This article looks at medical approaches to women's fertility in Argentina in the 1930s and explores the ways in which eugenics encouraged the reproduction of the fit and attempted to avoid the reproduction of the unfit. The analysis concentrates on three main aspects: biotypology (the scientific classification of bodies), endocrine therapy, and sterilization. The article concludes by suggesting that a eugenically oriented obstetrical and gynecological practice encouraged both endocrine treatments (to achieve the ideal fertile woman) and sterilization, which, in spite of being legally banned, found a subtle application.