Strategies for reduction of neonatal mortality.

Infant mortality rates in developed countries have shown significant decreases in recent years. Two-thirds of infant mortality still occurs in the neonatal period and our aim in this study was to review the causes of these neonatal deaths and see where further improvements may be possible. A 6-yr review of all neonatal deaths of live-born infants over 500 g birthweight from 1991 to 1996 was made. The 1989 amended Wigglesworth classification was used to categorize cause of death and other perinatal variables were also recorded. Results show there were 34,375 births and 153 neonatal deaths. Classification of these deaths by Wigglesworth found 78 (51 per cent) due to congenital malformations, 58 (38 per cent) due to prematurity, 6 (4 per cent) due to asphyxia and 11 (7 per cent) due to specific other causes. The corrected neonatal mortality was 2.18. Neural tube defects alone accounted for 10 per cent of the total neonatal mortality. Fifty-five out of 58 infants who died due to prematurity had birthweight < 1000 g and survival rates in this group compared well to international standards. We conclude that a reduction in neonatal mortality is possible but is most likely to result from community focused measures such as increased use of pre- and peri-conceptional folate.

Renal transplantation in pre-school children.

This short report describes the outcome of 13 renal transplants in 11 children under 5 years of age. Nine (82%) of the 11 recipients are alive; 2 children died with functioning grafts. Approximately 50% of grafts are functioning at 5 years post transplantation. Children with congenital kidney malformations can be successfully managed to transplantation.

Metabolic consequences of dehydroepiandrosterone in lean and obese adult Zucker rats.

Several previously reported studies have shown that in rodents exogenously administered dehydroepiandrosterone (DHEA) can cause numerous metabolic changes. In the present study some additional metabolic effects of DHEA are presented using old lean and obese Zucker rats. With this experimental model most of the effects were found to occur in the obese rat. These included decreases in serum insulin and cholesterol as well as a decrease in hepatic acyl-CoA cholesterol-acyl transferase activity. In both lean and obese rats an increase in hepatic long-chain fatty acyl-CoA hydrolase was found. This increase in activity may partially explain DHEA's effect on decreasing body weight in rodents.

Assessment of infant physiology and neuronal development using magnetic resonance imaging.

Previous work has demonstrated both that there are substantial individual differences in the rate of physiological development,and that infants with risk factors for Sudden Infant Death Syndrome (SIDS) develop more slowly, suggesting that their increased vulnerability may be due to delayed neuronal development associated with compromised development in fetal or early neonatal life. This project aims to test the hypothesis that individual differences in the rate of physiological development of infants correlate with measurable differences in the rate of brain development as assessed by magnetic resonance imaging (MRI). Sixty infants were recruited to this study in three different groups that are known to have differing rates of physiological development. MRI was performed successfully in 49 cases at 6 weeks of age without sedation. Forty-one of these cases had full follow-up (15 normal; 19 IUGR; 11 'high risk'). Postnatal physiological development was assessed by measuring age-related deep body temperature patterns during sleep. Neuronal development was assessed by subjective analysis of MRI images and objective measurements relating to myelination using T1 and diffusion weighted (23 cases) MRI images. As expected the normal group acquired the adult temperature pattern earlier, but this was not statistically significant. All MRI scan appearances were within normal limits. Ranking cases subjectively in order of maturity revealed no significant pattern. The normal group had a significantly higher myelination score than the IUGR and 'high risk' groups (P = 0.001). This trend was also shown by the diffusion weighted myelination score but did not reach statistical significance. No significant differences were seen in both the subjective and objective MRI measurements and development of nocturnal temperature patterns. The results suggest there may be differences in neurodevelopment between the different groups at 6 weeks of age but these are not linked to late development of temperature patterns. It is therefore unlikely that this related to a global delay in maturation.

Nutritional factors and growth in children with sickle cell disease.

A study of growth and nutrition was conducted with 20 growth-retarded (GR) and 20 growth-normal (GN) preadolescent children with sickle cell disease (SCD). All children were matched for age, sex, hemoglobin disorder, and hematologic values. Ten normal children served as control subjects. Mean serum levels of retinol, retinol-binding protein, prealbumin, and zinc were significantly lower in the children with SCD than in normal children. Mean serum retinol and prealbumin levels were similar in the GR and GN sickle cell groups. Mean serum retinol-binding protein levels were lower in GR than in GN patients. Serum zinc levels, somatomedin C levels, and bone age were frequently abnormal in the patients with SCD, but these factors did not correlate with growth status. It was not possible to explain the poor growth in patients with SCD in this study solely on the basis of nutritional factors.

Perinatal factors influencing survival in extremely low-birthweight infants.

The majority of deaths in normally formed infants occur in extremely low birth weight infants (< 1000 g). Survival rates for these infants have improved greatly but still vary from centre to centre and accurate local outcome figures are important for counselling parents and upholding standards of care. In the Rotunda Hospital, Dublin, over the 6 year period from 1 January 1990 to 31 December 1995, there were 34 474 deliveries over 500 g birthweight. One hundred and twenty-six of these were normally formed infants between 500 g and 999 g. Our objective was to analyse the factors influencing survival in these extremely low birthweight (ELBW) infants. Overall survival in the group was 63%. The most significant factors influencing survival to 28 days were gestation and birthweight. Survival increased from 33% at 24 weeks to 100% at 28 weeks' gestation and from 29% at 500-599 g to 87% at 900-999 g birthweight. Having controlled for gestational age, none of the following variables had a significant effect on survival: year of birth; gender; multiple pregnancy; 1-minute Apgar score; maternal age; parity; use of antenatal steroids; a history of antepartum haemorrhage, pre-eclamptic toxaemia or prolonged rupture of membranes. A 5-min Apgar score > 5 increased the chance of survival by 3.97 (95% CI: 1.46- 10). Both mode of delivery and incidence of chorioamnionitis had an influence on survival which varied according to the gestational age. A larger cohort of survivors would illustrate the effect of these variables more clearly.