P-730 A feasibility study of the impact of the level of exposure to ambient air pollutants on outcomes of assisted reproductive technologies
Authors: Blyth U , Perkins M , Harrop S , Lennox K , Dang H , Namdeo A , Choudhary M 
Published: July 2024

Abstract

Study question
What is the impact of air pollution exposure on outcomes for couples having IVF treatment?

Summary answer
Environmental exposure to high levels of air pollutants may negatively influence IVF outcomes with potential implications for fertility treatment.

What is known already
Air pollutants are harmful substances in the atmosphere that have adverse effects on human health. Increased levels of air pollutants have been associated with respiratory disorders, cardiovascular disease, and increased morbidity in humans across all age groups. Existing evidence suggests that increased exposure to air pollutants may adversely affect fertility. The relationship between air pollutants and IVF outcomes remains poorly understood.

Study design, size, duration
This was an ethically approved prospective observational feasibility study conducted over a two-year period. Ten couples due to undergo an IVF cycle were recruited from a fertility centre in the UK. Environmental exposure to ambient air pollutant for particulate matter (PM) 2.5 and 10 micron size was measured using portable AirBeam monitors over the course of two weeks from commencement of the ovarian stimulation regime.

Participants/materials, setting, methods
Eligible participants were those aged 18-35 years old, undergoing fresh IVF, with a good ovarian reserve and ability to provide informed consent. Data of interest included: BMI, age, parity, ethnicity, smoking status. IVF data included: number of oocytes retrieved, embryo quality and cycle outcomes. AirBeam device data was extracted, analysed and correlated with IVF outcomes. Participants feedback was sought for qualitative input for future studies.

Main results and the role of chance
Total of 28,269 data points of ambient air pollutant data for PM 2.5 and 10 micron size were recorded amongst the ten participants. One participant was exposed to significantly high air pollutant levels during ovarian stimulation on certain days (PM2.5 - 81.06 µg/m³ and PM10 - 154.48 µg/m³) compared to standard annual air pollution level for the UK of 25 µg/m³ for PM2.5 and 40 µg/m³ for PM10.
Two women did not have embryo transfer due to embryo arrest. Of those who had transfer, 50% (n = 4) had positive pregnancy tests however three experienced early pregnancy losses. At the time of writing there was one ongoing single viable pregnancy.
On correlation of air quality data with clinical outcomes, the one participant who exhibited fluctuant very high exposure levels to the measured air pollutants, had unexpected low fertilization rate (20%) with IVF and no transfer due to embryo arrest.
Of the nine participants returning the questionnaire feedback, all but one rated it acceptable to most acceptable to carry the device around. The main barrier was the size of device and battery life. All respondents were willing to recommend others to participate in a future similar study confirming feasibility to recruit.

Limitations, reasons for caution
As a feasibility study, with a limited sample size, our findings should be interpreted cautiously. The small cohort limits the generalisability of our results. Further research with larger sample sizes is required to validate our findings.

Wider implications of the findings
Understanding the impact of air pollutants on IVF outcomes is important for developing evidence-based guidance and interventions to optimise fertility treatment efficacy. Our study demonstrates the feasibility of personal air quality monitoring and emphasises the necessity for larger scale research and the practicality of pollutant exposure measurements in fertility treatments.

Trial registration number
REC reference: 21/NE/0233 IRAS project ID: 294240. Theramex BIRTH Grant