Neonatal and postneonatal mortality in very low birthweight infants.

We reviewed 388 very low birthweight infants admitted to this neonatal intensive care unit over a four year period to determine the pattern of neonatal and postneonatal deaths up to age 2 years. Neonatal mortality is no longer an adequate indicator of outcome because deaths arising from perinatal events occur after the first month of life.     

Prevention of postneonatal mortality.

Studies of postneonatal mortality in Nottingham between 1974 and 1977 showed a familiar pattern of high death rates in socially deprived parts of the city. A birth scoring system was devised, which identified at birth 9% of infants in whom 53% of postneonatal deaths could be expected to occur From 1 January 1978 this group was identified by midwives and followed up intensively by health visitors. The postneonatal mortality in the city of Nottingham fell from 8.7/1000 live births in 1974 to 3.6/1000 in 1981. It was not possible, however, to show that the rate of improvement after the introduction of the birth scoring system was greater than the trend present before its introduction. The causes of postneonatal death, and their geographical and seasonal distribution, were similar in 1978-81 and 1974-77, despite an absolute fall in numbers. By 1981 the important risk factors were either recorded on the birth notification or known to the health visitor in any case. Although nurse managers and most health visitors have found the scheme useful in other respects--for example, resource allocation--it was considered that these could be achieved without a formal scoring system. Therefore, the birth scoring system was stopped at the end of March 1985. Health visitors are still being encouraged to pay more attention to high risk cases as a part of normal clinical practice.     

Native American postneonatal mortality

Although dramatic gains have been realized in lowering the incidence of neonatal deaths among native American infants to a level lower than the white race, postneonatal death rates for this population remain twice as high as in the white race. The limited data available reveal that excessive postneonatal deaths among native American infants largely result from preventable accidents and treatable acute medical conditions, such as pneumonia and gastroenteritis. This suggests that native American infants leave the hospital healthy but go to unsafe environments, which decrease their chances of survival past 1 year. In particular, the poorer socioeconomic conditions that native American families experience and the related problems of alcoholism, unemployment, and family disorganization contribute to the high rate of postneonatal mortality. Intervention programs to lower native American postneonatal mortality should focus on promoting prompt recognition of and health seeking for treatable medical conditions and prevention of accidents and other postneonatal health problems. The roots of the problem of native American postneonatal mortality lie in the socioeconomic conditions of many Indian communities and cannot be addressed without recognition of how these factors combine with the health care delivery system to diminish life expectancy for native American infants.     

International trends in postneonatal mortality.

Trends in mortality in the age groups 1-5 and 6-11 months from 1966 to 1987 for Australia, Canada, England and Wales, New Zealand, and Sweden were examined. Mortality rates for ages 1-5 months differed appreciably between countries, with Sweden lower than all other countries examined. Rates have decreased in Australia, Canada, and England and Wales, but increased in New Zealand and Sweden. Mortality reported as due to the sudden death syndrome (SIDS) increased dramatically in all countries, although much of the increase was probably due to diagnostic transfer from respiratory diseases. Over 80% of SIDS deaths occurred in the age group 1-5 months and SIDS accounted for about half of all deaths in this age group. For developed countries total mortality in those aged 1-5 months was an indirect measure of SIDS mortality. A real increase in SIDS has thus occurred in Sweden and New Zealand and possibly in other countries as well. Mortality in the age group 6-11 months has approximately halved in all countries examined over the study period.     

Size at birth and neonatal and postneonatal mortality

Birthweight is a crude indicator of size at birth. Some neonatologists and obstetricians have advocated the use of ponderal index and birthlength to characterize size at birth. This paper examines the associations between various size-at-birth indicators and neonatal and postneonatal mortality, with an emphasis on ponderal index and birthlength. Size at birth, gestational age and mortality data for about one million babies born alive in Sweden between 1987 and 1995 were collected from the Swedish Medical Birth Registry. A multinomial logit regression was used to estimate conditional odds ratios. Birthlength and ponderal index were independently associated with neonatal and postneonatal mortality. In the latter period, ponderal index was only weakly associated with mortality. The associations were not sensitive to exclusion of cases of congenital anomalies and adjustment for gestational age. Conclusion: Birthlength is strongly associated with both neonatal and postneonatal mortality; ponderal index is strongly associated with neonatal, but weakly with postneonatal mortality. The findings are consistent with previous hypotheses about a transient effect of ponderal index and a persistent effect of birthlength.     

Perinatal and postneonatal mortality in England and Wales among immigrants from the Indian subcontinent

Perinatal and postneonatal mortality among immigrants to England and Wales from India, Pakistan and Bangladesh (Asians) for the years 1982–85 showed significant differences not only between the immigrant and indigenous populations, but also among the different groups from the Indian subcontinent. Compared with the perinatal mortality rate of 10.1 per 1000 total births in UK born mothers, rates in infants of mothers born in India, Bangladesh, and Pakistan were 12.5, 14.3 and 18.8 respectively. In contrast, postneonatal mortality in infants of Indian and Bangladeshi origin (3.9 and 2.8 per 1000 live births respectively) was lower than in the indigenous population (4.1), with Pakistani infants experiencing the highest rate (6.4). Excess perinatal mortality in infants of Asian origin was apparent at most maternal ages and parities. Pakistani infants had the highest rates of perinatal and postneonatal mortality in all age, parity and birth weight groups. The Asian groups showed higher mortality from congenital anomalies in both the perinatal and the postneonatal period, the rates in Pakistani infants being almost double those in Indian and Bangaladeshi infants. A significant finding was the lower rates of sudden infant death in all the groups of Asian origin.     

Acid-base parameters and alveolar-arterial oxygen tension gradients in healthy neonatal and postneonatal infants

In a randomly selected group of asymptomatic neonatal and postneonatal infants, acid-base parameters and oxygen tension measurements in arterial blood (radial artery) were carried out during air and oxygen breathing. Acid-base results showed a mild, partially compensated metabolic acidosis, indicating adequate pulmonary function. Arterial oxygen tension was in the normal range for this age group. Calculated alveolar oxygen tension levels demonstrated alveolar-arterial gradients of about 30 mm Hg during air breathing and 320 mm Hg during O₂ breathing. Volumes of R-L shunts calculated from these gradients, were in the order of magnitude commonly found at this age, i.e., about 20% of right cardiac output. No differences were discernible between infants of appropriate weight for gestational age and small-for-date infants.

---

Zusammenfassung Bei einer randomisierten Gruppe von klinisch gesunden Kindern der neonatalen und postneonatalen Altersperiode wurden Säure-Basen-Parameter und O₂-Druckwerte währent Luft- und O₂-Atmung im arteriellen Blut (A. radialis) bestimmt. Die Mittelwerte der Säure-Basen-Messungen zeigten eine geringe, teilkompensierte metabolische Acidose; die niedrigen Pco₂-Werte lassen den Schluß auf eine normale Lungenfunktion zu. Die arteriellen Po₂-Werte lagen in dem für diese Altersgruppe gültigen Normbereich. Kalkulationen des alveolären Po₂-Wertes unter Zuhilfenahme eines Nomogramms erlaubten die Erstellung alveolär-arterieller Differenzgrößen, diese wiederum die Berechnung von Rechts-Links-Kurzschlüssen. Dabei ergaben sich Shuntvolumina von ca. 20% des Herzminutenvolumens, Werte wie sie auch in der Literatur angegeben werden. Statistisch signifikante Differenzen zwischen intrauterin dystrophierten Kindern und denjenigen mit normalem Geburtsgewicht für ihr Schwangerschaftsalter ließen sich nicht errechnen.

     

Brain maturation and damage in infants dying from chronic pulmonary insufficiency in the postneonatal period

The changes in the brains of 11 infants who survived from 29 days to 13 months after severe chronic pulmonary insufficiency are described.Brain maturation as assessed by myelination and gyral formation was within normal limits. In 5 infants the brain weight was less than normal if age was used in the comparison, but greater than normal if body weight was used.In addition to hypoxic or ischaemic damage, which was found in some degree in all cases except one, there were several other local lesions. These included periventricular leucomalacia 7, periventricular haemorrhage 1, hydrocephalus 2, and cystic encephalomalacia 3. Though the last is almost certainly due to vascular occlusion, this could not be shown. The possibility of cerebral embolism after umbilical vein catheterization is considered but not proven.     

Is the higher postneonatal mortality in lower social status groups due to SIDS?

In order to study the influence of sociodemographic factors, postneonatal mortality of all live births surviving the neonatal period registered in the Norwegian Medical Birth Registry in 1978–1982 were examined (n = 209 030). Postneonatal deaths (n = 634) were divided into two categories; deaths due to the sudden infant death syndrom (SIDS) (n = 359) and deaths due to other causes (non-SIDS) (n = 275). SIDS and non-SIDS deaths showed different relationships to sociodemographic factors, and the associations appeared to be different for first-born and later born children. SIDS mortality was highest for first-born offspring when the mother was young (adjusted relative risks (RR) 2.3) and had a low educational level (adjusted RR 4.9). For later-born offspring no association between maternal educational level and SIDS was found, while young maternal age (adjusted RR 4.4) and unmarried status (adjusted RR 2.3) were closely associated with SIDS. In the multivariate model, however, there were no statistically significant associations between non-SIDS and sociodemographic factors for firstborn or later-born children. Thus it appears that the increased postneonatal mortality in lower social groups can be explained by an association with SIDS.     

Congenital choanal atresia in North African infants

Eleven cases of congenital choanal atresia seen over a period of 2 years are described. Its incidence in the community was 1 in 3100 births. Twenty-seven per cent of cases were missed at birth, suggesting an even higher incidence. The anomaly was significantly commoner in infants of younger mothers with less than four children (P less than or equal to 0.05). Maternal polyhydramnios was present in three cases (P less than or equal to 0.0001). The sex incidence was equivocal and three infants were of low birthweight. The atresia was bilateral in the majority of the cases, and associated congenital anomalies were present in five of the 11 infants. Five underwent surgery with no complications.