Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 6710B Rockledge Drive Room 3119, MSC 7004, Bethesda, MD 20817, USA; The Emmes Corporation, Rockville, MD 20850, USA.
Hum Reprod. 2018 Jan 1;33(1):166-176. doi: 10.1093/humrep/dex341.
Does ambient air pollution affect fecundability?
While cycle-average air pollution exposure was not associated with fecundability, we observed some associations for acute exposure around ovulation and implantation with fecundability.
Ambient air pollution exposure has been associated with adverse pregnancy outcomes and decrements in semen quality.
STUDY DESIGN, SIZE, DURATION: The LIFE study (2005-2009), a prospective time-to-pregnancy study, enrolled 501 couples who were followed for up to one year of attempting pregnancy.
PARTICIPANTS/MATERIALS, SETTING, METHODS: Average air pollutant exposure was assessed for the menstrual cycle before and during the proliferative phase of each observed cycle (n = 500 couples; n = 2360 cycles) and daily acute exposure was assessed for sensitive windows of each observed cycle (n = 440 couples; n = 1897 cycles). Discrete-time survival analysis modeled the association between fecundability and an interquartile range increase in each pollutant, adjusting for co-pollutants, site, age, race/ethnicity, parity, body mass index, smoking, income and education.
Cycle-average air pollutant exposure was not associated with fecundability. In acute models, fecundability was diminished with exposure to ozone the day before ovulation and nitrogen oxides 8 days post ovulation (fecundability odds ratio [FOR] 0.83, 95% confidence interval [CI]: 0.72, 0.96 and FOR 0.84, 95% CI: 0.71, 0.99, respectively). However, particulate matter ≤10 microns 6 days post ovulation was associated with greater fecundability (FOR 1.25, 95% CI: 1.01, 1.54).
LIMITATIONS, REASONS FOR CAUTION: Although our study was unlikely to be biased due to confounding, misclassification of air pollution exposure and the moderate study size may have limited our ability to detect an association between ambient air pollution and fecundability.
While no associations were observed for cycle-average ambient air pollution exposure, consistent with past research in the United States, exposure during critical windows of hormonal variability was associated with prospectively measured couple fecundability, warranting further investigation.
STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Longitudinal Investigation of Fertility and the Environment study contract nos. #N01-HD-3-3355, NO1-HD-#-3356, N01-HD-3-3358 and the Air Quality and Reproductive Health Study Contract No. HHSN275200800002I, Task Order No. HHSN27500008). We declare no conflict of interest.
空气污染是否会影响生育能力？
虽然循环平均空气污染暴露与生育能力无关，但我们观察到排卵和着床周围的急性暴露与生育能力存在一些关联。
大气污染暴露与不良妊娠结局和精液质量下降有关。
研究设计、大小、持续时间： LIFE 研究（2005-2009 年），一项前瞻性的妊娠时间研究，招募了 501 对夫妇，对他们进行了长达一年的妊娠尝试随访。
参与者/材料、地点、方法： 在每个观察周期的卵泡期和增生期之前评估平均空气污染物暴露（n=500 对；n=2360 个周期），并在每个观察周期的敏感窗口评估每日急性暴露（n=440 对；n=1897 个周期）。离散时间生存分析模型研究了每个污染物的四分位距增加与生育能力之间的关系，调整了共污染物、地点、年龄、种族/民族、产次、体重指数、吸烟、收入和教育。
循环平均空气污染物暴露与生育能力无关。在急性模型中，排卵前一天接触臭氧和排卵后 8 天接触氮氧化物与生育能力下降相关（生育能力比值比[OR]0.83，95%置信区间[CI]：0.72，0.96 和 OR 0.84，95% CI：0.71，0.99）。然而，排卵后 6 天的颗粒物≤10 微米与更高的生育能力相关（生育能力比值比[OR]1.25，95%置信区间[CI]：1.01，1.54）。
局限性、谨慎的原因： 尽管由于混杂、空气污染暴露的错误分类以及适度的研究规模，我们的研究不太可能存在偏倚，但这可能限制了我们检测大气污染与生育能力之间关联的能力。
虽然在美国进行的既往研究一致表明，循环平均环境空气污染暴露没有关联，但在激素变化的关键窗口期暴露与前瞻性测量的夫妇生育能力有关，这值得进一步研究。
研究资金/利益冲突： 这项工作得到了美国国立儿童健康与人类发展研究所内部研究计划的支持（生育和环境的纵向研究合同编号：#N01-HD-3-3355、NO1-HD-#-3356、N01-HD-3-3358 和空气质量与生殖健康研究合同号：HHSN275200800002I，任务订单号：HHSN27500008）。我们没有申报任何利益冲突。
