Table 1 Main characteristics of studies included in the systematic review and meta-analysis
Reference (author and year of publication) | Study location and period | Study design (sample size) | Database of the population | ART treatments of the population (age) | Outcomes of interest | windows of exposure | Air pollutant assessed | Air pollutant indicator | Exposure assessment method | Average pollutant concentration | Adjustment covariates | Main finding |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Boulet et al. 2019 [18] | USA 2010–2012 | Cohort study (253,528) | Centers for Disease Control and Prevention’s National ART Surveillance System | IVF with fresh embryos (all ages) | Clinical pregnancy; Live birth | Cycle start to oocyte retrieval; Oocyte retrieval to embryo transfer; embryo transfer + 14 days | PM2.5 and O3 | National Air Monitoring Stations/State and Local Air Monitoring Stations and numerical output from the Models- 3/Community Multiscale Air Quality | Bayesian downscaler models | PM2.5 mean (9.2 to 9.5 μg/m3); O3 mean (38.1 to 38.5 ppb) | Patient age, parity, infertility diagnosis, number of prior ART cycles, number oocytes retrieved, and season and year of cycle start | Clinical pregnancy: RR = 1.01 (1.000–1.02) for O3 from oocyte retrieval to embryo transfer; RR = 1.01 (1.000–1.02) for O3 from embryo transfer + 14 days Live birth: RR = 1.01 (1.002–1.02) for O3 from cycle start to oocyte retrieval; RR = 1.01 (1.004–1.02) for O3 from oocyte retrieval to embryo transfer; RR = 1.04 (1.004–1.03) for O3 from embryo transfer + 14 days |
Choe et al. 2018 [19] | Korea 2006–2014 | Cohort study (4,581) | Clinical records from fertility Centre of the Gangnam CHA Hospital | IVF with fresh embryos (20–44) | Biochemical pregnancy; Clinical pregnancy; Live birth | Start of controlled ovarian stimulation to oocyte retrieval; oocyte retrieval to embryo transfer; embryo transfer to hCG test; start of controlled ovarian stimulation to hCG test | PM10, NO2, CO, SO2 and O3 | 40 air quality monitoring sites in Seoul obtained from the National Institute of Environmental Research | A district average was assigned as individual exposures for women living in the same district | PM10 mean (47.6 to 50.6 μg/m3); NO2 mean (33.6 to 34.8 ppb); SO2 mean (5.3 to 5.5 ppb); CO (664.2 to 681.5 ppb); O3 mean (34.0 to 34.5 ppb) | Women’s age, BMI, number of oocytes retrieved, ICSI, number of embryos transferred, blastocyst transfer, season and year of oocyte retrieval | Clinical pregnancy: HR = 0.93 (0.87–0.99) for NO2 and HR = 0.94 (0.89–1.00) for CO from start of controlled ovarian stimulation to oocyte HR = 0.92 (0.85–0.99) for PM10, HR = 0.93 (0.86–1.00) for NO2 and HR = 0.93 (0.87–1.00) for CO from embryo transfer to hCG test Biochemical pregnancy: HR = 1.17 (1.04–1.33) for PM10 and HR = 1.18 (1.03–1.34) for NO2 from embryo transfer to hCG test |
Dai et al. 2021 [34] | China 2013–2019 | Cohort study (6,659) | Reproductive Medicine Management System from the fertility center of the First Affiliated Hospital of Zhengzhou University Clinical | IVF with fresh embryos (20–49) | Clinical pregnancy; Live birth | 85 days before oocyte retrieval; Gn start to oocyte retrieval | PM2.5, PM10, AQI | Daily China National Environmental Monitoring Center | Average daily concentration for PM2.5, PM10 and AQI | 85 days before the oocyte retrieval: PM2.5 mean 73.19 μg/m3, PM10 mean 130.71 μg/m3, and AQI mean 116.40 Start of Gn to oocyte retrieval: PM2.5 mean 73.55 μg/m3, PM10 mean 130.62 μg/m3, and AQI mean 117.11 | Patient characteristics, including maternal age, BMI, number of retrieved oocytes, education, infertility types, fertilization method, and protocols were obtained from the CCRM system | Clinical pregnancy: OR = 0.838 (0.723–0.971) for PM2.5 and OR = 0.818 (0.705–0.950) for PM10 during 85 days before oocyte retrieval; OR = 0.852 (0.736–0.987) for PM2.5 from Gn start to oocyte retrieval Live birth: OR = 0.852 (0.736–0.987) for PM2.5 and OR = 0.850 (0.733, 0.986) for PM10 85 days before oocyte retrieval; OR = 0.817 (0.733, 0.986) for PM2.5 from Gn start to oocyte retrieval |
Gonzalez-Comadran et al. 2021 [39] | Spain 2014–2018 | Cohort study (194) | Clinical records from Hospital del Mar de Barcelona, CIRH and Hospital Universitari Quirón-Dexeus | IVF with fresh versus frozen-thawed embryos (Clinical pregnancy: 36.44 ± 0.33, No pregnancy: 37.20 ± 0.25) | Clinical pregnancy | 15 days before embryo transfer; 3 days before embryo transfer; the same day of transfer; 7 days after transfer | PM2.5, PM10 and NO2 | European Study of Cohorts for Air Pollution Effects | Land use regression modeling following a standardized protocol | NO2 mean (36.05 to 38.01 μg/m3); NOX mean (62.09 to 65.41 μg/m3); PM2.5 mean (10.35 to 10.57) μg/m3; PM2.5ab mean (1.62 to 2.02 1 unitat); PM10 mean (21.83 to 22.31 μg/m3) | Age, BMI, physical activity, smoking intensity, adherence to Mediterranean diet, socioeconomic status, number and quality of the embryos transferred, and the type of endometrial preparation | Clinical pregnancy: OR = 1.84 (1.00–3.39) for PM2.5 three days before the embryo transfer |
Iodice et al. 2021 [40] | Italy 2014–2017 | Cohort study (2,122) | Clinical records from the Centro Scienze Natalit` a of IRCCS Ospedale San Raffaele, Milan, Italy | IVF and ICSI with fresh or frozen embryos (37.3 ±â¶Ä‰4.3) | Clinical pregnancy; Biochemical pregnancy | 14 days preceding the oocyte retrieval; on the day of oocyte retrieval | PM10 | Monitoring stations of the ARPA Lombardy air quality network | ARIA Regional Modelling, a chemical-physical model of air quality | Mean Day 0–7: 34.1μg/m3; Mean Day 0–14: 34μg/m3 | Female age, BMI, AMH levels, progesterone levels at hCG triggering, indications to ART cycles, days of the week | Clinical pregnancy: OR = 1.052 (1.002–1.105) from Day-9 to day 0, OR = 1.054 (1.005–1.106) from Day-10 to day 0, OR = 1.066 (1.014–1.120) from Day-11 to day 0, OR = 1.072 (1.020–1.127) from Day-12 to day 0, OR = 1.050 (0.999–1.104) from Day-13 to day 0 |
Jin et al. 2022 [35] | China 2015–2020 | Cohort study (6,564) | Clinical records from the center for reproductive medicine of the First Affiliated Hospital of Zhengzhou University | IVF with fresh embryos (31.2) | Clinical pregnancy | From 90 days before oocyte retrieval to Gn start; from Gn start to oocyte retrieval; from oocyte retrieval to embryo transfer; from embryo transfer to 35 days after transfer; from 90 days before oocyte retrieval to 35 days after transfer | PM2.5, PM10, NO2, SO2, CO and O3 | 13 monitoring stations in Zhengzhou | PM2.5, PM10, NO2, SO2, CO: 24-h average values of all monitoring stations O3: the maximum 8-h rolling average concentration level of all monitoring stations | PM2.5 median (42.73 to 50.39 μg/m3), PM10 median (94.1 to 111.12 μg/m3), NO2 median (43.67 to 48,51 μg/m3), SO2 median (11.31 to 12.93 μg/m3), CO median (0.92 to 0.99 mg/m3) and O3 median (114.83 to 128.63 μg/m3) | The female's age, BMI, duration of stimulation, No. of retrieved oocytes, baseline FSH, duration of infertility, endometrial thickness on transfer day, No. of embryo transfer, stage of embryos transfer, and year of transfer | Clinical pregnancy: OR = 0.915 (0.869–0.963) for PM2.5, OR = 0.924 (0.870–0.982) for SO2, OR = 0.894 (0.846–0.945) for CO, OR = 0.920 (0.873–0.970) for NO2 and OR = 1.070 (0.870–0.982) for O3 from Gn start to oocyte retrieval; OR = 0.929 (0.876–0.985) for SO2 and OR = 1.081 (1.030–1.133) for O3 from Gn start to oocyte retrieval; OR = 0.894 (0.850–0.941) for PM2.5, OR = 0.912 (0.867–0.960) for PM10, OR = 0.866 (0.814–0.922) for SO2, OR = 0.849 (0.800–0.900) for CO and OR = 0.866 (0.820–0.914) for NO2 and OR = 1.113 (1.060–1.167) for O3 from embryo transfer to 35 days after transfer |
Legro et al. 2010 [6] | USA 2000–2007 | Cohort study (7,403) | Clinical records from three centers: Penn State College of Medicine in Hershey, PA, USA; Shady Grove Fertility in Rockville, MD, USA and Columbia University College of Physicians and Surgeons in New York, NY, USA | IVF (35.0 ±â¶Ä‰4.5) | Clinical pregnancy; Live birth | From medication start to oocyte retrieval; from oocyte retrieval to embryo transfer; from embryo transfer to pregnancy test (14 days); from embryo transfer to the date of live birth | PM2.5, PM10, SO2, NO2 and O3 | All ambient criteria air pollutant concentration data recorded at monitors operating in the contiguous USA | An established national-scale, log-normal kriging method were used to spatially estimate daily mean concentrations of criteria pollutants at addresses of subjects | PM2.5 mean (14.01 to 14.45 μg/m3); PM10 mean (23.80 to 24.10 μg/m3); SO2 mean (0.057 to 0.063 ppm); NO2 mean (0.018 to 0.019 ppm); O3 mean (0.037 to 0.038 ppm) | Patient’s age, IVF center and the year and season of oocyte retrieval | Live birth: OR = 0.76 (0.66–0.86) for NO2 from embryo transfer to pregnancy test; OR = 1.26 (1.10–1.44) for O3 from medication start to oocyte retrieval; OR = 0.62 (0.48–0.81) for O3 from embryo transfer to live birth; OR = 0.90 (0.82–0.99) for PM2.5 during embryo culture |
Li et al. 2020 [41] | China 2014–2019 | Cohort study (9,941) | Clinical records from the Second Hospital of Hebei Medical University, Shijiazhuang City, China | IVF and ICSI with fresh embryos (20–47) | Clinical Pregnancy; Biochemistry pregnancy | Preantral follicle stage to Gn start (75 days); Gn start to embryo transfer (11 days); Gn start to embryo transfer (4 days); embryo transfer to serum hCG test (14 days); primordial follicle stage to serum hCG test (360 days) | PM2.5, PM10, NO2, SO2, CO, and O3 | Collected daily at 149 monitoring stations located at Hebei province | Spatiotemporal kriging model based on residential addresses | PM2.5 mean 70 ± 62 μg/m3; PM10, 120 ± 85 μg/m3; NO2, 37 ± 21 μg/m3; SO2, 30 ± 29 μg/m3; CO, 1.2 ± 1.0 mg/m3; O3, 103 ± 58 μg/m3 | Maternal age, Education, BMI, basal FSH, duration of infertility, total dosage of gonadotrophin, fertilization method, number of oocytes, number of embryo transferred, and endometrial thickness | Clinical pregnancy: OR = 0.95 (0.90–0.99) for PM2.5, OR = 0.93 (0.89–0.98) for PM10, OR = 0.89 (0.85–0.94) for NO2, OR = 0.94 (0.90–0.98) for SO2 and OR = 0.93 (0.89–0.97) for CO from preantral follicle stage to Gn starts; OR = 0.93 (0.88–0.97) for NO2 and OR = 0.96 (0.93–0.99) for SO2 from Gn start to embryo transfer; OR = 1.08 (1.02–1.14) for O3 from embryo transfer to serum hCG test; OR = 0.93 (0.88–0.98) for NO2 from primordial follicle stage to serum hCG test |
Liu et al. 2022 [26] | China, 2014–2018 | Cohort study (8,628) | The assisted reproductive electronic medical record system database of the Reproductive Medicine Center of The Third Affiliated Hospital of Zhengzhou University | IVF with fresh embryos (31.11 ±â¶Ä‰4.96) | Clinical pregnancy; Biochemical pregnancy; Live birth | Gn injection to oocyte retrieval; oocyte retrieval to embryo transfer; 1 day after embryo transfer to embryo transfer + 14 days and Gn injection to embryo transfer + 14 days | CO, NO2, O3, PM10, PM2.5 and SO2 | Real-time urban air quality data from the Ministry of Ecology and Environment of the People's Republic of China | Average daily concentrations retrieved from the monitoring station closest to the address of subject or to the study centre | CO median 1.22 mg/ m3; NO2 median 49 µg/m3; O3 median 105 µg/m3; PM10 median 124 µg/m3; PM2.5 median 61 µg/m3 and SO2 median 20 µg/m3 | Patient age, BMI, type of infertility, duration of infertility, infertility diagnosis, year cycle started, number of oocytes retrieved, fertilization method, number of embryos transferred, stage and quality of transferred embryos and endometrial thickness | Clinical pregnancy: OR = 0.81 (0.71–0.92) for PM10; OR = 0.82 (0.73–0.93) for SO2 1 day after embryo transfer to embryo transfer + 14 days; °¿¸é = 0.87 (0.76–1.00) for PM10 from gonadotrophin injection to embryo transfer + 14 days Biochemical pregnancy: OR = 1.55 (1.09–2.19) for PM10 from gonadotrophin injection to oocyte retrieval Live birth: OR = 0.88 (0.77–0.99) for PM10 1 day after embryo transfer to embryo transfer + 14 days |
Perin et al. 2010 [42] | Brazil 1997–2006 | Cohort study (348) | IVF database collected from CEERH, Specialized Center for Human Reproduction | IVF with fresh embryos (19–45) | Live birth | Follicular phase | PM10 | São Paulo State Environmental Protection Agency | 24-h arithmetical average of PM10 across all monitoring stations | Q1: ≤ 30.48 µg/m3, Q2: 30.49–42.00 µg/m3, Q3: 42.01–56.72 µg/m3, and Q4: > 56.72 µg/m3 | The year of IVF treatment and patient’s age | Clinical Pregnancy: OR = 5.05 (1.04–24.51) for PM10 |
Qiu et al. 2019 [21] | China 2014–2018 | Cohort study (1,455) | Clinical data were extracted from the patient database used in the fertility center of Shengjing hospital | IVF and ICSI with fresh embryos (33.3 ±â¶Ä‰4.1) | Clinical pregnancy | 85 days before the oocyte retrieval to start of Gn; start of Gn to oocyte retrieval; oocyte retrieval to embryo transfer; embryo transfer to hCG test; start of Gn to hCG test | PM10, PM2.5, NO2, CO, SO2 and O3 | 11 air quality monitoring stations in Shenyang obtained from Shenyang Environmental Protection Bureau of China | Each individual air pollution exposure was represented by the data from the nearest monitor station | PM2.5 median (48.25 to 55.48 µg/m3); PM10 median (91.75 to 102.29 µg/m3); SO2 median (27.20 to 36.55 µg/m3); CO median (0.90 to 0.94 µg/m3); NO2 median (41.75 to 43.16 µg/m3); O3 (100.04 to 106.00 µg/m3) | Maternal age, BMI, education, year of oocyte retrieval, number of retrieved oocytes, number of transferred embryos, fertilization method and stage of transferred embryos | Clinical pregnancy: °¿¸é = 0.87 (0.81–0.98) for O3 from Gn starting to oocyte retrieval; OR = 0.86 (0.78–0.95) for O3 one day before oocyte retrieval; OR = 1.12 (1.01–1.23) for CO two days before oocyte retrieval |
Quraishi et al. 2019 [43] | USA 2012–2013 | Cohort study (19,003) | Medical records from a network of private fertility clinics across the United States | IVF with fresh embryos (34.9 ±â¶Ä‰4.6) | Clinical pregnancy; Live birth | Period before the cycle to ovarian stimulation | PM2.5, PM10, and NO2 | Regulatory monitoring data from the Environmental Protection Agency Air Quality System and Interagency Monitoring of Protected Visual Environments networks | A national spatial model incorporating land-use regression and universal kriging | PM2.5 mean 8.7 ± 1.4 µg/m3, PM10 mean 14.9 ± 3.8µg/m3, and NO2 mean 9.0 ± 4.7 ppb | Age, BMI, race, and NSES, clinic indicators for Seattle, SF, LA, Baltimore/Chesterbrook, and Rockville | Live birth: RR = 0.96 (0.90–1.02) for PM2.5, RR = 0.98 (0.94–1.02) for PM10, RR = 0.96 (0.91–1.00) for NO2 before IVF start Positive hCG test: RR = 0.98 (0.9–1.02) for PM2.5, RR = 0.99 (0.95–1.01) for PM10, RR = 0.99 (0.95–1.02) for NO2 before IVF start |
Shi et al. 2021 [22] | China 2016–2019 | Cohort study (2,766) | Clinical records from the Centre for Assisted Reproduction of Shanghai First Maternity and Infant Hospital | IVF and ICSI with fresh or frozen embryos (32.7 ±â¶Ä‰3.9) | Biochemical pregnancy; Live birth | From three months before oocyte retrieval to serum hCG test; from serum hCG test to live birth outcome; from three months before oocyte retrieval to live birth outcome | PM2.5, PM10, NO2, SO2, CO and O3 | The concentrations of six criteria air pollutants were obtained from 16 air monitoring stations from the Shanghai environmental monitoring center | Available data from the nearest monitoring station were applied to estimate the concentrations of air pollutants for each participant | PM2.5 (34.2 to 36.1 µg/m3), PM10 (50.4 to 51.4 µg/m3), NO2 (31.0 to 31.5 µg/m3), SO2 (8.8 to 9.2 µg/m3), CO (0.68 to 0.69 mg/m3), O3 (93.6 to 110.3 µg/m3) | Female age, BMI, educational level, employment status, residential address, duration of infertility, causes of infertility, controlled ovarian stimulation protocols, duration of stimulation, total Gn dose, progesterone levels on trigger day, number of retrieved oocytes, fertilization method, endometrial thickness on the day of embryo transfer, year of embryo transfer, season of embryo transfer, type of embryo transfer, and number of embryo(s) transferred | Biochemical pregnancy: OR = 0.86 (0.75–0.99) for NO2 from three months before oocyte retrieval to serum hCG test Live birth: OR = 0.88 (0.79–0.99) for PM10 from serum hCG test to live birth outcome; OR = 0.88 (0.79–0.99) for PM10 from three months before oocyte retrieval to live birth outcome |
Tartaglia et al. 2022 [44] | France 2013–2019 | Cohort study (10,763) | The Reproductive Biology Department of Bordeaux University Hospital localised in Bordeaux, France and the Jean Villar Fertility Center localised in Bruges, France | IVF and ICSI with fresh or frozen embryos (Clinical pregnancy: 36.0 ± 5.7 No clinical pregnancy: 37.5 ± 6.2) | Clinical pregnancy | From oocyte retrieval to embryo transfer | PM10, PM2.5, NO2 and O3, BC | Air quality monitoring stations provided by ATMO Nouvelle Aquitaine | Pollution levels representative of the air quality of a large geographical area, which is the closest pollution monitoring station and is a good representation of the ambient pollution to which fertility centers are exposed | PM2.5 mean 56.5 ± 32.2 µg/m3; PM10 mean 36.4 ± 27.4 µg/m3; BC mean 4.3 ± 3.6 µg/m3; NO2 mean 56.2 ± 34.1 µg/m3; O3 mean 148 ± 83.1 µg/m3 | The season of IVF procedure, the ovarian reserve, woman’s age, BMI, smoking status, the oocyte fertilization method (IVF, ICSI) and site of residence, the number of transferred embryos | Clinical pregnancy: OR = 0.92 (0.86–0.98) for O3 during gametes and embryos culture |
Wan et al. 2022 [45] | China 2015–2018 | Cohort study (3,698) | Clinical records from fertility center of Ruijin hospital affiliated to Shanghai Jiaotong university | IVF and ICSI with frozen embryos (No pregnancy: 33.93 ±â¶Ä‰5.00; Clinical pregnancy: 33.64 ±â¶Ä‰5.00) | Clinical pregnancy | 30 days before embryo transfer | PM2.5, PM10, SO2, CO, NO2, and O3 | Nearest monitor station according to each patient’s address | Each individual air pollution exposure was represented by the data from the nearest monitor station | PM2.5 mean 41.07 ± 14.89 μg/m3; PM10 mean 57.33 ± 15.63 μg/m3 SO2 mean 12.50 ± 4.54 μg/m3 CO mean 0.76 ± 0.16 mg/m3 NO2 mean 42.49 ± 12.14 μg/m3 O3 mean 96.83 ± 32.09 μg/m3 | Maternal age, antral follicle count (AFC), AMH, fertilization method, duration of current infertility, infertility types, embryos scores, transfer times | Clinical pregnancy: OR = 0.906 (0.816–0.989) for NO2 and OR = 0.931 (0.881–0.995) for O3 30 days before embryo transfer |
Wang et al. 2019 [46] | China, 2013–2016 | Cohort study; (11,148) | Cllinical records form the affiliated Chenggong Hospital of Xiamen University | IVF and ICSI with fresh embryos (31.5 ±â¶Ä‰4.48) | Clinical pregnancy; Live birth | From oocyte retrieval to embryo transfer/cryopreservation | PM2.5, PM10, SO2, NO2, CO and O3 | Three fixed air quality monitoring stations in the city | Estimation of pollutant concentrations at the IVF clinical site was based on an inverse distance weighting interpolation modeling method | PM2.5 median 30.26 μg/m3; PM10 median 51.99 μg/m3; SO2 median 12.86 μg/m3; CO median 0.66 μg/m3; NO2 median 30.79 μg/m3; O3 median 82.6 μg/m3 | Maternal age, BMI, order of embryo transfer, primary infertility, duration of infertility, diagnosis of tubal problem, polycystic ovary syndrome and endometriosis, basal antral follicle count, starting dose of gonadotrophin, type of GnRH analog, endometrial thickness and pattern, oocyte yield, number of embryos transferred, stage of embryos transferred, presence of top-quality embryos transferred and distance from catheter tip to fundal, type of endometrial preparation and indicators for FET | Live birth: OR = 0.63 (0.53–0.74) for SO2 and OR = 0.69 (0.58–0.82) for O3 in frozen-thawed embryo transfer cycles Clinical pregnancy: OR = 0.88 (0.78–0.99) for SO2 in fresh embryo transfer cycles; OR = 0.64 (0.54–0.75) for PM2.5, OR = 0.82 (0.69–0.97) for PM10, OR = 0.80 (0.68–0.94) for CO and OR = 0.66 (0.56–0.78) for O3 in frozen-thawed embryo transfer cycles |
Wang et al. 2023 [47] | China 2015–2018 | Cohort study (2,431) | Jiangsu Birth Cohort Study, an ongoing prospective cohort study on women who received ART treatments in the Women's Hospital of Nanjing Medical University and the Suzhou Affiliated Hospital of Nanjing Medical University | IVF and ICSI with fresh or frozen embryos (31.3 ±â¶Ä‰4.3) | Biochemical pregnancy; Clinical pregnancy; Live birth | Preantral follicle phase; oocyte growth phase; oocyte selection phase; oocyte maturation phase; the duration from oocyte retrieval to embryo transfer; the duration from embryo transfer to serum hCG test; the duration from hCG test to 30 days after embryo transfer | PM2.5 | Ground hourly PM2.5 concentration measured by a local monitoring station of the National Air Quality Monitoring Network from the China National Environmental Monitoring Center | Exposure assessment method of aerosol optical depth was used to predict the long-term trends of ground-level PM2.5 at 1 km spatial revolution | PM2.5 mean 45.4 μg/m3 | Maternal age, BMI, parity, center, maternal education, basal FSH, duration of infertility, infertility type, stimulation protocol, number of transferred embryos, fertilization method and stage of transferred embryo | Clinical pregnancy: RR = 0.98 (0.96–1.00) for PM2.5 during oocyte selection phase (20–11 days before oocyte retrieval) Biochemical pregnancy: RR = 1.06 (1.00–1.13) for PM2.5 in the duration from hCG test to 30 days after embryo transfer |
Wu et al. 2021 [48] | China 2014–2018 | Cohort study (20,835) | Clinical data extracted from the database of five reproductive centers in four provincials in Northern China | IVF and ICSI with fresh or frozen embryos (32.37 ±â¶Ä‰4.39) | Biochemical pregnancy; Clinical pregnancy; Live birth | 85 days prior to oocyte retrieval to oocyte retrieval; Gn start to oocyte retrieval; oocyte retrieval to embryo transfer in fresh embryo transfer cycles; 30 days prior to frozen embryo transfer to embryo transfer in FET cycles; embryo transfer to serum hCG test; 85 days prior to oocyte retrieval to hCG test in fresh embryo transfer cycles; 30 days before frozen embryo transfer to hCG test in FET cycles | PM2.5, PM10, O3, NO2, CO and SO2 | The air monitoring station nearest to the residential site obtained from the China National Environmental Monitoring Centre | Average concentrations of these six air pollutants using data from the nearest monitoring station as approximate individual exposure | PM2.5 median (73.00 to 82.31 μg/m3); PM10 median (115.29 to 119.56 μg/m3); O3 median (44.87 to 53.39 μg/m3); SO2 median (19.50 to 20.91 μg/m3); NO2 median (11.50 to 14.47 μg/m3); CO median (0.93 to 1.04 mg/m3) | Female age, BMI, smoking status, infertility type, infertility cause, duration of infertility, ovarian hyperstimulation protocol, the year and season of treatment, and residential city, the endometrium preparation regimen and indicators of FET | Biochemical pregnancy: OR = 0.889 (0.827–0.956) for O3, OR = 0.904 (0.846 to 0.966) for CO from 85 days prior to oocyte retrieval to oocyte retrieval; OR = 0.895 (0.835, 0.960) for O3, OR = 0.907 (0.839 to 0.981) for NO2, OR = 0.921 (0.864 to 0.981) for CO from Gn start to oocyte retrieval; OR = 0.920 (0.861 to 0.983) for O3, 0.924 (0.857 to 0.995) for NO2, OR = 0.936 (0.879 to 0.996) for CO from oocyte retrieval to embryo transfer in fresh embryo transfer cycles; OR = 0.904 (0.846 to 0.966) for CO from embryo transfer to serum hCG test; OR = 0.895 (0.833 to 0.963) for O3, OR = 0.901 (0.845 to 0.964) for CO from 85 days prior to oocyte retrieval to hCG test in fresh embryo transfer |
Zeng et al. 2020 [20] | China, 2014–2019 | Cohort study (1,139) | Clinical records from Reproductive Center of West China Second University Hospital, Sichuan University | IVF and ICSI with fresh embryos (33.50 ±â¶Ä‰4.38) | Biochemical pregnancy; Clinical pregnancy | From Gn start to oocyte retrieval; from oocyte retrieval to embryo transfer; from embryo transfer to serum HCG test; from embryo transfer to ultrasound sound test for pregnancy | PM2.5, PM10, SO2, NO2, CO and O3 | The concentrations were obtained from the China National Environmental Monitoring Centre | For each district, we calculated average ambient air pollutant concentration for aforementioned criteria pollutants | PM2.5 mean 58.5 ± 43.52 μg/m3, PM10 mean 95.51 ± 64.81 μg/m3, NO2 mean 47.77 ± 21.75 μg/m3, SO2 mean 13.88 ± 8.26 μg/m3, CO mean 0.97 ± 0.44 μg/m3, O3 mean 98.41 ± 54.56 mg/m3 | Age, BMI, education level, number of embryos transferred, and district fixed effect | In women under 35 years old: Biochemical pregnancy: OR = 1.004 (1.002–1.006) for O3, OR = 0.957 (0.938–0.976) for SO2 and OR = 0.992 (0.986–0.998) for NO2 from Gn start to oocyte retrieval; OR = 0.995 (0.992–0.999) for PM2.5, OR = 0.988 (0.978–0.999) for NO2 and OR = 0.624 (0.495–0.787) for CO from oocyte retrieval to embryo transfer; OR = 0.995 (0.992–0.998) for PM2.5, OR = 0.997 (0.994–0.999) for PM10, OR = 0.953 (0.939–0.969) for SO2, OR = 0.983 (0.977–0.989) for NO2, OR = 0.517 (0.411–0.649) for CO from embryo transfer to serum HCG test Clinical pregnancy: OR = 1.005 (1.003–1.007) for O3 and OR = 0.959 (0.941–0.978) for SO2 from Gn start to oocyte retrieval; OR = 0.996 (0.994–0.999) for PM2.5, OR = 1.003 (1.001–1.005) for O3, OR = 0.99 (0.982–0.998) for NO2 and OR = 0.671 (0.553–0.815) for CO from oocyte retrieval to embryo transfer; OR = 0.994 (0.99–0.998) for PM2.5, OR = 0.996 (0.993–0.999) for PM10, OR = 1.004 (1.001–1.007) for O3, OR = 0.946 (0.919–0.974) for SO2, OR = 0.979 (0.973–0.985) for NO2 and OR = 0.474 (0.358–0.626) for CO from embryo transfer to serum HCG test |
Zhang et al. 2022 [49] | China, 2015–2019 | Cohort study (12,665) | Clinical records from the Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University | IVF and ICSI with fresh or frozen embryos (30.35 ±â¶Ä‰4.1) | Live birth; Biochemical pregnancy; Clinical pregnancy | 90 days prior to oocyte retrieval; one year prior to oocyte retrieval; the day of oocyte retrieval to the serum hCG test or the end of the pregnancy; one year prior to oocyte retrieval to the serum hCG test or the end of the pregnancy | PM10, PM2.5, SO2, NO2, CO and O3 | The data were provided by Shanghai Meteorological Bureau Yangtze River Delta Center, which were obtained from 149 national-standard monitoring stations of China National Environmental Monitoring Center | Available data from the nearest monitoring station were applied to estimate the concentrations of air pollutants for each participant | PM2.5 mean (41.85 to 44.79 μg/m3); PM10 mean (64.37 to 70.02 μg/m3); CO mean (0.78 to 0.81 mg/m3); NO2 mean (39.79 to 40.56 μg/m3); SO2 mean (13.04 to 15.51 μg/m3); O3 mean (213.61 to 262.06 μg/m3) | Female age, BMI, employment status, education level, type of embryo transfer, number of embryos transferred, stimulation protocols, fertilization method, number of oocytes retrieved, and endometrial thickness | Biochemical pregnancy: OR = 0.92 (0.87–0.97) for PM10, OR = 0.91 (0.86–0.96) for PM2.5, OR = 0.93 (0.90, 0.97) for SO2, OR = 0.95 (0.91–0.99) for CO 90 days prior to oocyte retrieval; OR = 0.85 (0.81–0.90) for PM10, OR = 0.79 (0.74–0.84) for PM2.5, OR = 0.85 (0.82–0.89) for SO2, OR = 0.86 (0.84–0.93) for CO, OR = 1.14 (1.08–1.20) for O3 one year prior to oocyte retrieval Live birth; OR = 0.95 (0.90–1.00) for PM10, OR = 0.94 (0.89–0.98) for PM2.5, OR = 0.93 (0.90–0.97) for SO2 and 0.95 (0.91–0.99) for CO 90 days prior to oocyte retrieval; OR = 0.89 (0.84–0.93) for PM10, OR = 0.82 (0.77–0.87) for PM2.5, °¿¸é = 0.87 (0.83–0.91) for SO2, OR = 0.91 (0.87–0.96) for CO, OR = 1.13 (1.07–1.19) for O3 one year prior to oocyte retrieval Clinical pregnancy: OR = 0.95 (0.90, 0.99) for PM2.5, OR = 0.94 (0.91, 0.98) for SO2, OR = 0.95 (0.91, 0.99) for CO 90 days prior to oocyte retrieval; OR = 0.86 (0.82–0.90) for PM10, OR = 0.80 (0.75–0.85) for PM2.5, OR = 0.86 (0.82–0.90) for SO2, OR = 1.00 (0.96–1.04) for NO2, OR = 0.90 (0.86–0.94) for CO, OR = 1.14 (1.08–1.20) for O3 one year prior to oocyte retrieval |