Growth patterns of low birth weight preterm infants: a longitudinal analysis of a large, varied sample

Prenatal tobacco and cannabis co-exposure and offspring obesity development from birth to mid-childhood

BACKGROUND

Although the association between prenatal tobacco exposure and child obesity risk is well-established, less is known about co-exposure to tobacco and cannabis.

OBJECTIVE

Determine the relation between prenatal substance co-exposure and obesity risk.

METHODS

In a diverse sample of pregnant women, we examined the association between prenatal substance exposure (tobacco-only and co-exposure) and child BMI (kg/m2 ) trajectories from birth to mid-childhood (n = 262), overweight/obese status based on BMI percentiles from toddlerhood (24 months) to mid-childhood (9-12 years), and adiposity outcomes at mid-childhood (fat mass [kg], fat mass [%] and fat free mass [kg]; n = 128). Given that the major goal of this study was to examine the associations between prenatal substance exposure and child outcomes, we oversampled pregnant women for substance use (with tobacco as the primary focus).

RESULTS

Multilevel models demonstrated that children in both exposure groups had a steeper increase in BMI trajectory from birth to mid-childhood and among co-exposed children, girls had a steeper increase than boys. Odds ratio of having obesity by mid-childhood was 12 times higher among those co-exposed than non-exposed. Co-exposure led to significantly greater fat mass and fat mass % compared with no exposure, but exposure to only tobacco was no different than no exposure.

CONCLUSIONS

Results highlight potentiating effects of cannabis exposure in the context of maternal tobacco use in pregnancy on obesity risk and the importance of multi-method assessments of obesity.

Postnatal Growth Trajectories and Neurodevelopmental Outcomes Following Bevacizumab Treatment for Retinopathy of Prematurity

Purpose

To investigate the postnatal growth and neurodevelopment of infants with retinopathy of prematurity (ROP) treated with intravitreal bevacizumab (IVB).

Patients and Methods

This was a retrospective comparative study. A total of 262 infants were divided among three study groups: 22 treated with intravitreal bevacizumab, 55 treated with laser, and 185 with ROP that resolved without treatment. Infants with nonviable course or hydrocephalus, a source of non-physiologic weight gain, were excluded. Neurodevelopment was assessed with Bayley III scores at 17–28 months if available and presence of hearing loss or cerebral palsy. Weekly weight, height, and head circumference from birth through 50 weeks postmenstrual age (PMA) were modeled to determine differences in growth trajectories following treatment.

Results

Comparison of postnatal growth curves from the time of treatment to 50 weeks PMA showed no significant differences in growth trajectories between groups after adjusting for the corresponding growth parameters at birth. Comparison of Bayley scores in patients with available data (n = 120) showed no significant differences. There was an increased risk of cerebral palsy in the IVB group after logistic regression adjusting for baseline confounders, but this did not retain statistical significance after applying the false discovery rate correction for multiple testing.

Conclusion

To our knowledge, this is the first large retrospective study to examine longitudinal growth in infants treated with IVB compared to controls. There were no significant differences in postnatal growth or neurodevelopmental outcomes between groups, which overall continue to support the safety of bevacizumab treatment for ROP.

Associations of infant appetitive traits during milk feeding stage with age at introduction to solids and sweet food/beverage intake

BACKGROUND

Suboptimal feeding behaviors during infancy, such as introducing solids prior to 4 months and providing foods containing added sugars, are associated with increased risk of later obesity. Although focus group studies suggest that infant appetitive traits during milk feeding stage may influence complementary feeding practices, quantitative evidence on this relationship is lacking.

METHODS

This study included women who were followed from first trimester to 1-year postpartum. At 6-months postpartum, mothers (n = 217) completed the Baby Eating Behavior Questionnaire which assesses infant appetitive traits during exclusive milk-feeding (food responsiveness, satiety responsiveness, slowness in eating, enjoyment of food and general appetite). Mothers reported infant dietary intake via a food frequency questionnaire (FFQ) administered at 6, 9 and 12 months, from which age at introduction to solids and sweet foods/beverages, and 6- and 12-month sweet food/beverage intake frequency, were calculated. Linear regression analyses examined the relationship of appetitive traits with age at introduction to solids and sweet foods/beverages, and frequency of sweet food/beverage intake, whereas logistic regression examined associations of appetitive traits with odds of introduction to solids prior to 4 months.

RESULTS

Greater infant enjoyment of food was associated (B±SE = 0.45 ± 0.18, p = 0.01) with higher age at introduction to solids. Slowness in eating was inversely associated with 12-month sweet food/beverage intake frequency (B±SE = -0.25 ± 0.10, p = 0.01). Other associations of appetitive traits with age at introduction to solids and sweet food/beverage exposure were not statistically significant.

CONCLUSIONS

Findings imply that lower infant enjoyment of food and greater speed of eating during the period of exclusive milk-feeding could be associated with suboptimal complementary feeding practices. Understanding how parents respond to infant appetitive traits may be important considerations in efforts to promote appropriate complementary feeding practices during infancy.

What is the effect of preterm birth on permanent tooth crown dimensions? A systematic review and meta-analysis

BACKGROUND

The permanent tooth formation process may be disrupted in preterm infants with potential discrepancies in size and subsequent occlusal disturbances.

OBJECTIVE

To systematically analyse and quantitively synthesize the available evidence regarding the impact of preterm birth on permanent tooth crown dimensions.

SEARCH METHODS

Unrestricted searches in 6 databases and manual searching of the reference lists in relevant studies were performed up to March 2021 (Medline via PubMed, CENTRAL, Cochrane Database of Systematic Reviews, Scopus, Web of Science, ProQuest Dissertations and Theses Global).

SELECTION CRITERIA

Observational studies investigating permanent tooth crown dimensions in preterm and control full-term born individuals.

DATA COLLECTION AND ANALYSIS

Following study retrieval and selection, relevant data were extracted, and the Newcastle-Ottawa scale was used to assess the selection, comparability, and outcome domains. Exploratory synthesis and meta-regression were carried out using the random effects model.

RESULTS

Three studies were located from the initially retrieved records and the assessments with the Newcastle-Ottawa scale identified issues regarding the selection and comparability domains. Overall, the mesiodistal and the buccolingual dimensions of the permanent teeth in both dental arches tended to be smaller in children born prematurely than full term children. Subgroup analyses showed statistically significant differences for the extremely preterm to control group comparisons for the incisors and the first molars. Meta-regression showed a modificatory effect of gestational age and racial background but not of birth weight and gender on tooth size. The quality of available evidence was rated at best as moderate.

CONCLUSIONS

Premature birth could potentially be associated with reduced tooth-crown dimensions in some permanent teeth especially in children born extremely preterm. Although the results from these observational studies should be approached with caution until more information becomes available, the possible clinical implications in terms of diagnosis and treatment planning should be considered.

REGISTRATION

PROSPERO (CRD42020182243).

Development of growth equations from longitudinal studies of body weight and height in the full term and preterm neonate: From birth to four years postnatal age

Physiologically based pharmacokinetic (PBPK) models are developed from compound-independent information to describe important anatomical and physiological characteristics of an individual or population of interest. Modeling pediatric populations is challenging because of the rapid changes that occur during growth, particularly in the first few weeks and months after birth. Neonates who are born premature pose several unique challenges in PBPK model development. To provide appropriate descriptions for body weight (BW) and height (Ht) for age and appropriate incremental gains in PBPK models of the developing preterm and full term neonate, anthropometric measurements collected longitudinally from 1,063 preterm and 158 full term neonates were combined with 2,872 cross-sectional measurements obtained from the NHANES 2007-2010 survey. Age-specific polynomial growth equations for BW and Ht were created for male and female neonates with corresponding gestational birth ages of 25, 28, 31, 34, and 40 weeks. Model-predicted weights at birth were within 20% of published fetal/neonatal reference standards. In comparison to full term neonates, postnatal gains in BW and Ht were slower in preterm subgroups, particularly in those born at earlier gestational ages. Catch up growth for BW in neonates born at 25, 28, 31, and 34 weeks gestational age was complete by 13, 8, 6, and 2 months of life (males) and by 10, 6, 5, and 2 months of life (females), respectively. The polynomial growth equations reported in this paper represent extrauterine growth in full term and preterm neonates and differ from the intrauterine growth standards that were developed for the healthy unborn fetus.

Monitoring postnatal growth of preterm infants: present and future

BACKGROUND

There is no consensus with regard to which charts are most suitable for monitoring the postnatal growth of preterm infants.

OBJECTIVE

We aimed to assess the strategies used to develop existing postnatal growth charts for preterm infants and their methodologic quality.

DESIGN

A systematic review of observational longitudinal studies, having as their primary objective the creation of postnatal growth charts for preterm infants, was conducted. Thirty-eight items distributed in 3 methodologic domains ("study design," "statistical methods," and "reporting methods") were assessed in each study. Each item was scored as a "low" or "high" risk of bias. Two reviewers independently selected the studies, assessed the risk of bias, and extracted data. A total quality score [(number of "low risk" of bias marks/total number of items assessed) × 100%] was calculated for each study. Median (range, IQR) quality scores for each methodologic domain and for all included studies were computed.

RESULTS

Sixty-one studies met the inclusion criteria. Twenty-seven (44.3%) of the 61 studies scored ≥50%, of which 10 scored >60% and only 1 scored >66%. The median (range, IQR) quality score for the 61 included studies was 47% (26-75%, 34-56%). The scores for the domains study design, statistical methods, and reporting methods were 44% (19-67%, 33-52%), 25% (0-88%, 13-38%), and 33% (0-100%, 0-33%), respectively. The most common shortcomings were observed in items related to anthropometric measures (the main variable of interest), gestational age estimation, follow-up duration, reporting of postnatal care and morbidities, assessment of outliers, covariates, and chart presentation.

CONCLUSIONS

The overall methodologic quality of existing longitudinal studies was fair to low. To overcome these problems, the Preterm Postnatal Follow-up Study, 1 of the 3 main components of The International Fetal and Newborn Growth Consortium for the 21st Century Project, was designed to construct preterm postnatal growth standards from a prospective cohort of "healthy" pregnancies and preterm newborns without evidence of fetal growth restriction.

Trajectories of length, weight, and bone mineral density among preterm infants during the first 12 months of corrected age in China

Background

Limited evidence has been provided on the trajectories of length, weight, and bone mineral density (BMD) among preterm infants in early life in Asian countries.

Methods

We conducted a longitudinal study, which included 652 late preterm (gestational age: 34–36.9 weeks), 486 moderate preterm (32–33.9), 291 very preterm (28–31.9), 149 extremely preterm infants (≤28.9) and 1434 full-term peers (≥37) during the first 12 months of corrected age in Wuhan, China. Weight and length were measured at birth, once randomly before term, and every month thereafter. BMD was examined at 3, 6, 9 and 12 months using dual-energy X-ray absorptiometry.

Results

From birth to 12 months of corrected age, growth peaks in length and weight were observed at 1–3 months among preterm infants. No catch-up growth in length, weight, and BMD was observed among preterm infants. However, accelerated growth in length, weight, and BMD was found. Among extremely preterm infants, relative to full-term infants, length was −6.77 cm (95 % CI: −7.14, −6.40; P for trend < 0.001) lower during the first 12 months; weight was −1.23 kg (−1.33, −1.13; P for trend < 0.001) lower; and BMD was −0.070 g/cm²(−0.087, −0.053; P for trend < 0.001) lower; however, average growth rates of these measures were higher (Ps < 0.05). Small gestational age and low birth weight were independently associated with lower length, weight, and BMD.

Conclusion

Growth peaks in length and weight among preterm infants were observed at 1–3 months. No catch-up growth in length, weight, and BMD was observed, however, there was accelerated growth in length, weight, and BMD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0396-6) contains supplementary material, which is available to authorized users.

Evaluation of growth in very low birth weight preterm babies

AIM

The aim of this study was to evaluate physical growth of very low birth weight (VLBW) preterm babies at a mean age of three years and to investigate the factors which affected growth.

MATERIAL AND METHODS

The factors including maternal problems, prenatal problems, early neonatal problems, nutrition, familial socioeconomical status and presence of chronic disease which affected catch-up growth in terms of height and weight in VLBW infants followed up in the neonatal intensive care unit (NICU) of our hospital were examined. The target height formula was used in assessment of growht in height and the contribution of genetic properties was investigated. The points of the subjects on the growth curve were plotted according to the Percentile Curve of the Turkish Children prepared by Neyzi et al. The states of the subjects with and without intrauterine growth retardation (were compared. The study was intitiated after obtaining approval from the ethics committeee of our hospital (100/25.10.2005).

RESULTS

One hundred and seventeen preterm babies (57 females and 60 males) with a mean adjusted age of 35.8±2.39 80 of whom were appropriate for gestational age (AGA), 28 of whom were symmetrical (small gestational age) SGA and 9 of whom were asymmetrical SGA were included in the study. The mean gestational age (GA) was found to be 31±2.16 weeks and the mean birth weight (BW) was found to be 1271±226 g. The mean current height was found to be 92.06±4.90 cm. The mean weight was found to be 12.98±1.94 kg. The mean target height was calculated to be 163.66±8.1 cm (157.20 cm for the girls and 170.20 cm for the boys). It was found that 15 preterm babies (12.8%) could not achieve the target height (girls: 6%, boys: 6.8%). The risk factors related with failure to achieve target height were found to include ventilator treatment, presence of chronic disease, advanced stage intracranial bleeding (ICB), posthemorrhagic hydrocephalus, absence of breastfeeding, failure to sit at the table with the family and malnutrition. The maternal age, early rupture of membranes (PROM), preeclampsia, smoking, early neonatal problems, gender, being AGA and SGA, gestational age, birth weight and socioeconomical level were statistically insignificant in terms of achieving target height (p>0.05).

CONCLUSIONS

If very low birth weight preterm babies have no chronic disease and condition leading to neurodevelopmental retardation and if they are breastfed early and continuously (0-24 months), they can achieve catch-up growth similar to term babies. In examination of growth in terms of height, using target height may be more appropriate to shown the genetic potential.

Simulated growth trajectories and blood pressure in adolescence: Hong Kong's Chinese Birth Cohort

BACKGROUND

Patterns and amounts of growth may determine adult blood pressure. Growth at different phases is correlated and affects current size, making effects on blood pressure difficult to distinguish. We decomposed growth to 13 years into independent associations with blood pressure and estimated how reaching the same size by different routes could affect adolescent blood pressure.

METHODS

Using estimates from partial least squares for the associations of birth weight, height, and BMI at 3 months, growth at 3-9 months, 9-36 months, 3-8 years and 8-13 years and size at 13 years with SBP and DBP in 5247 term births (67% follow-up) from Hong Kong's 'Children of 1997' Birth Cohort, we estimated SBP and DBP at 13 years for 99 simulated growth trajectories resulting in the same size using nonparametric bootstrapping.

RESULTS

High birth weight followed by slower growth was associated with lower SBP in both sexes and DBP in boys. Greater height to 3 years followed by slower height growth was associated with lower SBP in boys. Higher BMI until 9 months followed by slower BMI growth was associated with lower blood pressure in boys.

CONCLUSION

High birth weight or larger early size was associated with lower blood pressure if followed by slower later growth, consistent with the fetal origin hypothesis. However, whether these patterns are due to fetal and infant metabolic programming or to allowing slower growth at periods when rapid growth is harmful is unknown.

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 <-2 SD of the respective 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.

Lifetime growth and blood pressure in adolescence: Hong Kong's "Children of 1997" birth cohort

OBJECTIVES

Blood pressure tracks from adolescence to adulthood and is positively associated with low birth weight and faster infant growth. Most observations are from Western populations; it is unclear whether these are biologically based or contextually specific. We examined the associations of growth with blood pressure in adolescence.

METHODS

Multivariable partial least squares regression was used to assess the associations of growth to ~11 years with blood pressure at ~11 years in 5813 term births from Hong Kong's Children of 1997 birth cohort. Growth was considered as gender- and age-specific z-scores for birth weight, BMI, and length at 3 months; change in z-scores for BMI and height at 3 to 9 months, 9 to 36 months, 3 to 7 years, and 7 to 11 years; and BMI and height at 11 years.

RESULTS

Birth weight was weakly inversely associated with systolic blood pressure in girls -0.58 mm Hg 95% confidence interval -1.05 to -0.12 (boys -0.21, -0.71 to 0.30). Childhood growth, particularly linear growth at 7 to 11 years (girls: 1.27, 0.56 to 1.98; boys 2.11, 1.39 to 2.83), as well as current height (girls: 2.40, 2.04 to 2.76, boys: 2.65, 2.29 to 3.01) and BMI (girls: 2.72, 2.35 to 3.09, boys: 2.72, 2.09 to 3.36) were associated with higher systolic blood pressure. Diastolic blood pressure was also positively associated with current size.

CONCLUSIONS

In the first study to examine simultaneously the role of pre- and postnatal growth in adolescent blood pressure, the role of late childhood growth predominated.

Biological maturity at birth, the course of the subsequent ontogenetic stages and age at menarche

The main aim of the study was to assess the influence of biological maturity at birth on growth processes in the subsequent years and during puberty in girls. The material of this study comes from the outpatient clinic cards and cross-sectional research on girls from the province of Wielkopolska in Poland. It includes data of 527 girls. The influence of perinatal maturity on body weight in the later stages of ontogeny was determined with the use of the Kruskal-Wallis test and the Mann-Whitney U test. In order to determine the relationship between perinatal maturity and age at menarche, the survival analysis module was used. The results show a diverse influence of perinatal maturity on the values of body weight achieved in later years of life. The indicated predictive factors included both birth weight and gestational age. In the examined girls menarche occurred between the 10th year and the 17th year of life (X¯=12.87, s=1.26; Me=13 years). The comparison showed a significant variation in age at menarche depending on the length of pregnancy (log-rank χ(2)(2)=27.068, p<0.0001) and birth weight (log-rank χ(2)(2)=23.241, p<0.0001). There was no variation in maturation of the examined girls conditioned by the occurrence of intra-uterine growth retardation (log-rank χ(2)(2)=2.046, p>0.05). Remote prognoses as to the postnatal development of preterm-born children and/or children with low birth weight indicate adverse influence of these variables on age at menarche. Perinatal biological maturity of a newborn conditions the course of postnatal development.

Growth and nutrient intakes of human milk-fed preterm infants provided with extra energy and nutrients after hospital discharge

OBJECTIVES

The purpose of this pilot study was to determine whether mixing a multinutrient fortifier to approximately one half of the human milk fed each day for a finite period after discharge improves the nutrient intake and growth of predominantly human milk-fed low birth weight infants. We also assessed the impact of this intervention on the exclusivity of human milk feeding.

METHODS

Human milk-fed (> or = 80% feeding per day) low birth weight (750-1800 g) infants (n = 39) were randomly assigned at hospital discharge to either a control or an intervention group. Infants in the control group were discharged from the hospital on unfortified human milk. Nutrient enrichment of human milk in the intervention group was achieved by mixing approximately one half of the human milk provided each day with a powdered multinutrient human milk fortifier for 12 weeks after discharge. Milk with added nutrients was estimated to contain approximately 80 kcal (336 kJ) and 2.2 g protein/100 mL plus other nutrients. Intensive lactation support was provided to both groups.

RESULTS

Infants in the intervention group were longer during the study period, and those born < or = 1250 g had larger head circumferences than infants in the control group. There was a trend toward infants in the intervention group to be heavier at the end of the intervention compared with those in the control group. Mean protein, zinc, calcium, phosphorus, and vitamins A and D intakes were higher in the intervention group.

CONCLUSIONS

Results from this study suggest that adding a multinutrient fortifier to approximately one half of the milk provided to predominantly human milk-fed infants for 12 weeks after hospital discharge may be an effective strategy in addressing early discharge nutrient deficits and poor growth without unduly influencing human milk feeding when intensive lactation support is provided.

Growth during the first two years predicts pre-school height in children born with very low birth weight (VLBW): results of a study of 1,320 children in Germany

Children born with very low birth weight (VLBW) are at risk of impaired growth. We aimed to study VLBW survivors (90.8%) born in 1998/1999 in the state of Baden-Württemberg (n = 2103) for whom growth data were available up to age six. Classification as appropriate for gestational age (AGA) or small for gestational age (SGA) depended on size at birth. Models to predict height SDS at 5 y were developed using data for 1 yr (Model 1) and 2 yrs (Model 2). The data of 1320 (63%) children were available: SGA: n = 730, AGA: n = 590. At 6 yrs, 8.3% AGA and 13.4% SGA children were short (<-2.0 SDS). The following factors explained Ht SDS at 5 (and 6) yrs (order of importance): (a) Model 1 (n = 1033; R2 = 0.52; error: 0.84 SDS): 1st yr Ht SDS, mid-parental height (MPH) SDS, 1 yr weight SDS, birth weight SDS; (b) Model 2 (n = 991; R2 = 0.72; error: 0.65 SDS): 1st yr Ht SDS; change (2nd yr) in Ht and weight SDS; MPH SDS; 1st yr weight SDS; birth weight SDS. Thus, some AGA and SGA children born VLBW remain short and preventive strategies need to be developed for those at risk.

Nutritional status of low-birthweight ethnic minority infants in Backan province, Vietnam

BACKGROUND

Birthweight and length have been reported to be important determinants of infant growth and future nutritional status. The study aims to describe the weight and length growth patterns during the first year of life of low-birthweight (LBW) ethnic minority infants in the mountainous province Backan, Vietnam.

METHODS

A total of 64 LBW and normal birthweight infants of ethnic minority mothers were recruited from 2001 to 2002 into a prospective cohort study. The weight and length of infants were measured monthly for 1 year. Data on nutritional status and feeding practices of the infants were collected from monthly health records and face-to-face interviews with mothers while their infants were 6 and 12 months of age.

RESULTS

Most of the increase in weight, length and catch-up to the 10th percentile for LBW infants occurred during the first 3 and 6 months for boys and for girls, respectively. After these ages, the mean weight and length diverged from National Center for Health Statistics (NCHS) reference curves to below the 10th percentile. LBW infants' weight-for-age z-scores was below the NCHS standard at birth (-2.16 SD), caught up after birth, became sustainable by 4 months, fell rapidly from the sixth month, then decreased to -2 SD at 12 months of age. LBW infants' length-for-age z-scores increased in the first month after birth, decreased in the second month and sharply increased again until 5 months of age before decreasing.

CONCLUSIONS

For LBW infants, it is difficult to achieve the same weight or length curves at 12 months of age as the NCHS standard.

Two methods for estimating age of newborns in catch-up growth studies

Catch-up growth has been the subject of many studies, but whether and when infants born preterm and with low birth weight achieve normal size is controversial. One of the reasons for diverse results is likely to be the difference in how the infants' ages are calculated. The aim of this work is to analyse the occurrence and chronological distribution of compensational events of 163 infants born preterm conducted according to both chronological and corrected age. Catch-up growth was defined as the compensation of body weight values to those included between +/-1 SD in the reference system. Data were analysed using the survival analysis. Catch-up growth events were observed in greater amount for gestation-adjusted age. The correction of age allows the indication of the age, corresponding to the correct time of birth, as the time of the most rapid growth velocity. Chronological age does not allow any particular time to be distinguished as the most characteristic moment for achievement of constitutional growth. Within the whole studied period there is a similar probability of growth equalisation. A description of the morphological development of preterm infants should not be made in comparison to the postnatal reference system without correction of age, but analyses considering chronological age are necessary when the influence of gestational age is considered.

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.

METHODS

1338 children born with a gestational age <32 weeks and/or a birth weight of <1500 grams were followed during a Dutch nationwide prospective study (POPS). Subgroups were classified as appropriate for gestational age and <32 weeks (AGA) or small for gestational age (<32 wks SGA and > or =32 wks SGA). Data were collected at different intervals from birth until 10 years for the 962 survivors and compared to reference values. The correlation between several factors and growth was analysed.

RESULTS

At 10 years the AGA children had attained normal height, whereas the SGA group demonstrated stunting, even after correction for target height (AGA: 0.0 SDS; SGA <32 wks: -0.29SDS and > or =32 wks: -0.13SDS). Catch-up growth was especially seen in the SGA children with a fast initial weight gain. BMI was approximately 1 SD below the population reference mean.

CONCLUSION

At 10 years of age, children born very preterm AGA show no stunting. However, many children born SGA, especially the very preterm, show persistent stunting. Early weight gain seems an important prognostic factor in predicting childhood growth.

Nutrition for preterm infants after hospital discharge

Preterm infants accrue significant nutrient deficits during hospitalization, and at the time of discharge most VLBW preterm infants have moderate to severe growth failure. Infants with significant morbidities and infants with ELBW have more severe growth failure since they regain birth weight at a later age, and they gain weight more slowly. Catch-up growth accelerates after hospital discharge. The rates of catch-up growth vary according to many factors including birth weight, gestational age, parental size, adequacy of intrauterine growth, neurologic impairment, clinical course, and nutrition. Most catch-up growth occurs within the first 2 to 3 years of life; however, compensatory catch-up growth may continue into adolescence and adulthood. Despite evidence of ongoing catch-up growth, the mean growth measurements of children and adults who were born preterm and with VLBW are lower than their term-born peers. Accelerated rates of catch-up growth are associated with better neurodevelopmental outcomes. Inadequate head circumference growth, in particular, may have long-term prognostic significance for later neurodevelopment in preterm infants. Nutrient-enriched formulas that provide 22 kcal/oz are often prescribed for VLBW preterm infants after hospital discharge. Several studies have reported that preterm infants fed the enriched versus standard term infant formulas have greater rates of catch-up growth during the first year of life, including greater increases in head circumference. The nutrient-enriched formulas appear to be of particular benefit for male infants. There is less information regarding the nutrient needs of breast-fed infants after hospital discharge. However, several studies have demonstrated that preterm infants fed unfortified human milk after discharge have growth rates and bone mass that are lower than formula-fed infants during infancy. The use of fortified human milk, or alternate feedings with a nutrient-enriched formula may be useful for breast-fed infants who have delays in catch-up growth. Additional studies are needed to determine whether enriched feedings might be of particular benefit for preterm infants who are at greater risk for postnatal growth failure, including infants born SGA, or with extremely low birth weights, intrauterine growth restriction, or chronic conditions such as bronchopulmonary dysplasia. The potential effect of nutritional programming on long-term outcomes of preterm infants also requires further investigation.

Postnatal growth retardation: a universal problem in preterm infants

BACKGROUND

Previous data from this unit suggest that postnatal growth retardation (PGR) is inevitable in preterm infants. However, the study was performed in a single level III neonatal intensive care unit and applicability of the findings to other level III or level I-II special care baby units was uncertain.

OBJECTIVES

To examine postnatal hospital growth and to compare growth outcome in preterm infants discharged from four level III tertiary care units and 10 level I-II special care baby units in the former Northern Region of the United Kingdom.

SUBJECTS/METHODS

Preterm infants (< or = 32 weeks gestation; < or = 1500 g) surviving to discharge were studied. Infants were weighed at birth and discharge. Body weight was converted into a z score using the British Foundation Growth Standards. To ascertain the degree of PGR, the z score at birth was subtracted from the z score at discharge. Data were evaluated using a combination of split plot (level III v I-II=main factor; individual centre=subfactor) and stepwise regression analyses. Results were considered significant at p < 0.05.

RESULTS

A total of 659 (level III, n = 335; level I-II, n = 324) infants were admitted over a 24 month period (January 1998-December 1999). No differences were detected in birth characteristics, CRIB score (a measure of illness in the first 24 hours of life), length of hospital stay, weight gain, weight at discharge, or degree of PGR between infants discharged from level III and level I-II units. Significant variation was noted in length of hospital stay (approximately 35%; p < 0.001), weight gain (approximately 33%; p < 0.001), weight at discharge (approximately 20%; p < 0.001), and degree of PGR (approximately 200%; p < 0.001) between the level III units. Even greater variability was noted in the duration of hospital stay (approximately 40%; p < 0.001), weight gain (approximately 60%; p < 0.001), weight at discharge (approximately 40%, p < 0.001), and degree of PGR (approximately 300%, p < 0.001) between the level I-II units.

CONCLUSIONS

These data stress the variable but universal nature of PGR in preterm infants discharged from level III and I-II neonatal intensive care units and raise important questions about nutritional support of these infants before and after hospital discharge.

Growth failure in the preterm infant: can we catch up?

Postnatal growth failure is extremely common in the very low birth weight and extremely low birth weight infant. Recent data from the National Institute of Child and Human Development (NICHD) Neonatal Research Network indicates that 16% of extremely low birth weight infants are small for gestational age at birth, but by 36 weeks corrected age, 89% have growth failure. Follow-up at 18 to 22 months corrected age shows that 40% still have weights, lengths, and head circumferences less than the 10th percentile. Growth failure is associated with an increased risk of poor neurodevelopmental outcome. Inadequate postnatal nutrition is an important factor contributing to growth failure, as most extremely low birth weight infants experience major protein and energy deficits during the neonatal intensive care unit hospitalization, in spite of the fact that nutrition sufficient to support intrauterine growth rates can generally be provided safely. Aggressive nutritional support--parenteral and enteral--is well tolerated in the extremely low birth weight infant and is effective in improving growth. Continued provision of appropriate nutrition (premature formula or fortified human milk) is important throughout the neonatal intensive care unit stay. After discharge, nutrient-enriched postdischarge formula should be continued for approximately 9 months post-term. Exclusively breast-fed infants require additional supplementation/fortification postdischarge as well. Additional trials are needed to address a number of important questions concerning the role of nutrition and growth on ultimate development.

Follow-up data their use in evidence-based decision-making

Experience with certain perinatal interventions, such as supplemental oxygen and dexamethasone, leads to the conclusion that follow-up data are needed to be well informed about the safety of certain perinatal interventions. Experience with indomethacin suggests that follow-up data also are regarded by some clinicians as a necessary aspect of evidence about effectiveness. Ideally, clinical trials of perinatal interventions might involve collection of data about neonatal predictors of outcome (such as a neuroimaging study and a standardized neurologic assessment); several developmental and neurologic assessments before school entry; a comprehensive evaluation of the child's cognitive function, behavioral competencies, and academic performance at 7 to 8 years of age; serial detailed assessments of the family psychosocial functioning; and an inventory of resources available for the child. Many clinical trials have not included follow-up after the neonatal period, and in such cases information about the effect of the intervention on participants' HRQL is incomplete. The approach taken in several recent trials, in which the outcome of interest is neurodevelopmental outcome at 18 months, attempts to strike a balance between a theoretical ideal (a comprehensive, longitudinal follow-up through school age) and a follow-up regimen that is not prohibitively expensive. Such trials include follow-up during the first 1 to 3 years of life, when major disabilities can be identified reliably, thereby providing moderately informative data about participants' eventual quality of life, related to the presence or absence of major disability. If, however, there is reason to suspect that the intervention has effects on the developing brain, follow-up after school entry may provide additional evidence pertinent to the risks and benefits of the intervention.

Evaluation of and recommendations for growth references for very low birth weight (< or =1500 grams) infants in the United States

OBJECTIVE

To determine the best available growth reference for evaluating the growth status of very low birth weight (VLBW; < or =1500 g) infants in the United States.

METHODS

We evaluated currently available growth references for VLBW infants in studies by Casey (Infant Health and Development Program [IHDP]), Brandt, Gairdner and Pearson, and Babson and Benda. We selected the 1 that best met a priori criteria and compared it with the new Centers for Disease Control and Prevention (CDC) growth charts. We evaluated the performance of both the selected VLBW reference and the CDC growth charts for use with VLBW infants by plotting data from 2 external data sets of VLBW infants (from Child Health and Development Studies [CHDS]) and linked the CDC's Pregnancy Nutrition Surveillance System/Pediatric Nutrition Surveillance System Data (PNSS/PedNSS) on both references. Age was adjusted for gestational age in all of the VLBW data set comparisons.

RESULTS

The IHDP reference met the greatest number of our evaluation criteria. The IHDP charts are the most recent, are based on a relatively large sample of VLBW infants in the United States, and are adjusted for gestational age at birth (using the standard of birth at 40 weeks) to account for prematurity. The IHDP VLBW infants, based on corrected postnatal age, compared with the non-VLBW infants included in the new CDC growth charts showed more rapid growth in length-for-age from birth (40 weeks) to 24 months, were nearly equivalent in weight-for-age at birth (40 weeks), yet demonstrated less rapid growth in weight-for-age from 40 weeks to 24 months. The performance evaluation of the IHDP and CDC growth reference based on the 2 external VLBW data sets (CHDS and PNSS/PedNSS) showed that the IHDP charts more closely matched the external data sets in relative position on the graphs and growth patterns for length-for-age, but the CDC growth charts more closely matched the external data sets in the growth pattern for weight-for-length. In weight-for-age, because of the lack of stability in the pattern, we could not determine which reference the external data growth pattern more closely matched.

CONCLUSIONS

Our evaluation of growth references for VLBW infants yielded no clear, simple recommendation. The inconsistencies in the discrepancies across anthropometric indices between the 2 external combined VLBW data sets (CHDS and PNSS/PedNSS) and the IHDP reference and the CDC growth charts make it difficult to recommend 1 reference. Therefore, we recommend using either the IHDP reference or the CDC growth charts to evaluate the growth of VLBW infants. The choice of which to use depends on its purpose. The IHDP reference is the best available reference for comparisons of the growth of a VLBW infant with those of other VLBW infants. The CDC growth charts allow comparison of the growth of a VLBW infant with that of non-VLBW infants.

Postdischarge nutrition for high risk neonates

Despite improvements in neonatal care, many preterm babies suffer growth failure during their hospitalization. This appears to persist through early childhood, and possibly into adolescence. The use of enriched formulas improves the early growth of preterm infants, although most if not all of the benefit seems to be lost by 18 months. This growth benefit seems to be restricted to male infants. The improved growth does not improve developmental outcome. Although there are no direct comparisons of 22 kcal/oz post-discharge formulas and 24 kcal/oz preterm formulas, they are probably equally effective. Exactly which component (or components) of enriched formulas is responsible for this growth advantage is not known. Preliminary studies suggest that it may not be protein. Whether this growth benefit leads to decreased morbidity from cardiovascular disease in later life has not been studied. Further research is urgently needed to assess what nutritional factors can improve catch up growth in high-risk infants and whether this improved growth leads to decreased long-term morbidity.

Nutrient requirements for preterm infant formulas

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.

Growth pattern of low birth weight babies in the first year of life

OBJECTIVE

The growth pattern of low birth weight (LBW) babies was studied prospectively in our hospital from September 1995 to august 1996.

METHOD

Every baby <1.5 kg birth weight (B.Wt), every 2nd baby between 1.5 to 2 kg, every 6th baby between 2 to 2.5 kg and 120 term appropriate for gestation (AGA) babies ( as controls) were included in the study. Severe birth asphyxia, multiple gestation, major malformations or severe birth trauma formed exclusion criteria. Weight, length and head circumference were measured in all babies at birth and at 2 monthly intervals till 1 year of age. All babies completing 1 year follow-up were included for final analysis. Growth distance curves were constructed separately for each parameter for the six categories based on birth weight (Groups I-VI) and on gestational age (Divisions A-F). Comparison was made between the LBW babies and the controls for growth pattern among the babies who completed 1 year follow up (total of 220 babies).

RESULT

The growth pattern for weight and length showed good catch up growth in babies >1.25 kg B.Wt. and >30 weeks gestation, reaching almost the same level as controls by 1 year of age. Babies with B.Wt <1.25 kg and <30 weeks gestation showed late and poor catch up growth, with considerable lag persisting at 1 year of age. Head circumference increased rapidly in all babies, with maximal growth rate initially followed by a steady decline. All babies showed catch up growth, although those <1.25 kg and <30 weeks gestation still lagged behind even at 1 year.

CONCLUSION

It was seen that the smallest and least mature babies had late and poor catch up growth. Recognition of the factors influencing catch up growth and adequate measures to improve growth (like attention to feeding practices) may improve the overall outcome of these babies.

Centers for Disease Control and Prevention 2000 growth charts for the United States: improvements to the 1977 National Center for Health Statistics version

OBJECTIVE

To present a clinical version of the 2000 Centers for Disease Control and Prevention (CDC) growth charts and to compare them with the previous version, the 1977 National Center for Health Statistics (NCHS) growth charts.

METHODS

The 2000 CDC percentile curves were developed in 2 stages. In the first stage, the empirical percentiles were smoothed by a variety of parametric and nonparametric procedures. To obtain corresponding percentiles and z scores, we approximated the smoothed percentiles using a modified LMS estimation procedure in the second stage. The charts include of a set of curves for infants, birth to 36 months of age, and a set for children and adolescents, 2 to 20 years of age.

RESULTS

The charts represent a cross-section of children who live in the United States; breastfed infants are represented on the basis of their distribution in the US population. The 2000 CDC growth charts more closely match the national distribution of birth weights than did the 1977 NCHS growth charts, and the disjunction between weight-for-length and weight-for-stature or length-for-age and stature-for-age found in the 1977 charts has been corrected. Moreover, the 2000 CDC growth charts can be used to obtain both percentiles and z scores. Finally, body mass index-for-age charts are available for children and adolescents 2 to 20 years of age.

CONCLUSION

The 2000 CDC growth charts are recommended for use in the United States. Pediatric clinics should make the transition from the 1977 NCHS to the 2000 CDC charts for routine monitoring of growth in infants, children, and adolescents.

Effects of biologic and experiential conditions on the pattern of growth in weight of premature and full-term infants

In this exploratory study we examined the contribution of biologic and experiential conditions to the pattern of growth in weight for premature and full-term infants. The three components of the pattern were: (a) the infant's weight level; (b) the linear growth rate; and (c) the quadratic growth rate. Biologic conditions were maturity at birth and gender. Experiential conditions included variables in the mother's caregiving and the infant's feeding behavior, nutrient intake, and acuity of illness. At 1, 4, 8, and 12 months, premature infants (n = 61) weighed significantly less than full-term infants (n = 53), but neither linear nor quadratic rates of weight gain were significantly different from the rates for the full-term infants. Multilevel analytic models showed that female gender significantly affected weight level and linear and quadratic growth rates. Negative affect and behavior in both the mother and the infant significantly increased the linear rate of weight gain. The interaction of several experiential conditions with the two biologic conditions, birth maturity and gender, affected growth outcomes. Further exploration of the model with a larger sample is indicated to enable simultaneous testing of biologic and experiential conditions.

Impact of Genetic potential and prematurity on growth outcomes

PURPOSE

To explore the relationship between genetic potential and catch-up growth in school-age children who were born prematurely.

STUDY DESIGN AND METHOD

This descriptive correlational study compared three groups of children who were born prematurely, sorted by birthweight groups into low, very low, and extremely low birthweight on measures of catch-up growth and body composition at school age (n = 45). Height and weight were compared to established norms for children of normal birthweight. Growth at school age and parental heights were also correlated.

RESULTS

Children in all birthweight groups achieved growth within normal ranges (two standard deviations from the mean) by school age. The growth of the extremely low birthweight group was in the lower range of normal. Maternal height was the best predictor of children's heights at 8 to 10 years of age.

CLINICAL IMPLICATIONS

Parents and providers can be reassured that many children overcome the adverse effects of prematurity on childhood growth. Throughout childhood, growth should be closely monitored using appropriate grids, and correcting for prematurity.

Feeding preterm infants after hospital discharge: growth and development at 18 months of age

We have shown that preterm infants fed a preterm formula grow better than those fed a standard term infant formula after hospital discharge. The purpose of this follow-up study was to determine whether improved early growth was associated with later growth and development. Preterm infants (< or =1750 g birth weight, < or =34 wk gestation) were randomized to be fed either a preterm infant formula (discharge to 6 mo corrected age), or a term formula (discharge to 6 mo), or the preterm (discharge to term) and the term formula (term to 6 mo). Anthropometry was performed at 12 wk and 6, 12, and 18 mo. Mental and psychomotor development were assessed using the Bayley Scales of Infant Development II at 18 mo. Differences in growth observed at 12 wk were maintained at 18 mo. At 18 mo, boys fed the preterm formula were 1.0 kg heavier, 2 cm longer, and had a 1.0 cm greater occipitofrontal circumference than boys fed the term formula. Boys fed the preterm formula were also 600 g heavier and 2 cm longer than girls fed the preterm formula. However, no differences were noted in MDI or PDI between boys fed the preterm formula and boys fed the term formula or between the boys fed preterm formula and girls fed the preterm formula. Overall, boys had significantly lower MDI than girls (mean difference, 6.0; p < 0.01), primarily reflecting lower scores in boys fed the term formula. Thus, early diet has long-term effects on growth but not development at 18 mo of age. Sex remains an important confounding variable when assessing growth and developmental outcome in these high-risk infants.

Permanent tooth crown dimensions in prematurely born children

AIM

The aim was to examine the effect of preterm birth on permanent tooth crown dimensions.

MATERIALS AND METHODS

The data consisted of 328 prematurely born white and black children and 1804 control children who participated in the cross-sectional study of the Collaborative Perinatal Project (USA) in the early 1960s and 1970s. The dental examinations were carried out in a standardized fashion at ages varying from 6 to 12 years in 95% of cases. Tooth crown size measurements were performed on the dental casts with an electronic measuring device and readout by two experienced observers according to precise definitions generally quoted in the anthropological and genetic literature. The preterm and control groups were divided by sex and race.

RESULTS

The results show both increased and decreased tooth crown dimensions in the prematurely born children. Significantly increased dimensions were found in the means of the intercuspal distances of the first permanent molars in the white boys and in the mesiodistal dimensions (MD) of the lower lateral incisors and the upper left first molar in the black girls. By contrast, there were decreased intercuspal distances, MD and labiolingual (LL) tooth crown dimensions in the white girls and black boys. The statistical method used was the Mann-Whitney's U-test (Willcoxon Rank-Sums test).

CONCLUSIONS

The findings partly support previous reports of decreased tooth crown dimensions in preterm infants, but the increased dimensions found in the preterm white boys and black girls differ from earlier reports. Our results indicate the importance of environmental factors including neonatal factors in determining permanent tooth crown dimensions. Growth patterns, the buffering capacity and the timing of sensitive moments in tooth crown volume gain may vary between the sexes and ethnic groups and the possible effect of the accelerated growth period in preterm infants (catch-up growth) may influence the determination of permanent tooth crown dimensions.

Infant growth patterns in the slums of Dhaka in relation to birth weight, intrauterine growth retardation, and prematurity

BACKGROUND

Relations between size and maturity at birth and infant growth have been studied inadequately in Bangladesh, where the incidence of low birth weight is high and most infants are breast-fed.

OBJECTIVE

This study was conducted to describe infant growth patterns and their relations to birth weight, intrauterine growth retardation, and prematurity.

DESIGN

A total of 1654 infants born in selected low-socioeconomic areas of Dhaka, Bangladesh, were enrolled at birth. Weight and length were measured at birth and at 1, 3, 6, 9, and 12 mo of age.

RESULTS

The infants' mean birth weight was 2516 g, with 46.4% weighing <2500 g; 70% were small for gestational age (SGA) and 17% were premature. Among the SGA infants, 63% had adequate ponderal indexes. The mean weight of the study infants closely tracked the -2 SD curve of the World Health Organization pooled breast-fed sample. Weight differences by birth weight, SGA, or preterm categories were retained throughout infancy. Mean z scores based on the pooled breast-fed sample were -2.38, -1. 72, and -2.34 at birth, 3 mo, and 12 mo. Correlation analysis showed greater plasticity of growth in the first 3 mo of life than later in the first year.

CONCLUSIONS

Infant growth rates were similar to those observed among breast-fed infants in developed countries. Most study infants experienced chronic intrauterine undernourishment. Catch-up growth was limited and weight at 12 mo was largely a function of weight at birth. Improvement of birth weight is likely to lead to significant gains in infant nutritional status in this population, although interventions in the first 3 mo are also likely to be beneficial.

Anaerobic performance in 5- to 7-yr-old children of low birthweight

PURPOSE

This study was intended to determine whether anaerobic muscle performance is deficient in 5- to 7-yr-old children of extremely low birthweight (ELBW, 500-999 g) and very low birthweight (VLBW, 1000-1499 g).

METHODS

Fourteen ELBW and 20 VLBW children were compared with 24 normal birthweight (NBW, >2500 g) term controls. Peak (PP) and mean (MP) muscle power were determined by the Wingate anaerobic test. Bioimpedance analysis and anthropometry were done to assess fat-free mass (FFM) and lean cross-sectional area of the thigh and calf.

RESULTS

The ELBW group had significantly lower MP and PP, compared with the VLBW and, in particular, with the NBW group. This lower performance was apparent also when values were corrected for total body mass (MP) and FFM (MP and PP), but not when corrected for cross-sectional area of thigh and calf.

CONCLUSION

The lower anaerobic muscle performance in ELBW children may be partly due to their smaller muscle mass, but may also reflect a low percentage of fast-twitch muscle fibers, low muscle phosphagen content, or deficiency in motor control.

Knee-heel length measurement in healthy preterm infants

AIM

To examine the reproducibility of crown-heel length measurement; the precision and reproducibility of knee-heel length measurement; and the association between the two in healthy preterm infants.

METHODS

Paired crown-heel and knee-heel lengths were measured on 172 occasions by three observers in 43 preterm infants between 205 and 458 days of postconceptional age.

RESULTS

Crown-heel length (CHL) measurement was highly reproducible, with a coefficient of variation (CV) of 0.41%. Knee-heel length (KHL) measurement was relatively precise (CV 0.78%), but less reproducible (intra-observer CV 1.77%, intra-observer CV 2.11%), especially in larger infants. The association between KHL and CHL was not consistent and varied with age. KHL was a poor predictor of CHL, with a 95% predictive interval of +/- 27.5 mm.

CONCLUSIONS

KHL was less reproducible than CHL, especially in larger infants, and a poor predictor of CHL.

The effects of prescribed versus ad libitum feedings and formula caloric density on premature infant dietary intake and weight gain

BACKGROUND

Although feedings that are organized on an ad lib basis (i.e., in response to infant cues of hunger and of satiation) could enhance an infant's self-regulatory capacities for feeding, ad lib feeding of fully nipple-fed premature infants in a special care nursery has not been examined.

OBJECTIVE

To study whether the caloric and protein intake and weight change of fully nipple-fed preterm infants differed by the feeding regimen (prescribed or ad lib) and by the caloric density of the formula (20- or 24-kcalories per ounce).

METHOD

The 78 infants who participated in the study were randomized to prescribed or ad lib feeding regimens and, within each regimen, were further randomized to receive either 20-calorie or 24-kcalorie per ounce formula. Dietary intake (volume/kg, caloric intake/kg) and weight change (grams/kg gained or lost) were assessed for each of the 5 study days. Multivariate data analysis was used to examine the effects of feeding regimen and caloric density on dietary intake and weight change, controlling biologic variables (infant gender, race, lung disease diagnosis, treatment with supplemental oxygen, gestational age and weight at birth, and weight on the day prior to full nipple-feeding).

RESULTS

Overall, the ad lib feeding regimen had a negative effect on volume intake and caloric intake. Weight gain was influenced by caloric intake, but not by feeding regimen or the caloric density of the diet. With increased full nipple-feeding experience, caloric intake of ad lib feeders approached that of the infants fed on the prescribed regimen.

CONCLUSIONS

Development of self-regulatory capacities through ad lib feeding experience was indicated by infant regulation of the volume of intake by the caloric density of the formula, an unexpected finding. Furthermore, the approach of the caloric intake of infants on the ad lib regimen to that of infants on the prescribed regimen suggests they had gained skill in regulating intake with experience. Whether or not the trend for similar intakes would continue beyond 5 days is a question for further study.

Neuromotor ability in 5- to 7-year-old children with very low or extremely low birthweight

This study was intended to determine the effects of extremely low birthweight (ELBW, 500 to 999 g) and very low birthweight (VLBW, 1000 to 1499 g) on neuromotor ability in 5- to 7-year-old children. Fourteen ELBW and 20 VLBW children were compared with 24 term control children of normal birthweight (NBW, >2500 g). Using quantitative assessment instruments, the following data were collected: maximal cycling speed during 30 seconds of cycling at 'zero' resistance, simple reaction time of the legs, and performance on components of a whole-body coordination test. The main findings were a slower reaction time, lower maximal cycling speed, and lower coordination scores in the ELBW group compared with the NBW group and, for some variables, with the VLBW group. The reduced motor performance in these children appears for the most part to be a reflection of impaired neuromotor control and motor development, rather than merely a smaller body or muscle size.

Feeding preterm infants after hospital discharge: effect of dietary manipulation on nutrient intake and growth

The objective of this study was to compare formula intake, the time of weaning, and growth in preterm infants (< or = 1750-g birth weight, < or = 34-wk gestation) fed a standard term or preterm infant formula after initial hospital discharge. Infants were randomized at hospital discharge to be fed a preterm infant formula from discharge to 6 mo corrected age (group A), a term formula from discharge to 6 mo (group B), or the preterm formula (discharge to term) and the term formula (term to 6 mo (group C). Infants were seen biweekly (discharge to term) and monthly (term to 6 mo), when intake was measured and anthropometry and blood sampling were performed. The results were analyzed using ANOVA. Although nutrient intake was similar, at 6 mo girls were lighter (6829 versus 7280 g) and shorter (64.4 versus 66.0 cm) than boys (p < 0.05). Patient characteristics were similar between the treatment groups. Although the volume of intake differed (B > C > A; p < 0.001), energy intake was similar in the groups. Because of differences in formula composition, protein, calcium, and phosphorus intakes differed (B < C < A; p < 0.001). Lower protein intakes were related to lower blood urea nitrogen levels (B < C < A; p < 0.001). At 6 mo, infant boys in B and C were lighter (6933, 6660 < 7949 g), shorter (65.3, 64.9 < 67.1 cm), and had a smaller head circumference (43.7, 43.7 < 44.8 cm; p < 0.05) than infants in group A. Preterm infants were found to increase their volume of intake to compensate for differences in energy density between formulas. After hospital discharge, infant boys fed a preterm formula grew faster than infant girls fed a preterm formula or infant boys fed a term formula.

Approaching the management of the neonatal intensive care unit graduate through history and physical assessment

NICU graduates, often ex-premature infants, offer unusual challenges to the primary care provider. History and physical assessment require an organized approach with meticulous attention to detail. These infants are at high risk for multiple problems including growth delays, nutrition and feeding problems, pulmonary sequelae, neurological sequelae and developmental delays, vision and hearing disturbances, as well as abnormalities in parent-infant bonding. This article emphasizes particular aspects of the history and physical examination that signify pathophysiology and sequelae common to the NICU graduate.

Relationship between head growth and neurodevelopmental outcome of Malaysian very low birthweight infants during the 1st year of life

A prospective study was carried out to (i) compare head growth patterns of 103 very low birthweight (VLBW, < 1500 g) Malaysian infants and 98 normal birthweight (NBW, 2500- < 4500 g) controls during the 1st year of life; and (ii) examine the relationship between neurodevelopmental outcome at 1 year of age and occipito-frontal head circumferences (OFC) at birth and at 1 year of age in VLBW babies. When compared with those of NBW infants at birth, mid-infancy and 1 year of age, the mean OFC ratios (observed/expected OFC at 50th percentile) of VLBW infants were significantly lower (p < 0.001). Small-for-gestational-age (SGA) VLBW babies had significantly lower mean OFC ratios than their appropriate-for-gestational-age (AGA) VLBW counterparts at birth (p < 0.001), but this difference was no longer seen at mid-infancy or at 1 year of age. Logistic regression analysis showed that abnormal late neonatal cranial ultrasound findings (odds ratio 8.5, 95% confidence interval 4.12-22.07; p < 0.001) and each additional day of oxygen therapy (odds ratio 1.15, 95% confidence interval 1.00-4.45; p = 0.045) were significant risk factors associated with neurodevelopmental disability at 1 year of age, while mean OFC ratios at birth or at 1 year of age were not. Poor postnatal head growth per se did not predict disability, but probably reflected the consequences of "brain injury" as evidenced by abnormal brain scans.

Medical outcomes in preterm infants

Many survivors of the newborn intensive care units who were premature do very well; some, however, go on to have a variety of medical complications related, in part, to their prematurity. An overview of the medical outcomes of prematurity are discussed in the areas of respiratory disease (bronchopulmonary dysplasia), gastrointestinal disorders (short gut syndrome and gastroesophageal reflux), growth and nutrition problems, vision, and hearing outcomes. These complications can be managed on a regular or vigilant outpatient basis and, if exacerbated, may require hospital management. Concepts to assist in family counseling on expected long-term medical outcomes of prematurity are discussed.

Outcome of very low birth weight infants at 12 to 18 months of age in Soweto, South Africa

OBJECTIVE

To describe the long-term outcome of very low birth weight infants growing up in poor socioeconomic conditions in Soweto, South Africa.

METHODS

A stratified sample of infants weighing < 1500 g surviving to hospital discharge was enrolled. Group 1 consisted of 49 infants 1000 to 1499 g who required mechanical ventilation; group 2 consisted of 39 infants 1000 to 1499 g who did not require mechanical ventilation; and group 3 consisted of 25 infants < 1000 g (such infants are not routinely ventilated). Growth and neurological status were recorded at follow-up visits at 3, 6, and 12 months' corrected age and the infants were evaluated further using the Bayley scales of infant development between 12 and 18 months.

RESULTS

Fifteen infants died during the period between hospital discharge and 1 year corrected age, and 12 others were lost to follow-up. Although some catch-up growth was noted in the early months, all group means for weight and length were below the 25th percentile at 1 year. Cerebral palsy was diagnosed in nine infants (8 from group 1). Periventricular leukomalacia and/or porencephaly was diagnosed in eight of the nine infants during their initial hospital stay and was also the strongest negative predictor of the Bayley scores. Higher maternal education and better intrauterine growth were associated with higher Bayley scores.

CONCLUSIONS

Mortality after hospital discharge in this study cohort was extremely high. However, despite marked differences in socioeconomic conditions and tertiary care facilities, the handicap rates were comparable with recent studies from developed countries, and some of the predictors of handicap, eg, periventricular leukomalacia and porencephaly, were also similar.