Explore the vast range of titles available.

Several studies have reported that birth by caesarean section is associated with increased risk of lower respiratory tract infections in the child, but it is unclear whether this applies to any caesarean section or specifically to planned caesareans. Furthermore, although infections of the upper respiratory tract are very common during childhood, there is a scarcity of studies examining whether caesarean is also a risk factor for this site of infection. We obtained data from two UK cohorts: the Millennium Cohort Study (MCS) and linked administrative datasets of the population of Wales through the Secure Anonymised Information Linkage (SAIL) databank. The study focused on term-born singleton infants and included 15,580 infants born 2000-2002 (MCS) and 392,145 infants born 2002-2016 (SAIL). We used information about mode of birth (vaginal delivery, assisted vaginal delivery, planned caesarean and emergency caesarean) from maternal report in the MCS and from hospital birth records in SAIL. Unplanned hospital admission for lower respiratory tract infection (LRTI) was ascertained from maternal report in the MCS and from hospital record ICD codes in SAIL. Information about admissions for upper respiratory tract infection (URTI) was available from SAIL only. Cox regression was used to estimate hazard ratios for each outcome and cohort separately while accounting for a wide range of confounders. Gestational age at birth was further examined as a potential added, indirect risk of planned caesarean birth due to the early delivery. The rate of hospital admission for LRTI was 4.6 per 100 child years in the MCS and 5.9 per 100 child years in SAIL. Emergency caesarean was not associated with LRTI admission during infancy in either cohort. In the MCS, planned caesarean was associated with a hazard ratio of 1.39 (95% CI 1.03, 1.87) which further increased to 1.65 (95% CI 1.24, 2.19) when gestational age was not adjusted for. In SAIL, the adjusted hazard ratio was 1.10 (95% CI 1.05, 1.15), which increased to 1.17 (95% CI 1.12, 1.22) when gestational age was not adjusted for. The rate of hospital admission for URTI was 5.9 per 100 child years in SAIL. Following adjustments, emergency caesarean was found to have a hazard ratio of 1.09 (95% CI 1.05, 1.14) for hospital admission for URTI. Planned caesarean was associated with a hazard ratio of 1.11 (95% CI 1.06, 1.16) which increased to 1.17 (95% CI 1.12, 1.22) when gestational age was not adjusted for. The risk of severe LRTIs during infancy is moderately elevated in infants born by planned caesarean compared to those born vaginally. Infants born by any type of caesarean may also be at a small increased risk of severe URTIs. The estimated effect sizes are stronger if including the indirect effect arising from planning the caesarean birth for an earlier gestation than would have occurred spontaneously. Further studies are needed to confirm these results.

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.

ObjectiveTo 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.MethodsThe 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.ResultsThe 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.ConclusionChildren 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.

Background: In the past few decades, birth has changed profoundly with a steep rise in the rates of caesarean birth in most high-income countries and elsewhere. Observational studies have linked caesarean birth to some long-term adverse health outcomes during childhood. These include asthma and its common symptom - wheezing, however little is known about the association with particular phenotypes of wheezing. There is also some evidence suggesting that caesarean birth increases susceptibility to common childhood infectious diseases, although the scope of studies available is limited. The aim of this DPhil research was to elucidate whether mode of birth is associated with an increased risk of childhood asthma or infectious disease, including those affecting the upper and lower respiratory tract as well as the gastrointestinal tract. Comparisons are made between each type of medically interventional delivery - assisted vaginal delivery, planned and emergency caesarean sections - and unassisted vaginal deliveries. Methods: Two data sources from the UK were used to investigate these questions in children born singleton at term and without major health problems at the time of birth. The first, the Millennium Cohort Study, is a nationally representative sample of children born in 2000-2002. The second is linked administrative datasets of the population of Wales including the children born in 2002-2016. Cox regression was used to calculate hazard ratios of hospital admission for respiratory and gastrointestinal infections and asthma. Multinomial logistic regression was used to estimate the relative risk ratio for experiencing various wheezing phenotypes during childhood. Findings: Having adjusted for confounders, planned and emergency caesarean sections were found to be risk factors of small magnitude (10-40% increase in risk) for various adverse child health outcomes. Planned caesarean sections were associated with an elevated risk of upper and lower respiratory tract infections during infancy and early childhood and persistent wheezing throughout childhood. Emergency caesarean sections were associated with increased risk of infectious diseases of the upper respiratory tract or gastrointestinal tract during infancy, and an increased risk of severe or poorly controlled asthma in later childhood. Assisted vaginal deliveries were not found to be associated consistently with any of the outcomes under study. Conclusion: This thesis provides modest strength of evidence to suggest that caesarean sections, whether planned or emergency, may increase the risk of infections of the respiratory or gastrointestinal tract requiring hospital admission during infancy. It also provides evidence to suggest the increased risk of respiratory morbidity such as severe asthma or persistent wheezing carries on into later childhood.