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 resuscitation of extremely low birthweight infants: a survey of practice in Italy

Delivery room management of extremely low birthweight infants (ELBWIs) has been little studied. A questionnaire was sent to the heads of the 86 Italian neonatal intensive care units provided with on site delivery. The practice of and approach to the resuscitation of ELBWIs were very different among the centres surveyed, reflecting a paucity of evidence and consequent uncertainty among clinicians.     

Rickets in extremely low birthweight infants

ABSTRACT. The effects of increasing the concentration of supplemental vitamin D was studied in two groups of ELBW infants (babies with a birth weight less than 1000 g) during the periods of July 1977 to December 1979 and throughout 1980. There were 21 ELBW infants in the first study period, with 7 infants developing active or Stage III rickets. A prospective study of ELBW infants during 1980 revealed 3 infants out of the 12 studied developing active or Stage III rickets. A new radiological classification for rickets of prematurity, Stage I to IV, is presented. Serial serum alkaline phosphatase levels were then compared with these radiological stages and a serial ALP of 500IU/l was found to be statistically significant in the biochemical diagnosis of rickets. As a result of our findings, we suggest that all ELBW should be supplemented with at least 800 IU of vitamin D daily.     

Perinatal factors and adverse outcome in extremely low birthweight infants.

Perinatal factors associated with death or disability at 2 years were identified in an inborn cohort of 196 live births with a birth weight of 500-999 g. Antepartum haemorrhage, multiple pregnancy, breech presentation, perinatal asphyxia, hypothermia on admission, hyaline membrane disease, persistent pulmonary hypertension, severe respiratory failure, and intraventricular haemorrhage were associated with increased mortality. Factors associated with increased survival included maternal hypertension, caesarean birth, increasing maturity or size at birth, female sex, and fetal growth retardation. Stepwise multiple discriminant function analysis showed that six factors correctly classified the outcome in 83% of infants: intraventricular haemorrhage was the most important factor followed by the presence of acidosis and hypoxia in the early neonatal period, birth weight, pre-eclamptic toxaemia, and caesarean birth. This study also showed that intraventricular haemorrhage, seizures, antepartum haemorrhage and delay in regaining birth weight were associated with increased disability among survivors.     

Neonatal follow-up of very low birthweight/extremely low birthweight infants to school age: a critical overview.

Neonatal follow-up studies of school age children, published in the last decade, were critically reviewed. Nine studies examined extremely low birthweight infants (less than or equal to 1000 g) and 16 involved very low birthweight infants (less than or equal to 1500 g). The majority of children had age appropriate I.Q. scores, however, there was a greater variability of test scores. There was an increased need for special education or remedial therapy. Visual-motor integration deficits were frequently reported. Behavioural difficulties were described. Fine and gross motor incoordination was identified. There was no conclusive correlation between perinatal course and school outcome. Gender did appear to influence outcome, in the small percent of studies which examined this variable, with females generally faring better. Low socioeconomic status was the most frequently reported predictor of poor outcome. Identified methodological limitations included heterogeneous samples, lack of control groups, high attrition, variable diagnostic criteria and lack of consensus regarding correction for prematurity.     

Referral to a regional centre improves outcome in extremely low birthweight infants.

Referral of extremely low birthweight infants (less than 1001 g) from district hospitals in a geographically defined area to a specialist regional centre significantly improved their chances of survival.     

Hypercalcaemia in extremely low birthweight infants.

We report 10 cases of hypercalcaemia associated with hypophosphataemia in the first two weeks of life in extremely low birthweight infants (birthweight less than 1000 g). At the time of diagnosis, the infants were fed mainly with expressed breast milk but they had also received intravenous nutrition. After treatment with additional phosphate plasma calcium concentrations returned to normal. There was a high incidence of rickets of prematurity in these infants.     

Radiological rickets in extremely low birthweight infants

Forty-eight infants of birthweight less than 1000 g who survived for more than 28 days, had wrist X-rays to prospectively determine the incidence of radiological rickets. Twelve infants (25%) had normal X-rays throughout, 10 infants (21%) showed osteopenia and 26 infants (54%) had classical changes of rickets of which 8 (17% of the total) had spontaneous fractures. There was poor correlation between peak values of serum alkaline phosphatase and the radiological changes.     

Stool microflora in extremely low birthweight infants

AIM: To serially characterise aerobic and anaerobic stool microflora in extremely low birthweight infants and to correlate colonisation patterns with clinical risk factors. METHODS: Stool specimens from 29 infants of birthweight <1000 g were collected on days 10, 20, and 30 after birth. Quantitative aerobic and anaerobic cultures were performed. RESULTS: By day 30, predominant species were Enterococcus faecalis, Escherichia coli, Staphylococcus epidermidis, Enterbacter cloacae, Klebsiella pneumoniae, and Staphylococcus haemolyticus. Lactobacillus and Bifidobacteria spp were identified in only one infant. In breast milk fed (but not in formula fed) infants, the total number of bacterial species/stool specimen increased significantly with time (2.50 (SE 0.34) on day 10; 3.13 (0.38) on day 20; 4.27 (0.45) on day 30) as did quantitative bacterial counts; Gram negative species accounted for most of the increase. On day 30, significant inverse correlations were found between days of previous antibiotic treatment and number of bacterial species (r=0.491) and total organisms/g of stool (r=0.482). Gestational age, birthweight, maternal antibiotic or steroid treatment, prolonged rupture of the membranes, and mode of delivery did not seem to affect colonisation patterns. CONCLUSIONS: The gut of extremely low birthweight infants is colonised by a paucity of bacterial species. Breast milking and reduction of antibiotic exposure are critical to increasing fecal microbial diversity.     

Neonatal intensive care for extremely low birthweight infants — a dilemma in perinatal medicine

ABSTRACT. In the 4-year period, 1977–1980, neonatal intensive care was given to all infants with the exception of 22 livebirths who died in the delivery room and 14 who had major congenital malformations. Of the 375 infants weighing 501–1500g at birth who were treated in the neonatal unit, 298 survived the neonatal period, of whom 60 were ≤1000g. A disproportionate amount of time was spent in treating these infants, including a significant percentage on non-survivors. Treatment for infants ≤1500g and ≤1000g contributed to 57% and 29% respectively of the intensive care workload. Although the cost of providing intensive care for these infants was substantial in terms of time, effort, emotion and money, their improved survival prospects nevertheless indicates that the rights of these infants need to be safeguarded. Neonatal paediatricians have a special responsibility to these infants and secondarily to their families and to the public at large, all of whom are being affected emotionally and financially by decisions made and outcomes achieved in the neonatal unit.     

Nutritional requirements of extremely low birthweight infants

Extremely low birthweight (ELBW) infants are unique in many developmental characteristics that determine nutritional requirements, including: low energy reserves (both carbohydrate and fat); higher metabolic rate (intrinsically, due to a higher body content of more metabolically active organs, e.g. brain, heart, liver); higher protein turnover rate (especially when growing); higher glucose needs for energy and brain metabolism; higher lipid needs to match the in utero rate of fat deposition, and for essential fatty acids for brain, neural and vascular development; excessive evaporative rates, and occasionally very high urinary water and solute losses; low rates of gastrointestinal peristalsis; limited production of gut digestive enzymes and growth factors; high incidence of stressful events (e.g. hypoxemia, respiratory distress, sepsis); and abnormal neurological outcome if not fed adequately. Postnatally, ELBW infants do not grow well, or at all, often for weeks. This leads to a virtual "growth deficit", which has unknown consequences (which for the most part are not good) and requires excessive feeding later on to catch up to normal growth rates and body composition. The major future challenge for the nutrition of these infants is to define more accurately their nutritional requirements, particularly in the early postnatal period, in order to feed them more appropriately, to reduce to a minimum the nutritional and growth deficits that they so commonly develop and to prevent neurodevelopmental handicaps that are the result of nutritional deficiencies.     

Blood counts in extremely low birthweight infants.

White blood, neutrophil, and platelet counts were higher in 101 infants with appropriate weight for gestational age than in 42 infants who were small for gestational age. The recognised postnatal rise in counts was seen in the infants of appropriate weight, but in the infants who were small for gestational age the counts fell for the first three days.     

Neurosensory outcome and growth at three years in extremely low birthweight infants: follow-up results from the Swedish national prospective study

A prospective national investigation comprising 633 extremely low birthweight (ELBW) infants born alive in the 2-y period 1990-1992 with a birthweight of ≤1000 g and gestational age of ≥23 completed weeks was conducted regarding neurosensory outcome and growth. Three-hundred and sixty-two (98%) surviving ELBW infants were assessed at a median age of 36 months, using a specially designed protocol. At follow-up, mean height, weight and head circumference in both boys and girls were significantly lower than the reference values. The incidence of cerebral palsy was 7% among all children and 14%, 10% and 3% in children born at 23-24, 25-26 and ≥27 gestational weeks, respectively. At least one obvious handicap was present in 14%, 9% and 3% of these three groups of children, respectively. After adjustment for gestational age, a significantly increased risk of handicap was found in children with intraventricular haemorrhage grade ≥3 and/or periventricular leucomalacia and in children with retinopathy of prematurity stage ≥3. The results show that more than 90% of ELBW children born at ≥25 completed gestational weeks were without neurosensory handicap at 36 months of corrected age. In infants born at 23-24 weeks of gestation, both survival and long-term outcome were less favourable.     

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, less than 1500 g) relatively 'healthy' infants were determined. Mean daily bilirubin values peaked on the fourth day of life at 188.1 mumol/l (s.e.m. = 5.3). Twenty-eight infants developed hyperbilirubinaemia (bilirubin greater than 260 mumol/l), at which time they were exposed to phototherapy. When individual peak bilirubin values were evaluated, the overall peak value was 213.9 mumol/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 greater than 170 mumol/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.     

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.     

Pulmonary air leak in extremely low birthweight infants.

The incidence of pulmonary air leak in 230 infants with a birth weight of 500-999 g who were ventilated was 41%. Pulmonary interstitial emphysema occurred in 35%, pneumothorax in 20%, pneumomediastinum in 3%, and pneumopericardium in 2%. The survival rates in those with or without pulmonary air leak were not significantly different in the first four years of the study period (46% v 53%). As the survival improved in infants without air leak during the second four years the difference in survival rates in infants with or without air leak became significant (30% v 71%). Effective measures of preventing pulmonary air leak are required before further improvement in the outcome of these extremely low birthweight infants can be achieved.     

Erythromycin improves gastrointestinal motility in extremely low birthweight infants

Erythromycin (EM) was administered to five extremely low birthweight infants (ELBWI) with delayed enteral feeding to evaluate the clinical effect on severely impaired gastrointestinal motility. Five patients studied responded well to EM administration without any adverse effects during the course. Four patients were given 15–30 mg/kg per day EM intravenously as a loading and thereafter 3–5 mg/kg per day as a maintenance dose. One patient responded well without loading. The infants could be fed enterally 4, 5, 6, 4 and 2 days after the initiation of EM administration, respectively. Erythromycin administration is a safe and useful way to facilitate gastrointestinal motility in ELBWI who require prolonged ventilator support with an increased risk for nutrient deprivation.     

Periventricular haemorrhage and leukomalacia in extremely low birthweight infants

Forty (49%) of 82 extremely low birthweight (ELBW, less than 1000 g) infants had periventricular haemorrhage (PVH). Ten (12%) had germinal layer haemorrhage (GLH) alone, 16 (20%) had intraventricular haemorrhage (IVH) and 14 (17%) had intracerebral haemorrhage (ICH). Almost all the cases of PVH had developed by 4 days of age. Small-for-gestational age infants (12% of study population) had a significantly lower incidence and severity of PVH than appropriate-for-gestational age infants. Of 94 infants born between 23 and 28 weeks gestation, 45 (48%) had PVH. The PVH incidence was 60% in those of 23-26 weeks and 38% in those of 27-28 weeks. The hospital survival rate of ELBW infants was 69% in those without PVH and 43% in those with PVH; 70% in GLH alone; 50% in IVH and 14% in ICH. Three survivors developed post-haemorrhage hydrocephalus of whom two required ventriculoperitoneal shunting. Five survivors developed periventricular leukomalacia (PVL) evidenced by cysts identified between 3 and 7 weeks of age. A significant decrease in the incidence of PVH occurred over the study period (67% in 1982, 38% in 1983 and 33% in 1984). This decrease was seen for all grades of PVH. The reasons for this decreased incidence are still to be ascertained but this trend suggests that improvements in neonatal intensive care have the potential to improve the neurological outcome of more recent ELBW survivors.