For women, LH excess affects ovaries, and in men, it affects the testes. Elevations in serum LH may result in increased androgen production that diminishes follicular function and reduces early embryo viability. Although LH receptors have not yet been identified in oocytes, excessive LH may disrupt granulosa cells (producing sex steroids) communication in the cumulus oophorus (cells surrounding the oocyte), which is critical to maintain the oocyte in the dictyate stage of meiosis (stage of arrested eggs until puberty) until ovulation. Elevated LH levels during the preovulatory period (before ovulation) may also negatively influence post-ovulatory (after ovulation) events such as conception and implantation.
A significant reduction in the rate of fertilization is observed in women with elevated LH levels undergoing treatment with in vitro fertilization (IVF). A higher likelihood of pregnancy is observed when the LH level is <10 IU/L and the miscarriage rate is significantly higher in women with LH levels >10 IU/L.
In men, high level of LH indicates that testicles don’t produce enough testosterone and it is the message for hypothalamus to produce more LH to compensate it. Basically, high LH level is associated with low level of testosterone and thus impairs the male’s fertility. A man with low levels of testosterone may lose his desire for sex. Testosterone levels can drop during a long period of sexual inactivity. Sexual stimulation and sexual activity cause testosterone levels to rise.