In the medical-technological practice of in vitro fertilization (IVF), it is increasingly the couple, rather than an individual patient, that is considered the unit of (infertility) treatment. This article traces some mechanisms involved in the construction of medical interventions on female bodies as appropriate and effective therapeutic solutions to problems and diagnoses pertaining to male bodies. It traces the transformation of male infertility through shifts in localization and definition of the problem, concomitant reconceptualizations of the techniques involved, redistributions of properties, and specific ways of constructing "success. " It is argued that both the notion of the couple as the patient in cases of male infertility and the claim that IVF techniques are appropriate solutions to this couple's problem simultaneously presuppose and legitimize medical interventions on women's bodies. This double movement is produced by leaving exactly the required material work of physical interventions—and, consequently, the uneven distribution of costs between the sexes—out of scientific accounts of these practices.