compromised by poor growth in utero. SGA infants may be programmed for a number of adverse outcomes; the possibility that such events are altered by choice of postnatal diet is a key issue for future research.     

Longitudinal study of the pubertal growth spurt in children born small for gestational age without postnatal catch-up growth

Most children born small for gestational age (SGA) experience extensive catch-up growth during the first months of life (87%) and by the age of 2 years only 13% are below -2 SDS for height. The long-term outcome, including pubertal growth spurt, of the subset of children born SGA without postnatal catch-up (SGAWPC) has been evaluated in very few surveys, and in none of them was the landmarks of puberty well described. Thus, a longitudinal study was conducted in these children throughout puberty since this is the only reliable way to accurately evaluate the pubertal growth spurt. In an observational, retrospective and multicenter collaborative study, from an initial group of 553 SGA children, a subset of 15 boys (BW = 2,070 +/- 379.6 g) and 16 girls (BW = 2,244 +/- 331.1 g) SGAWPC whose data were recorded regularly during puberty were selected. Growth standards for growth and maturity during puberty were Tanner and Whitehouse and Spanish Hernandez and Sobradillo charts. In pubertal growth spurt, 'take-off' occurred later than in the reference populations with a height SDS deficiency of -2.3 and -2.2 for boys and -2.0 and -1.9 for girls, compared with Spanish and Tanner references, respectively. Peak height velocity was normal in chronology and intensity, but the total pubertal gain was smaller. However, considering their growth from the same chronological age at which the reference populations took off until adulthood, the total gain was not significantly different in the three cohorts (32.5 +/- 5.4 cm vs 30.9 +/- 4.4 in boys, and 23.3 +/- 4.1 vs 25.7 +/- 5.4 cm in girls - Spanish reference - and 27.2 +/- 6.3 vs 27.6 +/- 3.5 cm in boys - Tanner charts), except in the case of girls (21.1 +/- 3.9 vs 25.3 +/- 4.1 cm, p <0.005 - Tanner charts). Adult height was significantly reduced (161.9 +/- 3.9 cm in males and 147.0 +/- 2.6 cm in females). Therefore, although the pubertal growth was smaller in these children, puberty probably did not modify their short final height.     

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.     

Final height in short children born small for gestational age treated with growth hormone

The aim of this observational study was to assess the long-term growth responses to GH treatment of children born small for gestational age (SGA). GH treatment was begun before puberty and continued to final height (FH). Seventy-seven short (height SD score below -2) prepubertal children born SGA (below -2 SD for birth weight and/or birth length), with a broad range of GH secretory capacity, were treated with GH in a daily dose of 33 microg/kg (0.1 U/kg), beginning before the onset of puberty. We observed a difference between adult and pretreatment projected height of 1.3 SD (9 cm) for the entire group. Among the children treated for >2 y before puberty, this mean gain (i.e. difference) in final height was 1.7 SD, whereas the mean gain was 0.9 SD among those in whom treatment was begun <2 y before puberty. Better catch-up growth was observed in the younger (r=-0.56, p<0.0001), shorter (r=-0.49, p<0.0001), and lighter (r=-0.46, p<0.0001) subjects. We conclude that GH treatment improves the final height of short children born SGA. The height gain attained before the onset of puberty is maintained to final height. The younger, shorter, and lighter the child at the start of GH treatment, the better the response. Moreover, most of these SGA individuals treated with GH reach their target height.     

Postnatal growth in VLBW infants: significant association with neurodevelopmental outcome

OBJECTIVE: To study the significance of growth status at birth and postnatal growth on neurodevelopmental outcome in very low birth weight (VLBW) infants. STUDY DESIGN: Growth and neurodevelopment were examined in 219 VLBW (<1250 g) children, 94 small for gestational age (SGA) (<10th percentile) and 125 appropriate for gestational age (AGA) (>10th percentile). Outcome at age 2 was assessed with the Bayley Scales of Infant Development (Mental Developmental Index [MDI], Psychomotor Developmental Index [PDI]) and a standardized neurologic examination. RESULTS: SGA status was not associated with poor neurodevelopmental outcome. However, after adjustment for covariables including cerebral palsy (CP), SGA children with weight <10th percentile at age 2 had lower mean PDI than SGA children with catch-up growth to weight >10th percentile (mean [SD], 89.9 [17.4] versus 101.8 [14.5]; P<.001). AGA children with catch-down growth (weight <10th percentile at age 2) were, independent of CP, more likely to have lower mean MDI (94.9 vs 101.7, P=.05) and PDI (81.9 vs 95.1; P<.001) than AGA children remaining >10th percentile at age 2. They also more frequently had severe CP (22.9% vs 1.2%; P=.008). CONCLUSIONS: In VLBW children, the course of postnatal growth rather than the appropriateness of weight for gestational age at birth determines later neurodevelopmental outcome.