Associations of maternal exposure to fine particulate matter constituents during pregnancy with Apgar score and duration of labor: A retrospective study in Guangzhou, China, 2012-2017.

BACKGROUND: Limited evidence is available for demonstrating effects of prenatal PM2.5 and its components exposure on Apgar score and duration of labor. OBJECTIVE: We sought to investigate the associations between PM2.5 constituents, Apgar score and duration of labor, and evaluated the potential mediating role of duration of labor. METHODS: This study included 5396 participants. The V4·CH.02 was applied to assessing exposure to PM2.5 constituents. The associations between PM2.5 constituents Apgar score and duration of labor were examined by multivariate linear regression. Mediation analysis was conducted to estimate the potential mediation effect of duration of labor. RESULTS: Trimester-specific exposure to soil dust was significantly associated with 1-min Apgar score (1st trimester: OR: 1.03, 95% CI:0.97, 1.10; 2nd trimester: OR: 1.07, 95% CI: 1.01, 1.14; 3rd trimester: OR: 1.07, 95% CI: 1.01, 1.13), duration of first stage of labor (1st trimester: ß: 0.32, 95% CI: 0.07, 0.58; 2nd trimester: ß: 0.27, 95% CI: 0.04, 0.51; 3rd trimester: ß: 0.37, 95% CI: 0.13, 0.61) and duration of second stage of labor (1st trimester: ß: 0.04, 95% CI: -0.00, 0.09; 2nd trimester: ß: 0.05, 95% CI: 0.01, 0.10; 3rd trimester: ß: 0.05, 95% CI: 0.00, 0.09). The duration of labor mediated the relationship between soil dust and 1-min Apgar score. CONCLUSION: This study demonstrated that prenatal exposure to soil dust was significantly associated with the risk of abnormal 1-min Apgar score and extended stage of labor.

Effects of particulate matter exposure on semen quality: A retrospective cohort study.

BACKGROUND: Particulate matter (PM) exposure is closely associated with male infertility. Even though an association between poor semen quality and PM exposure has been widely accepted, which and when the semen parameter could be affected are still controversial. The purpose of this study is to estimate the effects of PM exposure on semen quality in Huai'an, China. OBJECTIVES AND METHODS: The study included 1955 men with 2073 semen samples between 2015 and 2017 with moderate to high exposure to air pollution in Huai'an, China. Three multivariable linear regression models were used to conduct exposure-response analyses for PM exposure and semen quality and to estimate the influence during different exposure periods by every 15 days period before ejaculation in all participants group and normal semen quality participants group. RESULTS: The average age of the observations was 28.9 ± 5.4 old years and the average abstinence period was 4.2 ± 1.5 days. The results showed high correlations between both PM2.5 and PM10 exposures throughout entire spermatogenesis and the declines of sperm count (ß: -0.93, p < 2 × 10-16 and ß: -1.00, p < 2 × 10-16), and sperm concentration (ß: -1.00, p < 2 × 10-16 and ß: -1.06, p < 2 × 10-16), and PM10 exposure decreased sperm total motility (ß: -0.60, p = 2.56 × 10-7), but not sperm progressive motility. Furthermore, PM2.5 exposure decreased sperm count and concentration during 15-75 lag days, and PM10 exposure showed significant association with sperm count and concentration during 0-75 lag days. PM2.5 and PM10 exposures during 45-59 lag days were both inversely associated with sperm total motility (all p value < 0.05). CONCLUSION: The present study revealed that ambient PM exposure throughout spermatogenesis during a long period, especially at early and middle stage were adversely associated with semen quality, sperm count and sperm concentration in particular.

Physical activity and blood pressure during pregnancy: Mediation by anxiety symptoms.

BACKGROUND: During pregnancy, physiological systems and psychological perceptions vary across individuals. Prenatal physical activity has been linked to reduced anxiety symptoms and lower blood pressure values. However, whether anxiety symptoms can mediate the relationship between physical activity and blood pressure during pregnancy remains unclear. METHODS: In this prospective cohort study, 1275 pregnant women enrolled in Nanjing, China. Life behaviours and anxiety symptoms were investigated during the first trimester. Anxiety symptoms were measured by the Self-Rating Anxiety Scale. Blood pressure values were taken during the third trimester. Multivariate linear regression models were used to estimate the associations of physical activity with anxiety symptoms and blood pressure, and mediating effect models were used to detect the regulating effect by anxiety. RESULTS: The participants were assigned to 3 groups based on their frequency and intensity of physical activity, and those who engaged in regular physical activity had lower blood pressure values. Anxiety symptoms were milder in the regular group than in the insufficient group. Partial mediating effect of anxiety on the association between regular physical activity and systolic blood pressure was significant after accounting for some confounders. LIMITATIONS: The participants' physical activity and anxiety symptoms were self-reported, as well as the lack of details of physical activity during pregnancy may restrict the power of our findings. CONCLUSIONS: Regular physical activity might be beneficial for anxiety and blood pressure. Physical activity likely stabilises systolic blood pressure by alleviating anxiety symptoms. Our research could provide a positive theoretical reference for guiding prenatal care.