The relationships between the number of oocytes and metals: iron ( r s =0.303; p =0.003) and calcium ( r s =−0.276; p =0.007) are significant, as well as between the number of mature oocytes with iron ( r s =0.319; p =0.002), calcium ( r s =−0.307; p =0.003) and sodium ( r s =−0.215; p =0.039) and are near to significance in the case of aluminium ( r s =−0.198; p =0.057).
Regarding the relationship between oocyte number and metals: Fe ( r s =0.303; p =0.003) and Ca ( r s = −0.276; p = 0.007) were significant and Al ( r s =−0.195; p = 0.061) and Na ( r s = −0.174; p = 0.095) were close to significance.
Several authors reported that FF Ca concentrations were higher in participants who did not achieve any pregnancy, the difference did not reach statistical significance level, compared to those who did; following ICSI attempts [ 36 ], this result does not clarify the role of Ca in ART.