Background: Mounting evidence implicates an association between ambient air pollution and impaired reproductive potential of human. Our study aimed to assess the association between air pollution and ovarian reserve in young, infertile women.Methods: Our study included 2276 Korean women who attended a single fertility center in 2016–2018. Women’s exposure to air pollution was assessed using concentrations of particulate matter (PM₁₀and PM_2.5), nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), and ozone (O₃) that had been collected at 269 air quality monitoring sites. Exposure estimates were computed for 1, 3, 6, and 12 months prior to the ovarian reserve tests. Anti-Müllerian hormone (AMH) ratio (defined as an observed-to-expected AMH based on age) and low AMH (defined as < 0.5 ng/mL) were employed as indicators of ovarian reserve. We included a clustering effect of 177 districts in generalized estimating equations approach. A secondary analysis was conducted restricting the analyses to Seoul residents to examine the association in highly urbanized setting.Results: The mean age was 36.6 ± 4.2 years and AMH level was 3.3 ± 3.1 ng/mL in the study population. Average AMH ratio was 0.8 ± 0.7 and low AMH was observed in 10.3% of women (n=235). The average concentration of six air pollutants was not different between the normal ovarian reserve and low AMH groups for all averaging periods. In multivariable models, an interquartile range (IQR)-increase in 1 month-average PM₁₀was associated with decrease in AMH ratio among total population (β= −0.06, 95% confidence interval: −0.11, 0.00). When we restrict our analysis to those living in Seoul, IQR-increases in 1 and 12 month-average PM_2.5were associated with 3% (95% CI: −0.07, 0.00) and 10% (95% CI: −0.18, −0.01) decrease in AMH ratio. The ORs per IQR increase in the six air pollutants were close to null in total population and Seoul residents.Conclusions: In a cohort of infertile Korean women, there was a suggestive evidence of the negative association between ambient PM concentration and ovarian reserve, highlighting the potential adverse impact of air pollution on women’s fertility.

Background: Benzodiazepines are frequently prescribed during pregnancy; however, evidence about possible teratogenicity is equivocal. We aimed to evaluate the association between first-trimester benzodiazepine use and the risk of major congenital malformations.Methods and findings: Using Korea’s nationwide healthcare database, we conducted a population-based cohort study of women who gave birth during 2011 to 2018 and their live-born infants. The exposure was defined as one or more benzodiazepine prescriptions during the first trimester. We determined the relative risks (RRs) and confidence intervals (CIs) of overall congenital malformations and 12 types of organ-specific malformations. Infants were followed from birth to death or 31 December 2019, whichever came first (up to 8 years of age). Propensity score fine stratification was employed to control for 45 potential confounders. Among a total of 3,094,227 pregnancies, 40,846 (1.3%) were exposed to benzodiazepines during the first trimester (mean [SD] age, 32.4 [4.1] years). The absolute risk of overall malformations was 65.3 per 1,000 pregnancies exposed to benzodiazepines versus 51.4 per 1,000 unexposed pregnancies. The adjusted RR was 1.09 (95% CI 1.05 to 1.13,p< 0.001) for overall malformations and 1.15 (1.10 to 1.21,p< 0.001) for heart defects. Based on mean daily lorazepam-equivalent doses, the adjusted RRs for overall malformations and heart defects were 1.05 (0.99 to 1.12,p= 0.077) and 1.12 (1.04 to 1.21,p= 0.004) for <1 mg/day and 1.26 (1.17 to 1.36,p< 0.001) and 1.31 (1.19 to 1.45,p< 0.001) for >2.5 mg/day doses, respectively, suggesting a dose–response relationship. A small but significant increase in risk for overall and heart defects was detected with several specific agents (range of adjusted RRs: 1.08 to 2.43). The findings were robust across all sensitivity analyses, and negative control analyses revealed a null association. Study limitations include possible exposure misclassification, residual confounding, and restriction to live births.Conclusions: In this large nationwide cohort study, we found that first-trimester benzodiazepine exposure was associated with a small increased risk of overall malformations and heart defects, particularly at the higher daily dose. The absolute risks and population attributable fractions were modest. The benefits of benzodiazepines for their major indications must be considered despite the potential risks; if their use is necessary, the lowest effective dosage should be prescribed to minimize the risk.Trial registration: ClinicalTrials.gov NCT04856436.

We investigated differences in the achievement of glycemic control among newly diagnosed type-2 diabetes patients according to gender using a multi-clinic retrospective cohort study. Optimal glycemic control was defined as hemoglobin A1c (HbA1c) of less than 6.5% after 1 year of diabetes management. A generalized linear mixed model, which controlled for the fixed effects of baseline characteristics and prescribed oral hypoglycemic agent (OHA), was used to calculate the probability of achieving the target HbA1c. The study included 2,253 newly diagnosed type-2 diabetes patients who completed 1 year of diabetic management, including OHA, in the 36 participating primary clinics. Within the study population, the women had an older average age, were less likely to smoke or drink alcohol, and showed lower levels of fasting blood glucose and HbA1c at the time of diagnosis. There were no significant differences by sex in prescribed OHA or median number of visits. After 1 year of diabetes management, 38.9% of women and 40.6% of men achieved the target HbA1c—a small but significant difference. This suggests that type-2 diabetes is managed less well in women than in men.

Choe SA, et al. J Korean Med Sci. 2017 Nov;33(4):e23. https://doi.org/10.3346/jkms.2018.33.e23