CPRD information relating to the analysis "The causal association between maternal mental illness and infection in pregnancy and neurodevelopmental disorders among 410,461 children- a population study using quasi- negative control cohorts and sibling analysis"
This provides information on the follwing:
Neurodevelopment disorders CPRD GOLD read codes. Maternal mental illness CPRD read codes. Infections –CPRD read codes for viral or non-viral infections recorded in primary care.
Structured abstract: Importance The consistent association between in-utero exposure to maternal infection or mental illness and neurodevelopmental disorders (NDD), suggests causality. Objectives To be causal, we hypothesised there are specific in-utero effects evidenced by 1) stronger associations between infection or mental illness and NDD incidence during compared to outside of pregnancy; and 2) higher NDD incidence among exposed compared to unexposed siblings. Design Cohort study. Setting UK primary and secondary care dataset. Participants Three cohorts of children born between 1st January 1990 to 31st December 2017 and their mothers. Children were either exposed or unexposed to maternal mental illness and maternal infection during pregnancy; and/or 1 year and 2 years prior to pregnancy. A sibling cohort was constructed from the pregnancy cohort. Exposures Maternal exposures were identified from the primary care record. NDDs (autism spectrum disorder, attention deficit disorder, intellectual disability, cerebral palsy and epilepsy) were extracted from the child’s primary and secondary care record. We extracted information on potential maternal confounders (age, smoking status, comorbidities, BMI, history of NDD); child confounders (gender, ethnicity, birth year); and area-level confounders (region and level of deprivation). Main outcomes/measures We calculated the incidence rate of NDDs for exposed and unexposed offspring in each cohort; and compared rates using Cox-regression models, unadjusted and adjusted for potential confounders. Results The analysis included 410,461 children of 297,426 mothers and 2,793,018 person-years of follow-up with 8900 NDD cases (incidence rate = 3.2 per 1000 person years). After adjustments, a moderate association with maternal mental illness was observed for each cohort (pregnancy adjusted HR=1.58, 95%CI 1.46-1.72; 1 year adj.HR=1.49, 95%CI 1.39-1.60; 2 year adj.HR=1.62, 95%CI 1.50-1.74); and to a lesser extent, of maternal infection (pregnancy adj. HR= 1.16, 95%CI 1.10-1.22; 1 year adj.HR=1.20, 95%CI 1.14-1.27; 2 year adj.HR=1.19 95%CI 1.12-1.25). There was no evidence of increased NDD risk in siblings discordant for maternal exposures during pregnancy: mental illness HR=0.98, 95%CI 0.78-1.23; infection HR=0.98, 95%CI 0.89-1.08. Conclusion In this large population study, we found no specific association between maternal mental illness or infection in-utero and NDD incidence and, therefore, no causal evidence.