Comparing regional infant death rates: the influence of preterm births <24 weeks of gestation

Effect of national guidance on survival for babies born at 22 weeks' gestation in England and Wales: population based cohort study

Objectives

To explore the effect of changes in national clinical recommendations in 2019 that extended provision of survival focused care to babies born at 22 weeks' gestation in England and Wales.

Design

Population based cohort study.

Setting

England and Wales, comprising routine data for births and hospital records.

Participants

Babies alive at the onset of care in labour at 22 weeks+0 days to 22 weeks+6 days and at 23 weeks+0 days to 24 weeks+6 days for comparison purposes between 1 January 2018 and 31 December 2021.

Main outcome measures

Percentage of babies given survival focused care (active respiratory support after birth), admitted to neonatal care, and surviving to discharge in 2018-19 and 2020-21.

Results

For the 1001 babies alive at the onset of labour at 22 weeks' gestation, a threefold increase was noted in: survival focused care provision from 11.3% to 38.4% (risk ratio 3.41 (95% confidence interval 2.61 to 4.45)); admissions to neonatal units from 7.4% to 28.1% (3.77 (2.70 to 5.27)), and survival to discharge from neonatal care from 2.5% to 8.2% (3.29 (1.78 to 6.09)). More babies of lower birth weight and early gestational age received survival focused care in 2020-21 than 2018-19 (46% to 64% at <500g weight; 19% to 31% at 22 weeks+0 days to 22 weeks+3 days).

Conclusions

A change in national guidance to recommend a risk based approach was associated with a threefold increase in 22 weeks' gestation babies receiving survival focused care. The number of babies being admitted to neonatal units and those surviving to discharge increased.

Estimated neonatal survival of very preterm births across the care pathway: a UK cohort 2016-2020

OBJECTIVE

Currently used estimates of survival are nearly 10 years old and relate to only those babies admitted for neonatal care. Due to ongoing improvements in neonatal care, here we update estimates of survival for singleton and multiple births at 22+0 to 31+6 weeks gestational age across the perinatal care pathway by gestational age and birth weight.

DESIGN

Retrospective analysis of routinely collected data.

SETTING

A national cohort from the UK and British Crown Dependencies.

PATIENTS

Babies born at 22+0 to 31+6 weeks gestational age from 1 January 2016 to 31 December 2020.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Survival to 28 days.

RESULTS

Estimates of neonatal survival are provided for babies: (1) alive at the onset of care during the birthing process (n=43 763); (2) babies where survival-focused care was initiated (n=42 004); and (3) babies admitted for neonatal care (n=41 158). We have produced easy-to-use survival charts for singleton and multiple births. Generally, survival increased with increasing gestational age at birth and with increasing birth weight. For all births with a birthweight over 1000 g, survival was 90% or higher at all three stages of care.

CONCLUSIONS

Survival estimates are a vital tool to support and supplement clinical judgement within perinatal care. These up-to-date, national estimates of survival to 28 days are provided based on three stages of the perinatal care pathway to support ongoing clinical care. These novel results are a key resource for policy and practice including counselling parents and informing care provision.

Recent historic increase of infant mortality in France: A time-series analysis, 2001 to 2019

Background

The infant mortality rate (IMR) serves as a key indicator of population health.

Methods

We used data from the French National Institute of Statistics and Economic Studies on births and deaths during the first year of life from 2001 to 2019 to calculate IMR aggregated by month. We ran joinpoint regressions to identify inflection points and assess the linear trend of each segment. Exploratory analyses were performed for overall IMR, as well as by age at death subgroups (early neonatal [D0-D6], late neonatal [D7-27], and post-neonatal [D28-364]), and by sex. We performed sensitivity analyses by excluding deaths at D0 and using other time-series modeling strategies.

Results

Over the 19-year study period, 53,077 infant deaths occurred, for an average IMR of 3·63/1000 (4·00 in male, 3·25 in female); 24·4% of these deaths occurred during the first day of life and 47·8% during the early neonatal period. Joinpoint analysis identified two inflection points in 2005 and 2012. The IMR decreased sharply from 2001 to 2005 (slope: -0·0167 deaths/1000 live births/month; 95%CI: -0·0219 to -0·0116) and then decreased slowly between 2005 and 2012 (slope: -0·0041; 95%CI: -0·0065 to -0·0016). From 2012 onwards, a significant increase in IMR was observed (slope: 0·0033; 95%CI: 0·0011 to 0·0056). Subgroup analyses indicated that these trends were driven notably by an increase in the early neonatal period. Sensitivity analyses provided consistent results.

Interpretation

The recent historic increase in IMR since 2012 in France should prompt urgent in-depth investigation to understand the causes and prepare corrective actions.

Funding

No financial relationships with any organizations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work.

Are infant mortality rates increasing in England? The effect of extreme prematurity and early neonatal deaths

BACKGROUND

Infant mortality has been rising in England since 2014. We examined potential drivers of these trends.

METHODS

We used aggregate data on all live births, stillbirths and linked infant deaths in England in 2006-2016 from the Office for National Statistics. We compared trends in infant mortality rates overall, excluding births at <24 weeks of gestation, by quintile of SES and gestational age.

RESULTS

Infant mortality decreased from 4.78 deaths/1000 live births in 2006 to 3.54/1000 in 2014 (annual decrease of 0.15/1000) and increased to 3.67/1000 in 2016 (annual increase of 0.07/1000). This rise was driven by increases in deaths at 0-6 days of life. After excluding infants born at <24 weeks of gestation, infant mortality continued to decrease after 2014. The risk of infant death was 94% higher in the most versus least deprived SES quintile, which reduced to a 55% higher risk after adjusting for gestational age.

CONCLUSIONS

The observed increase in infant mortality rates since 2014 is wholly explained by an increasing number of deaths at 0-6 days of age among babies born at <24 weeks of gestation. Policies focused on improving maternal health to reduce preterm birth could substantially reduce the socio-economic gap in infant survival.

[Epidemiological difference could explain the higher infant mortality in Chile compared with Cuba]

INTRODUCTION

Cuba has the lowest infant mortality rate in Latin America, while Chile has an infant mortality rate above the average of Organization for Economic Cooperation and Development (OECD) countries.

OBJECTIVE

To compare the epidemiology of infant mortality between Chile and Cuba in order to find characteristics that may explain the differences found.

METHOD

Comparative analysis between Chile and Cuba of infant mortality rate, causes of mortality, live birth weight, and maternal age, in 2015.

RESULTS

Cuba had a lower infant, neonatal, early and late mortality than Chile, with no differences in post-neonatal mortality. Chile had a higher infant mortality due to, alterations of the nervous system, urinary system, chromosomal alterations, respiratory distress syndrome, and disorders related to the short duration of gestation. Chile had a higher frequency of mothers ≥ 35 years old and live births weighing <2,500 g. The possible effects of health inequities could not be analyzed due to lack of data.

CONCLUSIONS

It is possible to attribute the lower infant mortality rate in Cuba to: selective abortion due to congenital malformations and chromosomal anomalies, lower epidemiological risk of the Cuban pregnant population, and lower frequency of live births with low birth weight.

Ethnic and socioeconomic variation in cause-specific preterm infant mortality by gestational age at birth: national cohort study

OBJECTIVE

To describe ethnic and socioeconomic variation in cause-specific infant mortality of preterm babies by gestational age at birth.

DESIGN

National birth cohort study.

SETTING

England and Wales 2006-2012.

SUBJECTS

Singleton live births at 24-36 completed weeks' gestation (n=256 142).

OUTCOME MEASURES

Adjusted rate ratios for death in infancy by cause (three groups), within categories of gestational age at birth (24-27, 28-31, 32-36 weeks), by baby's ethnicity (nine groups) or area deprivation score (Index of Multiple Deprivation quintiles).

RESULTS

Among 24-27 week births (5% of subjects; 47% of those who died in infancy), all minority ethnic groups had lower risk of immaturity-related death than White British, the lowest rate ratios being 0.63 (95% CI 0.49 to 0.80) for Black Caribbean, 0.74 (0.64 to 0.85) for Black African and 0.75 (0.60 to 0.94) for Indian. Among 32-36 week births, all minority groups had higher risk of death from congenital anomalies than White British, the highest rate ratios being 4.50 (3.78 to 5.37) for Pakistani, 2.89 (2.10 to 3.97) for Bangladeshi and 2.06 (1.59 to 2.68) for Black African; risks of death from congenital anomalies and combined rarer causes (infection, intrapartum conditions, SIDS and unclassified) increased with deprivation, the rate ratios comparing the most with the least deprived quintile being, respectively, 1.54 (1.22 to 1.93) and 2.05 (1.55 to 2.72). There was no evidence of socioeconomic variation in deaths from immaturity-related conditions.

CONCLUSIONS

Gestation-specific preterm infant mortality shows contrasting ethnic patterns of death from immaturity-related conditions in extremely-preterm babies, and congenital anomalies in moderate/late-preterm babies. Socioeconomic variation derives from congenital anomalies and rarer causes in moderate/late-preterm babies. Future research should examine biological origins of extremely preterm birth.

Assessing the deprivation gap in stillbirths and neonatal deaths by cause of death: a national population-based study

OBJECTIVE

To investigate socioeconomic inequalities in cause-specific stillbirth and neonatal mortality to identify key areas of focus for future intervention strategies to achieve government ambitions to reduce mortality rates.

DESIGN

Retrospective cohort study.

SETTING

England, Wales, Scotland and the UK Crown Dependencies.

PARTICIPANTS

All singleton births between 1 January 2014 and 31 December 2015 at ≥24 weeks' gestation.

MAIN OUTCOME MEASURE

Cause-specific stillbirth or neonatal death (0-27 days after birth) per 10 000 births by deprivation quintile.

RESULTS

Data on 5694 stillbirths (38.1 per 10 000 total births) and 2368 neonatal deaths (15.9 per 10 000 live births) were obtained from Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK (MBRRACE-UK). Women from the most deprived areas were 1.68 (95% CI 1.56 to 1.81) times more likely to experience a stillbirth and 1.67 (95% CI 1.48 to 1.87) times more likely to experience a neonatal death than those from the least deprived areas, equating to an excess of 690 stillbirths and 231 neonatal deaths per year associated with deprivation. Small for gestational age (SGA) unexplained antepartum stillbirth was the greatest contributor to excess stillbirths accounting for 33% of the deprivation gap in stillbirths. Congenital anomalies accounted for the majority (59%) of the deprivation gap in neonatal deaths, followed by preterm birth not SGA (24-27 weeks, 27%).

CONCLUSIONS

Cause-specific mortality rates at a national level allow identification of key areas of focus for future intervention strategies to reduce mortality. Despite a reduction in the deprivation gap for stillbirths and neonatal deaths, public health interventions should primarily focus on socioeconomic determinants of SGA stillbirth and congenital anomalies.

Outcomes of Extremely Preterm Infants With Birth Weight Less Than 400 g

IMPORTANCE

Birth weight (BW) is an important predictor of mortality and morbidity. At extremely early gestational ages (GAs), BW may influence decisions regarding initiation of resuscitation.

OBJECTIVE

To characterize outcomes of liveborn infants with a BW less than 400 g.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective multicenter cohort study analyzed extremely preterm infants born between January 2008 and December 2016 within the National Institute of Child Health and Human Development Neonatal Research Network. Infants with a BW less than 400 g and a GA of 22 to 26 weeks were included. Active treatment was defined as the provision of any potentially lifesaving intervention after birth. Survival was analyzed for the entire cohort; neurodevelopmental impairment (NDI) was examined for those born between January 2008 and December 2015 (birth years with outcomes available for analysis). Neurodevelopmental impairment at 18 to 26 months' corrected age (CA) was defined as a Bayley Scales of Infant and Toddler Development, Third Edition, cognitive composite score less than 85, a motor composite score less than 85, moderate or severe cerebral palsy, gross motor function classification system score of 2 or greater, bilateral blindness, and/or hearing impairment. Data were analyzed from September 2017 to October 2018.

EXPOSURES

Birth weight less than 400 g.

MAIN OUTCOMES AND MEASURES

The primary outcome was survival to discharge among infants who received active treatment. Analysis of follow-up data was limited to infants born from 2008 to 2015 to ensure children had reached assessment age. Within this cohort, neurodevelopmental outcomes were assessed for infants who survived to 18 to 26 months' CA and returned for a comprehensive visit.

RESULTS

Of the 205 included infants, 121 (59.0%) were female, 133 (64.9%) were singletons, and 178 (86.8%) were small for gestational age. Almost half (101 of 205 [49.3%]) received active treatment at birth. A total of 26 of 205 infants (12.7%; 95% CI, 8.5-18.9) overall survived to discharge, and 26 of 101 actively treated infants (25.7%; 95% CI, 17.6-35.4) survived to discharge. Within the subset of infants with a BW less than 400 g and a GA of 22 to 23 weeks, 6 of 36 actively treated infants (17%; 95% CI, 6-33) survived to discharge. Among infants born between 2008 and 2015, 23 of 90 actively treated infants (26%; 95% CI, 17-36) survived to discharge. Two infants died after discharge, and 2 were lost to follow-up. Thus, 19 of 90 actively treated infants (21%; 95% CI, 13-31) were evaluated at 18 to 26 months' CA. Moderate or severe NDI occurred in 14 of 19 infants (74%).

CONCLUSIONS AND RELEVANCE

Infants born with a BW less than 400 g are at high risk of mortality and significant morbidity. Although 21% of infants survived to 18 to 26 months' CA with active treatment, NDI was common among survivors.

Estimating neonatal length of stay for babies born very preterm

OBJECTIVE

To predict length of stay in neonatal care for all admissions of very preterm singleton babies.

SETTING

All neonatal units in England.

PATIENTS

Singleton babies born at 24-31 weeks gestational age from 2011 to 2014. Data were extracted from the National Neonatal Research Database.

METHODS

Competing risks methods were used to investigate the competing outcomes of death in neonatal care or discharge from the neonatal unit. The occurrence of one event prevents the other from occurring. This approach can be used to estimate the percentage of babies alive, or who have been discharged, over time.

RESULTS

A total of 20 571 very preterm babies were included. In the competing risks model, gestational age was adjusted for as a time-varying covariate, allowing the difference between weeks of gestational age to vary over time. The predicted percentage of death or discharge from the neonatal unit were estimated and presented graphically by week of gestational age. From these percentages, estimates of length of stay are provided as the number of days following birth and corrected gestational age at discharge.

CONCLUSIONS

These results can be used in the counselling of parents about length of stay and the risk of mortality.

Comparing regional neonatal mortality rates: the influence of registration of births as live born for birth weight <500 g in Taiwan

OBJECTIVE

To investigate regional variation in the registration of births (still+live) as live born for birth weight <500 g and the impact on the city/county ranking of neonatal mortality rate (NMR) in Taiwan.

DESIGN

Population-based cross-sectional ecological study.

SETTING

20 cities/counties in Taiwan.

PARTICIPANTS

Registered births for birth weight <500 g and neonatal deaths in 2015-2016.

MAIN OUTCOME MEASURES

City/county percentage of births <500 g registered as live born and ranking of city/county NMR (deaths per 1000 live births) including and excluding live births <500 g.

RESULTS

The percentage of births <500 g registered as live born ranged from 0% in Keelung City (0/26) and Penghu County (0/4) to 20% in Taipei City (112/558), 24% in Hsinchu County (5/21) and 28% in Hualien County (9/32). The change in city/county ranking of NMR from including to excluding live births <500 g was most prominent in Taipei City (from the 15th to the 1st) followed by Kaohsiung City (from the 18th to the 14th).

CONCLUSIONS

The city/county NMR in Taiwan is influenced by variation in the registration of live born for births with uncertain viability. We recommend presenting city/county NMR using both criteria (with or without minimum threshold of gestation period or birth weight) for better interpretation of the findings of comparisons of city/county NMR.

Quantifying the burden of stillbirths before 28 weeks of completed gestational age in high-income countries: a population-based study of 19 European countries

BACKGROUND

International comparisons of stillbirth allow assessment of variations in clinical practice to reduce mortality. Currently, such comparisons include only stillbirths from 28 or more completed weeks of gestational age, which underestimates the true burden of stillbirth. With increased registration of early stillbirths in high-income countries, we assessed the reliability of including stillbirths before 28 completed weeks in such comparisons.

METHODS

In this population-based study, we used national cohort data from 19 European countries participating in the Euro-Peristat project on livebirths and stillbirths from 22 completed weeks of gestation in 2004, 2010, and 2015. We excluded countries without national data for stillbirths by gestational age in these periods, or where data available were not comparable between 2004 and 2015. We also excluded those countries with fewer than 10 000 births per year because the proportion of stillbirths at 22 weeks to less than 28 weeks of gestation is small. We calculated pooled stillbirth rates using a random-effects model and changes in rates between 2004 and 2015 using risk ratios (RR) by gestational age and country.

FINDINGS

Stillbirths at 22 weeks to less than 28 weeks of gestation accounted for 32% of all stillbirths in 2015. The pooled stillbirth rate at 24 weeks to less than 28 weeks declined from 0·97 to 0·70 per 1000 births from 2004 to 2015, a reduction of 25% (RR 0·75, 95% CI 0·65-0·85). The pooled stillbirth rate at 22 weeks to less than 24 weeks of gestation in 2015 was 0·53 per 1000 births and did not significantly changed over time (RR 0·97, 95% CI 0·80-1·16) although changes varied widely between countries (RRs 0·62-2·09). Wide variation in the percentage of all births occurring at 22 weeks to less than 24 weeks of gestation suggest international differences in ascertainment.

INTERPRETATION

Present definitions used for international comparisons exclude a third of stillbirths. International consistency of reporting stillbirths at 24 weeks to less than 28 weeks suggests these deaths should be included in routinely reported comparisons. This addition would have a major impact, acknowledging the burden of perinatal death to families, and making international assessments more informative for clinical practice and policy. Ascertainment of fetal deaths at 22 weeks to less than 24 weeks should be stabilised so that all stillbirths from 22 completed weeks of gestation onwards can be reliably compared.

FUNDING

EU Union under the framework of the Health Programme and the Bridge Health Project.

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.

Survival of very preterm infants admitted to neonatal care in England 2008-2014: time trends and regional variation

OBJECTIVE

To analyse survival trends and regional variation for very preterm infants admitted to neonatal care.

SETTING

All neonatal units in England.

PATIENTS

Infants born at 22⁺⁰-31⁺⁶ weeks^+daysgestational age (GA) over 2008-2014 and admitted to neonatal care; published data for admitted infants 22⁺⁰-25⁺⁶ weeks^+days GA in 1995 and 2006, and for live births at 22⁺⁰-31⁺⁶ weeks^+days GA in 2013.

METHODS

We obtained data from the National Neonatal Research Database. We used logistic regression to model survival probability with birth weight, GA, sex, antenatal steroid exposure and multiple birth included in the risk adjustment model and calculated annualpercentage change (APC) for trends using joinpoint regression. We evaluated survival over a 20-year period for infants <26 weeks' GA using additional published data from the EPICure studies.

RESULTS

We identified 50 112 eligible infants. There was an increase in survival over 2008-2014 (2008: 88.0%; 2014: 91.3%; adjusted APC 0.46% (95% CI 0.30 to 0.62) p<0.001). The greatest improvement was at 22⁺⁰-23⁺⁶ weeks (APC 6.03% (95% CI 2.47 to 3.53) p=0.002). Improvement largely occurred in London and South of England (APC: London 1.26% (95% CI 0.60 to 1.96); South of England 1.09% (95% CI 0.36 to 1.82); Midlands and East of England 0.15% (95% CI -0.56 to 0.86); and North of England 0.26% (95% CI -0.54 to 1.07)). Survival at the earliest gestations improved at a similar rate over 1995-2014 (22⁺⁰-25⁺⁶ weeks, APC 2.73% (95% CI 2.35 to 3.12), p value for change=0.25).

CONCLUSIONS

Continued national improvement in the survival of very preterm admissions masks important regional variation. Timely assessment of preterm survival is feasible using electronic records.

Survival of Infants Born at Periviable Gestational Ages

Periviable births are those occurring from 20 0/7 through 25 6/7 weeks of gestation. Among and within developed nations, significant variation exists in the approach to obstetric and neonatal care for periviable birth. Understanding gestational age-specific survival, including factors that may influence survival estimates and how these estimates have changed over time, may guide approaches to the care of periviable births and inform conversations with families and caregivers. This review provides a historical perspective on survival following periviable birth, summarizes recent and new data on gestational age-specific survival rates, and addresses factors that have a significant impact on survival.

Variability in Very Preterm Stillbirth and In-Hospital Mortality Across Europe

BACKGROUND AND OBJECTIVE

Stillbirth and in-hospital mortality rates associated with very preterm births (VPT) vary widely across Europe. International comparisons are complicated by a lack of standardized data collection and differences in definitions, registration, and reporting. This study aims to determine what proportion of the variation in stillbirth and in-hospital VPT mortality rates persists after adjusting for population demographics, case-mix, and timing of death.

METHODS

Standardized data collection for a geographically defined prospective cohort of VPTs (22⁺⁰-31⁺⁶ weeks gestation) across 16 regions in Europe. Crude and adjusted stillbirth and in-hospital mortality rates for VPT infants were calculated by time of death by using multinomial logistic regression models.

RESULTS

The stillbirth and in-hospital mortality rate for VPTs was 27.7% (range, 19.9%-35.9% by region). Adjusting for maternal and pregnancy characteristics had little impact on the variation. The addition of infant characteristics reduced the variation of mortality rates by approximately one-fifth (4.8% to 3.9%). The SD for deaths <12 hours after birth was reduced by one-quarter, but did not change after risk adjustment for deaths ≥12 hours after birth.

CONCLUSIONS

In terms of the regional variation in overall VPT mortality, over four-fifths of the variation could not be accounted for by maternal, pregnancy, and infant characteristics. Investigation of the timing of death showed that these characteristics only accounted for a small proportion of the variation in VPT deaths. These findings suggest that there may be an inequity in the quality of care provision and treatment of VPT infants across Europe.

Outcomes of infants born at 22-27 weeks' gestation in Victoria according to outborn/inborn birth status

OBJECTIVES

To compare mortality and serious morbidity rates between outborn and inborn livebirths at 22-27 weeks' gestation.

DESIGN

Population-based cohort study.

SETTING

Victoria, Australia.

PATIENTS

Livebirths at 22-27 weeks' gestation free of major malformations in 2010-2011.

INTERVENTIONS

Outcome data for outborn (born outside a tertiary perinatal centre) infants compared with inborn (born in a tertiary perinatal centre) infants were analysed by logistic regression, adjusted for gestational age, birth weight and sex.

MAIN OUTCOME MEASURES

Infant mortality and serious morbidity rates to hospital discharge.

RESULTS

541 livebirths free of major malformations were recorded. By 1 year, 49 (58%) outborns and 140 (31%) inborns died (adjusted OR (aOR) 2.78, 95% CI 1.52 to 5.09, p=0.001). In total, 445 infants were admitted to neonatal intensive care unit (NICU); 93 died by 1 year (14/49 outborns and 79/396 inborns), (aOR 1.75, 95% CI 0.87 to 3.55, p=0.12). There were no significant differences in rates of necrotising enterocolitis, intraventricular haemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia (BPD) or the combined outcome of death or BPD in outborn infants compared with inborn infants. Outborns had an increased risk of cystic periventricular leukomalacia (cPVL) compared with inborns (12.2% vs 2.8%, respectively; aOR 5.34, 95% CI 1.84 to 15.54, p=0.002).

CONCLUSIONS

Mortality rates remained higher for outborn livebirths at 22-27 weeks' gestation compared with inborn peers in 2010-2011. Outborn infants admitted to NICU did not have substantially different rates of mortality or serious morbidity compared with inborns, with the exception of cPVL. Longer-term health consequences of outborn birth before 28 weeks' gestation need to be determined.

Modelling Neonatal Care Pathways for Babies Born Preterm: An Application of Multistate Modelling

Modelling length of stay in neonatal care is vital to inform service planning and the counselling of parents. Preterm babies, at the highest risk of mortality, can have long stays in neonatal care and require high resource use. Previous work has incorporated babies that die into length of stay estimates, but this still overlooks the levels of care required during their stay. This work incorporates all babies, and the levels of care they require, into length of stay estimates. Data were obtained from the National Neonatal Research Database for singleton babies born at 24–31 weeks gestational age discharged from a neonatal unit in England from 2011 to 2014. A Cox multistate model, adjusted for gestational age, was used to consider a baby’s two competing outcomes: death or discharge from neonatal care, whilst also considering the different levels of care required: intensive care; high dependency care and special care. The probabilities of receiving each of the levels of care, or having died or been discharged from neonatal care are presented graphically overall and adjusted for gestational age. Stacked predicted probabilities produced for each week of gestational age provide a useful tool for clinicians when counselling parents about length of stay and for commissioners when considering allocation of resources. Multistate modelling provides a useful method for describing the entire neonatal care pathway, where rates of in-unit mortality can be high. For a healthcare service focussed on costs, it is important to consider all babies that contribute towards workload, and the levels of care they require.

Variations in very preterm birth rates in 30 high-income countries: are valid international comparisons possible using routine data?

OBJECTIVE

Concerns about differences in registration practices across countries have limited the use of routine data for international very preterm birth (VPT) rate comparisons.

DESIGN

Population-based study.

SETTING

Twenty-seven European countries, the United States, Canada and Japan in 2010.

POPULATION

A total of 9 376 252 singleton births.

METHOD

We requested aggregated gestational age data on live births, stillbirths and terminations of pregnancy (TOP) before 32 weeks of gestation, and information on registration practices for these births. We compared VPT rates and assessed the impact of births at 22-23 weeks of gestation, and different criteria for inclusion of stillbirths and TOP on country rates and rankings.

MAIN OUTCOME MEASURES

Singleton very preterm birth rate, defined as singleton stillbirths and live births before 32 completed weeks of gestation per 1000 total births, excluding TOP if identifiable in the data source.

RESULTS

Rates varied from 5.7 to 15.7 per 1000 total births and 4.0 to 11.9 per 1000 live births. Country registration practices were related to percentage of births at 22-23 weeks of gestation (between 1% and 23% of very preterm births) and stillbirths (between 6% and 40% of very preterm births). After excluding births at 22-23 weeks, rate variations remained high and with a few exceptions, country rankings were unchanged.

CONCLUSIONS

International comparisons of very preterm birth rates using routine data should exclude births at 22-23 weeks of gestation and terminations of pregnancy. The persistent large rate variations after these exclusions warrant continued surveillance of VPT rates at 24 weeks and over in high-income countries.

TWEETABLE ABSTRACT

International comparisons of VPT rates should exclude births at 22-23 weeks of gestation and terminations of pregnancy.

Towards reducing variations in infant mortality and morbidity: a population-based approach

Background

Our aims were (1) to improve understanding of regional variation in early-life mortality rates and the UK’s poor performance in international comparisons; and (2) to identify the extent to which late and moderately preterm (LMPT) birth contributes to early childhood mortality and morbidity.

Objective

To undertake a programme of linked population-based research studies to work towards reducing variations in infant mortality and morbidity rates.

Design

Two interlinked streams: (1) a detailed analysis of national and regional data sets and (2) establishment of cohorts of LMPT babies and term-born control babies.

Setting

Cohorts were drawn from the geographically defined areas of Leicestershire and Nottinghamshire, and analyses were carried out at the University of Leicester.

Data sources

For stream 1, national data were obtained from four sources: the Office for National Statistics, NHS Numbers for Babies, Centre for Maternal and Child Enquiries and East Midlands and South Yorkshire Congenital Anomalies Register. For stream 2, prospective data were collected for 1130 LMPT babies and 1255 term-born control babies.

Main outcome measures

Detailed analysis of stillbirth and early childhood mortality rates with a particular focus on factors leading to biased or unfair comparison; review of clinical, health economic and developmental outcomes over the first 2 years of life for LMPT and term-born babies.

Results

The deprivation gap in neonatal mortality has widened over time, despite government efforts to reduce it. Stillbirth rates are twice as high in the most deprived as in the least deprived decile. Approximately 70% of all infant deaths are the result of either preterm birth or a major congenital abnormality, and these are heavily influenced by mothers’ exposure to deprivation. Births at < 24 weeks’ gestation constitute only 1% of all births, but account for 20% of infant mortality. Classification of birth status for these babies varies widely across England. Risk of LMPT birth is greatest in the most deprived groups within society. Compared with term-born peers, LMPT babies are at an increased risk of neonatal morbidity, neonatal unit admission and poorer long-term health and developmental outcomes. Cognitive and socioemotional development problems confer the greatest long-term burden, with the risk being amplified by socioeconomic factors. During the first 24 months of life each child born LMPT generates approximately £3500 of additional health and societal costs.

Conclusions

Health professionals should be cautious in reviewing unadjusted early-life mortality rates, particularly when these relate to individual trusts. When more sophisticated analysis is not possible, babies of < 24 weeks’ gestation should be excluded. Neonatal services should review the care they offer to babies born LMPT to ensure that it is appropriate to their needs. The risk of adverse outcome is low in LMPT children. However, the risk appears higher for some types of antenatal problems and when the mother is from a deprived background.

Future work

Future work could include studies to improve our understanding of how deprivation increases the risk of mortality and morbidity in early life and investigation of longer-term outcomes and interventions in at-risk LMPT infants to improve future attainment.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Experiences with maternal and perinatal death reviews in the UK--the MBRRACE-UK programme

Established in 1952, the programme of surveillance and Confidential Enquiries into Maternal Deaths in the UK is the longest running such programme worldwide. Although more recently instituted, surveillance and confidential enquiries into perinatal deaths are also now well established nationally. Recent changes to funding and commissioning of the Enquiries have enabled both a reinvigoration of the processes and improvements to the methodology with an increased frequency of future reporting. Close engagement with stakeholders and a regulator requirement for doctors to participate have both supported the impetus for involvement of all professionals leading to greater potential for improved quality of care for women and babies.

Neonatal quality measures: time to show developmental progress?

Healthcare improvement is synonymous with quality measurement and involves assessing how well care is delivered and the results achieved in comparison with a desired standard or standards. Quality measurement has become part of routine healthcare in the developed world as a means of detecting inadequate quality performance which, if not dealt with promptly, can have far-reaching consequences as seen in recent well publicised UK examples. The growth in the use of quality measurement has led to increasing attention on the processes and measures employed--in particular how measures are chosen, reported and used. This has included consideration of the attributes that make a good quality measure using testing protocols to ensure that any potential measure is fit for purpose and using summative reporting frameworks. All of these tools are already used in some specialties outside neonatal care. This article explores this wider experience and considers how the lessons learnt might helpfully be applied to neonatal care.

Variation in classification of live birth with newborn period death versus fetal death at the local level may impact reported infant mortality rate

BACKGROUND

To better understand factors that may impact infant mortality rates (IMR), we evaluated the consistency across birth hospitals in the classification of a birth event as either a fetal death or an early neonatal (infant) death using natality data from North Carolina for the years 1995-2000.

METHODS

A database consisting of fetal deaths and infant deaths occurring within the first 24 hours after birth was constructed. Bivariate, followed by multivariable regression, analyses were used to control for relevant maternal and infant factors. Based upon hospital variances, adjustments were made to evaluate the impact of the classification on statewide infant mortality rate.

RESULTS

After controlling for multiple maternal and infant factors, birth hospital remained a factor related to the classification of early neonatal versus fetal death. Reporting of early neonatal deaths versus fetal deaths consistent with the lowest or highest hospital strata would have resulted in an adjusted IMR varying from 7.5 to 10.64 compared with the actual rate of 8.95.

CONCLUSIONS

Valid comparisons of IMR among geographic regions within and between countries require consistent classification of perinatal deaths. This study demonstrates that local variation in categorization of death events as fetal death versus neonatal death within the first 24 hours after delivery may impact a state-level IMR in a meaningful magnitude. The potential impact of this issue on IMRs should be examined in other state and national populations.

Long-term outcome for the tiniest or most immature babies: survival rates

This article focuses on the survival rates of the most immature babies considered viable from around the world. It discusses the various factors in terms of definition, inclusion criteria and policy which can result in marked differences in the apparent rates of delivery (all births), live birth, admission to neonatal intensive care and ultimately survival seen between otherwise similar countries, different regions of the same country, and even adjacent hospitals. Such variation in approach can result in major differences in reported survival and consequentially have large effects on apparent rates of adverse long-term outcome.

Prospective risk factor monitoring reduces intracranial hemorrhage rates in preterm infants

BACKGROUND

Intracranial hemorrhage occurs in 20% to 25% of neonates born before the 30th week of gestation or weighing less than 1500 grams at birth. These hemorrhages carry a risk of long-term neurocognitive damage. Measures for lowering the incidence of intracranial hemorrhage were evaluated.

METHODS

A working group at the University of Ulm, Germany, developed a prospective monitoring program for risk factors and a bundle of measures including altered clinical approaches to delivery, initial care of the neonate in the delivery room immediately after birth, and intensive care in the first few days thereafter. Adherence to these measures was checked once per week. The evaluation was performed prospectively for a period of 23 months (August 2010 to July 2012) with a 31-month period of historical controls (January 2008 to July 2010).

RESULTS

In the reference period before the intervention was introduced, 263 neonates weighing less than 1500 grams and with a median (quartile) gestational age at birth of 27.4 (25.4-29.9) weeks were treated. The incidence of intracranial hemorrhage was 22.1%, and that of high-grade hemorrhage was 9.1%. The mortality was 6.1%, and the rate of survival without brain hemorrhage was 74.5%. After the bundle of preventive measures was introduced, 191 neonates weighing less than 1500 grams and with a median (quartile) gestational age at birth of 28.0 (26.0, 30.3) weeks were treated. The incidence of intracranial hemorrhage dropped to 10.5% (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.25-0.73); the incidence of high-grade hemorrhage dropped to 3.7% (OR 0.36; 95% CI 0.14-0.89). The mortality was no different at 6.3%, and 85.3% of the children survived without a hemorrhage (OR 1.95, 95% CI 1.20-3.15). After statistical adjustment for higher gestational age, the OR for intracranial hemorrhage (IVH) was 0.49 (0.28-0.86) and the probability of survival without IVH improved (OR 1.68, 95% CI 1.01-2.81).

CONCLUSION

The rate of brain hemorrhage in premature neonates can be considerably lowered by prospective monitoring of risk factors.

Modelling time to death or discharge in neonatal care: an application of competing risks

BACKGROUND

Understanding length of stay for babies in neonatal care is vital for planning services and for counselling parents. While previous work has focused on the length of stay of babies who survive to discharge, when investigating resource use within neonatal care, it is important to also incorporate information on those babies who die while in care. We present an analysis using competing risks methodology which allows the simultaneous modelling of babies who die in neonatal care and those who survive to discharge.

METHODS

Data were obtained on 2723 babies born at 24-28 weeks gestational age in 2006-10 and admitted to neonatal care. Death and discharge alive are two mutually exclusive events and can be treated as competing risks. A flexible parametric modelling approach was used to analyse these two competing events and obtain estimates of the absolute probabilities of death or discharge.

RESULTS

The absolute probabilities of death or discharge are presented in graphical form showing the cause-specific cumulative incidence over time by gender, gestational age and birthweight. The discharge of babies alive generally occurred over a longer time period for babies of lower gestational age and smaller birthweight than for bigger babies.

CONCLUSION

This study has presented a useful statistical method for modelling the length of stay where there are significant rates of in-unit mortality. In health care systems that are increasingly focusing on costs and resource planning, it is essential to consider not only length of stay of survivors but also for those patients who die before discharge.