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.

Risk-reducing bilateral salpingo-oophorectomy (RRBSO) is the gold standard preventative option for BRCA mutation carriers at high risk for ovarian and breast cancer. However, when performed at the recommended ages of 35–45 years, RRBSO induces immediate premature surgical menopause, along with the accompanying adverse psychosocial, cardiovascular, bone, and cognitive health consequences. While these health consequences have been thoroughly studied in the general population, little is known about the long-term health outcomes in the BRCA population. Hormone replacement therapy (HRT) until the average age of natural menopause can help mitigate these health risks, yet the initiation of HRT is a complex decision among BRCA carriers due to concern of increasing the already high risk of breast cancer in these people. This review summarizes the current research on long-term non-cancer risks in BRCA carriers following RRBSO-induced premature surgical menopause, and highlights the existing evidence in support of HRT use in this population.

Oxytocin is a neuropeptide hormone that plays a key role in social behavior, stress regulation, and mental health. Synthetic oxytocin administration is a common obstetrical practice, and importantly, previous research has suggested that intrapartum exposure may increase the risk of neurodevelopmental disorders, such as autism spectrum disorder. This study aimed to examine the association between synthetic oxytocin exposure during labor and autism spectrum disorder diagnosis in the child. This population-based retrospective cohort study compared 2 cohorts of children: (1) all children born in British Columbia, Canada between April 1, 2000 and December 31, 2014 (n=414,336 births), and (2) all children delivered at Soroka University Medical Center in Be'er-Sheva, Israel between January 1, 2011 and December 31, 2019 (n=82,892 births). Nine different exposure groups were examined. Cox proportional hazards models were used to estimate crude and adjusted hazard ratios of autism spectrum disorder in both cohorts on the basis of induction and/or augmentation exposure status. To further control for confounding by indication, we conducted sensitivity analyses among a cohort of healthy, uncomplicated deliveries and among a group that was induced only for postdates. In addition, we stratified our analyses by infant sex to assess for potential sex differences. In the British Columbia cohort, 170,013 of 414,336 deliveries (41.0%) were not induced or augmented, 107,543 (26.0%) were exposed to oxytocin, and 136,780 (33.0%) were induced or augmented but not exposed to oxytocin. In the Israel cohort, 51,790 of 82,892 deliveries (62.5%) were not induced or augmented, 28,852 (34.8%) were exposed to oxytocin, and 2250 (2.7%) were induced or augmented but not exposed to oxytocin. On adjusting for covariates in the main analysis, significant associations were observed in the Israel cohort, including adjusted hazard ratios of 1.51 (95% confidence interval, 1.20-1.90) for oxytocin-augmented births and 2.18 (95% confidence interval, 1.32-3.57) for those induced by means other than oxytocin and not augmented. However, oxytocin induction was not significantly associated with autism spectrum disorder in the Israel cohort. In the Canadian cohort, there were no statistically significant adjusted hazard ratios. Further, no significant sex differences were observed in the fully adjusted models. This study supports that induction of labor through oxytocin administration does not increase the risk of autism spectrum disorder in the child. Our international comparison of 2 countries with differences in clinical practice regarding oxytocin administration for induction and/or augmentation suggests that previous studies reporting a significant association were likely confounded by the underlying indication for the induction.

Purpose: Given the increase in attention‐deficit/hyperactivity disorder (ADHD) diagnoses and stimulant medication use among female adults, this study describes the prevalence trends of perinatal ADHD stimulant medication use in British Columbia, Canada, along with characteristics and patterns of use.Methods: Using linked population‐based administrative data, we included all pregnant people with deliveries between January 2000 and December 2021. ADHD stimulant medication use was defined as filled prescriptions for dextro−/amphetamine, methylphenidate, or lisdexamfetamine. Prevalence trends were examined by medication type and age group. Characteristics were compared between those with and without prenatal stimulant medication dispensations. Patterns of use and discontinuation were assessed from 1 year preconception to 1 year postpartum.Results: Our cohort included 899,679 pregnancies. Prenatal ADHD stimulant medication use increased by 3.9 users per 1000 pregnancies (from 0.4 to 4.3/1000), primarily driven by dextro−/amphetamine. Medication use increased among all age groups, but was highest among pregnant people under 20 years old. Pregnant people taking stimulant medications were more likely to be nulliparous and lower in income, have hypertension and higher BMI, smoke during pregnancy, use other psychotropic medications, and deliver by cesarean section. Among those who used stimulant medications within 1 year preconception, 77% discontinued treatment before or during pregnancy. While use increased again within 12 months postpartum, it remained 45% lower than preconception levels.Conclusion: The 11‐fold increase in ADHD stimulant medication use during pregnancy and the high rate of discontinuation highlight the need for more research on the risks and benefits of medication for parent and child health.