Postnatal age at time of death in infants born at 24-32 weeks' gestation

Medical records of all 483 infants live-born at 24-32 weeks' gestation in our hospital during the years 1982-86 were reviewed in order to determine postnatal age at time of death for those who died in the first year after birth. Twenty-seven died from immaturity without receiving intensive care and 11 died from lethal congenital malformations. Eighty (18%) of the remaining 445 who received intensive care died: 31% on day 1, 45% on days 2-7, 12% on days 8-28 and 11% on days 29-365. The neonatal mortality rate for those receiving intensive care was 160/1000, and the postneonatal mortality rate was 20/1000. Delayed mortality was most common in infants of 26-27 weeks' gestation, with 20% (five) of their deaths occurring after 28 days. In each gestational age range, the majority of hospital admission days were occupied by survivors (24-25 weeks = 62%; 26-27 weeks = 91%; 28-29 weeks = 91%; 30-32 weeks = 99%) rather than non-survivors. Whilst postneonatal mortality is a significant concern, these data suggest that if infants born at less than 33 weeks' gestation are offered intensive care and survive the early neonatal period, the long-term outcome is more likely to be survival rather than delayed death. Furthermore, the majority of hospital admission days invested in such infants involves those who will be discharged home rather than those who will not.     

Sudden infant death syndrome and infant mortality in Aboriginal and non-Aboriginal infants

The aim of this study was to investigate sudden infant death syndrome (SIDS) in the context of total infant mortality for Aboriginal and non-Aboriginal infants. Deaths for infants born in Western Australia from 1980 to 1988 inclusive were ascertained from a total population data base. Infant mortality rates and rates by period and cause of death were calculated for both populations. Aboriginal infants had a mortality rate three times that for non-Aboriginal infants (23.6 cf. 7.9 per 1000 live births) and both populations showed a similar rate of decline in mortality over the study period. There were differences in the proportion of deaths occurring neonatally and postneonatally in the two populations. In terms of SIDS, 21% of the deaths in Aboriginal infants occurred neonatally compared with 7% for non-Aboriginal infants. The overall cause of infant death distribution differed significantly between the two populations ( P < 0.001). During the study period, Aboriginal infants showed a significant increase in deaths due to SIDS and a significant decrease in those due to birth defects and low birthweight. These results suggest it would be useful to review the pathology and diagnosis of sudden unexplained death in infancy.     

Late death of very low birthweight infants

The causes of 59 postneonatal deaths of very low birthweight infants were determined. Bronchopulmonary dysplasia (BPD) was the cause of 19 deaths. It also coexisted in 12/20 deaths from infection and 9/20 deaths from other causes. Improvement will be best achieved by advances in the prevention and treatment of BPD.     

Comparing Cause-Specific Infant Mortality in a West German State and the United States of America

ABSTRACT. The infant mortality rate in North Rhine Westphalia (NRW), the most populous West German state, has continuously been around 10 % higher than the German national average in the post-war period. Using white singleton data from the US 1980 National Infant Mortality Surveillance project (NIMS) and similar 1980/1981 data from NRW we compared infant mortality by birthweight and cause to describe the distribution of excess mortality in NRW. The US infant mortality rate was 8.7 deaths per 1000 live births, compared with 13.1/1000 for NRW (rate difference: 4.3/1000). Of the 4.3/1000 overall rate difference, 1.9/1000 was attributable to neonatal deaths, 2.4/1000 to postneonatal deaths. A major proportion, 2.0/1000, of the overall rate difference of 4.3/1000 was attributable to normal birthweight deaths postneonatally. 0.85/1000 of this 2.0/1000 rate difference was attributable to SIDS, 0.44/1000 to external causes and 0.42/1000 to infections.     

Neurological assessment at five years of age in infants born preterm

AIM: To evaluate the agreement between Touwen's neurological examination and a derived simplified one, created to be applied at the age of 5 y to infants born preterm. METHODS: 185 children born at a gestational age (GA) of <33 wk and/or with a birthweight <1501 g, free of cerebral palsy, underwent Touwen's neurological examination at a mean age of 5 y and 8 mo (5-6.5 y). One-hundred and seventy had a full examination and were included into the study. They were born at a mean GA of 30 wk (range 24-35 wk) with a mean birthweight of 1250 g (range 600-2690 g). A simplified examination, based on the clinical experience of two of the authors, was created a priori. The data were reviewed retrospectively and the concordance between the two forms was assessed. The reviewers were blinded to the original categorization from the long form. RESULTS: On the basis of the original Touwen's neurological examination, the 170 children were classified into 122 with a normal neurological examination, 41 with grade 1 minor neurological dysfunction (MND) and 7 with grade 2 MND, giving 28% of the cohort with MND. The concordance between the two forms was excellent, with an agreement in 169 out of 170 subjects. None of the infants with the most complex form of MND was misclassified. CONCLUSION: The simplicity of this examination could allow its diffusion and its use in follow-up programmes. It could improve the quality of routinely collected follow-up data of preterm neonates.     

Chronic oxygen dependency in infants born at 24–32 weeks' gestation: The role of antenatal and neonatal factors

Objectives: To study the incidence of chronic oxygen dependency (COD) among ventilated survivors born at 24–32 weeks gestation from 1986 to 1994 and to identify antenatal and neonatal factors that may have changed with time; and to identify antenatal and neonatal factors that could contribute to the development of COD in infants born at 24–32 weeks gestation using a case control model. Methodology: Infants born at 24–32 weeks gestation in one tertiary referral centre between 1986 and 1994 and admitted to the neonatal intensive care unit for respiratory support were studied. Data accumulated prospectively since 1986 in survivors of ventilation were analyzed to identify antenatal and neonatal factors that could have changed with time. The cohort of infants who developed COD were matched for gestation and time of birth with a control group of infants who did not have COD. Significant factors that could have contributed to the development of COD were identified using forward logistic regression analysis. Results: The number of mothers admitted for threatened premature labour (TPL), and pregnancy induced hypertension decreased with time while the use of antenatal steroids and maternal antibiotics increased. More infants were delivered by Caesarean section during the later years. There was an increase in neonatal septicaemia with time while there were decreases in hyaline membrane disease, pneumothorax, pulmonary interstitial emphysema, use of high peak inspiratory pressures (PIP) and high inspired oxygen. The incidence of COD decreased. The case controlled study revealed a significant positive association between COD and male gender, birthweight less than the 10th percentile for gestation, PIP over 30 cm H₂O, septicaemia and significant patent ductus arteriosus (PDA) requiring indomethacin. There was a negative association with TPL. Conclusions: Further decrease in COD can be achieved only if septicaemia, PDA and the use of high PIP can be avoided. The most effective way of reducing the incidence of COD is by reducing the incidence of prematurity.     

Changing mortality and causes of death in infants 23–27 weeks' gestational age

OBJECTIVE: To contrast the mortality rates and changes in the causes of death of very preterm infants (23-27 weeks), before and after the introduction of exogenous surfactant in 1991, and to identify any preventable causes of death remaining in the 1990s. METHODOLOGY: This was a cohort study on consecutive preterm infants of 23-27 weeks' gestational age born in the Royal Women's Hospital, Melbourne, a level III perinatal centre. The infants were livebirths free of lethal anomalies from two distinct eras, 1983-90, and 1992-96, inclusive. The main outcome measures were mortality during the primary hospitalization and the causes of death before and after the introduction of exogenous surfactant in 1991. RESULTS: In 1983-90, 261 of 508 livebirths (51.4%) of 23-27 weeks' gestational age died, a significantly higher proportion than the 109 of 384 (28.4%) livebirths who died in the period 1992-96. The mortality rate fell significantly with increasing gestational age and was lower at each week of gestational age in 1992-96. More infants who died in 1992-96 were treated intensively in the neonatal intensive care unit (NICU). Of the group of infants who died or who were treated intensively in NICU, respiratory causes of death predominated. However, the causes of death changed over time. In 1992-96 proportionally fewer infants died from respiratory causes (1983-90, 82.5%; 1992-96, 60.0%; odds ratio (OR) 0.31, 95%; confidence interval (CI) 0.16-0.57), but more from septic causes (1983-90, 14.3%; 1992-96, 43.8%; OR 4.9, 95%; CI 2.6-9.2). CONCLUSIONS: As the mortality rate has fallen over time, respiratory causes of death have diminished, but septic causes of death have increased. Further advances in the use of exogenous surfactant and respiratory support may reduce respiratory deaths. Effective strategies to reduce nosocomial infections are urgently required.     

Growth patterns in preterm infants born appropriate for gestational age

Aim:   This study aimed to document the growth patterns of a contemporary cohort of preterm infants born appropriate for gestational age (AGA). It was hypothesised that preterm AGA (PT-AGA) infants would display poorer growth than full-term AGA (FT-AGA) infants.
Methods:   Sixty-four PT-AGA infants and 64 FT-AGA infants were assessed at 0, 4, 8 and 12 months of corrected age (CA). Measurements of weight and length were recorded at each of the specified ages. Centers for Disease Control and Prevention growth data were used to calculate Z-scores for weight and length based on CA.
Results:   The mean length and weight Z-scores of PT-AGA infants were found to be significantly less than those of FT-AGA infants at term, 4, 8 and 12 months of CA ( P  < 0.001). The mean weight Z-score of PT-AGA infants was found to be less than their mean length Z-score at each time point, though the differences were not significant.
Conclusions:   The results of this study suggest that PT-AGA infants are likely to display poorer growth than FT-AGA infants until at least 1 year of CA. Long-term growth monitoring in this population is recommended.     

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.     

Changing survival and impairment rates at 18–24 months in outborn very low-birth-weight infants: 1984–1987 versus 1980–1983

Outcomes at 18–24 months corrected age of very low-birth-weight infants admitted to our Neonatal Intensive Care Unit in 1984–1987 (period 2) were compared with the outcomes of infants admitted in 1980–1983 (period 1) (total 1357 infants). In the 500–750–g birth-weight subgroup, the survival rate increased from 32 to 54% ( p = 0.002). Rates of moderate and severe impairment at 18–24 months (neurosensory deficit, or Bayley corrected mental developmental index <68) in this subgroup decreased from 41 to 15% ( p = 0.005), and in those without severe impairment, mean mental Bayley scores in periods 1 and 2 were 84 ± 18 and 90 ± 16, respectively (p = 0.20). Analysis after exclusion of small-for-gestational-age infants gave similar results. In the small-for-gestational-age infants of birth weight 500–750 g, the survival rate increased but the impairment rate was unchanged between periods. It is concluded that outcomes improved in 1984–1987 compared with 1980–1983 only for infants with birth weight of 500–750 g.     

Changing survival and impairment rates at 18–24 months in outborn very low-birth-weight infants: 1984–1987 versus 1980–1983

Outcomes at 18–24 months corrected age of very low-birth-weight infants admitted to our Neonatal Intensive Care Unit in 1984–1987 (period 2) were compared with the outcomes of infants admitted in 1980–1983 (period 1) (total 1357 infants). In the 500–750–g birth-weight subgroup, the survival rate increased from 32 to 54% ( p = 0.002). Rates of moderate and severe impairment at 18–24 months (neurosensory deficit, or Bayley corrected mental developmental index ≤68) in this subgroup decreased from 41 to 15% ( p = 0.005), and in those without severe impairment, mean mental Bayley scores in periods 1 and 2 were 84 ± 18 and 90±16, respectively (p = 0.20). Analysis after exclusion of small-for-gestational-age infants gave similar results. In the small-for-gestational-age infants of birth weight 500–750 g, the survival rate increased but the impairment rate was unchanged between periods. It is concluded that outcomes improved in 1984–1987 compared with 1980–1983 only for infants with birth weight of 500–750 g.     

Breastfeeding and catch-up growth in infants born small for gestational age

Postnatal growth was prospectively measured from birth to 1 y in 54 term infants born small for gestational age (SGA), fed either breast milk or a standard term infant formula. Breastfeeding was associated with a 0.36 and 0.64 standard deviation (SD) increase in weight at 2 weeks and 3 months of age. respectively, which persisted beyond the breastfeeding period (0.64 SD at 1 y). Breastfed infants also showed greater catch-up growth in head circumference [SD score (SDS) 0.53 higher at 3 months], and greater body length gain (SDS 0.68 higher at 6 months). This increased growth was independent of potentially confounding obstetric, social and demographic factors. Our findings suggest that breastfeeding may promote faster growth in infants compromised by poor growth in utero. SGA infants may be programmed for a number of adverse outcomes; the possibility that such events are altered by choice of postnatal diet is a key issue for future research.     

早产儿校正18~24月龄体格生长和神经发育水平研究

目的 应用动脉自旋标记（arterial spin labeling,ASL）成像技术测量的脑血流值（cerebral blood flow,CBF）评价支气管肺发育不良（bronchopulmonary dysplasia,BPD）早产儿局部大脑皮质血流灌注量。 方法 采用前瞻性研究方法,选择2021年8月—2022年6月在郑州大学第三附属医院产科出生并转入新生儿科的胎龄<32周、出生体重<1 500 g,于纠正胎龄35~40周完成头颅磁共振成像及ASL检查的90例早产儿为研究对象,根据是否诊断为BPD分为BPD组（n=45）和非BPD组（n=45）,比较两组早产儿ASL相同感兴趣区（额叶、颞叶、顶叶、枕叶、丘脑和基底神经节）CBF值的差异。 结果 与非BPD组早产儿相比,BPD组早产儿1 min Apgar评分更低,辅助通气时间更长,胎儿窘迫发生率更高,差异均有统计学意义（P<0.05）。应用多元线性回归分析控制头颅磁共振成像检查时纠正胎龄、日龄等混杂因素后,与非BPD组相比,BPD组左右两侧额叶、颞叶、顶叶、枕叶、基底神经节、丘脑的CBF值仍较高（P<0.05）。 结论 BPD可使早产儿大脑皮质血流灌注量增高,可能与前期缺氧、较长时间辅助通气有关。     

Fetal and neonatal mortality of small-for-gestational age infants

Fetal and neonatal mortality of small-for-gestational age (SGA) infants in 1968–1982 were studied in the region of the University Central Hospital of Turku, Finland. During the study period, there were 254 fetal and 127 neonatal deaths in SGA infants. The fetal mortality rate of SGA infants declined from 49.9/1000 to 14.0/1000. The neonatal mortality rate of SGA infants declined from 23.8/1000 to 8.3/1000. The severely SGA infants with a birth weight below the 2.5th percentile had three times higher neonatal mortality rates than SGA infants with a birth weight between the 2.5th and the 10th percentiles. The main causes of fetal deaths were maternal diseases, placental and cord complications and fetal malnutrition, even though there was a decline in all these groups. Malformations remained the main cause of neonatal death during the study period, while there was a decline in deaths due to asphyxia and respiratory distress syndrome (RDS). The high mortality rates of SGA infants emphasize the need for early diagnosis and special attention during pregnancy, delivery and the neonatal period.Abbreviations SGA small-for-gestational age - AGA appropriate-for-gestational age - UCHT University Central Hospital of Turku - RDS respiratory distress syndrome     

Energy substrate production in infants born small for gestational age

AIM: To investigate energy substrate production and its hormonal regulation in infants born small for gestational age. METHODS: Eleven infants, aged 24.4 +/- 5.3 hour, were studied following a fast of 4.0 +/- 0.6 hour. Gestational age was 35.4 +/- 2.8 weeks and birth weight 1804 +/- 472 g (<-2 SD). Rates of glucose production and lipolysis were analyzed using [6,6-(2)H(2)]-glucose and [2-(13)C]-glycerol. RESULTS: Plasma levels of glucose and glycerol were 4.1 +/- 1.1 mmol x L(-1) and 224 +/- 79 micromol x L(-1), respectively. Glucose appearance averaged 30.3 +/- 8.2 and glucose production rate 21.1 +/- 6.1 micromol x kg(-1) x minutes(-1). Glycerol production rate was 5.6 +/- 1.6 micromol x kg(-1) x minutes(-1), correlating strongly to birth weight (r = 0.904, p < 0.001). Of the glycerol produced, 55 +/- 22% was converted to glucose, corresponding to 8 +/- 3% of the glucose production. CONCLUSIONS: Even though the infants could produce energy substrates, lipolysis was reduced and the glucose production was in the low end of the normal range compared with infants born appropriate for gestational age. The correlation between glycerol production and birth weight indicates that lipolysis depends on the amount of stored fat. Data on insulin and insulin-like growth factor binding protein 1 support the view that insulin sensitivity in these infants is reduced in the liver but increased peripherally.     

Skin conductance measurements as pain assessment in newborn infants born at 22-27 weeks gestational age at different postnatal age

Background

To assess pain or stress in newborn infants submitted to intensive care is important but difficult, as different observational pain scales are not always reliable in premature infants. As an indicator of pain, skin conductance (SC) measurements have detected increased sweating in newborn infants > 28 gestational age (GA) submitted to heel lancing.

Objective

To measure SC during heel lancing and routine care in newborn infants, born at 22 to 27 GA, with special relation to postnatal age (PNA).

Methods

In six infants < 28 + 0 GA and 4 infants ≥ 28 + 0 GA spontaneous SC activity and behavioural state (Neonatal Pain Agitation and Sedation Scale (N-PASS)) was measured before, during and after each intervention. Measurements were repeated in each patient at different PNA.

Results

Baseline SC prior to intervention took longer time to stabilise and was higher in < 28 than in ≥ 28 + 0 PNA. The combination of heel lancing and squeezing gave an increased SC in < 28 PNA, whereas heel lancing alone gave the same SC response in ≥ 28 + 0 PNA. A possibly continued immature response in SC measurements was not observed. Oral glucose admission prior to heel lancing increased SC. Routine care did not give any changes in SC. Except during orogastric tube placement no signs of discomfort or pain could be detected by the neonatal pain, agitation and sedation scale (N-PASS) in < 28 PNA.

Conclusion

Changes in SC could be detected in infants at < 28 + 0 PNA and related to the combination of heel lancing and squeezing. A maturational development of the SC was observed in infants born < 28 GA. SC seems to be able to differentiate between pain and discomfort.     

Neonatal weight loss and gain patterns in caesarean section born infants: integrative systematic review

There is evidence that caesarean section delivery can impact on neonatal weight loss and weight gain patterns in the first 5 days of life. We conducted an integrative systematic review to examine the association of mode of delivery on early neonatal weight loss. Pubmed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Excerpta Medica dataBASE, and Medical Literature Analysis and Retrieval System Online were searched for relevant papers published before June 2019. Reference lists from the relevant papers were then backwards and forwards searched. As neonatal weight loss was reported in different formats, a meta‐analysis could not be carried out. Most studies did not distinguish between elective and emergency caesarean sections or instrumental and nonassisted vaginal deliveries. Seven papers were included. All papers except one found that caesarean section was associated with higher weight loss in the early days of life. Two papers presented data from studies on babies followed up to 1 month. One study found that on day 25, babies born by caesarean section had significantly higher weight gain than those born vaginally, while another found that by day 28, babies born vaginally gained more weight per day (11.9 g/kg/day) than those born by caesarean section (10.9 g/kg/day; p = .02). Overall, infants born by caesarean section lost more weight than those born vaginally, but due to the small number of studies included, more are needed to look at this difference and why it may occur. This discrepancy in weight between the two groups may be corrected over time, but future studies will need larger sample sizes and longer follow‐up periods to examine this.