Alexander Siegfried Busch says: “The human reproductive system is activated as early as shortly after birth. During the so-called minipuberty newborns reach adult levels of sex-hormones for a short period of time before the system is silenced again after several months. In boys, minipuberty helps the testis to find its final position in the scrotum and primes the testes for the second activation, i.e. puberty. Unlike puberty, minipuberty does not lead to the attainment of adult reproductive function but lays the foundation for future fertility. Disorders of minipuberty are associated lower reproductive health, e.g. undescended testes and risk of infertility. It remains unclear how minipuberty is activated and silenced as well as how minipuberty compensates for certain disorders to rescue fertility. My project will investigate regulation of minipuberty, the compensatory mechanism in disordered minipuberty in male preterm newborns and the overlap in the genetic basis of undescended testes with other risk factors.”