Neonatal mortality in NHS maternity units by timing and mode of birth: a retrospective linked cohort study.

OBJECTIVES: To compare neonatal mortality in English hospitals by time of day and day of the week according to care pathway. DESIGN: Retrospective cohort linking birth registration, birth notification and hospital episode data. SETTING: National Health Service (NHS) hospitals in England. PARTICIPANTS: 6 054 536 liveborn singleton births from 2005 to 2014 in NHS maternity units in England. MAIN OUTCOME MEASURES: Neonatal mortality. RESULTS: After adjustment for confounders, there was no significant difference in the odds of neonatal mortality attributed to asphyxia, anoxia or trauma outside of working hours compared with working hours for spontaneous births or instrumental births. Stratification of emergency caesareans by onset of labour showed no difference in mortality by birth timing for emergency caesareans with spontaneous or induced onset of labour. Higher odds of neonatal mortality attributed to asphyxia, anoxia or trauma out of hours for emergency caesareans without labour translated to a small absolute difference in mortality risk. CONCLUSIONS: The apparent 'weekend effect' may result from deaths among the relatively small numbers of babies who were coded as born by emergency caesarean section without labour outside normal working hours. Further research should investigate the potential contribution of care-seeking and community-based factors as well as the adequacy of staffing for managing these relatively unusual emergencies.

Gestational age and hospital admission costs from birth to childhood: a population-based record linkage study in England.

OBJECTIVE: To examine the association between gestational age at birth and hospital admission costs from birth to 8 years of age. DESIGN: Population-based, record linkage, cohort study in England. SETTING: National Health Service (NHS) hospitals in England, UK. PARTICIPANTS: 1 018 136 live, singleton births in NHS hospitals in England between 1 January 2005 and 31 December 2006. MAIN OUTCOME MEASURES: Hospital admission costs from birth to age 8 years, estimated by gestational age at birth (<28, 28-29, 30-31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 and 42 weeks). RESULTS: Both birth admission and subsequent admission hospital costs decreased with increasing gestational age at birth. Differences in hospital admission costs between gestational age groups diminished with increasing age, particularly after the first 2 years following birth. Children born extremely preterm (<28 weeks) and very preterm (28-31 weeks) still had higher average hospital admission costs (£699 (95% CI £419 to £919) for <28 weeks; £434 (95% CI £305 to £563) for 28-31 weeks) during the eighth year of life compared with children born at 40 weeks (£109, 95% CI £104 to £114). Children born extremely preterm had the highest 8-year cumulative hospital admission costs per child (£80 559 (95% CI £79 238 to £82 019)), a large proportion of which was incurred during the first year after birth (£71 997 (95% CI £70 866 to £73 097)). CONCLUSIONS: The association between gestational age at birth and hospital admission costs persists into mid-childhood. The study results provide a useful costing resource for future economic evaluations focusing on preventive and treatment strategies for babies born preterm.

SARS-CoV-2 tests, confirmed infections and COVID-19-related hospital admissions in children and young people: birth cohort study.

BACKGROUND: There have been no population-based studies of SARS-CoV-2 testing, PCR-confirmed infections and COVID-19-related hospital admissions across the full paediatric age range. We examine the epidemiology of SARS-CoV-2 in children and young people (CYP) aged <23 years. METHODS: We used a birth cohort of all children born in Scotland since 1997, constructed via linkage between vital statistics, hospital records and SARS-CoV-2 surveillance data. We calculated risks of tests and PCR-confirmed infections per 1000 CYP-years between August and December 2020, and COVID-19-related hospital admissions per 100 000 CYP-years between February and December 2020. We used Poisson and Cox proportional hazards regression models to determine risk factors. RESULTS: Among the 1 226 855 CYP in the cohort, there were 378 402 tests (a rate of 770.8/1000 CYP-years (95% CI 768.4 to 773.3)), 19 005 PCR-confirmed infections (179.4/1000 CYP-years (176.9 to 182.0)) and 346 admissions (29.4/100 000 CYP-years (26.3 to 32.8)). Infants had the highest COVID-19-related admission rates. The presence of chronic conditions, particularly multiple types of conditions, was strongly associated with COVID-19-related admissions across all ages. Overall, 49% of admitted CYP had at least one chronic condition recorded. CONCLUSIONS: Infants and CYP with chronic conditions are at highest risk of admission with COVID-19. Half of admitted CYP had chronic conditions. Studies examining COVID-19 vaccine effectiveness among children with chronic conditions and whether maternal vaccine during pregnancy prevents COVID-19 admissions in infants are urgently needed.

Gestational age at birth and academic attainment in primary and secondary school in England: Evidence from a national cohort study.

Preterm birth (<37 weeks' gestation) is a risk factor for poor educational outcomes. A dose-response effect of earlier gestational age at birth on poor primary school attainment has been observed, but evidence for secondary school attainment is limited and focused predominantly on the very preterm (<32 weeks) population. We examined the association between gestational age at birth and academic attainment at the end of primary and secondary schooling in England. Data for children born in England from 2000-2001 were drawn from the population-based UK Millennium Cohort Study. Information about the child's birth, sociodemographic factors and health was collected from parents. Attainment on national tests at the end of primary (age 11) and secondary school (age 16) was derived from linked education records. Data on attainment in primary school was available for 6,950 pupils and that of secondary school was available for 7,131 pupils. Adjusted relative risks (aRRs) for these outcomes were estimated at each stage separately using modified Poisson regression. At the end of primary school, 17.7% of children had not achieved the expected level in both English and Mathematics and this proportion increased with increasing prematurity. Compared to full term (39-41 weeks) children, the strongest associations were among children born moderately (32-33 weeks; aRR = 2.13 (95% CI 1.44-3.13)) and very preterm (aRR = 2.06 (95% CI 1.46-2.92)). Children born late preterm (34-36 weeks) and early term (37-38 weeks) were also at higher risk with aRR = 1.18 (95% CI 0.94-1.49) and aRR = 1.21 (95% CI 1.05-1.38), respectively. At the end of secondary school, 45.2% had not passed at least five General Certificate of Secondary Education examinations including English and Mathematics. Following adjustment, only children born very preterm were at significantly higher risk (aRR = 1.26 (95% CI 1.03-1.54)). All children born before full term are at risk of poorer attainment during primary school compared with term-born children, but only children born very preterm remain at risk at the end of secondary schooling. Children born very preterm may require additional educational support throughout compulsory schooling.

Associations between gestational age at birth and infection-related hospital admission rates during childhood in England: Population-based record linkage study.

BACKGROUND: Children born preterm (<37 completed weeks' gestation) have a higher risk of infection-related morbidity than those born at term. However, few large, population-based studies have investigated the risk of infection in childhood across the full spectrum of gestational age. The objectives of this study were to explore the association between gestational age at birth and infection-related hospital admissions up to the age of 10 years, how infection-related hospital admission rates change throughout childhood, and whether being born small for gestational age (SGA) modifies this relationship. METHODS AND FINDINGS: Using a population-based, record-linkage cohort study design, birth registrations, birth notifications and hospital admissions were linked using a deterministic algorithm. The study population included all live, singleton births occurring in NHS hospitals in England from January 2005 to December 2006 (n = 1,018,136). The primary outcome was all infection-related inpatient hospital admissions from birth to 10 years of age, death or study end (March 2015). The secondary outcome was the type of infection-related hospital admission, grouped into broad categories. Generalised estimating equations were used to estimate adjusted rate ratios (aRRs) with 95% confidence intervals (CIs) for each gestational age category (<28, 28-29, 30-31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 and 42 weeks) and the models were repeated by age at admission (<1, 1-2, 3-4, 5-6, and 7-10 years). An interaction term was included in the model to test whether SGA status modified the relationship between gestational age and infection-related hospital admissions. Gestational age was strongly associated with rates of infection-related hospital admissions throughout childhood. Whilst the relationship attenuated over time, at 7-10 years of age those born before 40 weeks gestation were still significantly higher in comparison to those born at 40 weeks. Children born <28 weeks had an aRR of 6.53 (5.91-7.22) during infancy, declining to 3.16 (2.50-3.99) at ages 7-10 years, in comparison to those born at 40 weeks; whilst in children born at 38 weeks, the aRRs were 1·24 (1.21-1.27) and 1·18 (1.13-1.23), during infancy and aged 7-10 years, respectively. SGA status modified the effect of gestational age (interaction P<0.0001), with the highest rate among the children born at <28 weeks and SGA. Finally, study findings indicated that the associations with gestational age varied by subgroup of infection. Whilst upper respiratory tract infections were the most common type of infection experienced by children in this cohort, lower respiratory tract infections (LRTIs) (<28 weeks, aRR = 10.61(9.55-11.79)) and invasive bacterial infections (<28 weeks, aRR = 6.02 (4.56-7.95)) were the most strongly associated with gestational age at birth. Of LRTIs experienced, bronchiolitis (<28 weeks, aRR = 11.86 (10.20-13.80)), and pneumonia (<28 weeks, aRR = 9.49 (7.95-11.32)) were the most common causes. CONCLUSIONS: Gestational age at birth was strongly associated with rates of infection-related hospital admissions during childhood and even children born a few weeks early remained at higher risk at 7-10 years of age. There was variation between clinical subgroups in the strength of relationships with gestational age. Effective infection prevention strategies should include focus on reducing the number and severity of LRTIs during early childhood.

Air Pollution, housing and respirfatory tract Infections in Children: NatIonal birth Cohort study (PICNIC): study protocol.

INTRODUCTION: Respiratory tract infections (RTIs) are the most common reason for hospital admission among children <5 years in the UK. The relative contribution of ambient air pollution exposure and adverse housing conditions to RTI admissions in young children is unclear and has not been assessed in a UK context. METHODS AND ANALYSIS: The aim of the PICNIC study (Air Pollution, housing and respiratory tract Infections in Children: NatIonal birth Cohort Study) is to quantify the extent to which in-utero, infant and childhood exposures to ambient air pollution and adverse housing conditions are associated with risk of RTI admissions in children <5 years old. We will use national administrative data birth cohorts, including data from all children born in England in 2005-2014 and in Scotland in 1997-2020, created via linkage between civil registration, maternity and hospital admission data sets. We will further enhance these cohorts via linkage to census data on housing conditions and socioeconomic position and small area-level data on ambient air pollution and building characteristics. We will use time-to-event analyses to examine the association between air pollution, housing characteristics and the risk of RTI admissions in children, calculate population attributable fractions for ambient air pollution and housing characteristics, and use causal mediation analyses to explore the mechanisms through which housing and air pollution influence the risk of infant RTI admission. ETHICS, EXPECTED IMPACT AND DISSEMINATION: To date, we have obtained approval from six ethics and information governance committees in England and two in Scotland. Our results will inform parents, national and local governments, the National Health Service and voluntary sector organisations of the relative contribution of adverse housing conditions and air pollution to RTI admissions in young children. We will publish our results in open-access journals and present our results to the public via parent groups and social media and on the PICNIC website. Code and metadata will be published on GitHub.

Gestational age at birth and child special educational needs: a UK representative birth cohort study.

OBJECTIVE: To examine the association between gestational age at birth across the entire gestational age spectrum and special educational needs (SENs) in UK children at 11 years of age. METHODS: The Millennium Cohort Study is a nationally representative longitudinal sample of children born in the UK during 2000-2002. Information about the child's birth, health and sociodemographic factors was collected when children were 9 months old. Information about presence and reasons for SEN was collected from parents at age 11. Adjusted relative risks (aRRs) were estimated using modified Poisson regression, accounting for confounders. RESULTS: The sample included 12 081 children with data at both time points. The overall prevalence of SEN was 11.2%, and it was inversely associated with gestational age. Among children born <32 weeks of gestation, the prevalence of SEN was 27.4%, three times higher than among those born at 40 weeks (aRR=2.89; 95% CI 2.02 to 4.13). Children born early term (37-38 weeks) were also at increased risk for SEN (aRR=1.33; 95% CI 1.11 to 1.59); this was the same when the analysis was restricted to births after labour with spontaneous onset. Birth before full term was more strongly associated with having a formal statement of SEN or SEN for multiple reasons. CONCLUSION: Children born at earlier gestational ages are more likely to experience SEN, have more complex SEN and require support in multiple facets of learning. This association was observed even among children born early-term and when labour began spontaneously.

Gestational age and hospital admissions during childhood: population based, record linkage study in England (TIGAR study).

OBJECTIVE: To examine the association between gestational age at birth and hospital admissions to age 10 years and how admission rates change throughout childhood. DESIGN: Population based, record linkage, cohort study in England. SETTING: NHS hospitals in England, United Kingdom. PARTICIPANTS: 1 018 136 live, singleton births in NHS hospitals in England between January 2005 and December 2006. MAIN OUTCOME MEASURES: Primary outcome was all inpatient hospital admissions from birth to age 10, death, or study end (March 2015); secondary outcome was the main cause of admission, which was defined as the World Health Organization's first international classification of diseases, version 10 (ICD-10) code within each hospital admission record. RESULTS: 1 315 338 admissions occurred between 1 January 2005 and 31 March 2015, and 831 729 (63%) were emergency admissions. 525 039 (52%) of 1 018 136 children were admitted to hospital at least once during the study period. Hospital admissions during childhood were strongly associated with gestational age at birth (<28, 28-29, 30-31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, and 42 weeks). In comparison with children born at full term (40 weeks' gestation), those born extremely preterm (<28 weeks) had the highest rate of hospital admission throughout childhood (adjusted rate ratio 4.92, 95% confidence interval 4.58 to 5.30). Even children born at 38 weeks had a higher rate of hospital admission throughout childhood (1.19, 1.16 to 1.22). The association between gestational age and hospital admission decreased with increasing age (interaction P<0.001). Children born earlier than 28 weeks had an adjusted rate ratio of 6.34 (95% confidence interval 5.80 to 6.85) at age less than 1 year, declining to 3.28 (2.82 to 3.82) at ages 7-10, in comparison with those born full term; whereas in children born at 38 weeks, the adjusted rate ratios were 1.29 (1.27 to 1.31) and 1.16 (1.13 to 1.19), during infancy and ages 7-10, respectively. Infection was the main cause of excess hospital admissions at all ages, but particularly during infancy. Respiratory and gastrointestinal conditions also accounted for a large proportion of admissions during the first two years of life. CONCLUSIONS: The association between gestational age and hospital admission rates decreased with age, but an excess risk remained throughout childhood, even among children born at 38 and 39 weeks of gestation. Strategies aimed at the prevention and management of childhood infections should target children born preterm and those born a few weeks early.

Linkage of maternity hospital episode statistics birth records to birth registration and notification records for births in England 2005-2006: quality assurance of linkage.

OBJECTIVES: The objectives of this study were to describe the methods used to assess the quality of linkage between records of babies' birth registration and hospital birth records, and to evaluate the potential bias that may be introduced because of these methods. DESIGN/SETTING: Data from the civil registration and the notification of births previously linked by the Office for National Statistics (ONS) had been further linked to birth records from the Hospital Episode Statistics (HES) for babies born in England. We developed a deterministic, six-stage algorithm to assess the quality of this linkage. PARTICIPANTS: All 1 170 790 live, singleton births, occurring in National Health Service hospitals in England between 1 January 2005 and 31 December 2006. PRIMARY OUTCOME MEASURE: The primary outcome was the number of successful links between ONS birth records and HES birth records. Rates of successful linkage were calculated for the cohort and the characteristics associated with unsuccessful linkage were identified. RESULTS: Approximately 92% (1 074 572) of the birth registration records were successfully linked with a HES birth record. Data quality and completeness were somewhat poorer in HES birth records compared with linked birth registration and birth notification records. The quality assurance algorithms identified 1456 incorrect linkages (<1%). Compared with the linked dataset, birth records were more likely to be unlinked if babies were of white ethnic origin; born to unmarried mothers; born in East England, London, North West England or the West Midlands; or born in March. CONCLUSIONS: It is possible to link administrative datasets to create large cohorts, allowing researchers to explore important questions about exposures and childhood outcomes. Missing data, coding errors and inconsistencies mean it is important that the quality of linkage is assessed prior to analysis.

Involving service users in the Birth Timing project, a data linkage study analysing the timing of births and their outcomes.

INTRODUCTION: We report on service user participation in a population-based data linkage study designed to analyse the daily, weekly and yearly cycles of births in England and Wales, the outcomes for women and babies, and their implications for the NHS. Public Involvement and Engagement (PI&E) has a long history in maternity services, though PI&E in maternity data linkage studies is new in the United Kingdom. We have used the GRIPP2 short form, a tool designed for reporting public involvement in research. OBJECTIVES: We aimed to involve and engage a wide range of maternity service users and their representatives to ensure that our use of patient-identifiable routinely collected maternity and birth records was acceptable and that our research analyses using linked data were relevant to their expressed safety and quality of care needs. METHODS: A three-tiered approach to PI&E was used. Having both PI&E co-investigators and PI&E members of the Study Advisory Group ensured service user involvement was part of the strategic development of the project. A larger constituency of maternity service users from England and Wales was engaged through four regional workshops. RESULTS: Two co-investigators with experience of PI&E in maternity research were involved as service user researchers from design stage to dissemination. Four PI&E study advisors contributed service user perspectives. Engagement workshops attracted around 100 attendees, recruited largely from Maternity Services Liaison Committees in England and Wales, and a community engagement group. They supported the use of patient-identifiable data, believing the study had potential to improve safety and quality of maternity services. They contributed their experiences and concerns which will assist with interpretation of the analyses. CONCLUSION: Use of PI&E 'knowledge intermediaries' successfully bridged the gap between data intensive research and lived experience, but more inclusivity in involvement and engagement is required. Respecting the concerns and questions of service users provides social legitimacy and a relevance framework for researchers carrying out analyses.

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.

Ethnic differences in singleton preterm birth in England and Wales, 2006-12: Analysis of national routinely collected data.

BACKGROUND: Data recorded at birth and death registration in England and Wales have been routinely linked with data recorded at birth notification since 2006. These provide scope for detailed analyses on ethnic differences in preterm birth (PTB). OBJECTIVES: We aimed to investigate ethnic differences in PTB and degree of prematurity in England and Wales, taking into account maternal sociodemographic characteristics and to further explore the contribution of mother's country of birth to these ethnic differences in PTB. METHODS: We analysed PTB and degree of prematurity by ethnic group, using routinely collected and linked data for all singleton live births in England and Wales, 2006-2012. Logistic regression was used to adjust for mother's age, marital status/registration type, area deprivation and mother's country of birth. RESULTS: In the 4 634 932 births analysed, all minority ethnic groups except 'Other White' had significantly higher odds of PTB compared with White British babies (ORs between 1.04-1.25); highest odds were in Black Caribbean, Indian, Bangladeshi and Pakistani groups. Ethnic differences in PTB tended to be greater at earlier gestational ages. In all ethnic groups, odds of PTB were lower for babies whose mothers were born outside the UK. CONCLUSIONS: In England and Wales, Black Caribbean, Indian, Bangladeshi, Pakistani and Black African babies all have significantly increased odds of being born preterm compared with White British babies. Bangladeshis apart, these groups are particularly at risk of extremely PTB. In all ethnic groups, the odds of PTB are lower for babies whose mothers were born outside the UK. These ethnic differences do not appear to be wholly explained by area deprivation or other sociodemographic characteristics.

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.

Timing of singleton births by onset of labour and mode of birth in NHS maternity units in England, 2005-2014: A study of linked birth registration, birth notification, and hospital episode data.

BACKGROUND: Maternity care has to be available 24 hours a day, seven days a week. It is known that obstetric intervention can influence the time of birth, but no previous analysis at a national level in England has yet investigated in detail the ways in which the day and time of birth varies by onset of labour and mode of giving birth. METHOD: We linked data from birth registration, birth notification, and Maternity Hospital Episode Statistics and analysed 5,093,615 singleton births in NHS maternity units in England from 2005 to 2014. We used descriptive statistics and negative binomial regression models with harmonic terms to establish how patterns of timing of birth vary by onset of labour, mode of giving birth and gestational age. RESULTS: The timing of birth by time of day and day of the week varies considerably by onset of labour and mode of birth. Spontaneous births after spontaneous onset are more likely to occur between midnight and 6am than at other times of day, and are also slightly more likely on weekdays than at weekends and on public holidays. Elective caesarean births are concentrated onto weekday mornings. Births after induced labours are more likely to occur at hours around midnight on Tuesdays to Saturdays and on days before a public holiday period, than on Sundays, Mondays and during or just after a public holiday. CONCLUSION: The timing of births varies by onset of labour and mode of birth and these patterns have implications for midwifery and medical staffing. Further research is needed to understand the processes behind these findings.

The contribution of gestational age, area deprivation and mother's country of birth to ethnic variations in infant mortality in England and Wales: A national cohort study using routinely collected data.

OBJECTIVES: We aimed to describe ethnic variations in infant mortality and explore the contribution of area deprivation, mother's country of birth, and prematurity to these variations. METHODS: We analyzed routine birth and death data on singleton live births (gestational age≥22 weeks) in England and Wales, 2006-2012. Infant mortality by ethnic group was analyzed using logistic regression with adjustment for sociodemographic characteristics and gestational age. RESULTS: In the 4,634,932 births analyzed, crude infant mortality rates were higher in Pakistani, Black Caribbean, Black African, and Bangladeshi infants (6.92, 6.00, 5.17 and 4.40 per 1,000 live births, respectively vs. 2.87 in White British infants). Adjustment for maternal sociodemographic characteristics changed the results little. Further adjustment for gestational age strongly attenuated the risk in Black Caribbean (OR 1.02, 95% CI 0.89-1.17) and Black African infants (1.17, 1.06-1.29) but not in Pakistani (2.32, 2.15-2.50), Bangladeshi (1.47, 1.28-1.69), and Indian infants (1.24, 1.11-1.38). Ethnic variations in infant mortality differed significantly between term and preterm infants. At term, South Asian groups had higher risks which cannot be explained by sociodemographic characteristics. In preterm infants, adjustment for degree of prematurity (<28, 28-31, 32-33, 34-36 weeks) fully explained increased risks in Black but not Pakistani and Bangladeshi infants. Sensitivity analyses with further adjustment for small for gestational age, or excluding deaths due to congenital anomalies did not fully explain the excess risk in South Asian groups. CONCLUSIONS: Higher infant mortality in South Asian and Black infants does not appear to be explained by sociodemographic characteristics. Higher proportions of very premature infants appear to explain increased risks in Black infants but not in South Asian groups. Strategies targeting the prevention and management of preterm birth in Black groups and suboptimal birthweight and modifiable risk factors for congenital anomalies in South Asian groups might help reduce ethnic inequalities in infant mortality.

Linkage of Maternity Hospital Episode Statistics data to birth registration and notification records for births in England 2005-2014: methods. A population-based birth cohort study.

INTRODUCTION: Maternity Hospital Episode Statistics (HES) data for 2005-2014 were linked to birth registration and birth notification data (previously known as NHS Numbers for Babies or NN4B) to bring together some key demographic and clinical data items not otherwise available at a national level. The linkage algorithm that was previously used to link 2005-2007 data was revised to improve the linkage rate and reduce the number of duplicate HES records. METHODS: Birth registration and notification linked records from the Office for National Statistics ('ONS birth records') were further linked to Maternity HES delivery and birth records using the NHS Number and other direct identifiers if the NHS Number was missing. RESULTS: For the period 2005-2014, over 94% of birth registration and notification records were correctly linked to HES delivery records. Two per cent of the ONS birth records were incorrectly linked to the HES delivery record and 5% of ONS birth records were linked to more than one HES delivery record. Therefore, a considerable amount of time was spent in quality assuring these files. CONCLUSION: The linkage rate for birth registration and notification records to HES delivery records steadily improved from 2005 to 2014 due to improvement in the quality and completeness of patient identifiers in both HES and birth notification data.

The economic costs of intrapartum care in Tower Hamlets: A comparison between the cost of birth in a freestanding midwifery unit and hospital for women at low risk of obstetric complications.

OBJECTIVE: to compare the economic costs of intrapartum maternity care in an inner city area for 'low risk' women opting to give birth in a freestanding midwifery unit compared with those who chose birth in hospital. DESIGN: micro-costing of health service resources used in the intrapartum care of mothers and their babies during the period between admission and discharge, data extracted from clinical notes. SETTING: the Barkantine Birth Centre, a freestanding midwifery unit and the Royal London Hospital's consultant-led obstetric unit, both run by the former Barts and the London NHS Trust in Tower Hamlets, a deprived inner city borough in east London, England, 2007-2010. PARTICIPANTS: maternity records of 333 women who were resident in Tower Hamlets and who satisfied the Trust's eligibility criteria for using the Birth Centre. Of these, 167 women started their intrapartum care at the Birth Centre and 166 started care at the Royal London Hospital. MEASUREMENTS AND FINDINGS: women who planned their birth at the Birth Centre experienced continuous intrapartum midwifery care, higher rates of spontaneous vaginal delivery, greater use of a birth pool, lower rates of epidural use, higher rates of established breastfeeding and a longer post-natal stay, compared with those who planned for care in the hospital. The total average cost per mother-baby dyad for care where mothers started their intrapartum care at the Birth Centre was £1296.23, approximately £850 per patient less than the average cost per mother and baby who received all their care at the Royal London Hospital. These costs reflect intrapartum throughput using bottom up costing per patient, from admission to discharge, including transfer, but excluding occupancy rates and the related running costs of the units. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: the study showed that intrapartum throughput in the Birth Centre could be considered cost-minimising when compared to hospital. Modelling the financial viability of midwifery units at a local level is important because it can inform the appropriate provision of these services. This finding from this study contribute a local perspective and thus further weight to the evidence from the Birthplace Programme in support of freestanding midwifery unit care for women without obstetric complications.