Association between caesarean birth and childhood cancer: An age-lagged approach.

AIM: We assessed the association between caesarean birth and age-specific risks of childhood cancer. METHODS: We followed a cohort of 1 034 049 children between 2006 and 2020 in Quebec, Canada, from birth until age 14 years. The exposure was caesarean, operative vaginal, or spontaneous vaginal birth. The outcome included haematopoietic or solid tumours. We calculated hazard ratios (HR) and 95% confidence intervals (CI) for the association between mode of delivery and childhood cancer in age-lagged analyses, adjusted for potential confounders. RESULTS: A total of 249 415 (24.1%) children were born by caesarean and 97 411 (9.4%) by operative vaginal delivery. Compared with spontaneous vaginal birth, caesarean was associated with 1.16 times the risk of any cancer (95% CI 1.04-1.30), 1.12 times the risk of haematopoietic cancer (95% CI 0.92-1.36) and 1.21 times the risk of solid tumours (95% 1.06-1.39). Associations strengthened at 2 years of age and were greatest for lymphoma and sarcoma. Operative vaginal birth was not significantly associated with the risk of cancer. CONCLUSION: Caesarean birth may be associated with selected childhood cancers, including lymphoma and sarcoma early in childhood. The underlying reasons for the associations require further investigation, including whether mucosal dysbiosis or labour hormone exposure explain the excess risk.

Relationship between suicide attempt and medical morbidity in adolescent girls.

This study assessed whether suicide attempts before 20 years of age were associated with medical morbidity later in life. We carried out a cohort study of 169,806 girls under age 20 years between 1989 and 2019 in Quebec, Canada. The cohort included 8086 girls admitted for suicide attempts, matched on age and year with 161,720 girls with no attempt. Outcomes included hospitalization for medical conditions, such as infection, allergic disorders, autoimmune disease, cardiovascular disease, cancer, and death from nonpsychiatric causes during 31 years of follow-up. We computed hazard ratios (HR) and 95% confidence intervals (CI) for the association of adolescent suicide attempt with these health outcomes using Cox regression models adjusted for preexisting mental illness, substance use disorders, and socioeconomic deprivation. Compared with matched controls, adolescent girls with suicide attempts had a greater risk of hospitalization for infection (HR 1.55, 95% CI 1.44-1.68), allergic disorders (HR 1.72, 95% CI 1.45-2.05), cardiovascular disease (HR 1.31, 95% CI 1.12-1.52), and mortality (HR 3.11, 95% CI 1.69-5.70). Associations were present regardless of the age at the time of the suicide attempt, but were stronger for girls with repeated attempts. Associations were also more pronounced within the first 5 years of the attempt, although suicide attempts remained strongly associated with mortality throughout the 31-year follow-up period. The findings suggest that adolescent girls with suicide attempts have an elevated risk of medical morbidity and mortality and may benefit from closer clinical management to prevent adverse health outcomes.

Association of placental pathology and gross morphology with autism spectrum disorders.

This study evaluated the association between placental pathology and gross morphology and the risk of autism spectrum disorders (ASD). We conducted a matched case-control study of children with confirmed ASD who were born between 2000 and 2017 at one of three university-affiliated hospitals in Montreal, Quebec. Cases, who were identified through the Montreal Children's Hospital Autism Spectrum Disorders Program, were matched to babies (1:5) born at the same hospital and on the same day. Multi-fetal births were excluded. Maternal demographics, pregnancy characteristics and placental pathologies were collected from hospital charts by abstractors blind to autism diagnoses. This current study consisted of data from a single-site that had pathology reports available. Pearson chi-square and Wilcoxon rank-sum tests were used to estimate p-values. Our study consisted of 107 ASD cases and 526 matched controls. Mothers of cases and controls were similar in terms of parity, gravidity, smoking status, BMI, rates of clinical chorioamnionitis, chronic hypertension, and gestational diabetes. Age at delivery of <25 years was more common among mothers of controls. Compared with controls, cases were more likely born male, <32 weeks of gestation, and weighing <1500 g. Cases and controls had similar rates of placental inflammation, vasculitis, and other placental pathologies. There were no differences in placental weight, placental thickness, umbilical cord length, and umbilical cord insertion between the two groups. In conclusion, placental pathology and gross morphology do not appear to be associated with ASD, suggesting that any perinatal determinants of autism are not likely to be mediated through placental pathology. LAY SUMMARY: Data from a matched case-control study consisting of neonates born between 2000 and 2017 at one of three McGill-affiliated hospitals were used to examine the relationship between placental pathology and morphology and the development of autism. No differences in placental pathology and gross morphology were found between those with and without autism, which suggests that placental abnormalities are unlikely to either cause or mediate the development of autism.

Fluid status in the first 10 days of life and death/bronchopulmonary dysplasia among preterm infants.

OBJECTIVE: To investigate the association between fluid and sodium status in the first 10 postnatal days and death/bronchopulmonary dysplasia (BPD) among infants born <29 weeks' gestation. STUDY DESIGN: Single center retrospective cohort study (2015-2018) of infants born 23-28 weeks'. Three exposure variables were evaluated over the first 10 postnatal days: cumulative fluid balance (CFB), median serum sodium concentration, and maximum percentage weight loss. Primary outcome was death and/or BPD. Multivariable logistic regression adjusting for patient covariates was used to assess the association between exposure variables and outcomes. RESULTS: Of 191 infants included, 98 (51%) had death/BPD. Only CFB differed significantly between BPD-free survivors and infants with death/BPD: 4.71 dL/kg (IQR 4.10-5.12) vs 5.11 dL/kg (IQR 4.47-6.07; p < 0.001). In adjusted analyses, we found an association between higher CFB and higher odds of death/BPD (AOR 1.56, 95% CI 1.11-2.25). This was mainly due to the association of CFB with BPD (AOR 1.60, 95% CI 1.12-2.35), rather than with death (AOR 1.08, 95% CI 0.54-2.30). CONCLUSION: Among preterm infants, a higher CFB in the first 10 days after delivery is associated with higher odds of death/BPD. IMPACT: Previous studies suggest that postnatal fluid status influences survival and respiratory function in neonates. Fluid balance, serum sodium concentration, and daily weight changes are commonly used as fluid status indicators in neonates. We found that higher cumulative fluid balance in the first 10 days of life was associated with higher odds of death/bronchopulmonary dysplasia in neonates born <29 weeks. Monitoring of postnatal fluid balance may be an appropriate non-invasive strategy to favor survival without bronchopulmonary dysplasia. We developed a cumulative fluid balance chart with corresponding thresholds on each day to help design future trials and guide clinicians in fluid management.