of FSH, can also be used in male patients to induce secondary sexual characteristic development alongside possible fertility induction. For females, hormone replacement involves the use of oestrogen and progesterone. Firstly, oestrogen is used in tablet or gel form in order to maximise breast development, then a combination of oestrogen and progesterone is used. Cyclical progesterone is normally required to help keep the endometrium (lining of the uterus) healthy. In males, the monitoring of treatment normally requires the measurement of serum testosterone, inhibin B, haematocrit and prostate-specific antigen (PSA). If injections are used, trough levels are taken to ensure an adequate level of testosterone is achieved throughout the injection cycle. In females monitoring normally consists of measurement of oestrogen, FSH, LH, inhibin B and anti-Müllerian hormone (AMH). Standard hormone replacement therapy will not normally induce fertility in either males or females, with no testicular growth in males. Early treatment as adolescents can help with psychological well-being of people with KS/CHH. Fertility treatments Gonadotropin therapy can be used in both male and female patients in order to achieve fertility for some people. Pulsatile GnRH therapy can also be used to induce fertility, especially in females, but its use is limited to a few specialist treatment centres. In males with KS/CHH, infertility is primarily due to the lack of sperm production within the testes. Sperm production can be achieved through either the use of GnRH administered via a microinfusion pump or through the use of gonadotropin injections (hCG, FSH, hMG). The time taken to achieve adequate sperm production for natural conception will vary from person to person. If the pre-treatment testes are very small and there has been a history of undescended testes it might take longer to achieve sperm production. In these cases, assisted reproductive technology, such as sperm retrieval using testicular sperm extraction (TESE) and/or intracytoplasmic sperm injection (ICSI), might be required. In females with KS/CHH, infertility is primarily due to the lack of maturation of eggs located within the ovaries. Ovulation induction can be achieved either with pulsatile GnRH therapy or alternatively with gonadotropin injections (hCG, FSH, hMG) given at set intervals to trigger the maturation and release of the egg for natural conception. Prognosis Reversal of symptoms has been reported in between 10% to 22% of cases. Reversal cases have been seen in both KS and normosmic CHH but appear to be less common in cases of KS