Search

Background: Prenatal antibiotic exposure induces changes in the maternal microbiome, which could influence the development of the infant's microbiome–gut–brain axis. Objectives: We assessed whether prenatal antibiotic exposure is associated with an increased risk of autism spectrum disorder (ASD) in offspring born at term. Methods: This population‐based retrospective cohort study included everyone who delivered a live singleton‐term infant in British Columbia, Canada between April 2000 and December 2014. Exposure was defined as filling antibiotic prescriptions during pregnancy. The outcome was an ASD diagnosis from the British Columbia Autism Assessment Network, with a follow‐up to December 2016. To examine the association among pregnant individuals treated for the same indication, we studied a sub‐cohort diagnosed with urinary tract infections. Cox proportional hazards models were used to estimate unadjusted and adjusted hazard ratios (HR). The analysis was stratified by sex, trimester, cumulative duration of exposure, class of antibiotic, and mode of delivery. We ran a conditional logistic regression of discordant sibling pairs to control for unmeasured environmental and genetic confounding. Results: Of the 569,953 children included in the cohort, 8729 were diagnosed with ASD (1.5%) and 169,922 were exposed to prenatal antibiotics (29.8%). Prenatal antibiotic exposure was associated with an increased risk of ASD (HR 1.10, 95% confidence interval [CI] 1.05, 1.15), particularly for exposure during the first and second trimesters (HR 1.11, 95% CI 1.04, 1.18 and HR 1.09, 95% CI 1.03, 1.16, respectively), and exposure lasting ≥15 days (HR 1.13, 95% CI 1.04, 1.23). No sex differences were observed. The association was attenuated in the sibling analysis (adjusted odds ratio 1.04, 95% CI 0.92, 1.17). Conclusions: Prenatal antibiotic exposure was associated with a small increase in the risk of ASD in offspring. Given the possibility of residual confounding, these results should not influence clinical decisions regarding antibiotic use during pregnancy. [ABSTRACT FROM AUTHOR]

Importance: Evidence from studies investigating the association of epidural analgesia use during labor and delivery with risk of autism spectrum disorder (ASD) in offspring is conflicting.Objective: To assess the association of maternal use of epidural analgesia during labor and delivery with ASD in offspring using a large population-based data set with clinical data on ASD case status.Design, Setting, and Participants: This population-based retrospective cohort study included term singleton children born in British Columbia, Canada, between April 1, 2000, and December 31, 2014. Stillbirths and cesarean deliveries were excluded. Clinical ASD diagnostic data were obtained from the British Columbia Autism Assessment Network and the British Columbia Ministry of Education. All children were followed up until clinical diagnosis of ASD, death, or the study end date of December 31, 2016.Exposures: Use of epidural analgesia during labor and delivery.Main Outcomes and Measures: A clinical diagnosis of ASD made by pediatricians, psychiatrists, and psychologists with specialty training to assess ASD. Cox proportional hazards models were used to estimate the hazard ratio of epidural analgesia use and ASD. Models were adjusted for maternal sociodemographics; maternal conditions during pregnancy; labor, delivery, and antenatal care characteristics; infant sex; gestational age; and status of small or large for gestational age. A conditional logistic regression model matching women with 2 births or more and discordance in ASD status of the offspring also was performed.Results: Of the 388 254 children included in the cohort (49.8% female; mean gestational age, 39.2 [SD, 1.2] weeks; mean follow-up, 9.05 [SD, 4.3] years), 5192 were diagnosed with ASD (1.34%) and 111 480 (28.7%) were exposed to epidural analgesia. A diagnosis of ASD was made for 1710 children (1.53%) among the 111 480 deliveries exposed to epidural analgesia (94 157 women) vs a diagnosis of ASD in 3482 children (1.26%) among the 276 774 deliveries not exposed to epidural analgesia (192 510 women) (absolute risk difference, 0.28% [95% CI, 0.19%-0.36%]). The unadjusted hazard ratio was 1.32 (95% CI, 1.24-1.40) and the fully adjusted hazard ratio was 1.09 (95% CI, 1.00-1.15). There was no statistically significant association of epidural analgesia use during labor and delivery with ASD in the within-woman matched conditional logistic regression (839/1659 [50.6%] in the exposed group vs 1905/4587 [41.5%] in the unexposed group; fully adjusted hazard ratio, 1.07 [95% CI, 0.87-1.30]).Conclusions and Relevance: In this population-based study, maternal epidural analgesia use during labor and delivery was associated with a small increase in the risk of autism spectrum disorder in offspring that met the threshold for statistical significance. However, given the likelihood of residual confounding that may account for the results, these findings do not provide strong supporting evidence for this association. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Antibiotics are commonly administered during labor and delivery, and research has suggested that fetal exposure to antibiotics can increase risk for autism spectrum disorder (ASD). We assessed whether antibiotic exposure during labor and delivery increased the risk of ASD in the offspring. METHODS: This retrospective cohort study included everyone who delivered a live singleton-term infant in British Columbia, Canada, between April 1, 2000, and December 31, 2014. This cohort included 569 953 deliveries. To examine the association among pregnant individuals being treated for the same indication, we studied a subcohort of those who tested positive for group B Streptococcus. Cox proportional hazards models were used to estimate unadjusted and adjusted hazard ratios in both cohorts. A sensitivity analysis was conducted using length of first stage of labor as a proxy measure for dose to assess for a dose--response relationship. RESULTS: In this population-based study, antibiotic use during labor and delivery was not associated with an increased risk of ASD in offspring. The unadjusted and adjusted hazard ratios were 1.29 (95% confidence interval, 1.24-1.35) and 0.99 (0.94-1.04), respectively; and 1.07 (0.90-1.27) and 0.88 (0.74-1.05), respectively, in the group B Streptococcus-positive cohort. We observed no substantial difference in the association between antibiotic exposure and ASD depending on length of the first stage of labor. CONCLUSIONS: Our findings suggest that concern for ASD should not factor into the clinical decision on whether to administer antibiotics during labor and delivery. Future research is needed to examine longer durations of prenatal antibiotic exposure. [ABSTRACT FROM AUTHOR]

Importance: The etiology of autism spectrum disorder (ASD) is poorly understood, but prior studies suggest associations with airborne pollutants., Objective: To evaluate the association between prenatal exposures to airborne pollutants and ASD in a large population-based cohort., Design, Setting, and Participants: This population-based cohort encompassed nearly all births in Metro Vancouver, British Columbia, Canada, from 2004 through 2009, with follow-up through 2014. Children were diagnosed with ASD using a standardized assessment with the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. Monthly mean exposures to particulate matter with a diameter less than 2.5 µm (PM2.5), nitric oxide (NO), and nitrogen dioxide (NO2) at the maternal residence during pregnancy were estimated with temporally adjusted, high-resolution land use regression models. The association between prenatal air pollution exposures and the odds of developing ASD was evaluated using logistic regression adjusted for child sex, birth month, birth year, maternal age, maternal birthplace, and neighborhood-level urbanicity and income band. Data analysis occurred from June 2016 to May 2018., Exposures: Mean monthly concentrations of ambient PM2.5, NO, and NO2 at the maternal residence during pregnancy, calculated retrospectively using temporally adjusted, high-resolution land use regression models., Main Outcomes and Measures: Autism spectrum disorder diagnoses based on standardized assessment of the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. The hypothesis being tested was formulated during data collection., Results: In a cohort of 132 256 births, 1307 children (1.0%) were diagnosed with ASD by the age of 5 years. The final sample size for the PM2.5-adjusted model was 129 439 children, and for NO and NO2, it was 129 436 children; of these, 1276 (1.0%) were diagnosed with ASD. Adjusted odds ratios for ASD per interquartile range (IQR) were not significant for exposure to PM2.5 during pregnancy (1.04 [95% CI, 0.98-1.10] per 1.5 μg/m3 increase [IQR] in PM2.5) or NO2 (1.06 [95% CI, 0.99-1.12] per 4.8 ppb [IQR] increase in NO2) but the odds ratio was significant for NO (1.07 [95% CI, 1.01-1.13] per 10.7 ppb [IQR] increase in NO). Odds ratios for male children were 1.04 (95% CI, 0.98-1.10) for PM2.5; 1.09 (95% CI, 1.02-1.15) for NO; and 1.07 (95% CI, 1.00-1.13) for NO2. For female children, they were for 1.03 (95% CI, 0.90-1.18) for PM2.5; 0.98 (95% CI, 0.83-1.13) for NO; and 1.00 (95% CI, 0.86-1.16) for NO2., Conclusions and Relevance: In a population-based birth cohort, we detected an association between exposure to NO and ASD but no significant association with PM2.5 and NO2.

Background: The major aim of this study was to investigate whether maternal risk factors associated with socioeconomic status and small for gestational age (SGA) might be viable targets of interventions to reduce differential risk of SGA by socioeconomic status (socioeconomic SGA inequality) in the metropolitan area of Vancouver, Canada., Methods: This study included 59,039 live, singleton births in the Vancouver Census Metropolitan Area (Vancouver) from January 1, 2006 to September 17, 2009. To identify an indicator of socioeconomic SGA inequality, we used hierarchical logistic regression to model SGA by area-level variables from the Canadian census. We then modelled SGA by area-level average income plus established maternal risk factors for SGA and calculated population attributable SGA risk percentages (PAR%) for each variable. Associations of maternal risk factors for SGA with average income were investigated to identify those that might contribute to SGA inequality. Finally, we estimated crude reductions in the percentage and absolute differences in SGA risks between highest and lowest average income quintiles that would result if interventions on maternal risk factors successfully equalized them across income levels or eliminated them altogether., Results: Average income produced the most linear and statistically significant indicator of socioeconomic SGA inequality with 8.9% prevalence of SGA in the lowest income quintile compared to 5.6% in the highest. The adjusted PAR% of SGA for variables were: bottom four quintiles of height (51%), first birth (32%), bottom four quintiles of average income (14%), oligohydramnios (7%), underweight or hypertension, (6% each), smoking (3%) and placental disorder (1%). Shorter height, underweight and smoking during pregnancy had higher prevalence in lower income groups. Crude models assuming equalization of risk factors across income levels or elimination altogether indicated little potential change in relative socioeconomic SGA inequality and reduction in absolute SGA inequality for shorter height only., Conclusions: Our findings regarding maternal height may indicate trans-generational aetiology for socioeconomic SGA inequalities and/or that adult height influences social mobility. Conditions affecting foetal and childhood growth might be viable targets to reduce absolute socioeconomic SGA inequality in future generations, but more research is needed to determine whether such an approach is appropriate.