Exploring the hidden cause of assisted reproductive technologies unfavorable outcomes through the biomonitoring study of heavy metals exposure among women.

BACKGROUND

Endocrine disrupting metals such as cadmium (Cd), lead (Pb) and mercury (Hg) may have significant influence on fertility issues among otherwise healthy women.

METHODS

In this study, fifty women with preserved ovarian function, undergoing in vitro fertilization (IVF) procedure were tested for heavy metals (Cd, Hg and Pb) in their morning urine samples using inductively coupled plasma mass spectrometry after microwave digestion.

RESULTS

None of the women had measurable lead in the urine samples while cadmium and mercury were quantified in 28% and 60% of the samples, respectively. Serum LH levels were significantly lower (p = 0.046) among women with measurable urinary cadmium values compared to those with cadmium below the limit of quantification (LOQ). The number of immature oocytes retrieved during transvaginal aspiration was significantly higher (p = 0.030) in women with mercury above LOQ in comparison to those below LOQ. The elevation of urinary mercury concentrations was followed by the increment AST and ALT (p = 0.035 and p = 0.001, respectively). Moreover, higher urinary mercury levels were positively associated with fasting and 2 h post-load serum glucose levels during oral glucose tolerance testing (p = 0.035 and p = 0.002, respectively). For the first time, statistically significant (p = 0.009) correlation was obtained between the urinary mercury concentration and serum LDH values. All the associations between mercury and the observed parameters remained significant after adjustments for age, BMI and time attempting to conceive were made.

CONCLUSIONS

Women undergoing IVF have considerable amount of cadmium and mercury in the urine samples, despite the absence of occupational exposure.