New Ballard Score, expanded to include extremely premature infants

Reference ranges for thyroid function tests in premature infants beyond the first week of life

OBJECTIVES

To establish reference ranges for the more sensitive assays of thyrotropin and the best available assays of free thyroxine in premature infants after the first week of life.

STUDY DESIGN

Free thyroxine measurements by direct equilibrium dialysis and thyrotropin measurements by third generation immunometric assay were measured in 120 healthy premature infants 25 to 36 weeks' gestation at birth and every 3 weeks until hospital discharge. Infants were stratified by postconceptional age. Differences in free thyroxine and thyrotropin levels among groups were determined by ANOVA. Correlations between hormone measurements and gestational and postnatal ages were sought by linear regression analysis. Reference ranges were determined as arithmetic (free thyroxine) and geometric (thyrotropin) mean+/-2 SD ranges.

RESULTS

From 120 infants, 164 samples were obtained and grouped by postconceptional age at sampling. Free thyroxine was not different among postconceptional age groups and did not correlate with gestational or postnatal age. The free thyroxine reference range based on these data was 10 to 33 pmol/l (0.8 to 2.6 ng/dl). Thyrotropin did not correlate with gestational age. There was a clinically trivial but statistically significant (r(2)=0.03, p<0.05) correlation of thyrotropin with postnatal age. The thyrotropin reference based on these data was 0.8 to 12 mU/l.

CONCLUSIONS

Free thyroxine was closely regulated in these premature infants and levels were similar to those in older children and adults, once the natal surge in thyrotropin has subsided. After the first week of life a single range for each hormone appeared appropriate for all premature infants until 40 weeks postconceptional age.

Postasphyxial encephalopathy in preterm neonates

OBJECTIVE

Perinatal asphyxia is an important determinant of infant neurological outcome. There are very few studies looking exclusively at postasphyxial encephalopathy in preterm neonates.

METHODS

We studied the neurologic and sonographic abnormalities in 40 preterm babies with severe birth asphyxia during their hospital stay and till 3 months corrected age.

RESULT

87.5 % of the asphyxiated preterm babies had neonatal neurologic abnormality, compared to only 17% of the control babies (p<0.0001). Generalised hypotonia and reduced activity were the commonest abnormalities (observed in 85% of asphyxiated babies) while depressed sensorium (60%) and seizures (35%) were seen in more severe cases. White matter disease (WMD-including periventricular flare, cerebral edema and periventricular leucomalacia) was significantly more frequent in the study cases (34.5% in study cases vs 7.5% in controls, p<0.0001) as was grade 3/4 intraventricular hemorrhage(IVH) (25% in study cases vs 2.5% in controls, p<0.0001). There was 11 fold higher mortality among the asphyxiated babies (23 deaths in study cases vs 2 in controls, p<0.0001).

CONCLUSION

The survivors had a significantly higher incidence of both mild and severe neurological abnormalities at corrected age of 3 months among the asphyxiated babies. There was a good correlation between the severity of the neonatal encephalopathy as well as the sonographic findings and the outcome.

Randomized trial of presumptive sexually transmitted disease therapy during pregnancy in Rakai, Uganda

OBJECTIVE

The purpose of this study was to assess presumptive sexually transmitted disease treatment on pregnancy outcome and HIV transmission.

STUDY DESIGN

In a randomized trial in Rakai District, Uganda, 2070 pregnant women received presumptive sexually transmitted disease treatment 1 time during pregnancy at varying gestations, and 1963 control mothers received iron/folate and referral for syphilis. Maternal-infant sexually transmitted disease/HIV and infant outcomes were assessed. Intent-to-treat analyses estimated adjusted rate ratios and 95% confidence intervals.

RESULTS

Sexually transmitted diseases were reduced: Trichomonas vaginalis (rate ratio, 0.28; 95% CI, 0.18%-0.49%), bacterial vaginosis (rate ratio, 0.78; 95% CI, 0.69-0.87), Neisseria gonorrhoeae /Chlamydia trachomatis (rate ratio, 0.43; 95% CI, 0.27-0.68), and infant ophthalmia (rate ratio, 0.37; 95% CI, 0.20-0.70). There were reduced rates of neonatal death (rate ratio, 0.83; 95% CI, 0.71-0.97), low birth weight (rate ratio, 0.68; 95% CI, 0.53-0.86), and preterm delivery (rate ratio, 0.77; 95% CI, 0.56-1.05); but there were no effects on maternal HIV acquisition or perinatal HIV transmission.

CONCLUSION

Reductions of maternal sexually transmitted disease improved pregnancy outcome but not maternal HIV acquisition or perinatal HIV transmission.

Diaphragm dimensions of the healthy preterm infant

BACKGROUND

The diaphragm is the major inspiratory muscle in the neonate; however, human neonatal diaphragm development has not been extensively studied. We hypothesized that diaphragm thickness (t(di)) would be positively related to postmenstrual age (PMA), body weight, body length, head circumference, and nutritional intake.

OBJECTIVES

To evaluate the evolution of diaphragm growth and motion in the healthy, preterm infant.

METHODS

We used ultrasound to measure t(di) at the zone of apposition to the rib cage and diaphragm excursion (e(di)) during inspiration. Thirty-four stable, preterm infants (16 males and 18 females) between 26 and 37 weeks' PMA were studied during quiet sleep at weekly intervals until the time of discharge or transfer from the neonatal intensive care unit. All infants were clinically stable and not receiving ventilatory support.

RESULTS

We found that 1) t(di) increased from 1.2 +/- 0.1 to 1.7 +/- 0.05 mm between 26 to 28 and 35 to 37 weeks' PMA; 2) t(di) was positively correlated with PMA (r = 0.40), body weight (r = 0.52), body length (r = 0.53), and head circumference (0.49), but not with postnatal nutritional intake (r = 0.09); and 3) e(di) decreased with increasing PMA.

CONCLUSIONS

Our findings suggest that diaphragm development in premature infants scales with body dimensions. We speculate that the increase in t(di) with age is likely attributable to increased diaphragm muscle mass, and the reduced e(di) with age may be resulting from a reduction in chest wall compliance.

Prenatal consultation with a neonatologist prior to preterm delivery

OBJECTIVE

Evaluate the usefulness of prenatal consultation with a neonatologist before preterm birth.

STUDY DESIGN

A questionnaire was administered to mothers 1 week before home discharge of their preterm infant in a single regional level III neonatal intensive care unit.

RESULTS

Sixty-seven mothers completed the questionnaire; 84% indicated the consult was useful and 71% were comforted by the consult. However, mothers < 30 weeks' gestation were less likely to be comforted after the consult compared to those > or = 30 weeks. Most frequently, mothers indicated that they were provided with too little detail about retinopathy of prematurity and intraventricular hemorrhage.

CONCLUSIONS

Most mothers delivering a preterm infant describe the prenatal consultation with a neonatologist as useful. The majority of mothers are comforted by the information presented.

Do very sick neonates born at term have antenatal risks? 1. Infants ventilated primarily for problems of adaptation to extra-uterine life

AIMS

1. Ascertain antenatal and intrapartum risk factors for term neonates ventilated primarily for 'perinatal asphyxia'. 2. Describe the neonatal morbidity and mortality.

METHODS

Population-based case control cohort study.

SETTING

Sydney and four large rural/urban health areas in New South Wales.

SUBJECTS

Singleton term infants, no major congenital anomaly: subset of 83 infants ventilated primarily for 'asphyxia' from 182 cases admitted to a tertiary neonatal intensive care unit (NICU) for mechanical ventilation, 550 randomly selected controls. Outcome. Risk factors for case status by maternal, antenatal, labor, delivery, and combined epochs, adjusted odds ratios (OR), 95 per cent confidence intervals (CI), p < 0.05.

RESULTS

Predictors of case status by multivariate epochs: Primigravida (1.8 [1.1, 2.8]), thyroid disease (7.8 [1.1, 57.0]), any antenatal complication (5.1 [3.0, 8.6]), growth restriction (4.2 [1.7, 10.4]), male gender (2.1 [1.3, 3.5]), gestational age >40 weeks (1.9 (1.1, 3.3)), prolonged rupture of membranes (9.7 [1.3, 72.5]), complicated labor (6.6 [3.7, 11.9]), induced labor (2.2 [1.3, 3.9]), prostaglandins 2.46 [1.23, 4.91]), maternal pyrexia (10.8 [2.8, 42.7]), placental hemorrhage in labor (OR 4.24 [1.45, 12.42]), forceps delivery (4.1 [1.9, 8.5]), emergency cesarean section (4.7 [2.6, 8.7]). Twenty case infants (24%) and no control infants died.

CONCLUSIONS

This study has shown maternal and antepartum risk factors for severe neonatal morbidity in term infants. More centers need to become interested in the term baby, so that a larger multicenter study can further elucidate the heterogeneous causal pathways to term neonatal morbidity.

Do very sick neonates born at term have antenatal risks? 2. Infants ventilated primarily for lung disease

AIMS

1. Ascertain antenatal and intrapartum risk factors for term neonates ventilated primarily for respiratory problems. 2. Describe the neonatal morbidity and mortality.

METHODS

Population-based case control cohort study.

SETTING

Sydney and four large rural/urban Health Areas in New South Wales, 1996.

SUBJECTS

Singleton term infants, no major congenital anomaly: subset of 99 infants ventilated primarily for respiratory problems from 182 cases admitted to a tertiary neonatal intensive care unit (NICU) for mechanical ventilation, and 550 randomly selected controls.

OUTCOME

Risk factors for case status by maternal, antenatal, labor, delivery, and combined epochs, adjusted Odds Ratios (OR), 95 per cent Confidence Intervals (CI), p<0.05.

RESULTS

Predictors of case status by multivariate epochs: mother's age > or =35 years (1.9 (1.1, 3.2) p=0.03), primigravida (1.8 (1.1, 2.8) p=0.01), any antenatal complication (3.8 (2.4, 5.9) p=0.0001), birth weight < 3rd percentile (3.7 (1.5, 9.1) p=0.006), gestational diabetes (2.9 (1.3, 6.9) p=0.01), maternal pyrexia (6.5 (1.6, 27.2) p=0.01), birth weight >90th percentile (1.8 (1.01, 3.2) p=0.047), gestation 37-38 weeks (2.3 (1.5, 3.6) p=0.0004), forceps (4.4 (2.1, 9.1) p=0.0001), elective cesarean section (3.7 (2.0, 6.5) p=0.0001), emergency cesarean section (4.5 (2.4, 8.4) p=0.0001). Case mortality rate was 5 per cent.

CONCLUSION

The pathways to neonatal respiratory morbidity in term infants are multifactorial. Several areas which warrant more in-depth study are: elective cesarean section at 37-38 weeks gestation, fetal growth restriction, macrosomia and the pattern of in-utero growth, maternal weight gain during pregnancy, gestational diabetes, pyrexia in labor and the role of chorioamnionitis.

The relationship of a mother's working model of feeding to her feeding behaviour

AIMS OF THE STUDY

This study aimed to examine the difference the attunement of a mother's working model of feeding to her infant makes for her positive feeding affect and behaviour, accounting for infant and mother conditions.

BACKGROUND/RATIONALE

The concept of a mother's working model of feeding is derived from attachment theory. Caregiving, including feeding, is a component of this theory. The conditions that may influence the attunement of a mother's working model of feeding to her infant include infant birth maturity status (premature, full-term), age at assessment, and robustness, indexed by weight-for-age z score (WAZ). Mother conditions include symptoms of depression and feeding practice (breast feeding or exclusive bottle feeding).

DESIGN/METHODS

Participants in this longitudinal study were 99 mothers and their infants (47 full-term, 52 premature, very low birth weight). After written informed consent was given, home assessments were made when infants were approximately 1, 4, 8 and 12 months old (adjusted age for premature infants). Working model attunement was assessed with a video-assisted interview. A mother's positive affect and behaviour, including sensitivity and responsiveness, were rated from videotaped feeding interaction.

RESULTS/FINDINGS

Repeated measures analysis with a general linear mixed model showed a significant positive relationship with positive affect and behaviour for both working model attunement and the WAZ score and a significant negative relationship for symptoms of depression. Neither birth maturity status, infant age, nor feeding practice had a significant effect on mother's positive affect and behaviour during feeding.

CONCLUSIONS

Nurses' efforts to enhance the attunement of a mother's working model of feeding may help mothers feed with greater positive affect and behaviour. Further study of how the attunement of a mother's feeding expectations and intentions are related to her symptoms of depression and with what she makes of the infant's growth and well-being is needed. The theoretical model needs testing with infants from the entire premature population.

Thyroxine and illness severity in very low-birth-weight infants

The objective of this study was to determine the relationship between thyroxine (T4) and illness severity in a population of preterm infants. We investigated a cohort of infants with birth weights 1,500 g or less from a single level III neonatal intensive care unit who received a minimum of one cranial sonogram to screen for intraventricular hemorrhage (IVH) and one newborn screen for T4 during a 2-year period, (n = 284). The Score for Neonatal Acute Physiology (SNAP) was used to measure illness severity. T4 and SNAP were investigated in relationship to mortality, IVH, and severe IVH. T4 correlated inversely with SNAP (R = -0.46, p < 0.01). Infants with severe IVH and mortality had lower T4 and higher SNAP scores when compared to infants without these conditions. These differences persisted after controlling for the confounding effect of gestational age. Analysis of receiver operator curves indicated that high SNAP and low T4 were equivalently associated with IVH, severe IVH, and mortality. Our data indicate that T4 is associated with illness severity in very low-birth-weight infants. Low T4 levels and high SNAP scores are both associated with the outcomes of IVH and mortality in very low-birth-weight infants.

Increments in whole body bone mineral content associated with weight and length in pre-term and full-term infants during the first 6 months of life

BACKGROUND

The objective of the present study was to assess bone mineral content (BMC) of the whole skeleton in pre-term and full-term healthy infants and the factors influencing BMC, such as bone area, birth weight, birth length, current weight, current length, gender, and gestational age.

METHODS

Forty-eight healthy full-term infants and 34 healthy premature infants fed predominantly with intact human milk were studied. BMC was measured monthly with dual energy X-ray absorptiometry (DEXA). At the same time, length and weight were measured and registered. Pre-term infants were studied at 60-day intervals.

RESULTS

For both full-term and pre-term infants, BMC increased during the first months of life. However, the values of pre-term infants never reached the values of full-term infants, even after correcting for age and weight. For both full-term and pre-term infants, BMC was significantly correlated at the second month with birth weight (r = 0.901), birth length (r = 0.860), gestational age (r = 0.803), bone area (r = 0.960), current weight (r = 0.920), and current length (r = 0.840, p <0.001 for all correlation coefficients). Multivariate analysis revealed that bone area was the most important factor in predicting BMC.

CONCLUSIONS

Pre-term children have lower BMC than full-term children. The main factor explaining this apparent osteopenia is bone area. Pre-term children have a higher daily mineralization rate than full-term children, but this catch-up mineralization is not enough to reach BMC levels seen in full-term children.

Preterm labour at 34--36 weeks of gestation: should it be arrested?

Currently, preterm labour is treated with tocolytic agents and prenatal steroids until the 34th week of gestation only. Our objective in this study was to assess this practice. Seven-year records of all preterm infants born in our institution at 34--36 weeks of gestation, were evaluated retrospectively. All babies, born in singleton well-dated pregnancies, without maternal, medical or obstetric complications, and by normal vaginal delivery, were included. Their length of hospital stay and perinatal complications were compared across gestational age groups of 34, 35 and 36 weeks. Of the 207 babies included, statistically significant reductions in the rates of respiratory distress syndrome (15.0% vs. 3.2%), nosocomial sepsis (5.0% vs. 0%) and apnoea of prematurity (11.7% vs. 2.2%), and consequently, in length of hospital stay (16 +/- 2.7 vs. 4 +/- 0.3 days) occurred between 34 and 36 weeks of gestation. The severity of respiratory distress syndrome also declined significantly. The changes were most noticeable after 35 weeks of gestation, and it was concluded that neonatal complications are still prevalent at 34 and 35 weeks. Therefore, we propose that labour should not be induced at 34 and 35 weeks of gestation and that tocolytic agents and maternal prenatal steroids may be considered in preterm labour during this period.

One-year outcome of auditory-tactile-visual-vestibular intervention in the neonatal intensive care unit: effects of severe prematurity and central nervous system injury

Thirty-seven infants with severe central nervous system injury or extreme prematurity were randomly assigned to a multisensory (auditory-tactile-visual-vestibular) intervention or control group. Intervention began in the hospital at 33 weeks' postconceptional age and continued twice daily in the home until 2 months' corrected age. Mother-infant interactions during feedings were videotaped, and the Bayley Scales of Infant Development were administered. Control mothers stimulated their infants more during feeding, but these significant differences dissipated by 4 months. The presence of periventricular leukomalacia was associated with significantly poorer mental development, regardless of group assignment. Experimental infants tended to exhibit better motor and mental performance and had 23% fewer cerebral palsy diagnoses at 1 year, but these trends were not statistically significant. The type of brain injury was more important in determining 1-year developmental outcome than type of postnatal experience, suggesting that periventricular leukomalacia presents a major challenge for infant development.

Disproportionate alterations in body composition of large for gestational age neonates

OBJECTIVE

The objective was to compare dual-energy x-ray absorptiometry-measured body composition between large (LGA) and appropriate (AGA) birth weight for gestational age neonates.

STUDY DESIGN

LGA term infants (n = 47) with birth weights > or =4000 g were compared with 47 gestational age-matched AGA infants; 11 LGA infants were born to mothers with gestational (9) or pregestational diabetes (2). Dual-energy x-ray absorptiometry scans were performed at 1.8 +/- 1.0 days after birth.

RESULTS

Body weight and length were the dominant predictors of body composition in LGA and AGA neonates. However, LGA neonates had significantly (P <.001, all comparisons) higher absolute amounts of total body fat, lean body mass, and bone mineral content and had significantly (P <.001, all comparisons) higher proportions of total body fat and bone mineral content but lower lean body mass as a percent of body weight. The changes for total body fat and lean body mass as a percent of body weight were greatest (P <.001) in LGA infants whose mothers had impaired glucose tolerance.

CONCLUSION

LGA neonates have higher body fat and lower lean body mass than AGA infants. Impaired maternal glucose tolerance exaggerated these body composition changes.

Background electroencephalographic (EEG) activities of very preterm infants born at less than 27 weeks gestation: a study on the degree of continuity

AIMS

To clarify the features of the background electroencephalographic (EEG) activities in clinically well preterm infants born at less than 27 weeks gestation and to outline their chronological changes with increasing postconceptional age (PCA).

METHODS

EEGs of clinically well premature infants born at less than 27 weeks gestation were recorded during the early postnatal period. The infants were separated into three groups according to their PCA at the time of EEG recording (21-22 weeks PCA, 23-24 weeks PCA, and 25-26 weeks PCA). The mean and maximum duration of interburst intervals (IBIs), the mean duration of bursts, and the percentage of continuous and discontinuous patterns in each PCA group were evaluated.

RESULTS

There were three infants at 21-22 weeks PCA, seven at 23-24 weeks PCA, and five at 25-26 weeks PCA. Eighteen EEG recordings were obtained. The mean and maximum IBI duration decreased with increasing PCA. The percentage of continuous patterns increased with increasing PCA. Conversely, the percentage of discontinuous patterns decreased with increasing PCA.

CONCLUSIONS

In premature infants born at less than 27 weeks gestation, the characteristics of the background EEG activities were similar to those of older premature infants. These changes reflect the development of the central nervous system in this period.

Changes of leptin and metabolic hormones in preterm infants: a longitudinal study in early postnatal life

OBJECTIVES

Very little is known concerning the physiological role of leptin and growth in the early postnatal period and the association of leptin with other metabolic hormones in preterm infants. This study aims to investigate these relationships, and to explore the longitudinal and dynamic profile of leptin and metabolic hormones including insulin, ACTH, cortisol and FT4 in this category of patient. We also postulate that a rapid increase in body weight and body mass index in the first few weeks of life may be associated with a corresponding increase in serum leptin if the 'adipoinsular axis' is active at this stage.

DESIGN

A longitudinal study in a cohort of preterm infants < 34 weeks gestation for the first five weeks of postnatal life.

PATIENTS AND METHODS

Sixty-one preterm newborns < 34 weeks gestation were prospectively enrolled. Blood samples were collected in the morning when the newborns were 24 h of age (day 1), and on days 5, 14 and 35 of life. Serum leptin, insulin, cortisol, FT4, glucose and plasma ACTH concentrations were analysed using standard biochemical methods. Spearman's correlation coefficient was used to assess the inter-relationship of different metabolic hormones on the first day of life, and the relationship between metabolic hormones on day 1 and anthropometric or clinical parameters. The mixed-effects models were further used for analysing the multiple longitudinal measurements, and also for comparing the hormone concentrations between day 1 (baseline) and their corresponding levels on days 5, 14 and 35.

RESULTS

Serum leptin on day 1 (baseline) was significantly associated with serum insulin (r = 0.30, P < 0.05) and insulin:glucose ratio (r = 0.29, P < 0.05) in infants < 34 weeks gestation. Female preterm infants had significantly higher serum leptin (P < 0.05) and insulin (P < 0.05) levels than male infants. In addition, the duration between the last dose of antenatal dexamethasone and delivery significantly influenced the serum concentrations of leptin (r = - 0.27, P < 0.05), cortisol (r = 0.52, P < 0.001), plasma ACTH (r = 0.28, P < 0.05) and insulin:glucose ratio (r = - 0.27, P < 0.05) on the first day of life. Despite significant increase in body weight (P < 0.00001) and body mass index (P < 0.00001) by day 35 when compared to birth weight, no corresponding significant changes were observed for serum leptin, insulin and FT4. However, there was an increasing though statistically nonsignificant trend in serum leptin after day 14 of life.

CONCLUSION

This study characterized the longitudinal profile of leptin and metabolic hormones in preterm infants < 34 weeks gestation in the first 5 weeks of life. Serum leptin was significantly associated with serum insulin and insulin:glucose ratio supporting the hypothesis that an 'adipoinsular axis' exists and is likely to be functional before 34 weeks of gestation. Although a significant increase in body weight was demonstrated by day 35, no significant corresponding changes occurred with regard to serum leptin. We postulate that the limited quantity of adipose tissue at this stage of development might have contributed to this observation. Moreover, our results also showed that the duration between the last dose of antenatal corticosteroid and delivery could influence the postnatal concentrations of adipoinsular and pituitary-adrenal hormones. Thus, it is possible that antenatal dexamethasone might affect fetal growth and development via these neuroendocrine pathways in early intrauterine life.

Screening guidelines for retinopathy of prematurity: the need for revision in extremely low birth weight infants

OBJECTIVE

To determine whether significant retinopathy of prematurity (ROP) can be detected before 31 to 33 weeks' postmenstrual age (PMA) in extremely low birth weight (ELBW) infants.

METHODS

Medical records of all ELBW infants (<1000 g at birth) admitted to our regional perinatal center between April 1995 and January 1999 were reviewed retrospectively. Screening examinations for ROP were routinely performed at 4 to 6 weeks' chronological age (CA) from birth and followed at least every other week. Data were collected for infants who developed ROP. We determined the PMA at which the first screening eye examination demonstrated prethreshold disease and the subsequent examination that showed threshold disease (if it occurred). The percentages of infants who developed prethreshold ROP diagnosed at </=31 weeks' PMA and of those who progressed to threshold ROP before 34 weeks' PMA were determined.

RESULTS

All 258 ELBW infants were screened for ROP. Seventy-eight infants (30%) were diagnosed with prethreshold ROP. Twenty-seven of these infants (35%) progressed to threshold ROP. Ten infants who progressed to threshold ROP were <34 weeks' PMA at the time of this diagnosis. Of these 10 infants, 3 were diagnosed at 31 weeks' PMA, 4 at 32 weeks', and 3 at 33 weeks'.

CONCLUSION

More than 80% of ELBW infants who developed prethreshold disease in this cohort were </=33 weeks' PMA. The joint statement screening option of independently using 31 to 33 weeks' PMA for the first eye examination would have led to a diagnosis of threshold ROP on first examination in as many as 13% (10/78) of our patients. Early identification of prethreshold ROP is important for providing timely intervention in this rapidly progressive disease. Therefore, ELBW infants should receive initial ROP screening using the CA guideline of 4 to 6 weeks rather than the 31- to 33-week postconceptional age guideline.

Neonatal thermal care, part III: The effect of infant position and temperature probe placement

PURPOSE

Accurate management of infant temperature requires appropriate placement of temperature monitoring probes. Currently, there is a lack of consensus regarding placement of skin temperature probes and the effect on temperature monitoring of the infant's lying on the probe. The objective of this study was to compare abdomen and back skin temperatures when infants were positioned supine and prone.

DESIGN

A quasi-experimental design was used to randomize infants to prone or supine position. Infant back, abdomen, and axillary temperatures were measured at one-minute intervals with small disposable thermocouples over a one-hour period.

SAMPLE

Twenty-three infants, weight 820-2,400 gm, gestational age 27-37 weeks, postnatal age three to ten days.

MAIN OUTCOME VARIABLE

Gradient between abdomen and back temperature.

RESULTS

Both mean abdomen and mean back temperatures differed significantly by position (t-test, p = .003 and .028, respectively). Weight and postnatal age did not have an effect on the mean difference between abdomen and back temperature. Results indicate that probe placement and infant positioning are important factors altering measurement of skin temperature.

Neonatal outcome of spontaneous and assisted twin pregnancies

OBJECTIVES

Over the last 10 years, diffusion of assisted reproduction techniques (ovarian stimulation, IVF, GIFT) has led to an increased incidence of multiple pregnancies and consequently, of the related obstetric-neonatal problems. In this study, multiple births have been studied, with particular reference to the twin births occurring in the Gemelli hospital, Rome. The hospital is also a reference centre for obstetric pathologies and infertility treatment. In particular, attention has been focused on neonatal outcome, comparing twins born from spontaneous and assisted pregnancies.

STUDY DESIGN

228 neonates from spontaneous twin pregnancies and 32 from assisted twin pregnancies were taken into consideration with regard to: premature birth, low birth-weight, intrauterine growth retardation, weight discordance, Apgar score, major neonatal diseases, and mortality.

RESULTS

Results showed a significant higher incidence of prematurity and low birth-weight, as well as a significant lower gestational age, occurring more frequently in twins resulting from assisted pregnancies than in twins from spontaneous pregnancies. Furthermore, the incidence of severe depression at birth and respiratory disease was significantly higher in twins from assisted pregnancies than in those from spontaneous pregnancies, despite similar gestational age and birth-weight.

Plasma fatty-acid composition and antioxidant capacity in low birth-weight infants fed formula enriched with n-6 and n-3 long-chain polyunsaturated fatty acids from purified phospholipids

OBJECTIVE

To determine whether a formula containing n-6 and n-3 long-chain polyunsaturated fatty acids (LCP) from purified phospholipids increases the content of 20:4n-6 and 22:6n-3 of plasma lipids and modifies the plasma antioxidant capacity in low-birth-weight infants.

STUDY DESIGN

Seventeen infants were fed a conventional formula for low birth-weight infants (F), and 17 a formula containing n-6 and n-3 LCP from purified pig-brain phospholipids (LCP-F). Fourteen infants receiving human milk from a human milk bank were used as a reference (HM). Growth index were measured and blood samples were taken at entry and after 15 days and 30 days of feeding.

RESULTS

In infants fed LCP-F the levels of 22:6n-3 in total plasma lipids and in plasma phospholipids and triglycerides were higher than in infants fed F and closer to the levels of HM group throughout the study. Docosahexaenoic acid concentration in total plasma lipids was 3.46+/-0.19 mg/dl in infants fed LCP-F and 2.08+/-0.20 in infants fed F after 15 days of feeding (P<0.001), and 3.83+/-0.30 and 2.15+/-0.20 in infants fed LCP-F and F respectively, after 30 days of feeding (P<0.001). The concentration of 20:4n-6 in the LCP-F was significantly higher than in the F group at 15 and 30 days of feeding. Plasma antioxidant capacity did not differ significantly between the study groups.

CONCLUSION

Feeding low birth-weight infants a formula containing LCP phospholipids results in an increase of n-3 and n-6 LCP in plasma towards that of infants fed human milk.

Very low birth weight outcomes of the National Institute of Child health and human development neonatal research network, January 1995 through December 1996. NICHD Neonatal Research Network

OBJECTIVES

To determine the mortality and morbidity for infants weighing 401 to 1500 g (very low birth weight [VLBW]) at birth by gestational age, birth weight, and gender.

STUDY DESIGN

Perinatal data were collected prospectively on an inborn cohort from January 1995 through December 1996 by 14 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network and were compared with the corresponding data from previous reports. Sociodemographic factors, perinatal events, and the neonatal course to 120 days of life, discharge, or death were evaluated.

RESULTS

Eighty four percent of 4438 infants weighing 501 to 1500 g at birth survived until discharge to home or to a long-term care facility (compared with 80% in 1991 and 74% in 1988). Survival to discharge was 54% for infants 501 to 750 g at birth, 86% for those 751 to 1000 g, 94% for those 1001 to 1250 g, and 97% for those 1251 to 1500g. The incidence of chronic lung disease (CLD; defined as receiving supplemental oxygen at 36 weeks' postmenstrual age; 23%), proven necrotizing enterocolitis (NEC; 7%), and severe intracranial hemorrhage (ICH; grade III or IV; 11%) remained unchanged between 1991 and 1996. Furthermore, 97% of all VLBW infants and 99% of infants weighing <1000 g at birth had weights less than the 10th percentile at 36 weeks' postmenstrual age. Mortality for 195 infants weighing 401 to 500 g was 89%, with nearly all survivors developing CLD. Mortality in infants weighing 501 to 600 g was 71%; among survivors, 62% had CLD, 35% had severe ICH, and 15% had proven NEC.

CONCLUSIONS

Survival for infants between 501 and 1500 g at birth continued to improve, particularly for infants weighing <1000 g at birth. This improvement in survival was not associated with an increase in major morbidities, because the incidence of CLD, proven NEC, and severe ICH did not change. However, poor postnatal growth remains a major concern, occurring in 99% of infants weighing <1000 g at birth. Mortality and major morbidity (CLD, severe ICH, and NEC) remain high for the smallest infants, particularly those weighing <600 g at birth.

Is human myometrial sampling at the time of cesarean delivery safe?

OBJECTIVE

The mechanism for the initiation of human labor remains unknown and is under extensive investigation. Myometrium from patients in labor and not in labor is the ideal tissue to study structural, cellular, and molecular changes that occur during parturition. This study was designed to determine whether myometrial sampling at the time of cesarean delivery increases maternal morbidity.

STUDY DESIGN

This is a prospective cohort study including 118 study and 236 control patients. A full-thickness myometrial sample was obtained from the superior edge of a transverse uterine incision at the time of cesarean delivery. Demographics and standard surgical morbidity data were collected. Statistical methods used included univariate and multivariate analysis.

RESULTS

The study and control groups did not differ significantly with respect to age, gravidity, parity, birth weight, and Apgar scores. The estimated intraoperative blood loss was greater in the control group (P <.02); however, the change in hematocrit level (preoperative vs postoperative values) was not different. There were no significant differences in the rates of endometritis, wound infection, and venous thrombosis up to 6 weeks post partum. When study and control patients were stratified into term in labor, term not in labor, preterm in labor, and preterm not in labor categories and compared for maternal morbidity, there were still no significant differences for any of the outcome measures evaluated.

CONCLUSION

On the basis of our data, human myometrial sampling at cesarean delivery does not increase overall maternal morbidity, irrespective of gestational age and the presence or absence of labor.

A new score for postnatal clinical assessment of fetal maturity in newborn infants

OBJECTIVES

To investigate the clinical repeatability of Klimek's method of fetal maturity assessment in newborns.

METHODS

A cohort of 800 consecutive singletons was assessed immediately after birth by a pediatrician, who was unaware of the infants' gestational age. The assessment, according to Klimek's method, consisted of six criteria to evaluate posture and skin appearance, and each variable was scored from 0 to 2 points. After dividing the material into two identical groups, the results were compared with those obtained by means of Ballard's method.

RESULTS

Statistical analysis did not show statistically significant differences between the compared averages in both groups. A significant correlation between the clinically compared methods of fetal maturity grading was found (r> or =0.69, t> or =19, and P<0.001).

CONCLUSIONS

Klimek's method of fetal maturity assessment offers a possibility of objective evaluation of maturity immediately after birth. The clinical methods used to date do not have such advantages. Moreover, they require the evaluation of 12-34 parameters, their point range is more complex and their results are given on the scale of 10-50 points. In each of the applied divisions of observed newborns, there was found a high, statistically significant correlation between the indexes evaluating maturity by means of both comparable methods (i.e. Ballard and Klimek scores), which do not take into account weight and fetal age, but refer directly to fetal maturity. The new scale, which has been proposed, is simple and produces comparable results encompassing full maturity in the range of only 6-12 points.

Leptin and metabolic hormones in infants of diabetic mothers

AIMS

To investigate the effect of maternal diabetes on leptin in term newborns and to determine whether leptin correlates with insulin and its associated biochemical parameters in support of the hypothesis that a functional "adipoinsular axis" might exist at this stage of development.

METHODS

A total of 116 term newborns were prospectively enrolled and categorised into three groups: 44 were infants of non-diabetic mothers (control group C); 41 were infants born to mothers with gestational diabetes on dietary treatment (group D); and 31 were infants born to mothers with gestational or pregestational diabetes on insulin treatment (group I).

RESULTS

No significant difference in serum leptin was observed between the three groups; the results of the study population were therefore pooled and analysed. Serum leptin correlated significantly with serum insulin, insulin:glucose ratio, birth weight, body length, body mass index, placenta weight, and maternal HbA(1c). Female infants had significantly higher serum leptin than male infants. All parameters except placenta weight and body length remained significantly associated with serum leptin when multivariate stepwise regression analysis was applied. Subgroup analysis revealed a significant correlation between serum leptin and cortisol in group D.

CONCLUSIONS

There was no significant difference in serum leptin between infants born to diabetic and non-diabetic mothers, though infants born to mothers requiring insulin treatment had the highest median serum leptin concentrations. The significant association between serum leptin and insulin or insulin:glucose ratio supports the hypothesis that a functional adipoinsular axis might exist in term newborns. Furthermore, the significant correlation between maternal HbA(1c) and circulating leptin of the studied infants suggests that the clinical control of maternal diabetes could affect the regulation of serum leptin in these infants.

Leptin and metabolic hormones in preterm newborns

AIM

To investigate the inter-relation between leptin and other metabolic hormones in preterm and term infants and to explore whether a functional "adipoinsular axis" might exist in preterm newborns.

METHODS

A total of 140 preterm and term newborns were prospectively recruited and categorised according to gestation length. Blood samples were taken at 24 hours (day 1), and on day 4-5 of life.

RESULTS

Serum leptin, cortisol, free thyroxine, and plasma ACTH on day 1 were significantly higher in term than in preterm infants. The relation between serum leptin and gestation followed a non-linear pattern; the slope of the curve began to increase steeply between 33 and 35 weeks gestation. Serum leptin on day 1 was significantly associated with serum insulin, insulin:glucose ratio, and plasma ACTH in infants less than 34 weeks gestation; serum leptin on day 1 and day 4-5 were significantly correlated with insulin:glucose ratio in infants 34 or more weeks gestation. Significant changes in the pattern of metabolic hormones were observed in the first week of life. Serum insulin and plasma glucose were significantly increased between day 1 and day 4-5; serum leptin was significantly decreased.

CONCLUSIONS

The circulating leptin concentration increases markedly after 34 weeks gestation and bears a close temporal relation with the exponential accumulation of body fat mass during that period. The inter-relation between serum leptin and insulin or insulin:glucose ratio before and after 34 weeks gestation indicates that the "adipoinsular axis" is likely to be functional in early (<34 weeks gestation) intrauterine life. The rapid decline in the circulating concentrations of leptin after birth may be of physiological advantage to preterm and term newborns by limiting their body energy expenditure and conserving nutritional reverses for subsequent growth and development.

Thyroid function in very-low-birth-weight infants with intraventricular hemorrhage

The objective of this investigation was to study the natural course of thyroid function in infants with intraventricular hemorrhage (IVH). A cohort of infants < 1,500 grams birth weight, n=247, were included in the analysis. Total T4 and thyrotropin from newborn screening during the 1st week of life (Test 1) and from repeat screening at 2-4 weeks postnatal age (Test 2) were compared in infants with IVH (n=43) and a group of infants without IVH. Fifty-nine percent of infants still had transient hypothyroxinemia at the time of Test 2. After multivariate analysis, infants with IVH had an increased odds of having a T4 < or = 6 microg/dL on Test 1 (OR 2.8, 95% CI 1.2-6.5), but at the time of Test 2 IVH was not associated with an increased odds of having a low T4. Only gestational age (OR 1.6, 95% CI 1.1-2.5) remained associated with an increased odds of having an extremely low T4 (< or = 4 microg/dL) at this time. Transient hypothyroxinemia remains common at 2-4 weeks of age in preterm infants. IVH is not independently associated with having a low T4 at this time.

Physiologic predictors of lumbar spine bone mass in neonates

Dual energy x-ray absorptiometry (DXA) of the lumbar spine (LS) was measured in 201 singleton infants with birth weights from 1152 to 3970 g and gestational ages from 27 to 42 wk. All infants were well and studied at a mean (+/-SD) of 2.1 (+/-1.6) days after birth. There were 75 Caucasian (46 males, 29 females) and 126 African American infants (58 males, 68 females). Scan acquisition of the first to fourth lumbar vertebrae was performed with a single beam whole body scanner (Hologic QDR 1000/W densitometer, Hologic Inc, Waltham, MA, U.S.A.) using the infant spine mode. Scan analysis was performed with software version 4.57Q and consistent region of interest. The SD of difference for duplicate LS scans is <1.4% at a mean bone mineral content (BMC) of 2.14 g. Results show that LS BMC, area, bone mineral density (BMD) increased by approximately 550%, 280% and 180%, respectively, between 27 and 42 wk gestational age. Body mass accounted for about 70% and 55% of the variance in BMC and BMD respectively. In contrast, the infant's length appears to be the best determinant of LS area and accounts for about 75% of the variance in LS area. Race, gender or season has little or no effect on LS bone mass. There was progressive increase in BMC and area from first to fourth lumbar vertebra but BMD was significantly higher only at the fourth lumbar vertebra. We conclude that DXA LS can be performed even in small preterm infants. Its excellent precision, low radiation exposure and rapid scan acquisition offers promise as a useful tool for widespread use in pediatrics. Our data may be used as a basis for further studies in physiologic and pathologic situations that may affect bone mineralization in infants.

[Gastric probe used in pre-term newborns: study of changes in flexibility of constituent polymer]

The pre-term newborn care at neonatal units, which makes continued use of orogastric probes have drawn our attention to an apparent alteration in probes flexibility upon removal thereof for routine replacement at approximately 72 hours. Due to the lack of elements explaining such facts and information as to whether or not such findings are additional risks to the health condition of such children, the main objective of this study was as follows: to compare the flexibility of vinyl-made gastric probes use for pre-term newborn at 24 48 and 72 hours.

Body composition in human infants at birth and postnatally

The predictive values of anthropometric measurements, race, gender, gestational and postnatal ages, and season at birth and at study for the total body dual energy X-ray absorptiometry (DXA)-derived lean mass (LM), fat mass (FM) and fat mass as a percentage of body weight (%FM) were determined in 214 singleton appropriate birth weight for gestational age infants [101 Caucasian (60 boys, 41 girls) and 113 African American (55 boys, 58 girls)]. Gestational ages were 27-42 wk and the infants were studied between birth and 391 d, weighing between 851 and 13446 g. In addition, predictive value of body weight, LM and FM for DXA bone measurements was also determined. Scan acquisition used Hologic QDR 1000/W densitometer and infant platform and scans without significant movement artifacts were analyzed using software 5.64p. Body weight, length, gender and postnatal age were significant predictors of LM (adjusted R:(2) >0. 94) and FM (adjusted R:(2) >0.85). Physiologic variables had little predictive value for %FM except in the newborns (adjusted R:(2) 0. 69). Body weight was the dominant predictor of LM and FM, although length had similar predictive value for LM with increasing postnatal age. Female infants had less LM and more FM throughout infancy (P: < 0.01). LM or FM offered no advantage over body weight in the prediction of bone mass measurements. DXA is a useful means with which to determine body composition, and our data are important in the design and assessment of nutritional intervention studies.

Plasma and urine riboflavin during riboflavin-free nutrition in very-low-birth-weight infants

BACKGROUND

Very-low-birth-weight (VLBW; birth weight <1500 g) infants receive enteral and parenteral nutriture that provides greater daily riboflavin (vitamin B2) than does term infant nutriture, and elevated plasma riboflavin develops in these infants after birth. The purpose of this study was to measure plasma and urine riboflavin concentrations in VLBW infants during riboflavin-free nutrition. Our hypothesis was that elevated plasma riboflavin develops in VLBW infants because of high daily intake and immature renal riboflavin elimination.

METHODS

Eighteen clinically healthy VLBW infants received parenteral nutrition and preterm infant formula during the first postnatal month. On postnatal days 10 and 28, the infants received specially prepared riboflavin-free enteral and parenteral nutrition for the 24-hour study period. Serial collections of plasma were made at time 0 and at 12 and 24 hours. Urine was collected continuously for the 24-hour period in 4-hour aliquots. Samples were analyzed for riboflavin concentration.

RESULTS

During the 24-hour riboflavin-free study period on postnatal day 10, plasma riboflavin decreased 56% from 185 +/- 37 ng/mL (mean +/- SEM), and urine riboflavin decreased 75% from 3112 +/- 960 mg/mL. Similarly, on postnatal day 28, plasma riboflavin decreased 79% from 184 +/- 32 ng/mL, and urine riboflavin concentration decreased 91% from 5092 +/- 743 ng/mL during the 24-hour riboflavin-free study period. Riboflavin half-life (t(1/2)) was 18.5 hours on postnatal day 10 and decreased 48% by postnatal day 28. Riboflavin elimination was 145.1 +/- 20.6 mg/kg per day on postnatal day 10 and increased 40% by postnatal day 28.

CONCLUSION

The VLBW infants who received parenteral nutrition and preterm infant formula had elevated plasma riboflavin on postnatal days 10 and 28. Plasma riboflavin t(1,2) was shorter and renal riboflavin elimination was greater on postnatal day 28 than on postnatal day 10. Plasma riboflavin was normal after 24 hours of riboflavin-free nutrition. The pattern of plasma and urine riboflavin in VLBW infants suggests a lower daily intake would maintain plasma riboflavin close to normal.

Linear hyperechogenicity within the basal ganglia and thalamus of preterm infants

Linear hyperechogenicity (LHE) within the basal ganglia and thalamus is an uncommon sonographic finding in preterm infants and is of unclear significance. The study objectives were to determine the clinical characteristics and neurodevelopmental outcome in preterm infants who develop LHE. Ten preterm and 20 control infants were evaluated developmentally at 18 months adjusted age using the Bayley Scales of Infant Development. LHE was diagnosed at 4 weeks (range = 1-11). Antenatal glucocorticoid therapy was more common in infants with LHE than in the control infants (90% vs 45%). Four (44%) of nine LHE infants and no control infants were positive for cytomegalovirus (P = 0.02, and three of 10 LHE infants and no control infants had a hypothyroid (P = 0.03). The mental development scores and behavioral evaluation results were lower in the infants with LHE than in the control infants (73.7 +/- 9.7 vs 83.7 +/- 9.4, P = 0.01 and 23.7 +/- 20.1 vs 43.9 +/- 25.4, P = 0.04, respectively). The infants without LHE also had poorer motor quality (22.8 +/- 20. 5 vs 55.7 +/- 37.4, P = 0.02) and lower emotional regulation scores (25.7 +/- 16 vs 42.3 +/- 24, P = 0.06) than the control infants. Preterm infants with LHE are at an increased risk of adverse neurodevelopmental outcome and, in particular, cognitive and behavioral performance. The sonographic evolution of LHE may be a marker of a diffuse insult to the brain.

The conceptualization, measurement, and validation of transient mechanical birth trauma

An index of transient mechanical birth trauma (TMBT), consisting of the presence or absence of molding, cephalohematoma, subconjunctival hemorrhage, body bruising, facial bruising, petechiae, forceps marks, diminished arm movements, and sensitivity to sudden position changes, was measured on a convenience sample of 196 healthy newborns. Six dimensions of the Neonatal Behavioral Assessment Scale (NBAS) and other newborn measures also were assessed. Vaginally delivered newborns had more TMBT than those delivered by cesarean section and of newborns delivered vaginally, macrosomics had more TMBT than nonmacrosomics. TMBT positively correlated with range of state, individual reflex items of resistance to left and right arm movement, predominant state during the NBAS exam, and time to complete the NBAS exam. TMBT negatively correlated with newborn state instability and 1- and 5-minute Apgars. The results supported the measure's validity and are discussed in terms of implications for practice and further research to explore TMBT's usefulness.

Antenatal use of ambroxol for the prevention of infant respiratory distress syndrome

OBJECTIVE

Our purpose was to evaluate the efficacy and safety of ambroxol for the prenatal prophylaxis of infant respiratory distress syndrome (IRDS).

STUDY DESIGN

This was a prospective study with 2 groups of pregnant patients with premature labor or with premature rupture of membranes at an estimated gestation between 27 to 34 completed weeks. Ambroxol treatment group consisted of 39 subjects in whom 1,000 mg of ambroxol diluted in 500 ml of 5% glucose solution was given intravenously for 4 hours once a day for 3 days, while the control group consisted of 41 subjects in whom ambroxol was not administered. Main measures included Apgar scores, clinical signs of one or more of the following: respiratory rate of > 60/min, intercostal retraction, alar flaring, expiratory grunting, cyanosis on room air and radiological evidence of IRDS. Chi-square test was used to determine the statistical significance of the results.

RESULTS

Tolerable maternal side effects were noted. Profile of newborns delivered were similar in both groups. Incidence of IRDS was significantly less in the treatment group (p < 0.01).

CONCLUSIONS

Antenatal administration of ambroxol resulted in a significant decrease in the incidence of IRDS as well as perinatal morbidity and mortality. Due to the efficacy and safety of this drug, it might be useful for the prevention of IRDS.

Determinants of blood pressure in very low birth weight neonates: lack of effect of antenatal steroids

OBJECTIVES

To define the range of normal blood pressures (BP) for very low birth weight (VLBW;</=1500 g) neonates and to study perinatal variables affecting BP measurements after birth, including the effects of antenatal steroids.

STUDY DESIGN

Antenatal steroids were rarely administered at Parkland Memorial Hospital before May 1994, permitting us to establish a cohort of VLBW neonates exposed to antenatal steroids [n=70, 1166+/-253 (S.D.) g, and 28.7+/-2.1 weeks] who were matched with neonates delivered during the prior year (n=46, 1100+/-241 g, 28.9+/-1.8 weeks). Maternal and neonatal charts were abstracted for pertinent data, and neonatal BP measurements (determined directly when an arterial catheter was available or indirectly by the oscillometric method) were extracted every 3 h for the first 12 h and every 6 h until 72 h postnatal.

RESULTS

Antenatal steroids did not affect BP immediately after birth or for the subsequent 72 h postnatal. Therefore, data from all neonates </=1500 g were combined and the pattern of BP change over 72 h postnatal assessed. Systolic, diastolic and mean BP increased (P<0.001) 33%, 44% and 38%, respectively, during the first 72 h. Although neonates weighing </=1000 g and 1001-1500 g demonstrated gradual increases (P<0.001) in systolic, diastolic and mean BP by 72 h, values were consistently lower (P<0.01) in neonates </=1000 g. Of interest, only 11 neonates (9.5%) were treated for clinical hypotension.

CONCLUSIONS

In VLBW neonates antenatal steroids do not modify BP measurements either immediately after birth or the 30-40% rise occurring in the first 72 h postnatal. Further, BP is developmentally regulated and is gestationally and birth weight dependent. These data provide additional insight into assessing the need for treating hypotension.

Outcomes of children of extremely low birthweight and gestational age in the 1990s

Advances in perinatal care have improved the chances for survival of extremely low birthweight (<800 grams) and gestational age (<26 weeks) infants. A review of the world literature reveals that among regional populations, survival at 23 weeks' gestation ranges from 2 to 35%, at 24 weeks' gestation 17 to 62% and at 25 weeks' gestation 35 to 72%. These wide variations may be accounted for by differences in population descriptors, in the criteria used for starting or withdrawing treatment, in the reported duration of survival and differences in care. Major neonatal morbidity increases with decreasing gestational age and birthweight. At 23 weeks' gestation, chronic lung disease occurs in 57 to 86% of survivors, at 24 weeks in 33 to 89% and at 25 weeks' gestation in 16 to 71% of survivors. The rates of severe cerebral ultrasound abnormality range from 10 to 83% at 23 weeks' gestation, 9 to 64% at 24 weeks and 7 to 22% at 25 weeks' gestation Of 77 survivors at 23 weeks' gestation, 26 (34%) have severe disability (defined as subnormal cognitive function, cerebral palsy, blindness and/or deafness). At 24 weeks' gestation, the rates of severe neurodevelopmental disability range from 22 to 45%, and at 25 weeks' gestation 12 to 35%. When compared with children born prior to the 1990s, the rates of neurodevelopmental disability have, in general, remained unchanged. We conclude that, with current methods of care, the limits of viability have been reached. The continuing toll of major neonatal morbidity and neurodevelopmental handicap are of serious concern.

Physiology of infants with very low birth weight

Advances in neonatal management have resulted in dramatic increases in survival in infants with birth weights less than 1,500 g. Extensive basic science and clinical research has led to a more comprehensive understanding of the physiological differences between the VLBW infant and larger neonates. Meticulous attention must be paid to appropriate fluid, electrolyte, nutrition, and temperature maintenance to achieve homeostasis and growth. Additionally, the clinician must be aware of the diagnostic and treatment modalities for the common complications seen in the premature infant to minimize mortality and long-term morbidity.

Neonatal outcome in small for gestational age infants: do they really better?

BACKGROUND

There still is a controversy as to the neonatal outcome of small for gestational age (SGA) infants compared to a appropriate for gestational age (AGA) preterm infants. As a part of a randomized multicenter trial on timing of bovine surfactant therapy, we aimed at investigating short-term outcome variables in SGA-infants compared with AGA-infants.

METHODS

SGA-infants were classified weighing below the 10th percentile at birth and were compared to AGA-infants in terms of prenatal and neonatal characteristics and neonatal outcome.

RESULTS

A total of 317 infants were enrolled, 59 SGA- and 258 AGA-infants. Both groups did not differ in gestational age, however, SGA-infants had a lower birth weight. Preterm premature rupture of fetal membranes was observed more frequently in AGA-, preeclampsia in SGA-infants. The rate of intubation, severity of RDS, rate of surfactant administration, pulmonary airleaks and days on the ventilator did not differ between both groups. However prolonged nasal CPAP, supplemental oxygen therapy and chronic lung disease at 28 days and 36 weeks was diagnosed more often in SGA-infants. Furthermore mortality was significantly higher in SGA-infants as well as total NICU and total hospital days.

CONCLUSION

As SGA-infants have an increased mortality rate and an increased risk for developing chronic lung disease, further studies should focus on prevention of intrauterine growth restriction and its complications.

Differential effects of breast- and formula-feeding on preterm infants' sleep-wake patterns

OBJECTIVE

To compare sleep-wake patterns of breastfed and formula-fed preterm infants.

DESIGN

Data were taken from an exploratory study of infant biorhythm maturation. Parents completed a 24-hour diary of infant Sleep, Awake, and Cry states and feedings, recorded at 30-minute intervals. Infant health data were collected from medical records and parents' reports.

SETTING

Infants were studied in the home after discharge from a neonatal intensive-care unit.

PARTICIPANTS

The convenience sample included 12 breastfed and 25 formula-fed preterm infants (gestational age, 26-33 weeks; corrected postnatal age, 4-6 weeks). Groups were comparable in terms of gestational age, postnatal age, Apgar scores, maternal age, and home environment.

MAIN OUTCOME MEASURE

The 24-hour recording period was divided into day (0600-1800) and night (1800-0600). Study variables were Day, Night, and 24-hour Sleep, Awake, and Cry.

RESULTS

Breastfed preterm infants exhibited more Day Cry and 24-hour Cry than did formula-fed infants. Infants demonstrated a diurnal pattern in Cry, Awake, and Sleep. Breastfed preterm infants cried approximately 1 hour per day more than formula-fed infants.

CONCLUSION

Preterm breastfed infants experienced more cry than did formula-fed infants. The relationship between feeding method and sleep-wake pattern has implications for supporting lactation as well as for research design.

Long chain polyunsaturated fatty acid formation in neonates: effect of gestational age and intrauterine growth

The present study was designed to evaluate the effect of gestational age and intrauterine growth on the long chain polyunsaturated fatty acid (LCP) synthesis from dietary precursors in neonates as reflected by plasma pools. These have been considered conditionally essential nutrients for normal growth, sensory maturation, and neurodevelopment. In vivo elongation/desaturation of deuterated d5-linoleic acid (d5-LA) to form arachidonic acid (AA), and d5-alpha-linolenic acid (d5-LNA) to form docosahexaenoic acid (DHA), was studied in 19 preterm appropriate-for-gestational-age (AGA) infants, 11 AGA term, and 11 intrauterine growth-retarded (IUGR) infants. They received a dose of 50 mg/kg body weight of d5-LA and d5-LNA enterally during the first days of life; d5-labeled derivatized fatty acids were determined in blood samples obtained at 24, 48, and 96 h after dosing. Lipids were extracted and fatty acids analyzed by gas chromatography and negative ion mass spectrometry. Mean concentrations, microg/mL, and d5/d0 for n-3 and n-6 precursor and products were computed at various times and were also integrated over the complete study period. Significantly higher time-integrated concentration of d5-AA and d5-DHA were observed in preterm infants relative to the other two groups. Time-integrated enrichment of DHA relative to LNA was 100-fold lower in preterms, 410-fold lower in term, and 27-fold lower in IUGR infants. Similar significant declines in product to precursor enrichments were noted for the n-6 series. A significant negative correlation of AA and DHA formation based on time-integrated d5/d0 ratios with gestational age was noted; product/ precursor enrichment versus gas chromatography for the n-6 series had an r of -0.5, p = 0.001, and for the n-3 series had an r of -0.6, p = 0.0001. Birth weight or weight adequacy did not add further strength to the relationship. We conclude that LCP formation from deuterated precursors occurs as early as 26 wk gestation, and in fact is more active at earlier gestational ages; growth retardation appears to slow down or diminish LCP formation. No quantitative estimates of LCP synthesis or nutritional sufficiency can be derived from these data.

[Validity of neonatal clinical assessment for estimation of gestational age: comparison of new ++Ballard+ score with date of last menstrual period and ultrasonography]

The objective of this article is to evaluate the accuracy of the New Ballard (NB) score in detecting prematurity. Date of last menstrual period (LMP) and ultrasonography (USG) are used as reference procedures. First, an assessment of inter-observer reliability of the NB score measurements and the USG reports was carried out. Regarding the NB scores, the kappa coefficient and the Intraclass Correlation Coefficient were, respectively, 0.74 (CI 95% 0.49-0.99) and 0.88 (CI 95% 0.78-0.93). For the USG analysis an Intraclass Correlation Coefficient of 0.96 (CI 95% 0.91-0.98) was found. Turning to validity, sensitivity of the NB score was below 0.70 in all but one comparison, irrespective of which procedure was taken as reference. Although specificity was consistently above 0.90, results suggest that the diagnostic ability of the NB score to detect prematurity is far from ideal. The proportion of false negatives may be a warning against its use alone, both in clinical practice and in epidemiological research contexts. Rather, the procedure should be recommended mainly as an accessory diagnostic tool.

Penile length of newborns in Singapore

Micropenis is an important sign in congenital hypopituitarism and various disorders. Documented norms for penile length exist only for babies of Caucasian and Middle-Eastern origin. This study was carried out to establish such norms for Asian newborns. We studied 228 male live births within their first three days of life. Stretched penile lengths were marked off on unmarked wooden spatulas, which were placed vertically along the dorsal aspect of the penis, with one rounded end on the pubic bone. The mean penile length +/- S.D. for the full-term Asian baby was 3.6 +/- 0.4 cm. Race had a significant effect: Chinese 3.5 cm, Malay 3.6 cm and Indian 3.8 cm. Penile length correlated with birth weight and gestational age. Asian babies thus have similar norms to Caucasian babies. An Asian newborn whose penis measures less than 2.6 cm has micropenis and may need prompt investigation for underlying endocrine disorders.

Risk factors for chronic lung disease in the surfactant era: a North Carolina population-based study of very low birth weight infants. North Carolina Neonatologists Association

OBJECTIVE

To identify risk factors for chronic lung disease (CLD) in a population-based cohort of very low birth weight infants, born in an era of surfactant usage. We specifically investigated the effects of antenatal steroids, nosocomial infection, patent ductus arteriosus (PDA), fluid management, and ventilator support strategies.

METHODS

Data were prospectively collected on 1244 infants born in North Carolina in 1994 with birth weights 500 to 1500 g, and treated at 1 of the 13 intensive care nurseries across the state. The outcome of interest was CLD, defined as dependency on supplemental oxygen at 36 weeks' postmenstrual age. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression models.

RESULTS

Among 865 survivors to 36 weeks' postmenstrual age, 224 (26%) had CLD. Nosocomial infection (OR: 2.0; 95% CI: 1.4-3.3), fluid intake on day 2 (OR: 1.06 per 10 mL increase; 95% CI: 1.01-1.11), and the need for ventilation at 48 hours of life (OR: 2.2; 95% CI: 1.3-3.7) were associated with an increased risk of CLD. Among infants ventilated at 48 hours, nosocomial infection (OR: 1.64; 95% CI: 1.02-2.62) and PDA (OR: 1.9; 95% CI: 1.2-3.1) were associated with an increased risk. No association was found with antenatal steroid receipt or increased levels of ventilator support.

CONCLUSION

This analysis suggests that with widespread use of surfactant, nosocomial infection, PDA, and water balance persist as risk factors for CLD.

Reference range for serum cortisol in well preterm infants

AIM

To establish a reference range for serum cortisol concentrations in preterm infants with a gestational age of less than 30 weeks during the first two weeks of life.

METHODS

Infants were prospectively classified by the following exclusion criteria: surfactant administration, arterial hypotension, acute or uncontrolled infection, ventricular haemorrhage II degrees or above, serum glucose < 2.2 mmol/l, exchange transfusion, stress as a result of any kind of examination or nursing for at least 4 hours before blood sampling. The cortisol value was measured once using radioimmunoassay in each infant.

RESULTS

In appropriate for gestational age (AGA) infants (n = 37, median gestational age 27.7 weeks, median birthweight 1030 g) the distribution of the cortisol concentrations was non-Gaussian. These had a nearly normal distribution, when log(10) values of the data were used. The points determined by mean (2 SD) on the logarithmic scale were transformed back to the original units to provide a reference range: 73-562 nmol/l. Gestational age was significantly (p = 0.033) associated with cortisol values (log(10)) with a regression coefficient (standard error) of -0.045 (0.020). Small for gestational age (SGA) infants (n = 8) had significantly higher cortisol values (median 357 nmol/l) than AGA infants (median 199 nmol/l) (p=0.028).

CONCLUSIONS

There is a strictly defined reference range of serum cortisol concentrations in AGA preterm infants.

Cranial sonography in very-low-birth-weight infants: do all infants need to be screened?

The objective of the study was to develop clinical screening criteria to diagnose infants with intraventricular hemorrhage (IVH) and cystic periventricular leukomalacia (PVL). We performed a case-control investigation of two cohorts of very-low-birth-weight infants (n = 505, combined cohorts). Univariate and multivariate analyses were performed from data obtained in cohort 1 to develop screening criteria for IVH and cystic PVL. The screening criteria were then applied to cohort 2. The screening criteria for IVH had a sensitivity of only 51%, a specificity of 62%, a positive predictive value of 31%, and a negative predictive value of 79%. Screening criteria for cystic PVL had a sensitivity of only 22%, a specificity of 58% a positive predictive value of 2%, and a negative predictive value of 95%. These data suggest that using clinical criteria to determine which infants should receive screening cranial sonography for IVH and cystic PVL would miss a substantial number of infants with these conditions.

The design of the multicenter study of light reduction in retinopathy of prematurity (LIGHT-ROP)

BACKGROUND

The LIGHT-ROP Study was a multicenter, prospective, randomized, controlled, clinical trial designed to determine if a reduction in ambient light exposure to premature infants' eyes would reduce the incidence of retinopathy of prematurity (ROP). Previous clinical reports were contradictory and had one or more methodological flaws.

METHODS

The LIGHT-ROP trial was designed in rigorous fashion to include randomization to treatment or control groups, masking of examiners, an adequate sample size of high-risk infants, a universal ROP classification system, a reliable and reproducible ophthalmologic examination protocol, a controlled method of light reduction, and monitoring of light levels in the nursery. The multicenter trial was conducted at three centers in Buffalo, Dallas, and San Antonio, with a separate coordinating center in Houston. The trial also utilized a separate data and safety monitoring committee.

CONCLUSION

The design of the LIGHT-ROP study represents the most rigorous and largest clinical trial to date. It has demonstrated that light reduction does not reduce the incidence of confirmed ROP in high risk infants.

Effects of skin-to-skin holding on general movements of preterm infants

The study objective was to test the hypothesis that the effect of skin-to-skin (STS) holding increases the ratio of rest to activity in low birth weight preterm infants. Ten infants with birthweight < 2,000 grams were videotaped before and after STS holding. Video recordings were analyzed to determine the number of general movements. We found no statistically significant difference between the percentage of general movements over the two periods. We conclude that the ratio of rest-activity before and after STS holding does not change as measured by occurrence of general movements.

Transverse cerebellar diameter on cranial ultrasound scan in preterm neonates in an Australian population

OBJECTIVE

Fetal measurement of transverse cerebellar diameter (TCD) has been shown to correlate well with gestational age (GA), even in the presence of growth retardation. The aim of this study was to define the normal range of TCD in preterm neonates in an Australian population between 23 and 32 weeks GA.

METHODOLOGY

Infants admitted to the Royal Women's Hospital, Melbourne, having routine cranial ultrasound scans (< 1500 g and/or of gestational age ≤ 32 weeks at birth) had their TCD measured on a cranial scan performed during the first 3 days of life. The posterior fossa was examined through the asterion using a General Electric LOGIQ 500 scanner (GE Medical Systems, Waukesha, USA) and TCD measurement was taken in the coronal plane.

RESULTS

106 infants < 1500 g and/or of GA ≤ 32 weeks at birth had their TCD measured between 1 January 1997 and 30 November 1997. Transverse cerebellar diameter and associated 95% confidence intervals are described for infants between 23 and 32 weeks GA. The linear regression equation relating TCD and GA was: TCD (mm) = -12.9 + 1.61 × GA (weeks). R² = 0.80, P < 0.001.

CONCLUSION

This is the only study of TCD measurement using cranial ultrasound in a group of preterm newborns, and forms the basis for nomograms of TCD which can be used as a tool to assist in the assessment of GA, even in growth-retarded preterm newborns, and in the diagnosis of cerebellar hypoplasia.