Synthetic pyrethroids exposure among women from fertility clinic and embryological outcomes- is there an association?

Abstract

Introduction: Pyrethroids exposure has been associated with adverse reproductive outcome. However, there is no study that explore the effect of environmental exposure and embryological outcomes. This question was addressed in the prospective cohort of couples undergoing fertility treatment. Methods: We included 450 women aged 25-45 undergoing assisted reproductive technology (ART) cycle at Infertility Clinic in Poland. A urine sample were collected at the time of fertility procedure(s) to assess four urinary synthetic pyrethroids concentrations (3-phenoxybenzoic acid (3PBA), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (cis-DCCA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA), cis-2,2-dibromovinyl-2,2-dimethylocyclopropane-1-carboxylic acid (DBCA)) using validated gas chromatography ion-tap mass spectrometry and calculated for cycle-specific for each metabolite. To evaluate effect of environmental exposure to synthetic pyrethroids and embryological outcomes (methaphase II (MII) oocyte yield, top quality embryo, fertilization rate, implantation rate) multivariable generalized linear mixed analyses with random intercepts was prepared. Results: Urinary 3-PBA concentrations decrease MII oocyte count (p=0.007) in the four quartile (>75 percentyl) compared to women in the first quartile (≤ 25 percentyl). Additionally when 3-PBA was treated as continuous variable the negative association between exposure to pyrethroids and MII oocyte count was also observed (p=0.012). Exposure to other pyrethroids metabolities (CDCCA, TDCCA, DBCA) were not related to any of the examined embryological outcomes. Conclusions: The exposure to synthetic pyrethroids may be associated with poorer embryological outcome among couples seeking fertility treatments. As this is the first study on this topic, the results need to be confirmed in further studies. Keywords: embryological outcomes, urinary pyrethroids concentrations, environmental exposure, IVF treatment