Inguinal hernia: a common problem of premature infants weighing 1,000 grams or less at birth.

Thirty percent of 37 consecutive surviving premature infants weighing 1,000 gm or less at birth were noted to develop inguinal hernias. Incarceration occurred in two infants. One infant suffered a cardiac arrest during repair of the hernia. In view of the increased survival now being reported in these tiny prematures, it is important that physicians recognize the high incidence and potential hazards of this congenital anomaly in surviving premature infants weighing 1,000 gm or less at birth.     

Cognitive and educational outcomes in early adulthood for infants weighing 1000 grams or less at birth

AIM: To assess the intelligence quotient (IQ) and academic achievement in early adulthood of a cohort of extremely-low-birthweight (ELBW 1000 g) subjects. METHODS: All 82 ELBW survivors consecutively born in or referred to a single tertiary center in 1976-1981 were traced at a mean age of 18 y. Three disabled children had died. Fifty-nine subjects (75%) had their IQ tested and 69 (87%) responded to a questionnaire. They were compared to 44 term, normal birthweight (NBW) matched controls. Outcome measures were: IQ (Wechsler Adult Intelligence Scale) and educational outcome. The main outcome variables were compared between groups and analyzed for neonatal and demographic data and in the ELBW group for childhood data. RESULTS: There was a strong relationship (r2=0.55, p<0.0001) between childhood and adult IQ for the 41 ELBW subjects tested at both ages (6.1+/-1.3 and 18.4+/-1.9 y). Differences were significant between ELBW and NBW groups: in mean full-scale IQ (94+/-12 vs 108+/-14), verbal IQ (93+/-12 vs 106+/-14) and performance IQ (97+/-14 vs 109+/-16) (p<0.0001). Differences between ELBW and NBW groups in prevalence of IQ<85 (19 vs 2%, p=0.012), of schooling in a regular curriculum for age (36 vs 68%, p=0.0011), of requirement for special classes or schools (33 vs 9%, p=0.0032), and of obtainment of secondary school diploma for those 18 y or older (56 vs 85%, p=0.018) were largely due to fathers' socio-economic score. CONCLUSION: ELBW subjects had a mean adult IQ in the normal range; however, it was one standard deviation below that of NBW subjects and they had more school failures. Despite this, more than half of ELBW subjects aged 18 y or more had obtained their secondary school diploma.     

Growth and development of infants weighing less than 800 grams at birth

A prospective study of infants weighing less than 800 g at birth and cared for in a single neonatal intensive care unit between 1977 and 1980 was conducted. Neonatal mortality was 80%; neurodevelopmental outcome was assessed in 16 of the 18 survivors. Mean birth weight for these 16 was 730 g; mean gestational age was 26 weeks. Perinatal asphyxia, respiratory distress, apnea, mechanical ventilation, and chronic pulmonary disease were commonplace. Symptomatic intracranial hemorrhage, seizures, sepsis, or meningitis did not occur in survivors. Of the 16 infants, 13 (81%), including all three with birth weight less than 700 g, were without major CNS handicaps and were developing appropriately at 6 months to 3 years of age. Only one of the 16 had clearly subnormal mental development. None had a major visual or hearing impairment. Apgar scores at one and five minutes were significantly related to outcome; apnea, mechanical ventilation, and chronic pulmonary disease were not. These data suggest that a remarkably hopeful outcome is possible for the few survivors of extremely low birth weight.     

Prognosis for infants weighing 1000 g or less at birth

During the 10 years 1966-1975, 148 infants weighing less than or equal to 1000 g were admitted to the Neonatal Unit of University College Hospital. 48 (32%) survived the neonatal period. The neonatal survival rate for infants weighing less than or equal to 750 g was 8% and for infants weighing 751-1000 g, 41% 9 infants died later, leaving 39 (26%) long-term survivors, all of whom are being followed-up. The progress of the 27 older children, born in 1966-74 (median birthweight 899 g, range 648-998 g; median gestational age 28 weeks, range 24-35 weeks), was assessed at ages between 15 months and 8 years (median 3 years). No abnormalities were detected in 21 infants (78%): 2 (7%) had major handicaps and 4 (15%) minor handicaps. We conclude that provided intensive care methods are available, the prognosis for infants weighing less than or equal to 1000 g is now better than in the past.     

Prolonged mechanical ventilation and intracranial hemorrhage: impact on developmental progress through 18 months in infants weighing 1,200 grams or less at birth

In this prospective, longitudinal study, the relative impact of intracranial hemorrhage and prolonged mechanical ventilation on developmental progress during the first 18 months of life of infants weighing 1,200 g or less at birth was examined. A total of 159 surviving infants were divided into two groups: infants with and those without intracranial hemorrhage. These groups were then subdivided into groups of infants receiving prolonged mechanical ventilation (greater than 21 days) and those mechanically ventilated for 21 days or less, thus creating four subgroups. Group 1 (intracranial hemorrhage and prolonged mechanical ventilation) and group 3 (intracranial hemorrhage and no prolonged mechanical ventilation) showed no statistically significant differences for severity of intracranial hemorrhage, persistence of ventriculomegaly, or presence of periventricular leukomalacia. A repeated-measures analysis of variance demonstrated a main effect for prolonged mechanical ventilation on outcome as measured by the Bayley Mental Development Index and Bayley Psychomotor Development Index at 4, 8, 12, and 18 months of age (corrected for prematurity). Forward stepwise regression revealed prolonged mechanical ventilation to the best predictor of Bayley indexes at all ages except 4 months of age, for which the Psychomotor Development Index was best predicted by length of hospitalization. No main effect for intracranial hemorrhage was demonstrated, but the motor performance of infants with intracranial hemorrhage declined significantly with age. By contrast prolonged mechanical ventilation was associated with uniformly poor performance at every age and serves as a powerful marker for poor developmental progress during the first 18 months of life in infants weighing 1,200 g or less at birth.     

Patterns of fungal colonization in preterm infants weighing less than 1000 grams at birth

BACKGROUND: Colonization with Candida spp. is an important risk factor for systemic infection in very low birth weight (VLBW; <1500 g) and extremely low birth weight (ELBW, <1000 g) infants. ELBW infants are at a higher risk than VLBW infants for fungal sepsis and its associated mortality, but few studies have examined fungal colonization exclusively in ELBW infants. METHODS: Fungal colonization data were analyzed retrospectively in 50 high risk ELBW infants. Weekly surveillance fungal cultures of the skin, gastrointestinal tract, respiratory tract and umbilicus had been performed from birth through the first 6 weeks of life. Colonization was analyzed for time of initial colonization, site, species and spread of Candida from one site to another. RESULTS: Candida was isolated from surveillance cultures in 31 of 50 (62%) infants. Colonization was inversely proportional to gestational age. Initial week of both the fungal colonization of the skin [1 (0-6) week, median (range)] and gastrointestinal tract [2 (0-6)] preceded colonization of the respiratory tract [3 (1-6)] (P = 0.0001). Among infants colonized by only 1 of the species, colonization at 2 or more sites occurred similarly with Candida albicans (77%) and Candida parapsilosis (85%), whereas colonization at 3 or more sites occurred more frequently with C. albicans (69%) compared with C. parapsilosis (23%) (P = 0.047). CONCLUSIONS: Fungal colonization occurs on the skin and gastrointestinal tract before the respiratory tract. In addition, C. albicans is more likely than C. parapsilosis to colonize multiple sites.     

Prognosis for infants weighing 1000 g or less at birth.

During the 10 years 1966-1975, 148 infants weighing less than or equal to 1000 g were admitted to the Neonatal Unit of University College Hospital. 48 (32%) survived the neonatal period. The neonatal survival rate for infants weighing less than or equal to 750 g was 8% and for infants weighing 751-1000 g, 41% 9 infants died later, leaving 39 (26%) long-term survivors, all of whom are being followed-up. The progress of the 27 older children, born in 1966-74 (median birthweight 899 g, range 648-998 g; median gestational age 28 weeks, range 24-35 weeks), was assessed at ages between 15 months and 8 years (median 3 years). No abnormalities were detected in 21 infants (78%): 2 (7%) had major handicaps and 4 (15%) minor handicaps. We conclude that provided intensive care methods are available, the prognosis for infants weighing less than or equal to 1000 g is now better than in the past.     

Mid- and long-term outcome of 166 premature infants weighing less than 1,000 g at birth,all small for gestational age

This longitudinal study reported the mid- and long-term neurodevelopmental outcome of 166 premature infants born with an extremely low birth weight (<1,000 g), all small for gestational age (<10th percentile birth weight for gestational age). Nine girls were lost to follow-up before 3 years of age, and 6 children were excluded a posteriori because of specific conditions diagnosed in the 1st year of life (severe abnormalities in 5). Of the remaining 151 children, 2% had cerebral palsy, 15% had lesser motor disturbances (reduced to 2% after psychomotor training), 8% had early severe developmental delays, and added mild and moderate delays and increasing cognitive gaps amounted to 28% in the 14th year. Visual deficits increased with age up to 63% of the older children. Seven children had deafness and 13 had hearing losses after otitis media. Language delays were observed at some stage in 31% of cases, as well as behavioral disturbances in 42% (severe problems in 12%). At last evaluation, 34% of the children were normal (12% of the older ones), 51% had minor deficiencies, 18% had moderate and 3% had major disabilities. Children entered the first grade in the 7th year in only 84% of cases, which dropped to 63% at proper level in the second grade; 47% entered high school at the proper age, 7/15 obtained the 'baccalauréat' in the 19th/20th year. The school performance was heavily dependent on the socioeconomic and cultural level of the family.     

Consistency and change in the development of premature infants weighing less than 1,501 grams at birth

Ninety-four infants with birth weights less than 1,501 g were evaluated on neurologic functioning and mental abilities at 1 year and, again, at 3 to 4 years of age. Results of the examination showed high correspondence in neurologic status and in mental ability between infancy and the preschool period, particularly for children who were diagnosed as clearly normal or abnormal at 1 year. In addition, poorer performance in a test of infant mental ability (which relies primarily on sensorimotor skills), in motor skills, and in neurologic functioning, respectively, were linked to lower IQ, difficulties in expressive language, and articulation deficits at the preschool age. Socioeconomic status predicted 3-year IQ scores and changes in mental ability scores but was not a factor in determining either preschool age neurologic status or changes in neurologic status in the children studied. Socioeconomic status of the children was less predictive of preschool outcome than results of the 1-year examinations.     

Premature infants weighing less than 1000 grams: mortality, morbidity and short-term neurologic outcome

The outcome of 60 premature infants weighing less than 1,000 g at birth and consecutively born during the years 1986 to 1988 is reported. Forty-two (70%) of them were inborn. The overall mortality rate was 42%, but only 26% in the inborn group instead of 78% in the outborn group (P less than 0.001). The mortality rate was higher for the appropriate for gestational age infants (56%) than for the growth retarded infants (14%, P less than 0.01). The main neonatal problems were the following: hyaline membrane disease (63%), patent ductus arteriosus (7%), bronchopulmonary dysplasia (8%), necrotizing enterocolitis (15%), intraventricular hemorrhages (45%) and periventricular leukomalacia (12%). Twenty percent (7/35) of the surviving infants showed abnormal neurodevelopmental outcome, with only one (3%) having major handicap. No correlation was found between gestational age and neuro-developmental outcome.     

Catch-up growth in 166 small-for- gestational age premature infants weighing less than 1,000 g at birth

Catch-up growth was studied in 166 children born with an extremely low birth weight (<1,000 g) and small-for-gestational age (SGA, <10th percentile birth weight for gestational age). Of these children 159 were followed up for between 4 and 18 years (median 9 years). Group A, SGA <10th percentile of Lubchenco curves only; group B, <10th percentile of Mamelle's curves but >5th percentile, and group C, <5th percentile of Mammelle's curves. Catch-up growth was considered to be achieved when height, weight, and head circumference (HC) reached -2 SD of French reference data and remained above this limit afterwards. Catch-up growth in height was achieved in 126/156 children or 81% (group A 88%; group B 84%; group C 74%), before 3 years of age in 100/127 (78%). Seven children below -2 SD received growth hormone (1 child who caught up was excluded from the results). Catch-up growth in weight was achieved in 126/159 children or 79% (group A 86%; group B 82%; group C 73%), before 3 years of age in 87/126 (69%). Catch-up growth in HC was achieved in 126/156 or 81% (group A 78%; group B 92%; group C 77%), before 3 years of age in 102/127 (80%). Overall catch-up growth was achieved for all three parameters in 65% of children, two of three parameters in 19%, and one of three parameters in 8%. Eleven children never caught up on any parameter. While weight is a lesser concern and HC is not liable to intervention, a greater number of short children might benefit from growth hormone therapy.     

Nine-year follow-up of infants weighing 1 500 g or less at birth

A nine-year follow-up of 116 children born consecutively in 1971-74 with a birthweight of 1 500 g or less showed that 59 had died. Of those who were alive, four had severe motor and/or mental handicaps and three were blind because of retrolental fibroplasia. The low birthweight children without severe handicaps were found to have impaired motor function, speech defects and impaired school achievement more often than the controls. There was a significant correlation between the test results at the age of five and nine years, which indicates that children with school failure can be recognized and early remedial treatment started before school or on starting school.     

Changing two-year outcome of infants weighing 500 to 999 grams at birth: a hospital study.

Survival and neurodevelopmental outcome to 2 years were determined for two cohorts of infants weighing 500 to 999 gm at birth, born in a tertiary maternity hospital. Live births increased over time from an annual average of 48.7 in the first era (January 1977 to March 1982) to 64.6 in the second era (January 1985 to December 1987), largely from referrals of additional mothers with pregnancy complications. In the first era, 33.6% (86/256) of infants survived to 2 years; the survival rate improved significantly to 45.9% (89/194) in era 2. After adjustment for birth weight, the odds ratio for survival in era 2 versus era 1 was 1.39 (95% confidence interval = 1.12, 1.73; p less than 0.01). One known survivor in each era was not seen at 2 years of age. In the first era, 59.3% (51/86) of 2-year-old children were free of disability compared with 68.5% (61/89) in era 2 (NS), but the Mental Development Index of the Bayley Scales improved significantly, from 90.0 in era 1 to 98.0 in era 2. For infants weighing less than 800 gm at birth, not only did the 2-year survival rate improve, adjusted for birth weight (odds ratio = 1.53; 95% confidence interval = 1.06, 2.20; p less than 0.05), but there was also a significant reduction in neurologic disabilities in survivors (p = 0.03). For infants weighing 800 to 999 gm at birth, there was a significant improvement in the survival rate, adjusted for birth weight (odds ratio = 1.37; 95% confidence interval = 1.04, 1.79; p less than 0.05), but the rate of neurologic disabilities was unchanged. Increased survival in our tertiary maternity center was achieved without increasing the annual number of severely disabled 2-year-old survivors.     

Two year longitudinal followup of premature infants weighing less than or equal to 1,200 grams at birth: sequelae of intracranial hemorrhage

Intracranial hemorrhage (ICH) is a major problem for the premature infant, occurring in more than one-third of surviving infants weighing less than or equal to 1,500 g at birth. The literature on perinatal ICH, as it relates to neurodevelopment outcome, is briefly reviewed, and preliminary results from our two-year followup of 75 less than or equal to 1,200-g infants are summarized. An analysis of pathophysiology, diagnosis, classification, and followup indicates that risk for ICH and its sequelae increases as gestational age and birth weight decrease. Hydrocephalus apparently no longer presents significant risk beyond that conveyed by the original hemorrhage. However, persistent posthemorrhagic ventriculomegaly and/or periventricular abnormalities serve as significant "markers" of risk for neuromotor delay through two years of age. In contrast, recovery of normal ventricular morphology by term gestational age apparently indexes a degree of recovery from ICH and predicts a more normal developmental outcome through the first two postnatal years.     

Mortality, morbidity, growth and development of babies weighing 501-1,000 grams and 1,001-1,500 grams at birth

During the five-year period, January 1980 to December 1984, 149 babies of extremely low birthweight (ELBW; 501-1,000 g) and 296 of very low birthweight (VLBW; 1,001-1,500 g) were admitted to King's College Hospital, Neonatal Intensive Care Unit. The survival rates were 51.7% and 82.8% respectively. There were more peri- and postnatal problems in the ELBW babies than the VLBW babies and these differences were highly significant. All surviving babies born between January 1980 and December 1982 were followed up until aged two. The ELBW children had a higher incidence of neuro-developmental sequelae than those of VLBW especially when both major and minor problems were considered. Their developmental quotients were lower at one and two years. Significantly more ELBW children were of short stature and low weight (less than 3rd centile). By two years of age the differences between ELBW and VLBW children in stature and mean DQ had lessened.     

Antecedents of periventricular haemorrhage in infants weighing 1250 g or less at birth.

Fifty infants who weighed 1250 g or less at birth were studied with serial real time cerebral ultrasound to evaluate the temporal relation of various perinatal factors to the onset and progression of periventricular haemorrhage (PVH). The significant antecedents of PVH were severe bruising at birth, low birthweight, short gestation, ratio of arterial oxygen pressure (PaO2) to fractional inspired oxygen (FiO2), and haematocrit on admission, hyaline membrane disease, assisted ventilation, pneumothorax, administration of tubocurarine, hypercapnia, hypoxaemia, and hypotension. Case control studies, in which infants with PVH at 26 weeks'' and 28 weeks'' gestation were compared with matched infants without PVH, confirmed that the antecedents identified were independent of gestational influences. A multivariate discriminant analysis for the antecedents of PVH showed that hyaline membrane disease, hypercapnia, and short gestation correctly classified presence or absence of PVH in 78% of the study group. A similar analysis comparing infants with germinal layer haemorrhage or intraventricular haemorrhage with those who developed intracerebral extension of haemorrhage showed that three factors found on admission (hypothermia, a low PaO2:FiO2 ratio, and severe bruising) combined to classify correctly 90% of the haemorrhages. Our data suggest that prevention of perinatal trauma and asphyxia as well as respiratory illness, especially hyaline membrane disease, and stabilisation of blood gas tensions, blood pressure, and haematocrit within the physiological range, are likely to be the most effective ways of preventing PVH in extremely preterm infants.