Echocardiographic Evaluation of Patent Ductus Arteriosus in Preterm Infants.

Patent ductus arteriosus (PDA) is part of the typical morbidity profile of the preterm infant, with a high incidence of 80-90% in extremely low birth weight infants born before 26 weeks of gestation. Whereas spontaneous closure of the ductus arteriosus (DA) is likely in term infants, it is less so in preterm ones. PDA is associated with increased mortality and various comorbidities including cardiac failure, need for respiratory support, bronchopulmonary dysplasia, pulmonary or intracranial hemorrhage, and necrotizing enterocolitis; however, there is no proven causality between these morbidities and the presence of DA. Thus, the indication to close PDA remains highly controversial. This paper focuses on echocardiographic evaluation of PDA in the preterm infant and particularly on the echocardiographic signs of hemodynamic significance.

Value of postmortem studies in deceased neonatal and pediatric intensive care unit patients.

Worldwide, various autopsy studies have shown a decrease in the diagnostic error rate over the last years. The cause of this positive development is mainly due to the improvement of modern medicine. However, intensive care unit patients are thought to have a higher risk for diagnostic errors, which is documented in several studies in the adult population. In contrast, there is only limited information about diagnostic errors in pediatrics, particularly in pediatric and neonatal intensive care units. The aims of this study were to analyze the spectrum of childhood death, determine the prevalence and distribution of autopsy-confirmed diagnostic errors, and describe patient characteristics that might have influenced the discordance between antemortem and postmortem findings. We analyzed 143 autopsy reports from 2004 to 2013 and correlated these with clinical reports. The overall autopsy rate during this interval was 20.3%. The leading causes of death were congenital malformations (28%), diseases closely associated with perinatal disorders (25%), disorders of the cardiovascular system (18%), and infections (15%). Additional findings were obtained in 23% of the autopsies. Major diagnostic errors were found in 6%, the lowest reported value in a developed country as yet. Most cases (75%) showed complete concordance between clinical diagnoses and postmortem findings, in line with improvements in diagnostic and therapeutic processes over the last decades. In conclusion, autopsy of neonates, infants, and children represents an important tool for monitoring the quality of pediatric and neonatal medical care.

Epidemiology of Methicillin-Susceptible Staphylococcus aureus in a Neonatology Ward.

OBJECTIVE: In-hospital transmission of methicillin-susceptible Staphylococcus aureus (MSSA) among neonates remains enigmatic. We describe the epidemiology of MSSA colonization and infection in a 30-bed neonatal ward. DESIGN: Multimodal outbreak investigation SETTING: A public 800-bed tertiary care university hospital in Switzerland METHODS: Investigations in 2012-2013, triggered by a MSSA infection cluster, included prospective MSSA infection surveillance, microbiologic screening of neonates and environment, onsite observations, and a prospective cohort study. MSSA isolates were characterized by pulsed-field gel electrophoresis (PFGE) and selected isolates were examined for multilocus sequence type (MLST) and virulence factors. RESULTS: Among 726 in 2012, 30 (4.1%) patients suffered from MSSA infections including 8 (1.1%) with bacteremia. Among 655 admissions in 2013, 13 (2.0%) suffered from MSSA infections including 2 (0.3%) with bacteremia. Among 177 neonates screened for S. aureus carriage, overall 77 (44%) tested positive. A predominant PFGE-1-ST30 strain was identified in 6 of 30 infected neonates (20%) and 30 of 77 colonized neonates (39%). This persistent clone was pvl-negative, tst-positive and belonged to agr group III. We found no environmental point source. MSSA carriage was associated with central vascular catheter use but not with a particular midwife, nurse, physician, or isolette. Observed healthcare worker behavior may have propagated transmission via hands and fomites. Despite multimodal interventions, clonal transmission and colonization continued and another clone, PFGE-6-ST5, became predominant. CONCLUSIONS: Hospital-acquired MSSA clones represent a high proportion of MSSA colonization but not MSSA infections in neonate inpatients. In contrast to persisting MSSA, transmission infection rates decreased concurrently with interventions. It remains to be established whether eradication of hospital-acquired MSSA strains would reduce infection rates further.

Case series of Bifidobacterium longum bacteremia in three preterm infants on probiotic therapy.

BACKGROUND: The use of probiotics as prophylaxis for necrotizing enterocolitis (NEC) in preterm infants is being increasingly practised. OBJECTIVE: We report, for the first time, a case series of 3 preterm, very-low-birth-weight (VLBW) infants who developed bacteremia with Bifidobacterium longum on probiotic therapy with Infloran® containing viable B. longum. METHODS: We retrospectively reviewed data of 3 infants (of gestational age <30 weeks and birth weight <1,230 g). They were admitted to the neonatal intensive care unit. Clinical data were retrieved from their medical records. RESULTS: In infants 1 and 2, B. longum was isolated from the blood cultures when they were on probiotic therapy with Infloran or shortly after, respectively, and was interpreted as transient bacteremia. The clinical presentation of these infants did not require antibiotic treatment after the isolation of B. longum. Infant 3 developed an NEC despite probiotic therapy with Infloran and the blood cultures showed B. longum growth. This infant required explorative laparotomy and antibiotic treatment. The clinical isolates of B. longum and the strain of the Infloran capsule showed an identical profile on biochemical, mass-spectrometric and molecular analyses, suggesting a direct correlation between the administration of probiotics and bacteremia with B. longum in all 3 infants. CONCLUSIONS: The occurrence of bacteremia with bifidobacteria after its prophylactic administration in VLBW infants and its possible clinical consequences are a matter of concern. In the interests of safety, the use of probiotics in such a population should be indicated with caution and requires further investigation.

[Vertical HIV infection is preventable but remains challenging]. / Die vertikale HIV-Infektion kann heute erfolgreich verhütet werden, bleibt aber eine Herausforderung.

The frequency of HIV mother-to-child transmission in Switzerland is nowadays < 1 %, if the pregnant woman receives successful anti-HIV treatment and the newborn apt post-exposure prophylaxis (PEP) and is not breast-fed. The interdisciplinary approach in arranging the maternal anti-HIV treatment, birth mode and PEP for the child is essential. Nevertheless, HIV infection in the child needs to be considered when it presents with compatible signs and symptoms, as HIV infection of the mother may escape diagnosis.

Cardiovascular biomarkers pro-atrial natriuretic peptide and pro-endothelin-1 to monitor ductus arteriosus evolution in very preterm infants.

BACKGROUND: The diagnostic and prognostic appraisal of patent ductus arteriosus (PDA) in preterm infants is still debatable. AIMS: To compare plasma cardiovascular biomarkers with echocardiographic indices alongside ductus arteriosus (DA) evolution in very preterm infants within the first week of life. METHODS: Mid-regional pro-atrial natriuretic peptide (MR-proANP) and C-terminal pro-endothelin-1 (CT-proET-1) levels were prospectively measured on the second and sixth days of life (DOL) in 52 preterm infants born before 32weeks of gestation. Echocardiographic indices to define DA patency and significance were simultaneously obtained. Logistic regression and receiver operating characteristics (ROC) analyses were used to assess and quantify the biomarkers' diagnostic capacities. RESULTS: Thirty infants exhibited PDA on DOL 2; in 21 of these infants, DA was characterized as hemodynamically significant. Treatment failure after a first course of indomethacin was noted in 8 infants (DOL 6), whereas 7 participants underwent later surgical ligation. The diagnostic accuracy of cardiovascular biomarkers was moderate on DOL 2 but high on DOL 6. PDA was the only significant predictor of MR-proANP levels on DOL 6, independent of the effect of clinical confounders (regression coefficient 0.426, R(2) 0.60). Infants with MR-proANP ≥850pmol/l on DOL 2 had 3.9-fold higher risk (95% CI 1.01 to 14.5) of being diagnosed with significant DA, whereas infants with MR-proANP ≥700pmol/l on DOL 6 had 7.1-fold higher risk (1.9 to 27.2) for pharmaceutical treatment failure. CONCLUSION: The cardiovascular plasma biomarker MR-proANP is a promising candidate for monitoring PDA evolution in very preterm infants.

Manufactured volvulus.

BACKGROUND/PURPOSE: Malrotation with a common mesentery is the classical pathology allowing midgut volvulus to occur. There are only a few reports of small bowel volvulus without malrotation or other pathology triggering volvulation. We describe three cases of small bowel volvulus in very premature newborns with a perfectly normal intra-abdominal anatomy and focus on the question, what might have set off volvulation. METHODS: In 2005 to 2008, three patients developed small bowel volvulus without any underlying pathology. Retrospective patient chart review was performed with special focus on clinical presentation, preoperative management, intraoperative findings, and potential causative explanations. Mean follow-up period was 46 months. RESULTS: All patients were born between 27 and 31 weeks (mean 28 weeks) with a birth weight between 800 and 1,000 g (mean 887 g). They presented with an almost identical pattern of symptoms including sudden abdominal distension, abdominal tenderness, erythema of the abdominal wall, high gastric residuals, and radiographic signs of ileus. All of them were treated with intensive abdominal massage or pelvic rotation to improve bowel movement before becoming symptomatic. CONCLUSIONS: Properistaltic maneuvers including abdominal massage and pelvic rotation may cause what we term a "manufactured" volvulus in very premature newborns. Thus, this practice was stopped.

Health-related quality of life and behavior of triplets at adolescent age.

OBJECTIVES: To assess health-related quality of life (HRQoL) and behavior of triplets compared with matched singletons at adolescent age and to identify medical and sociodemographic predictors of outcome. STUDY DESIGN: Fifty-four triplets (19 sets, mean [SD] gestational age 32.0 [2.4] weeks, birth weight 1580 [450] g) and 51 gestational age-, birth weight-, and sex-matched singleton controls self-rated their HRQoL at age 14.5 (0.3) years. Proxy reports about HRQoL and behavior were obtained by parents and teachers. HRQoL was measured with the Kidscreen-52 questionnaire child and parent form, and behavior with the Achenbach Child Behavior Checklist. RESULTS: Self- and parent-reported HRQoL values was similar in both groups except for the dimensions "mood and emotions" and "autonomy," which were better (P = .001, P = .03) in triplets. Parents reported significantly less behavioral problems in triplets compared with controls. Compared with community norms, both HRQoL and behavior measures in triplets were in the normal range. Parent-reported HRQoL was predicted by dichorionicity. CONCLUSIONS: HRQoL and behavioral outcome in adolescent triplets was good in our study and was, in some aspects, better than in matched singleton controls. Dichorionicity is an important outcome determinant.

Plasma C-terminal pro-endothelin-1 and the natriuretic pro-peptides NT-proBNP and MR-proANP in very preterm infants with patent ductus arteriosus.

BACKGROUND: In very preterm infants, clinical decision-making, such as closing a patent ductus arteriosus (PDA), may be aided by measuring circulating natriuretic and endothelial pro-peptides. OBJECTIVES: To investigate the association between perinatal characteristics, PDA echocardiography and plasma concentrations of stable pro-peptides of B-type natriuretic peptide (NT-proBNP), atrial natriuretic peptide (MR-proANP) and endothelin-1 (CT-proET-1). METHODS: A prospective, cross-sectional, single-center study was performed in 66 infants who were less than 32 weeks of gestational age. Pro-peptide concentrations were determined at birth and at day 2-3 of life. RESULTS: Plasma concentrations of all 3 pro-peptides increased on average 2- to 5-fold from birth to day 2-3 of life. NT-proBNP and MR-proANP were closely related at birth and at day 2-3 (Rs 0.902 and 0.897, respectively, p < 0.001), whereas CT-proET-1 was related to NT-proBNP and MR-proANP at birth (Rs 0.478 and 0.460, respectively, p < 0.001) but not at day 2-3. Birth weight was negatively related to all 3 pro-peptides at birth (p < 0.01); however, preeclampsia and compromised placental perfusion were associated with elevated NT-proBNP and MR-proANP concentrations at birth. At day 2-3, MR-proANP and NT-proBNP correlated significantly with the ductal diameter (Rs 0.416 and 0.415, respectively, both p = 0.011), whereas CT-proET-1 correlated with the left atrium/aorta ratio (Rs 0.506, p = 0.027). CT-proET-1 was elevated in infants with treated compared to untreated PDA [median (5-95% range) 388 (272-723) vs. 303 (152-422) pmol/l, p = 0.011], but not NT-proBNP or MR-proANP. CONCLUSION: CT-proET-1 is a promising predictor in determining the need for PDA intervention.

Prevention of hypernatraemic dehydration in breastfed newborn infants by daily weighing.

UNLABELLED: Hypernatraemic dehydration, which predominantly appears in breastfed neonates, can cause serious complications, such as convulsions, permanent brain damage and death, if recognised late. Weight loss > or = 10% of birth weight could be an early indicator for this condition. In this prospective cohort study from October 2003 to June 2005 in the postnatal ward of the University Hospital Zurich, Switzerland, all term newborns with birth weight > or = 2,500 g were weighed daily until discharge. When the weight loss was > or = 10% of birth weight, serum sodium was measured from a heel prick. Infants with moderate hypernatraemia (serum sodium = 146-149 mmol/l) were fed supplementary formula milk or maltodextrose 10%. Infants with severe hypernatraemia (serum sodium > or = 150 mmol/l) were admitted to the neonatal unit and treated in the same way, with or without intravenous fluids, depending on the severity of the clinical signs of dehydration. A total of 2,788 breastfed healthy term newborns were enrolled. Sixty-seven (2.4%) newborns had a weight loss > or = 10% of birth weight; 24 (36%) of these had moderate and 18 (27%) severe hypernatraemia. Infants born by caesarean section had a 3.4 times higher risk for hypernatraemia than those born vaginally. All newborns regained weight 24 h after additional fluids. CONCLUSION: In our study, one out of 66 healthy exclusively breastfed term neonates developed hypernatraemic dehydration. Daily weight monitoring and supplemental fluids in the presence of weight loss > or = 10% of birth weight allows early detection and intervention, thereby preventing the severe sequellae of hypernatraemic dehydration.

The contribution of pulse oximetry to the early detection of congenital heart disease in newborns.

UNLABELLED: Approximately half of all newborns with congenital heart disease are asymptomatic in the first few days of life. Early detection of ductal-dependant cardiac malformations prior to ductal closure is, however, of significant clinical importance, as the treatment outcome is related to the time of diagnosis. Pulse oximetry has been proposed for early detection of congenital heart disease. The aims of the present study were: 1) to determine the effectiveness of a pulse-oximetric screening performed on the first day of life for the detection of congenital heart disease in otherwise healthy newborns and 2) to determine if a pulse-oximetric screening combined with clinical examination is superior in the diagnosis of congenital heart disease to clinical examination alone. This is a prospective, multi-centre study. Postductal pulse oximetry was performed between six and twelve hours of age in all newborns of greater than 35 weeks gestation. If pulse-oximetry-measured arterial oxygen saturation was less than 95%, echocardiography was performed. Pulse oximetry was performed in 3,262 newborns. Twenty-four infants (0.7%) had repeated saturations of less than 95%. Of these infants, 17 had congenital heart disease and five of the remaining seven had persistent pulmonary hypertension. No infant with a ductal-dependant or cyanotic congenital heart disease exhibited saturation values greater or equal to 95%. CONCLUSION: postductal pulse-oximetric screening in the first few days of life is an effective means for detecting cyanotic congenital heart disease in otherwise healthy newborns.

End-of-life decisions in delivery room and neonatal intensive care unit.

BACKGROUND: The increase in neonatal survival in recent decades has been followed by an increase in later disabilities. This has given rise to many new ethical issues. In different countries, efforts are being made to define ethical guidelines regarding withholding or withdrawing intensive care and end-of-life decisions in critically ill newborn infants. These guidelines have to be differentiated from ethical decision-making models which structure the process of decision making for an individual child. Such a framework has been in existence in our clinic for 10 years. AIM: The aims of this study were to evaluate how end-of-life decisions are taken in our perinatal centre and to analyse whether these decisions are consistent with our framework for structured ethical decision making. METHODS: 199 consecutive neonatal deaths over 5 y were evaluated. RESULTS: In 157 cases (79%), end-of-life decisions were taken according to our ethical framework; in the remaining 42 cases (21%), the baby died before this could be done. In 92% of cases, parents were involved in the decision and, in all cases but one, agreed with the decision. A patient's life was never intentionally and actively terminated. CONCLUSION: In contrast to earlier years, in-hospital death in our clinic is nowadays usually preceded by structured and documented medical end-of-life decisions.

Methadone maintenance program in a Swiss perinatal center: (I): Management and outcome of 89 pregnancies.

BACKGROUND: Although methadone maintenance is the standard treatment of opiate addiction in pregnancy, opinion as to its utility is divided. The aim of this study was to analyze polydrug abuse, pregnancy outcome and fetomaternal complications among pregnant women in a major Swiss methadone maintenance program. METHODS: Prospective data collection of all pregnant opiate addicts and their neonates from 1996 to 2001. RESULTS: Maternal complications occurred in 73% and fetal complications in 34% of the pregnancies. The average methadone dose at delivery in the 89 pregnancies was 40.9 +/- 32.7 (0-150) mg/day. Sixty-four percent of the women were co-users of cocaine and/or heroin. Birthweight was lower in polydrug abusers than in near-exclusive methadone users (p = 0.001). CONCLUSION: The high rate of maternal complications demonstrates the need for further improvement in antenatal management of opiate addiction in pregnancy. Methadone maintenance is inefficient in preventing pregnancy exposure to additional illicit drug consumption. Additional illicit heroin and/or cocaine abuse does not seem to increase the incidence of fetomaternal complications during pregnancy, but reverses the positive impact of methadone on birthweight. Heroin-assisted treatment may be a more effective method of minimizing the use of street drugs.

Methadone maintenance program in pregnancy in a Swiss perinatal center (II): neonatal outcome and social resources.

BACKGROUND: The aim of the study was to analyze the neonatal impact of a methadone maintenance program in pregnancy, and the social resources of the families involved. METHODS: Descriptive analysis of neonatal data in live births after 24 weeks of gestation in pregnant women enrolled in a methadone maintenance program. The data of 86 babies were analyzed. RESULTS: Median gestational age was 38 (0)/(7) (31-41) weeks; 21 babies (24%) were premature. Median birthweight was 2662 (1340-4050) g; 27% of babies were growth retarded (<3rd centile), and 13% had microcephaly (<3rd centile). Sixty-two percent developed abstinence syndrome requiring pharmacological treatment for a median 47 days. Child Protective Services (CPS) were involved in 56% of cases, and 42% of newborns required placement outside the mother's home. CONCLUSIONS: Babies born to women on methadone had a fourfold higher incidence of prematurity, a ninefold higher incidence of intrauterine growth retardation (IUGR), and a fourfold higher incidence of microcephaly compared with the normal population. Sixty-two percent required pharmacological treatment for abstinence syndrome and 42% required placement.

Detection of hyperbilirubinaemia in jaundiced full-term neonates by eye or by bilirubinometer?

UNLABELLED: The aim of this study was to compare predictions of hyperbilirubinaemia by eye, performed by trained physicians and nurses, with predictions obtained using two commercial bilirubinometers. Jaundice was assessed in 92 white and 48 non-white healthy full-term neonates using three non-invasive methods and by total serum bilirubin as the reference method. Clinical assessment of cephalocaudal progression of jaundice was carried out independently by a physician and by nurses. Simultaneously, the Minolta Airshields JM-102 was applied on the sternum, the BiliCheck on both the forehead and the sternum, and finally, serum bilirubin concentrations were determined. The Minolta JM-102 showed the best performance with r2 = 0.90, an intraclass correlation coefficient (ICC) of 0.93, and a 95% confidence interval (CI) of +/- 4 units (approx. 56 micromol/l). The BiliCheck performed slightly better on the forehead than over the sternum with r2=0.90, an ICC of 0.88, and a CI of +/- 62 microtmol/l. Assessment of jaundice by eye was least accurate with r2 = 0.74, an ICC of 0.67, and a CI of +/- 1.5 zones (corresponding to 75 Lmol/l). Skin pigmentation and ambient light both adversely affected noninvasive bilirubin estimation. CONCLUSION: All three non-invasive methods are well suited for estimation of serum bilirubin but show large confidence intervals. In healthy term newborns, hyperbilirubinaemia (>250 Lmol/l) can be safely ruled out by eye if jaundice does not reach the abdomen or the extremities (Kramer zones 1 and 2), with < 22 units ( < 230 micromol/l) for the Minolta JM-102, or with a cut-off of 190 microlmol/l for the Bili-Check. If these respective thresholds are exceeded, serum bilirubin concentrations should be measured.

Triplets and quadruplets in Switzerland: comparison with singletons, and evolution over the last decade.

AIMS: Main objectives were 1) to determine the incidence of higher multiple births from 1995 to 1998 in Switzerland, and 2) to evaluate neonatal mortality and morbidity. Secondary objectives were 3) to compare the results with those of matched singletons, and 4) to compare the present data to the first Swiss study (1985-1988). METHODS: Retrospective analysis of maternal and neonatal data obtained from all Swiss hospitals. RESULTS: The incidence of triplet births was 1/3247 and that of quadruplet births 1/81,186. The median gestational age was 32 5/7 weeks for triplets, and 28 6/7 weeks for quadruplets. The median birth weight was 1665 g for triplets and 1076 g for quadruplets. Perinatal mortality was 6% for triplets and 19% for quadruplets. Respiratory distress syndrome was the major morbidity as diagnosed in 52% of triplets and 81% of quadruplets. A comparison of triplets with matched singletons showed no significant differences in morbidity and mortality. Compared with the first Swiss study, the mortality rate decreased, while the incidence of triplets increased but decreased for quadruplets. CONCLUSION: The incidence of higher-order multiple births in Switzerland dropped for quadruplets in the last decade but has increased for triplets. The mortality and morbidity of triplets is comparable to that of singletons with a similar gestational age.

Slow blood sampling from an umbilical artery catheter prevents a decrease in cerebral oxygenation in the preterm newborn.

OBJECTIVE: Blood sampling from an umbilical artery catheter (UAC) placed in a high position (thoracal 6-9) has the potential to produce clinically significant changes in cerebral blood flow and, thereby, in cerebral oxygenation. This may contribute to cerebral impairment in preterm newborn infants. Therefore, we set up a study to determine the effects of different sampling speeds through a UAC on cerebral oxygenation in preterm infants. METHODS: Thirty pairs of measurements were conducted on 20 preterm infants (median gestational age: 30.14 weeks; median birth weight: 1170 g). For each infant, 2 blood samplings (both 2.3 mL, including flush volume) through the UAC in high position were taken at 2 different speeds (20 and 40 seconds) in alternating sequence. Cerebral oxygenation was measured noninvasively by near-infrared spectroscopy. Concentration changes in cerebral oxygenated hemoglobin (O2Hb) and deoxygenated hemoglobin (HHb), along with the tissue oxygenation index (TOI; O2Hb/[O2Hb + HHb] x 100), were recorded while blood was withdrawn and subsequently reinfused. RESULTS: A significant decrease in O2Hb and TOI occurred during blood sampling within 20 seconds (median DeltaO2Hb: -1.5 micromol/L; range: -4.1-2.3; median DeltaTOI: -0.6%; range: -6.3-2.3), whereas HHb increased (median DeltaHHb: 0.4 micromol/L, range: -1.1-3.9). No significant change was found in O2Hb, HHb, and TOI when sampling time was extended to 40 seconds. CONCLUSION: Our results show that blood withdrawal over 20 seconds from a UAC in high position significantly decreases cerebral O2Hb and TOI in preterm infants. Prolonging sampling time to 40 seconds can prevent this phenomenon.

Early treatment with erythropoietin beta ameliorates anemia and reduces transfusion requirements in infants with birth weights below 1000 g.

OBJECTIVE: To investigate whether recombinant erythropoietin (rhEPO) reduces the need for transfusion in extremely low birth weight (ELBW) infants (birth weight 500-999 g) and to determine the optimal time for treatment. METHODS: In a blinded multicenter trial, 219 ELBW infants were randomized on day 3 to one of 3 groups: early rhEPO group (rhEPO from the first week for 9 weeks, n = 74), late rhEPO group (rhEPO from the fourth week for 6 weeks, n = 74), or control group (no rhEPO, n = 71). All infants received enteral iron (3-9 mg/kg/day) from the first week. The rhEPO beta dose was 750 IU/kg/week. Success was defined as no transfusion and hematocrit levels never below 30%. RESULTS: Success rate was 13% in the early rhEPO group, 11% in the late rhEPO group, and 4% in the control group (P =.026 for early rhEPO versus control group). Median transfusion volume was 0.4 versus 0.5 versus 0.7 mL/kg/day (P =.02) and median donor exposure was 1.0 versus 1.0 versus 2.0 (P =.05) in the early rhEPO group, the late rhEPO group, and the control group, respectively. Infection risk was not increased and weight gain was not delayed with rhEPO beta. CONCLUSION: Early rhEPO beta treatment effectively reduces the need for transfusion in ELBW infants.