One-year survival and outcomes of infants born at 22 and 23 weeks of gestation in Sweden 2004-2007, 2014-2016 and 2017-2019

OBJECTIVE

To explore associations between perinatal activity and survival in infants born at 22 and 23 weeks of gestation in Sweden.

DESIGN/SETTING

Data on all births at 22 and 23 weeks' gestational age (GA) were prospectively collected in 2004-2007 (T1) or obtained from national registers in 2014-2016 (T2) and 2017-2019 (T3). Infants were assigned perinatal activity scores based on 3 key obstetric and 4 neonatal interventions.

MAIN OUTCOME

One-year survival and survival without major neonatal morbidities (MNM): intraventricular haemorrhage grade 3-4, cystic periventricular leucomalacia, surgical necrotising enterocolitis, retinopathy of prematurity stage 3-5 or severe bronchopulmonary dysplasia. The association of GA-specific perinatal activity score and 1-year survival was also determined.

RESULTS

977 infants (567 live births and 410 stillbirths) were included: 323 born in T1, 347 in T2 and 307 in T3. Among live-born infants, survival at 22 weeks was 5/49 (10%) in T1 and rose significantly to 29/74 (39%) in T2 and 31/80 (39%) in T3. Survival was not significantly different between epochs at 23 weeks (53%, 61% and 67%). Among survivors, the proportions without MNM in T1, T2 and T3 were 20%, 17% and 19% for 22 weeks and 17%, 25% and 25% for 23 weeks' infants (p>0.05 for all comparisons). Each 5-point increment in GA-specific perinatal activity score increased the odds for survival in first 12 hours of life (adjusted OR (aOR) 1.4; 95% CI 1.3 to 1.6) in addition to 1-year survival (aOR 1.2; 95% CI 1.1 to 1.3), and among live-born infants it was associated with increased survival without MNM (aOR 1.3; 95% CI 1.1 to 1.4).

CONCLUSION

Increased perinatal activity was associated with reduced mortality and increased chances of survival without MNM in infants born at 22 and 23 weeks of GA.

Trends, Characteristic, and Outcomes of Preterm Infants Who Received Postnatal Corticosteroid: A Cohort Study from 7 High-Income Countries

INTRODUCTION

Our objective was to evaluate the temporal trend of systemic postnatal steroid (PNS) receipt in infants of 24-28 weeks' gestational age, identify characteristics associated with PNS receipt, and correlate PNS receipt with the incidence of bronchopulmonary dysplasia (BPD) and BPD/death from an international cohort included in the iNeo network.

METHODS

We conducted a retrospective study using data from 2010 to 2018 from seven international networks participating in iNeo (Canada, Finland, Israel, Japan, Spain, Sweden, and Switzerland). Neonates of 24 and 28 weeks' gestational age who survived 7 days and who received PNS were included. We assessed temporal trend of rates of systemic PNS receipt and BPD/death.

RESULTS

A total of 47,401 neonates were included. The mean (SD) gestational age was 26.4 (1.3) weeks and birth weight was 915 (238) g. The PNS receipt rate was 21% (12-28% across networks) and increased over the years (18% in 2010 to 26% in 2018; p < 0.01). The BPD rate was 39% (28-44% across networks) and remained unchanged over the years (35.2% in 2010 to 35.0% in 2018). Lower gestation, male sex, small for gestational age status, and presence of persistent ductus arteriosus (PDA) were associated with higher rates of PNS receipt, BPD, and BPD/death.

CONCLUSION

The use of PNS in extremely preterm neonates increased, but there was no correlation between increased use and the BPD rate. Research is needed to determine the optimal timing, dose, and indication for PNS use in preterm neonates.

Five-minute Apgar score and outcomes in neonates of 24-28 weeks' gestation

OBJECTIVES

To assess associations between 5 min Apgar score and mortality and severe neurological injury (SNI) and to report test characteristics in preterm neonates.

DESIGN, SETTING AND PATIENTS

Retrospective cohort study of neonates 24⁰ to 28⁶ weeks' gestation born between 2007 and 2016 and admitted to neonatal units in 11 high-income countries.

EXPOSURE

5 min Apgar score.

MAIN OUTCOME MEASURES

In-hospital mortality and SNI defined as grade 3 or 4 periventricular/intraventricular haemorrhage or periventricular leukomalacia. Outcome rates were calculated for each Apgar score and compared after adjustment. The diagnostic characteristics and ORs for each value from 0 versus 1-10 to 0-9 versus 10, with 1-point increments were calculated.

RESULTS

Among 92 412 included neonates, as 5 min Apgar score increased from 0 to 10, mortality decreased from 60% to 8%. However, no clear increasing or decreasing pattern was identified for SNI. There was an increase in sensitivity and decrease in specificity for both mortality and SNI associated with increasing scores. The Apgar score alone had an area under the curve of 0.64 for predicting mortality, which increased to 0.73 with the addition of gestational age.

CONCLUSIONS

In neonates of 24-28 weeks' gestation admitted to neonatal units, higher 5 min Apgar score was associated with lower mortality in a graded manner, while the association with SNI remained relatively constant at all scores. Among survivors, low Apgar scores did not predict SNI.

Development and Validation of a Mortality Prediction Model in Extremely Low Gestational Age Neonates

INTRODUCTION

Understanding factors that associate with neonatal death may lead to strategies or interventions that can aid clinicians and inform families.

OBJECTIVE

The aim of the study was to develop an early prediction model of neonatal death in extremely low gestational age (ELGA, <28 weeks) neonates.

METHODS

A predictive cohort study of ELGA neonates was derived from the Swedish Neonatal Quality Register between the years 2011 to May 2021. The goal was to use readily available clinical variables, collected within the first hour of birth, to predict in-hospital death. Data were split into a train cohort (80%) to build the model and tested in 20% of randomly selected neonates. Model performance was assessed via area under the receiver operating characteristic curve (AUC) and compared to validated mortality prediction models and an external cohort of neonates.

RESULTS

Among 3,752 live-born extremely preterm infants (46% girls), in-hospital mortality was 18% (n = 685). The median gestational age and birth weight were 25.0 weeks (interquartile range [IQR] 24.0, 27.0) and 780 g (IQR 620, 940), respectively. The proposed model consisted of three variables: birth weight (grams), Apgar score at 5 min of age, and gestational age (weeks). The BAG model had an AUC of 76.9% with a 95% confidence interval (CI) (72.6%, 81.3%), while birth weight and gestational age had an AUC of 73.1% (95% CI: 68.4%,77.9%) and 71.3% (66.3%, 76.2%). In the validation cohort, the BAG model had an AUC of 68.9%.

CONCLUSION

The BAG model is a new mortality prediction model in ELGA neonates that was developed using readily available information.

Neonatal Intensive Care Unit-Level Patent Ductus Arteriosus Treatment Rates and Outcomes in Infants Born Extremely Preterm

OBJECTIVES

To assess associations between neonatal intensive care unit (NICU)-level patent ductus arteriosus (PDA) treatment rates (pharmacologic or surgical) and neonatal outcomes.

STUDY DESIGN

This cohort study included infants born at 24-28 weeks of gestation and birth weight <1500 g in 2007-2015 in NICUs caring for ≥100 eligible infants in 6 countries. The ratio of observed/expected (O/E) PDA treatment rates was derived for each NICU by estimating the expected rate using a logistic regression model adjusted for potential confounders and network. The primary composite outcome was death or severe neurologic injury (grades III-IV intraventricular hemorrhage or periventricular leukomalacia). The associations between the NICU-level O/E PDA treatment ratio and neonatal outcomes were assessed using linear regression analyses including a quadratic effect (a square term) of the O/E PDA treatment ratio.

RESULTS

From 139 NICUs, 39 096 infants were included. The overall PDA treatment rate was 45% in the cohort (13%-77% by NICU) and the O/E PDA treatment ratio ranged from 0.30 to 2.14. The relationship between the O/E PDA treatment ratio and primary composite outcome was U-shaped, with the nadir at a ratio of 1.13 and a significant quadratic effect (P<.001). U-shaped relationships were also identified with death, severe neurologic injury, and necrotizing enterocolitis.

CONCLUSIONS

Both low and high PDA treatment rates were associated with death or severe neurologic injury, whereas a moderate approach was associated with optimal outcomes.

Preventive strategies and factors associated with surgically treated necrotising enterocolitis in extremely preterm infants: an international unit survey linked with retrospective cohort data analysis

OBJECTIVES

To compare necrotising enterocolitis (NEC) prevention practices and NEC associated factors between units from eight countries of the International Network for Evaluation of Outcomes of Neonates, and to assess their association with surgical NEC rates.

DESIGN

Prospective unit-level survey combined with retrospective cohort study.

SETTING

Neonatal intensive care units in Australia/New Zealand, Canada, Finland, Israel, Spain, Sweden, Switzerland and Tuscany (Italy).

PATIENTS

Extremely preterm infants born between 24⁰ to 28⁶ weeks' gestation, with birth weights<1500 g, and admitted between 2014-2015.

EXPOSURES

NEC prevention practices (probiotics, feeding, donor milk) using responses of an on-line pre-piloted questionnaire containing 10 questions and factors associated with NEC in literature (antenatal steroids, c-section, indomethacin treated patent ductus arteriosus and sepsis) using cohort data.

OUTCOME MEASURES

Surgical NEC rates and death following NEC using cohort data.

RESULTS

The survey response rate was 91% (153 units). Both probiotic provision and donor milk availability varied between 0%-100% among networks whereas feeding initiation and advancement rates were similar in most networks. The 9792 infants included in the cohort study to link survey results and cohort outcomes, revealed similar baseline characteristics but considerable differences in factors associated with NEC between networks. 397 (4.1%) neonates underwent NEC surgery, ranging from 2.4%-8.4% between networks. Standardised ratios for surgical NEC were lower for Australia/New Zealand, higher for Spain, and comparable for the remaining six networks.

CONCLUSIONS

The variation in implementation of NEC prevention practices and in factors associated with NEC in literature could not be associated with the variation in surgical NEC incidence. This corroborates the current lack of consensus surrounding the use of preventive strategies for NEC and emphasises the need for research.

An International Comparison of Death Classification at 22 to 25 Weeks' Gestational Age

OBJECTIVES

To explore international differences in the classification of births at extremely low gestation and the subsequent impact on the calculation of survival rates.

METHODS

We used national data on births at 22 to 25 weeks' gestation from the United States (2014; n = 11 144), Canada (2009-2014; n = 5668), the United Kingdom (2014-2015; n = 2992), Norway (2010-2014; n = 409), Finland (2010-2015; n = 348), Sweden (2011-2014; n = 489), and Japan (2014-2015; n = 2288) to compare neonatal survival rates using different denominators: all births, births alive at the onset of labor, live births, live births surviving to 1 hour, and live births surviving to 24 hours.

RESULTS

For births at 22 weeks' gestation, neonatal survival rates for which we used live births as the denominator varied from 3.7% to 56.7% among the 7 countries. This variation decreased when the denominator was changed to include stillbirths (ie, all births [1.8%-22.3%] and fetuses alive at the onset of labor [3.7%-38.2%]) or exclude early deaths and limited to births surviving at least 12 hours (50.0%-77.8%). Similar trends were seen for infants born at 23 weeks' gestation. Variation diminished considerably at 24 and 25 weeks' gestation.

CONCLUSIONS

International variation in neonatal survival rates at 22 to 23 weeks' gestation diminished considerably when including stillbirths in the denominator, revealing the variation arises in part from differences in the proportion of births reported as live births, which itself is closely connected to the provision of active care.

Intrapartum GBS screening and antibiotic prophylaxis: a European consensus conference

Group B streptococcus (GBS) remains worldwide a leading cause of severe neonatal disease. Since the end of the 1990s, various strategies for prevention of the early onset neonatal disease have been implemented and have evolved. When a universal antenatal GBS screening-based strategy is used to identify women who are given an intrapartum antimicrobial prophylaxis, a substantial reduction of incidence up to 80% has been reported in the USA as in other countries including European countries. However recommendations are still a matter of debate due to challenges and controversies on how best to identify candidates for prophylaxis and to drawbacks of intrapartum administration of antibiotics. In Europe, some countries recommend either antenatal GBS screening or risk-based strategies, or any combination, and others do not have national or any other kind of guidelines for prevention of GBS perinatal disease. Furthermore, accurate population-based data of incidence of GBS neonatal disease are not available in some countries and hamper good effectiveness evaluation of prevention strategies. To facilitate a consensus towards European guidelines for the management of pregnant women in labor and during pregnancy for the prevention of GBS perinatal disease, a conference was organized in 2013 with a group of experts in neonatology, gynecology-obstetrics and clinical microbiology coming from European representative countries. The group reviewed available data, identified areas where results were suboptimal, where revised procedures and new technologies could improve current practices for prevention of perinatal GBS disease. The key decision issued after the conference is to recommend intrapartum antimicrobial prophylaxis based on a universal intrapartum GBS screening strategy using a rapid real time testing.

Monitoring of pain and stress in an infant with asphyxia during induced hypothermia: a case report

The purpose of this article was to study an infant who suffered from asphyxia undergoing induced hypothermia with regard to (1) describe the pain and stress as measured by physiological variables skin conductance algesimeter (SCA) and pain rating scales, (2) the correlation between SCA and pain rating scales, and (3) how temperature cycles in the cooling blanket affect the response of the sympathetic nervous system as measured by the SCA and physiological variables. A single prospective case study was used for this article. Data were recorded every 15 minutes for 96 hours. Each observation was categorized according to treatment phase: cooling 0 to 72 hours, rewarming, and controlled normal temperature up to 96 hours. Structured observations were carried out and all nursing care was documented. In addition, 5 periods with no other nursing interventions were identified in which data were recorded every minute for analysis. Skin conductance algimetry showed a variable response during treatment. During cooling, 68% of the 15-minute periods, signs of stress and pain were recorded. During rewarming, the corresponding figure was 83%. During the time sequences with normal temperature, 89% of the periods were associated with stress and pain. During 80% of the nursing procedures, the SCA showed stress and pain. There was no correlation between the pain-rating scales and SCA. When the cooling blanket temperature was lower than core temperature, the infant had more stress and pain according to SCA (P < .001) and an increase in heart rate and blood pressure (P < .001). In infants during induced hypothermia, SCA seem to detect pain and stress. Future evaluation of SCA for the detection of pain and stress during hypothermia treatment is necessary. Pain-rating scales do not appear reliable in this case report.

Short-term outcome after active perinatal management at 23-25 weeks of gestation. A study from two Swedish tertiary care centres. Part 1: maternal and obstetric factors

AIMS

To provide descriptive data on women who delivered at 23-25 wk of gestation, and to relate foetal and neonatal outcomes to maternal factors, obstetric management and the principal reasons for preterm birth.

METHODS

Medical records of all women who had delivered in two tertiary care centres in 1992-1998 were reviewed. At the two centres, policies of active perinatal and neonatal management were universally applied. Logistic regression models were used to identify prenatal factors associated with survival.

RESULTS

Of 197 women who delivered at 23-25 wk, 65% had experienced a previous miscarriage, 15% a previous stillbirth and 12% a neonatal death. The current pregnancy was the result of artificial reproduction in 13% of the women. In 71%, the pregnancy was complicated either by pre-eclampsia, chorioamnionitis, placental abruption or premature rupture of membranes. Antenatal steroids were given in 63%. Delivery was by caesarean section in 47%. The reasons for preterm birth were idiopathic preterm labour in 36%, premature rupture of membranes in 41% and physician-indicated deliveries in 23% of the mothers. Demographic details, use of antenatal steroids, caesarean section delivery and birthweight differed between mothers depending on the reason for preterm delivery. Of 224 infants, 5% were stillbirths and 63% survived to discharge. On multivariate logistic regression analysis comprising prenatally known variables, reasons for preterm birth were not associated with survival. Advanced gestational duration (OR: 2.43 per wk; 95% CI: 1.59-3.74), administration of any antenatal steroids (OR: 2.21; 95% Cl: 1.14-4.28) and intrauterine referral from a peripheral hospital (OR: 2.93; 95% CI: 1.5-5.73) were associated with survival.

CONCLUSIONS

Women who deliver at 23-25 wk comprise a risk group characterized by a high risk of reproductive failure and pregnancy complications. Survival rates were similar regardless of the reason for preterm birth. Policies of active perinatal management virtually eliminated intrapartum stillbirths.

Heparin binding by the HIV-1 tat protein transduction domain

The protein transduction domain from the HIV-1 tat protein (termed PTD-tat) has been fused to the C-terminus of a model cargo protein, the IgG binding domain of streptococcal protein G. We demonstrate that PG-Ctat (PTD-tat fused to the C-terminus of protein G) binds to a heparin affinity column. PG-Ctat binds with relatively high affinity, as shown by its elution at 1.6 M NaCl. The heparin binding properties of PTD-tat are consistent with the idea that heparan sulfate, an analog of heparin found at the cell surface, plays a role in the translocation of PTD-tat fusions. We suggest that the heparin-binding properties of PTD-tat can be exploited for purification of PTD-tat fusions in the absence of affinity tags.

Adherence and surface properties of buoyant density subpopulations of group B streptococci, type III

From clinical isolates of group B streptococci, buoyant density subpopulations with variable amounts of type-specific polysaccharide can be derived. The ability of these subpopulations to adhere to vaginal epithelial cells and to glass was assessed by using [3H]-labeled bacteria. Subpopulations with no or minute amounts of capsule showed good adherence capacity and a hydrophobic cell surface. In contrast, a large capsule made the bacteria less adherent and rendered their surface hydrophilic. A negative cell surface charge, judged by determination of the z-potential, was directly related to the amount of capsule. Proteinase K treatment of less encapsulated variants significantly decreased the cell hydrophobicity. The ability of a GBS strain to express different surface characteristics may be a mechanism for adaptation to environmental changes, and may thereby contribute to the pathogenicity of GBS.

Economic aspects of care of the elderly

The health care costs in the industrialized countries have increased continuously parallel to the aging of the population. There is however only a minor part of the cost increase that can be attributed to the changing age structure. Sweden, which at least till the year 2000 will have the world's oldest population, spends 30 billion Swedish Crowns (approx. 4 billion US $) on medical care and social services for the aged (65 years or older), which amounts to 5% of the GNP. Long-term estimates (year 2000) of the future age-standardized costs show that in Sweden health care and social services resources for the aged must increase at an average annual rate of 1.3% in order to maintain the same standard as in the beginning of the 1980s. The experience from studies in the municipalities of Sundsvall and Vetlanda in Sweden have demonstrated that many transfers to institutions have been 'unnecessary' i.e. could have been avoided through increased medical care and support efforts in the homes of the elderly. Results from the above municipalities show the potential savings which might be realized in the long run if care of the elderly will be more concentrated on home care rather than on institutional care. If Sundsvall and Vetlanda were representative of Sweden as a whole, the annual costs of care for the elderly could be decreased by between 1 and 2 billion Skr, which corresponds to 5-10% of the total costs.