For men, kidney transplantation itself has little effect on fertility, but the commonly used immunosuppressants can have toxic effects on sperm, and some patients will develop oligozoospermia or even azoospermia after taking the drugs; on the other hand, these drugs are also teratogenic, and if fertility is to be carried out, one needs to be fully prepared for the fact that the fetus is likely to develop malformations due to these drugs. In addition, according to foreign literature, sexual dysfunction may occur in men after kidney transplantation, but this problem is not very obvious in my patient group at present. It is presumed that patients who have problems may be related to problems such as surgical strikes and side effects of drugs, which affect sexual function. For women, my advice is better not to have children, because in addition to the toxic effects of drugs etc. mentioned above, the uterus dilates during pregnancy squeezing the kidneys in the pelvis and affecting each other. However, if a woman strongly wants to have a child, pregnancy is not completely forbidden. You can have your obstetrician monitor the fetus and fetal position frequently to ensure that there are no developmental malformations or other problems at all before completing the birth, and successful cases are now common in Japan and abroad. Both men and women, especially for women, should never stop taking medication because of childbirth. If pregnancy is planned, the doctor can appropriately switch the patient to some less toxic drugs and monitor the effect regularly; the process of adjusting the medication is complicated and also requires the doctor to feel to find the right drug and dosage. If a woman is unexpectedly pregnant, the medication does not need to be adjusted, and further consultation and treatment in obstetrics department is active.