Outcome of very low birthweight infants who required prolonged hospitalization

Abstract Over a 4 year study period, 294 infants with a birthweight ≤ 1500 g survived their initial hospitalization; 103 (35%) were discharged after a gestational age of 40 weeks. The postdischarge infant mortality was significantly higher in those with prolonged initial hospitalization compared with the remaining survivors (6% vs 1%). During the first 2 years, significant infections were found in 66% and rehospitalization in 54% of the children who had prolonged initial hospitalization. At 2 years, 34% were below the 10th centile for weight as were 39% for height; head circumferences were normal. Major disability (27% vs 15%) and developmental delay (13% vs 4%) were significantly more common in survivors with prolonged initial hospitalization compared with the remaining survivors. The study demonstrated the continuing toll of perinatal morbidity among very low birthweight infants who required prolonged hospitalization and emphasized the need for comprehensive medical and social support, not only during their initial hospitalization, but also after discharge.     

Very low birthweight infants: outcome in a sub-Arctic population

Objective : To evaluate the outcome for very low birthweight (VLBW) infants in northern Norway. Subjects and methods: All live born infants ( n = 536) with birthweight ≤1500g born during 1978–89 to women residing in the northern health region of Norway were studied retrospectively. Data were from the Medical Birth Registry (MBR), hospital records and from follow-up recordings to 4 y of age at maternal and child health centres. Stillborn infants ( n = 269) with birthweight ≤1500g during the same period were also registered. Results : The annual incidence of live born VLBW infants (7.1/1000 live births) did not change, but the proportion of infants born alive before 26 weeks'gestation increased and the stillborn part decreased significantly. The Caesarean section (CS) rate, antenatal transfer and the use of a neonatal transport team increased significantly. Four hundred and seventy-five infants (89%) were considered viable at birth, 347 (65%) survived to 1 y and 343 (64%) to 4y. The likelihood of survival was independently related to female gender. The trend for survival to 4y of age did not increase significantly. Thirty children suffered from cerebral palsy (8.7% of survivors, 5.6% of live births) and the cerebral palsy rate for infants with birthweight 751-1000 g decreased. The proportion of survivors considered to be normal or mild disabled increased and the part suffering from moderate or severe disability decreased significantly. Conclusions : In spite of long distances and unfavourable climatic conditions VLBW infants can be adequately cared for in this sparsely populated region of Norway.     

Neonatal jaundice in 'healthy' very low birthweight infants

The daily bilirubin levels during the first week of life in 94 premature very low birthweight (VLBW, < 1500g) relatively 'healthy' infants were determined. Mean daily bilirubin values peaked on the fourth day of life at 188.1 μmol/l (s.e.m. = 5.3). Twenty-eight infants developed hyperbilirubinaemia (bilirubin > 260 μmol/l), at which time they were exposed to phototherapy. When individual peak bilirubin values were evaluated, the overall peak value was 213.9 μmol/l (s.e.m. = 5.1) occurring at 4.81 days (s.e.m. = 0.11), although the value is most likely an underestimate, since the 28 pre-phototherapy values were not truly peak values. Seventy-six (81%) infants experienced bilirubin levels > 170 μmol/l. The method of delivery apparently had no impact on the bilirubin levels.
All the infants remained well and progressed satisfactorily.'Healthy' VLBW infants experience a much greater incidence and severity of neonatal jaundice than mature infants with the same clinical status.     

Transcutaneous bilirubinometry in very low birthweight infants

AIM: To evaluate whether transcutaneous bilirubinometry (TcB) would be a reliable and efficient screening technique for hyperbilirubinaemia in very low birthweight (VLBW, < or =1500 g) infants in an intensive care unit setting. METHODS: TcB measurements (Minolta Airshield Jaundice Meter JM-102, Osaka, Japan) were obtained immediately before or within 10 min following routine blood sampling for plasma bilirubin concentration measurements in 124 VLBW infants not receiving phototherapy. The relationship between the two techniques was analysed by linear regression analysis. A plasma bilirubin > or =150 micromol/l was defined as hyperbilirubinaemia. The sensitivity and specificity of possible TcB cut-off readings to detect hyperbilirubinaemia was evaluated. RESULTS: There was a significant correlation between the measurements of both techniques (p < 0.0001, r = 0.68). In the present study, a TcB cut-off reading of 14 would have reduced the need for plasma bilirubin measurements by 26% without missing true hyperbilirubinaemia. CONCLUSION: The data suggest that TcB will improve VLBW infant care in an intensive care unit setting by reducing the need for invasive bilirubin concentration measurements.     

Inguinal hernia in very low birthweight children: A continuing risk to age 8 years

The prevalence of inguinal hernia repair up to 8 years of age was determined in 205 inborn children of birthweight less than 1500 g who had survived to the age of 8 years; 37 (18.0%) of the children required surgery for inguinal hernia, significantly more frequently for boys than girls (32.0% and 3.9% respectively). The cumulative percentage of inguinal hernia operations in boys was 8.7% during primary hospitalization, 20.4% by 2 years, 30.1% by 5 years and 32.0% by 8 years; 36.4% (12 of 33) hernias in boys occurred beyond 2 years of age. The risk of hernia in boys was only marginally higher in those who required assisted ventilation and in those of birthweight less than 1000 g. Very low birthweight infants, particularly boys, are at risk of developing an inguinal hernia not only in infancy but also to at least 8 years of age.     

Audiological evaluation of very low birthweight infants

A population of consecutively surviving very low birthweight (VLBW) infants comprising 41 infants (24 female) birthweight less than 1000 g and 108 infants (63 female) birthweight 1000-1500 g received detailed audiological evaluation. The audiological test battery comprised auditory brainstem evoked response (ABR) prior to hospital discharge, behavioural audiometry and tympanometry at 8-12 months and monitoring as necessary. The ABR results were interpreted with reference to a normative group of 36 full-term infants (birthweight 2.4-4.5 kg). Of the 142 VLBW infants completing audiological evaluation, one (0.7%) had evidence of moderate-severe high frequency sensorineural hearing loss, 83 (58.5%) evidence of conductive dysfunction (18 severe, 42 moderate and 23 mild) and only 58 (40.8%) normal hearing. The 19 infants with severe auditory impairment were more likely to have suffered moderate-severe apnoea, greater than or equal to two courses of mechanical ventilation, prolonged oxygen therapy and recurrent upper respiratory tract infections in the first year of life than infants without severe impairment (P less than 0.05). Because of the incidence of conductive pathology, difficulties occurred when attempting to compare ABR status at 36-42 weeks postmenstrual age with peripheral hearing status at 8-12 months as assessed by visual reinforcement orientation audiometry (VROA) and impedance audiometry. The most useful ABR test parameters as screening measures of peripheral auditory status were Wave I-III-V morphology, wave V threshold levels and wave V absolute latency values when used in combination as a test battery.(ABSTRACT TRUNCATED AT 250 WORDS)     

The long-term neurodevelopmental outcome for very low birthweight (VLBW) infants with 'dystonic' signs at 4 months of age

Abstract  As very low birthweight (VLBW) infants are at a high risk of developmental handicap, it is important to establish predictors of long-term adverse outcome at an early age so that early intervention can be instituted. Longitudinal neurodevelopmental assessments were performed in 107 VLBW infants at 1,4, 8 and 12 months corrected age. Eighteen were diagnosed as 'dystonic' at 4 months of age.
This study compared the outcomes at 4 and 6 years for 15 of the 18 dystonic with 75 of the 89 non-dystonic VLBW infants, respectively. At 9 years of age, nine dystonic and 54 non-dystonic infants were assessed on the Rutter Behaviour Questionnaire. Dystonic children had a lower mean General Cognitive Index (GCI; P= 0.001) and a higher incidence of disability as measured by the Burns Neuro-Sensori-Motor Developmental Assessment Scale (P = 0.0005) and Kitchen disability grading (P = 0.001). Even if the minor neurological aberrations of the premature dystonia syndrome in VLBW infants abate by one year of life, these infants still constitute a high-risk group for subsequent neurodevelopmental disability and therefore require close observation and probably early intervention.     

α-Fetoprotein levels in fullterm and very low birthweight infants

Plasma α-fetoprotein (α-FP) levels were determined in fullterm and very low birthweight (VLBW) infants in the first week of life and serially in a cohort of VLBW infants for the first 24 weeks after delivery. A rapid decline in α-FP levels was observed in both the fullterm and VLBW infants initially. Beyond 2 weeks of age, there was a gradual, linear decline until 6 weeks, followed by a more rapid period of decline from 6 to 16 weeks. The decline in the ensuing weeks demonstrated an asymptotic pattern. The half-life of α-FP was 7.5 days in the first week of life in both fullterm and preterm infants, 28.7 days from 2 to 6 weeks of life and 11.9 days from 6 to 16 weeks of life in VLBW Infants.     

Distribution of plasma Vitamin E levels in supplemented very low birthweight infants

Abstract The distribution of plasma Vitamin E (VE) was determined in 25 very low birthweight (VLBW) infants who were supplemented with 100 mg/kg per day of α-tocopherol acetate, given intragastrically. Their mean birthweight was 917 g and mean gestational age was 28 weeks. Mean plasma VE levels after 1 and 6 weeks' supplementation were 2.7 mg/dL (s.e.m. = 1.0) and 6.4 mg/dL (s.e.m. = 1.4), respectively (the difference was not significant). There was wide variability in plasma VE levels in these infants despite being on an identical dose of tocopherol. Plasma VE was < 0.5 mg/dL in 12% of samples, 0.5–3.0 mg/dL in 32%, 3.1–5.0 mg/dL in 18%, and 5.1–20 mg/dL in 38%. Fifteen of the 25 infants had at least one level in the range which has been associated with an increased incidence of septicaemia and necrotizing enterocolitis (> 5.0 mg/dL).
These data suggest that if a policy of VE supplementation for VLBW infants is chosen, monitoring of plasma VE levels appears necessary so that the dosage can be adjusted in order to maintain plasma VE within the optimal range. This study's dosage regimen of supplementing infants with 100 mg/kg per day of VE was associated with a high incidence of elevated plasma VE levels and it is concluded that it is not advisable to use such large doses of VE in the premature newborn.     

Early neurodevelopmental outcome of very low birthweight infants

ABSTRACT. In the 18 months, January 1979 to July 1980, 149 infants who weighed ≤1500g at birth were cared for in the neonatal intensive care unit at Queen Victoria Medical Centre, Melbourne. During this period the neonatal survival rate for infants weighing 501–1000g was 57% and for those weighing 1001–1500g was 91%. Of the 123 neonatal survivors, four died within the first year after birth. One hundred and seventeen (98%) of 119 surviving infants have been assessed at follow-up. At a mean age of 12.3 months (corrected for prematurity), 11 (9%) survivors had physical handicaps only and four (3%) had developmental delay, including one child who was also physically handicapped. Nine of the 14 children with a defined handicap were considered to have significant functional handicap. Therefore 108 (92%) survivors are able to function within the normal range. These results suggest that the chance of survival for infants of very low birthweight has continued to increase whereas their handicap-rate has remained stable and relatively low.     

Necrotizing enterocolitis in very low birthweight infants: a four-year experience

Fifty (13%) of 375 infants who weighed 1500 g or less at birth had necrotizing enterocolitis (NEC). Haematological changes suggestive of sepsis occurred in 83% and positive bacteriological cultures were found in 38%, the most common organism isolated being Clostridium perfringens. Complications included intestinal perforation in six patients and recurrence of NEC in five, of whom one subsequently developed an intestinal stricture. Five of the eight nursery deaths were secondary to peritonitis and overwhelming sepsis from NEC. In spite of the discontinuation of milk feeds for prolonged periods, satisfactory caloric intake and weight gain were achieved with parenteral nutrition in the survivors. Of the 41 long-term survivors, six (15%) were found to have a disability at 2 years of ago, corrected for prematurity, compared with 48 (20%) of 241 very low birthweight survivors from the same study period who did not have NEC. None had evidence of gastrointestinal dysfunction. Six (15%) children remained below the 10th percentile for both weight and height. This study showed that early diagnosis and therapy for NEC in very tow birthweight infants were associated with a favourable short- and long-term outcome.     

Longitudinal study of very low birthweight infants: Intelligence and aspects of school progress at 14 years of age

Abstract Consecutive surviving children weighing less than 1501 g when born in 1966–70 were followed prospectively: 87% (146/168) attended normal secondary schools, 4% (7/168) attended schools for those with special needs and 9% (15/168) were untraced. The psychologist assessed 140 children at a mean age of 14.5 years. The mean WISC-R Verbal Score of 89.7 was almost identical to that achieved by the children at 8 years of age (89.2). Thirty three children (24%) had delay in Reading Accuracy on the Neale Analysis of Reading Ability, whilst 66 children (48%) were delayed on the Comprehension Scale. Social class and duration of maternal education were significant predictors of the WISC-R Verbal Scores and Reading Comprehension at 14.5 years but the total variance explained was small. The Bayley Development Index (MDI) available for half of the children at 2 years often underestimated their potential as defined by the WISC-R Verbal Score at 14.5 years. The 8 year intelligence (WISC-R) and reading measures (Neale) were significantly and highly associated with the corresponding measures at 14.5 years. It was concluded that 8 years was an appropriate age to evaluate the outcome of the children and to identify many of those needing educational intervention. The spasmodic nature and sometimes short duration of the help received by many of the children underlines the need for more appropriate intervention for children with learning difficulties.     

Surgery is safe in very low birthweight infants with necrotizing enterocolitis

The aim of this study was to determine how the operative event itself affects very low birthweight (VLBW) infants (< 1500 g) with necrotizing enterocolitis (NEC) undergoing surgery, and to try to identify preventable factors leading to perioperative morbidity and mortality. Eighty-five VLBW infants developed NEC during a 6-year period; 34 of those required emergent celiotomies. Data were collected retrospectively from hospital charts available on 33 infants. Birthweight ranged from 566 g to 1415 g (mean +/- SD: 961+/-262 g) and gestational age from 24 to 34 wk (28+/-3.2 wk). Thirty infants had been fed premature formula (first feed at 5+/-3.6 d) prior to the onset of symptoms and three had not been fed at all. Age at NEC symptoms was 19+/-15 d. Infants < 1000 g developed NEC much longer after the first feed compared to infants > 1000 g (p < 0.002; t-test). In 42% of the children, intraoperative blood pressure fell at least 20% from the preoperative value. Body temperature dropped from a preoperative 36.5+/-0.340 degrees C to 35.5+/-1.20 degrees C (p < 0.005), although in all children two or more heating devices were employed in the operating room. All infants survived the procedure. Six infants with pannecrosis died within 72 h of the operative event. In an appropriate setting, operative intervention under general anesthesia is well tolerated by VLBW infants with NEC. Since hypothermia was a major problem, the authors have modified their approach and now no longer transport these infants to the operating room. Instead, these infants are operated upon in the neonatal intensive care unit, directly on an infant radiant warmer system.     

Chronic lung disease in very low birthweight infants: A 5-year review

To determine the incidence, clinical spectrum and outcome of very low birthweight (VLBW) infants with chronic lung disease (CLD), and evaluate associated factors.

Methodology:

Retrospective review of 265 VLBW infants managed in the NICU from January 1988 to December 1992.

Results:

The overall neonatal survival rate for VLBW infants was 83%. Sixty-five (25%) infants had CLD, of whom 42% had severe CLD. Mortality in infants with CLD was 11%. In contrast with infants without CLD, CLD infants had significantly higher risk of adverse neurodevelopment with cerebral palsy documented in 13.5% and functional disability recorded in 34.6% at 2 years corrected age. Factors associated with the development of CLD included; decreasing birthweight (OR 0.98, Cl 0.97–0.99), septicaemia (OR 4.96, Cl 1.57–15.65), necrotizing enterocolitis (OR 119.07, Cl 4.98–2845.04), hyaline membrane disease (OR 5.34, Cl 1.83–15.55), patent ductus arteriosus (OR 4.46, CI 1.75–11.36) and increasing fraction of inspired oxygen concentration in the first week of life (OR 1.09, Cl 1.04–1.14).

Conclusions:

Chronic lung disease occurs frequently in VLBW infants and is associated with a high incidence of adverse neurodevelopment. Further studies to clarify the role of non-respiratory factors such as patent ductus arteriosus (PDA) and sepsis in the pathogenesis of CLD may reduce the incidence or prevent the development of CLD in these preterm infants.     

Predictors of neurodevelopmental outcome of Malaysian very low birthweight children at 4 years of age

OBJECTIVE: To determine neonatal, early developmental and social risk factors that predict the neurocognitive and behavioural outcome of very low birthweight (VLBW) preschool children at four years of age. METHODOLOGY: From a cohort of 151 eligible VLBW survivors born in Kuala Lumpur Maternity Hospital, 116 (76.8%) were prospectively followed up from birth till four years. A standardised neurological examination was performed at one and four years to determine the presence of impairment and cerebral palsy, respectively. Cognitive development was assessed using the Mental Scale of the Bayley Scales of Infant Development (MDI) at one year and the Weschler Preschool and Primary Scale of Intelligence-Revised (WIPPSI-R) at four years. Motor coordination was assessed using the Movement Assessment Battery for Children (Movement-ABC). Mothers completed the Child Behaviour Checklist (CBCL) and Parenting Stress Index (PSI) questionnaires. Logistic and multiple regression analyses were used to determine factors associated with cerebral palsy, IQ scores, Movement-ABC and CBCL scores. RESULTS: Factors associated with cerebral palsy were lower MDI scores at one year (P = 0.001) and late neonatal cranial ultrasound abnormalities (P = 0.036). Minor (P = 0.016) or major impairment (P = 0.003) at one year of age and a low level of paternal education (P = 0.01) were associated with poor motor function on the Movement-ABC scale. Lower levels of maternal education (P < 0.001), impairment at one year (P = 0.002) and late neonatal cranial ultrasound abnormalities (P = 0.039) predicted Full Scale IQ scores. Higher PSI scores (P = 0.001), younger mothers (P = 0.003) and late neonatal cranial ultrasound abnormalities (P = 0.009) were associated with worsened child behaviour scores on the CBCL scale. CONCLUSION: Social factors and the caregiving environment were important determinants of cognitive and behavioural outcome. Cranial ultrasound abnormalities in the late neonatal period and the developmental status at one year might be useful in identifying high risk infants in need of long-term surveillance.     

Plasma thrombomodulin level in very low birthweight infants at birth

Objective: Plasma soluble thrombomodulin level reflects endothelial damage. The plasma thrombomodulin level at birth is increased in asphyxiated full-term infants. There is no report of plasma thrombomodulin level in premature infants. To determine the thrombomodulin level in premature infants and whether it might reflect endothelial damage, we examined the plasma thrombomodulin level in very low birthweight (VLBW) infants at birth. Methods: Forty-five VLBW infants, of whom 14 had perinatal asphyxia complications, were recruited. As a control, 50 full-term infants wimout complications were also studied. Plasma thrombomodulin concentration, pH, base deficit, serum creatinine and D-dimer concentration, platelet count and fibrinogen concentration were measured within 1 hour after birth. Results: There were significant differences in plasma pH, creatinine concentration, platelet count, antithrombin in activity and D-dimer concentration between VLBW infants and full-term infants. Plasma thrombomodulin concentration (39. 0 (16. 6–93. 7) vs 27. 0 (16. 6–39. 1) μg/L, p < 0. 0001) and plasma taombomodulin-to-serum creatinine ratio (0. 82 (0. 19–2. 65) vs 0. 47 (0. 24–0. 70) μg/μmol, p < 0. 0001) were significantly higher in VLBW infants than those in full-term infants. By univariate analyses for all neonates, there were significant relations between plasma thrombomodulin concentration and gestational age, birthweight, plasma pH, creatinine concentration, platelet count and antithrombin in activity. A stepwise multiple linear regression model using the above variables as dependent factors showed only birthweight contributed significantly to plasma thrombomodulin concentration (plasma thrombomodulin concentration (μg/1) = 45. 677–0. 006 (birthweight; g), r²= 0. 323, p < 0. 0001, n= 94). Plasma thrombomodulin concentration and plasma thrombomodulin-to -serum creatinine ratio in VLBW infants with asphyxia were higher than in those without asphyxia, but not significantly different (43. 2 ± 17. 7 vs 38. 3 ± 8. 5 μg/1 and 0. 92 ± 0. 60 vs 0. 83 ± 0. 37 μg/μmol). Conclusion: Plasma thrombomodulin level in VLBW infants shows a high value at birth, and we consider the main factor responsible for this elevation may be endothelial damage or low clearance rate of thrombomodulin, which may be related to early gestational age.     

Renal impairment in very low birthweight infants following antenatal indomethacin administration

Three cases of neonatal renal insufficiency in very low birthweight (VLBW) infants following repeated antenatal administration of indomethacin to prevent premature labor are reported. Three pregnant women received indomethacin (total doses of 150–850 mg) for 3–14 days from admission until delivery. The gestational ages and birthweights of the infants ranged from 24 to 28 weeks and 612 to 1432 g, respectively. Oliguria, early onset of hyperkalemia and prolonged renal dysfunction occurred after birth. Renal failure did not improve in one infant. Despite the efficacy of indomethacin for tocolysis in premature labor, VLBW infants born after repeated maternal administration near the time of delivery may have developed impairment of the premature kidney.     

Prolonged low-dose indomethacin therapy for patent ductus arteriosus in very low birthweight infants

To determine the efficacy and side-effects of prolonged low-dose indomethacin therapy in very low birthweight (VLBW; <1500 g) infants with a haemodynamically significant patent ductus arteriosus (hsPDA).

Methodology:

Very low birthweight infants admitted over a 16 month period were studied (6 months, retrospectively and 10 months, prospectively). Cross-sectional and M-Mode echocardiograms with pulsed-wave and colour Doppler were performed to assess the significance of ductal patency.

Results:

Forty-one (28%) of 148 VLBW infants were diagnosed to have hsPDA. Indomethacin therapy was successful in 90% after the first course, increasing to 95% after the second course. The recurrence rate after the first course was 3%. Minor and transient complications included oliguria, urea retention, hyponatraemia and thrombocytopenia. Although three infants had focal bowel perforation and the fourth had bowel perforation associated with necrotizing enterocolitis, the incidence of gastrointenstinal pathology was not significantly different from infants without hsPDA and not given indomethacin.

Conclusions:

Very low birthweight infants with hsPDA have a high response rate and low recurrence rate to prolonged lowdose indomethacin therapy. Side-effects were mild and transient. However, it is prudent to be cautious when administering indomethacin in critically ill infants <1000 g with hsPDA who manifest clinical features of bowel ischaemia.     

Usefulness of an early neurofunctional assessment in predicting neurodevelopmental outcome in very low birthweight infants

OBJECTIVE: To evaluate whether early neurofunctional assessment may be useful in predicting neurodevelopmental outcome in children of very low birth weight (VLBW). DESIGN: Observational longitudinal study. SETTINGS: Northern Italy. PATIENTS: A total of 250 VLBW children (129 boys, 121 girls) born consecutively 1996-1999. MAIN OUTCOME MEASURES: Neurodevelopment at 36 months of chronological age, classified in accordance with the classification of Tardieu and the International classification of functioning. RESULTS: Of the infants exhibiting normal neurodevelopment (n = 183) or major dysfunction (n = 17) at 3 months of corrected age, 72% and 94% respectively did not change their score during the study. Minor dysfunctions at 3 months of corrected age were transient in 17 (34%) children. After adjustment for neonatal variables, neurodevelopment at 3 months of corrected age remained predictive of dysfunction at 36 months (odds ratio = 4.33, 95% confidence interval 2.05 to 9.12). If the results for the normal and minor dysfunction groups were pooled, the predictive qualities of the 3 month neurofunctional assessment were: sensitivity 0.5, specificity 0.99, positive predictive value 0.94, negative predictive value 0.93. CONCLUSION: Early neurofunctional evaluation may be useful in predicting later neurodevelopmental outcome in VLBW children.     

Psychosocial and psychomotoric development of very low birthweight infants with necrotizing enterocolitis

Twenty-six very low birthweight infants (VLBI) were treated for necrotizing enterocolitis (NEC). We investigated their consecutive health problems and psychosocial development. Method: One to 13 years after onset of NEC, follow-up studies were performed in 12 of the surviving children. Identical follow-up studies were performed in 6 VLBI who had been operated on for diseases other than NEC (control group). We used a detailed interview, a Denver test and a drawing test. Results: Five children of the NEC group had major persistent health problems that impaired their psychomotoric and psychosocial development (including hearing impairment, concomitant strabismus, early onset bronchiai asthma). Nine of 12 VLBI of the NEC group showed signs of reduced social contact, logopaedic problems and minimal partial skill reductions. Conclusion: We found similar results in both children who suffered from NEC and in a small control group of VLBI who had not suffered from NEC, therefore impaired psychomotoric and psychosocial development is probably due to prematurity.