Exposure to toxic metals/metalloids in the environment and in vitro fertilization outcomes in a population group from Romania.

Globally, the infertility prevalence (both genders) has shown a gradual upward trend, with a 0.5%-0.7% annual rise in infertility rates between 1990 and 2021. An increasing proportion of women in Romania experiencing infertility are resorting to in vitro fertilization (IVF) to achieve pregnancy. Our study included 47 women who completed an IVF cycle at the 1st Obstetrics and Gynecology Clinic (Cluj-Napoca), between April - October 2019, and July - December 2022. All participants completed a questionnaire. We collected data from the participant medical records on antral follicle count, levels of hormones, response to ovarian stimulation, number of retrieved oocytes, thickness of the endometrial mucosa, and IVF endpoints (fertilized oocytes, number and quality of embryos, pregnancy, live births). Urine, blood, ovarian follicular fluid, and endometrial flushing fluid specimens were collected at the time of oocyte retrieval, for metal and genetic analysis. Lead (Pb), arsenic (As) and cadmium (Cd) levels were measured in biological samples collected from our study participants using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique. In approximately 19% of the analyzed samples, the total urinary As exceeded the reference value of 15 µg/L. Also, in 15% of the samples, urinary Cd exceeded the reference value of 2 µg/L, while the blood Pb levels were below 10 µg/dl. Our study results indicated no significant differences as regards the IVF outcomes in relation with low-level As, Cd and Pb exposure, whereas higher tobacco smoke exposure, assessed via urinary cotinine, was linked to a lower fertilized oocytes and blastocysts number.