A 25-year-old woman, diagnosed with Kallmann's syndrome and wanting to become pregnant, visited our hospital. Because her serum gonadotropin levels indicated hypogonadotropic hypogonadism, a main symptom of Kallmann's syndrome, we attempted to induce ovulation using a low-dose human menopausal gonadotropin (hMG) step-up protocol. In this protocol, 75 IU of hMG was used as an initial dose and this was continued for the first 14 days because adequate follicular development was not achieved. The dose of hMG was subsequently increased to 150 IU for the next 7 days. After 22 days from the start of stimulation, two follicles had developed, and were ovulated using an injection of human chorionic gonadotropin. She became pregnant, and her pregnancy was uneventful during the first trimester; however, in the second trimester both uterine contractions and blood pressure could not be controlled, and at 27 weeks’ gestation she delivered a male infant weighing 830 g by cesarean section.