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Biomedical subjects

L W Doyle

Publications and source records attributed to L W Doyle.

At least 73 records · Page 4Linked to original sources
PubMed1994

The obstetrician and the extremely immature fetus (24-26 weeks): outcome to 5 years of age.

The aims of this study were to determine the outcome to 5 years of age for fetuses 24-26 weeks of gestational age from the obstetric viewpoint, and to determine if their outcome has improved over time. Consecutive fetuses with gestational ages from 24-26 weeks born at the Royal Women's Hospital, Melbourne, during 2 separate eras, Era 1 (1977-1982; n = 198) and Era 2 (1985-1987; n = 128) were studied and their outcome to 5 years of age determined. Fetuses referred with lethal malformations or clearly dead before the onset of labour were excluded. The stillbirth rates were similar in both eras (Era 1 23.7%, Era 2 21.9%), but the proportion of survivors to 5 years of age was much higher in Era 2 (Era 1 19.7%, Era 2 30.5%, X2 = 5.0, p < 0.03; odds ratio 1.80; 95% confidence interval [CI] 1.07 to 3.04). Overall, both the proportion and the absolute number of severely disabled children fell over time; 4 children survived with severe sensorineural disability in the 5 1/4 years of Era 1, but only one child in the 3 years of Era 2. From the obstetric viewpoint, only 1.5% of total births survived with a severe sensorineural disability, no higher than the rate expected for children born at term. Fetuses born at 24-26 weeks of gestational age need not contribute disproportionately to the number of severely disabled children in the community; furthermore, their outcome is improving over time. From the obstetrician's viewpoint, survival chances rather than sensorineural outcome should dominate decision-making at these extremely preterm gestations.

Cerebral Palsy↗
PubMed1994

Ultrasound-guided fetal intravascular transfusions for severe erythroblastosis, 1984-1993.

The results of the first 10 years' experience in ultrasound-guided fetal intravascular transfusions at the Royal Women's Hospital were reviewed. Since the first transfusion, a variety of techniques have been employed in 78 fetuses, all with severe erythroblastosis. A total of 288 intrauterine transfusions have been attempted with an overall survival rate of 75.6% (59 of 78). The overall survival rate for delivered fetuses improved from 64.3% (18 of 28) in 1984-1987, to 82.0% (41 of 50) in 1988-1993. There was a total of 33 hydropic fetuses, of whom 20 (60.6%) survived, significantly fewer compared with 86.7% (39 of 45) of the nonhydropic fetuses (odds ratio [OR] 0.25, 95% confidence interval [CI] 0.09 to 0.70, p < .01). Fetuses who were sicker at the time of transfusion, as reflected by larger haemoglobin deficits, had lower survival rates, as did those requiring transfusions at earlier gestational ages. When these variables were allowed for, the survival rate significantly improved over time (OR 6.3, 95% CI 1.3 to 30.4, p < 0.05), probably reflecting the increased skill of the ultrasonologists, but the presence of hydrops per se was no longer important. Variations of the technique employed, such as exchange or intraperitoneal transfusion, or different sites for transfusion, were not significantly related to survival.

Blood Transfusion, Intrauterine↗
PubMed1993

Long-term outcome of infants born preterm.

This chapter outlines some of the many long-term health problems to be expected in surviving preterm children. They have higher rates of sensorineural impairments (such as cerebral palsy, and visual, auditory and intellectual impairments) and sensorineural disabilities from these impairments, than children born at term. In addition, they grow poorly and have higher rates of other health problems, including poorer respiratory health in early childhood. There is little doubt that preterm children contribute disproportionately to the prevalence of health problems in childhood. However, there are still many gaps in our knowledge of the outcome for preterm survivors, particularly regarding outcome in adulthood. Obstetricians and neonatologists working in intensive care, as well as parents, want to know the long-term outcome for preterm children born today, not that of children born a generation ago when fewer preterm children (particularly those of extremely low birthweight) survived. Despite the many problems, the conclusion is that most preterm children are as healthy as term children, suffering only usual childhood illnesses; we feel confident that the majority make, and will continue to make, useful contributions to their families and the societies in which they live.

Cohort Studies↗
PubMed1993

The cost of improving the outcome for infants of birthweight 500-999 g in Victoria. The Victorian Infant Collaborative Study Group.

The aim of this study was to conduct an economic evaluation of neonatal intensive care for extremely low birthweight (ELBW) infants born in the state of Victoria. Two distinct eras (1979-80 and 1985-87) were compared. Follow-up data at 2 years of age were available for all 89 survivors from the 351 live births in 1979-80, and for 211 of 212 survivors from the 560 live births in 1985-87. The overall cost-effectiveness for ELBW infants during 1985-87 compared with 1979-80 was $104,990 ($A 1987) per additional survivor, or $5390 ($A 1987) per additional life year gained. Cost-effectiveness improved with increasing birthweight. If the quality of life of the survivors was considered, the economic outlook was more favourable. The cost per quality-adjusted life year gained was $5090 ($A 1987), approximately one-tenth of that obtained from the only previous full economic evaluation of neonatal intensive care. Although neonatal intensive care is expensive, it compares favourably with some other health care programmes, particularly as the outcome for ELBW infants continues to improve.

Birth Weight↗
PubMed1993

Assessment of short stature in very low birthweight children.

The aims of this study of short very low birthweight (VLBW) children at or after 8 years of age were to determine: (i) if there were any unsuspected organic causes for their growth failure; and (ii) whether any children might be suitable for treatment with synthetic growth hormone. Thirty-seven of 195 (19%) VLBW children seen at 8 years had heights < 10th centile, and of these only 40% (10/25) of families offered an assessment were concerned enough to have the child fully evaluated. No child had an unsuspected organic cause of short stature. The children's parents were significantly shorter than expected for Caucasians (mean parental height s.d. score = -1.06 (s.d. 0.72), t = -5.9, P < 0.001). On average, the bone age of the short children was delayed by 14.9 months (s.d. 18.8 months) compared with chronological age (t = -3.4, P < 0.01). When compared with their parents, the children's mean height s.d. score for their bone age was not significantly different (mean height s.d. score for bone age = -0.83 (s.d. 1.3), t = 0.6, NS). Only three children qualified for treatment with synthetic growth hormone; all three had been small for gestational age at birth and had birthweights < 1000 g. In conclusion, in short VLBW children, only a minority of families and children are likely to be concerned enough about short stature to be fully assessed; an unsuspected organic cause for growth failure is unlikely, and only a few will qualify for synthetic growth hormone therapy.

Body Height↗
PubMed1993

Sensorineural outcome at 2 years for survivors of erythroblastosis treated with fetal intravascular transfusions.

OBJECTIVE: To determine the sensorineural outcome at 2 years of age in a complete cohort of survivors of fetal intravascular transfusions. METHODS: From March 1984 to May 1990, 38 of 52 consecutive fetuses (73%) suffering from severe erythroblastosis survived attempted intravascular transfusions at the Royal Women's Hospital, Melbourne. At 2 years of age, corrected for prematurity where appropriate, the survivors had a psychological assessment, including the mental developmental index of the Bayley scales, and a standardized neurodevelopmental examination. RESULTS: Only one transfused child had a severe sensorineural disability, with severe developmental delay and multiple minor motor seizures. Another child was moderately disabled with spastic hemiplegia. In neither case were complications of an intravascular transfusion the likely explanation for the disability. Only one other child had a mental developmental index in the suspect range. The remaining 35 children (92.1%) had no sensorineural disability. The overall rate of sensorineural impairments and disabilities was lower in the group transfused than in previous reports of survivors of intraperitoneal transfusions. The mean mental developmental index was significantly higher in the transfused group than in a control group of normal birth weight children. CONCLUSION: Children who survive fetal intravascular transfusions compare favorably not only with other high-risk survivors, but also with low-risk children.

Blood Transfusion, Intrauterine↗
PubMed1993

Cognition, school performance, and behavior in very low birth weight and normal birth weight children at 8 years of age: a longitudinal study.

Cognition, school performance, and behavior were assessed at 8 years of age in 132 very low birth weight (VLBW) children free of major sensorineural impairments, and the results were contrasted with a randomly selected control group of normal birth weight (NBW) children. Considering their fragile beginnings, the majority of VLBW children were developing normally and were reading and performing in most academic and social areas as well as the NBW children. However, VLBW children were significantly inferior to NBW children on tests of cognition, including tests of intelligence and visual memory, and on teacher's reports of motor skills and initiative. In addition, proportionally more VLBW children (20.5%) than NBW children (5.9%) were reported by their parents to be not coping at school.

Brain Damage, Chronic↗
PubMed1992

Improvement in outcome for very low birthweight children: apparent or real?

OBJECTIVE: To determine whether improvement in the survival rate of infants with a birthweight of less than 1501 g was accompanied by an increase in the rate of neurological impairment or disability among the survivors. DESIGN, SETTING AND PATIENTS: Two cohorts of consecutive very low birthweight infants (birthweight less than 1501 g) in one tertiary perinatal centre were followed prospectively to eight years of age; for both cohorts, comparison groups of children of birthweight more than 1501 g were randomly selected from hospital births. INTERVENTIONS: The first cohort was born before the introduction of assisted ventilation (1966-1970), the second after assisted ventilation was well established (1980-1982). MAIN OUTCOME MEASURES: Comparisons between cohorts, at eight years of age, of the survival rates and the rates of severe sensorineural impairments and disabilities. RESULTS: The survival rate for very low birthweight infants to eight years of age almost doubled between these cohorts, from 37.1% to 67.8% (odds ratio [OR], 3.4; 95% confidence interval [CI], 2.5-4.7; chi 2 = 57.6; P much less than 0.0001). The biggest gain was the increase in non-disabled survivors at eight years of age, from 52.6% in the first cohort to 80.8% in the second cohort (OR, 3.5; 95% CI, 2.2-5.7; chi 2 = 26.7; P less than 0.0001). Furthermore, the rate of severe disabilities in survivors fell substantially, from 13.6% to 4.1% (OR, 0.31; 95% CI, 0.14-0.69; chi 2 = 8.3; P less than 0.01). Of specific impairments, the rate of severe sensorineural deafness fell substantially (3.2% to 0%: OR, 0.14, 95% CI, 0.02-0.81; chi 2 = 4.8; P less than 0.05), as did the rate of severe intellectual impairment (13.0% to 2.7%: OR, 0.25; 95% CI, 0.11-0.57; chi 2 = 10.7; P less than 0.002). Only the rate of cerebral palsy increased, but not significantly (2.6% to 6.8%; OR, 2.6; 95% CI, 0.89-7.6; chi 2 = 3.0). CONCLUSIONS: It has been possible to improve the survival rate of very low birthweight infants over time without increasing the number of severely disabled survivors. Whether the long-term outcome for these infants is continuing to improve with more recent advances in perinatal care remains to be determined.

Cerebral Palsy↗
PubMed1992

Very low birth weight and growth to age 8 years. I: Weight and height.

We determined the heights and weights at ages 2, 5, and 8 years for the following three cohorts of children: group 1 with birth weights between 500 and 999 g; group 2 with birth weights between 1000 and 1499 g; and group 3 with birth weights more than 2500 g. By age 8 years, group 3 children were significantly heavier and taller than all children in groups 1 and 2 combined; group 1 children were significantly shorter than those in group 2, but their weights were similar. From ages 2 to 5 years, annual increments in weight and height were similar in all three groups; however, between ages 5 and 8 years, children in group 3 grew faster than those in groups 1 and 2 combined, and children in group 1 had smaller height increments than those in group 2. Of children with birth weights less than 1500 g, with a weight or height under the 10th percentile at age 2 years, only approximately one half were still below the 10th percentile for the corresponding measurement at age 8 years. Health variables determined before birth, such as maternal height or birth weight ratio, were more important than health after birth in predicting a height or weight below the 10th percentile at age 8 years in children with birth weights less than 1500 g.

Body Height↗
PubMed1992

Very low birth weight and growth to age 8 years. II: Head dimensions and intelligence.

The occipitofrontal circumference was measured in all available children in the following cohorts at ages 2, 5, and 8 years: group 1, consisting of 79 children with birth weight between 500 and 999 g; group 2, with 111 children with birth weight between 1000 and 1499 g; and group 3 with 56 children with birth weight greater than 2500 g; all were white with no signs of moderate or severe cerebral palsy. National Center for Health Statistics reference values indicated substantially more children with an occipitofrontal circumference lower than the 10th percentile, particularly at age 2 years, compared with Nellhaus reference data. Occipitofrontal circumference was the head measurement best correlated with the Full Scale IQ on the Wechsler Intelligence Scale for Children-Revised. Dolichocephaly, often seen in very-low-birth-weight children was unrelated to IQ, and correction of occipitofrontal circumference for dolichocephaly was rarely of clinical importance.

Analysis of Variance↗
PubMed1992

Is there a lower limit for birth-weight/gestational age and antenatal steroid therapy?

The aim of this study was to determine if there is a lower limit for birth-weight/gestational age below which antenatal steroid therapy may not improve fetal survival. The association between antenatal steroid therapy and survival to 2 years of age was assessed in 2 cohorts of children of birth-weight below 800 g or of gestational ages below 27 weeks. Antenatal steroid therapy was associated with significantly higher survival rates in infants of birth-weight 500-599 g and 700-799 g, and at gestational ages of 25 and 26 weeks. There were few survivors before 25 weeks and none below 500 g birth-weight. After adjustment for extraneous prognostic variables, antenatal steroid therapy was associated overall with approximately a doubling of the survival rates of infants of birth-weight 500-799 g, and of gestational ages 24-26 weeks. In the absence of maternal contraindications, if the goal is to deliver a surviving infant, this study suggests that the obstetrician may assist the survival chances of the tiniest and most immature infants by treating the mother with steroids before birth, with no apparent lower limit of birth-weight or gestational age.

Birth Weight↗
PubMed1992

Audiologic assessment of extremely low birth weight infants: a preliminary report.

The aim of this study was to assess all relevant aspects of auditory function, including acuity and perception, of a cohort of extremely low birth weight (< 1000 g) children who survived to 8 years of age; 42 of the 59 consecutive survivors born over a 4-year period from January 1, 1977, had a full auditory assessment. Of the 42 children, 4 (9.5%) had a sensorineural hearing impairment, 5 (11.9%) had a conductive hearing impairment, 24 (57.1%) had figure/ground differentiation problems, and 20 (47.6%) had a short-term auditory memory problem. The 4 children with sensorineural hearing impairments had had significantly higher maximum concentrations of bilirubin in the newborn period (median 167 mumol/L vs 138 mumol/L and had required more intensive care; at 8 years of age they were significantly disadvantaged in verbal ability. The 5 children with conductive hearing impairments were not significantly different on any perinatal or other 8-year outcome variables. The proportion with figure/ground differentiation problems (57.1%) was significantly higher than in a normative population (11.7%, chi 2 = 24.2). Extremely low birth weight children with figure/ground differentiation problems were more likely to be restless in the classroom (45.0% [9/20]) than those without these problems (16.7% [2/12]), but the difference was not statistically significant (chi 2 = 2.7). Children with short-term auditory memory problems had significantly higher maximum bilirubin concentrations in the newborn period (median 152 mumol/L vs 137.5 mumol/L). At 8 years of age they had significantly reduced intelligence and reading ability.(ABSTRACT TRUNCATED AT 250 WORDS)

Audiometry↗
PubMed1992

Respiratory health and lung function in 8-year-old children of very low birth weight: a cohort study.

In comparison with a cohort of normal birth weight children, those of very low birth weight (less than 1501 g birth weight) had more wheezing illnesses and hospital readmissions for respiratory problems in the first 2 years of life; from 2 years to 8 years of age respiratory health was unrelated to birth weight. Lung function measurements at 8 years of age in very low birth weight children were similar to expected values; few children had severely abnormal lung function. On univariate analyses, forced vital capacity (FVC) and forced expired volume in 1 second (FEV1), but not flow rates, were lower in children who had survived bronchopulmonary dysplasia. However, the univariate analyses were misleading, because bronchopulmonary dysplasia occurred more frequently with lower birth weight, and lower birth weight in turn was strongly related to reduced FVC and FEV1. After adjusting for birth weight and other potential confounding variables, FVC and FEV1 were unrelated to bronchopulmonary dysplasia, and to neonatal ventilation. Flow rates were largely uninfluenced by perinatal events, but were reduced in children with asthma or recurrent bronchitis at 8 years of age. Passive smoking was unrelated to lung function at 8 years of age. However, the effects of passive or active smoking, or perinatal events, on respiratory function or health beyond 8 years of age in very low birth weight survivors remain to be determined.

Birth Weight↗
PubMed1992

Changing obstetric practice and 2-year outcome of the fetus of birth weight under 1000 g.

The aim of this study was to assess the outcome up to 2 years of age for the fetus of birth weight 500-999 g, over time and in association with changes in obstetric care. Two consecutive cohorts of infants of birth weight 500-999 g were compared from two eras, 1977-1982 and 1985-1987, and their outcome up to 2 years of age was determined with particular emphasis on the effect of various obstetric interventions at the time of birth, such as cesarean delivery, electronic fetal monitoring, antenatal steroid therapy, and tocolytic therapy. The outcome to 2 years was analyzed by logistic function regression to adjust for imbalances in confounding perinatal variables. In the latter era, the survival rate to 2 years increased significantly by almost 50%, and only 7% of the survivors were severely disabled. The rates of delivery by cesarean and of electronic fetal monitoring both increased significantly in the latter era, but neither was associated with the improved outcome. The only variable associated with an improved outcome that was amenable to obstetric intervention at the time of birth was antenatal steroid therapy, which was used equally in both eras. The obstetrician may aid the fetus of birth weight 500-999 g by giving the mother steroids to accelerate fetal lung maturity, but cesarean cannot be recommended as the routine mode of delivery unless there are recognized maternal or fetal indications.

Delivery, Obstetric↗