Purpose: Evidence on the association of maternal use of antibacterials during pregnancy with childhood asthma remains inconsistent. Confounding or biases may jeopardize the association, thus hampering causal inference. We tested the hypothesis that maternal antibacterial use during pregnancy causally increases the risk of childhood asthma up to four years of age, with effect modification by mode of delivery, exclusive breastfeeding, postnatal antibacterial exposure, and lower respiratory tract infections (LRTI). Methods: We used data from the 2015 Pelotas Birth Cohort Study. Antibacterial use during pregnancy was collected from self-reports. Information on child asthma was obtained from maternal reports of the child’s asthma diagnosis. We performed a double-bias adjustment using multivariable Logistic regression after inverse probability of treatment weighting. Effect modification by mode of delivery, exclusive breastfeeding, postnatal antibacterial exposure, and child lower respiratory tract infections were investigated. Progestogens used during pregnancy were assessed as an exposure negative control. Results: The analytical sample included 3942 children. The prevalence of asthma diagnosis was 10.6% (95% CI 9.7-11.6). There was no evidence of a causal effect of maternal antibacterial use during pregnancy on asthma at age 4. There was evidence of an effect among those who did not use postnatal antibacterials. We found no evidence of a causal effect in the negative control analysis. Conclusion: We observed no association between the use of antibacterials during pregnancy and asthma up to age 4. In the main analysis, there was evidence of effect modification by postnatal antibacterials, which was absent in the negative control analysis.

Purpose: Non-communicable diseases (NCDs) contribute to high-risk pregnancies, and medications are widely prescribed during this period. The present study aimed to describe the medication used for the following pre- and during-pregnancy NCDs: hypertensive disorders, diabetes, mental health problems (depression/anxiety), and respiratory diseases (asthma/bronchitis) among pregnant women. NCD multimorbidity and the simultaneity of NCD risk factors (alcohol consumption, smoking, physical inactivity, and overweight/obesity) according to sociodemographic and health variables were analyzed. Methods: We used data from the 2015 Pelotas Birth Cohort. Medications were classified using the Anatomical Therapeutic Chemical classification recommended by the World Health Organization for each NCD according to pregnancy trimesters. NCD multimorbidity was defined as two or more diseases that occurred before and during pregnancy. Results: The prevalence of NCD multimorbidity was 2.4% (CI95% 1.9-2.9). Considering all four NCDs, the frequency of medication used for NCD treatment was 13.5% (CI95% 12.5-14.6). More than half of the sample (54.3%) presented two or more NCD risk factors. Multimorbidity was higher among black-skinned women in the lowest income quintiles and the lowest level of education. Also, multimorbidity was higher among women who attended fewer antenatal care consultations and who had a hospitalization during pregnancy. Medication use for NCD treatment was higher among women with NCD multimorbidity, and the frequency of NCD multimorbidity was higher in women who had two or more risk factors. Conclusion: These findings may be attributed to socioeconomic inequalities. Understanding NCD multimorbidity during pregnancy supports healthcare policies and helps to unveil health inequalities.

Purpose: Pediatric off-label medicine use increased during the COVID-19 pandemic, exposing children to non-evidence-based treatments. We describe the use of off-label COVID-19 medicines and supplements among children from the 2015 Pelotas Birth Cohort, stratified by sociodemographic and health-related characteristics. Methods: Data from the 6–7-year follow-up were analyzed. Mothers/caregivers reported children’s use of off-label medicines (azithromycin, chloroquine/hydroxychloroquine, ivermectin, nitazoxanide) and supplements (vitamin C, vitamin D, and zinc), collected with sociodemographic and health-related characteristics. Also, two scores were analyzed: 1) child’s COVID-19 burden score (considering negative experiences such as death or distancing from a close person due to COVID-19, and risk factors such as living with old individuals or having asthma, bronchitis, or obesity) and 2) preventive behavior score (never or rarely outdoor exposure during COVID-19 and vaccine uptake against COVID-19). Hierarchical logistic regression analyses were used to identify factors associated with off-label medicine and supplement use. Results: Among 3,098 children, 13.9% (95%CI 12.7-15.2) used off-label medicines and supplements for COVID-19. The use increased with higher COVID-19 burden scores and decreased with higher preventive behavior scores. Off-label medicine use was associated with the child’s skin color, being separated from a relative due to COVID-19, and unvaccinated status for COVID-19. Children with higher maternal education and who experienced the death and drift apart of a close person or relative due to COVID-19 were more likely to use off-label supplements. Conclusions: These findings highlight behavioral responses during a health emergency and underscore the need for stronger regulatory oversight and targeted public health actions.