This Mendelian Randomization (MR) study revealed that higher circulating levels of sex hormone-binding globulin (SHBG) are linked to a reduced risk of female infertility, particularly in cases of anovulation.Specifically, SHBG levels were found to be inversely associated with various types of female infertility, notably with anovulation.The SHBG levels were not related to male infertility or tubal-origin female infertility. This evidence concerns the gene SHBG and male infertility.