When providing a medical treatment of any sort, physicians are generally expected to produce a diagnosis of a medical problem that the treatment is intended to correct. In most cases, the medical problem is one that anyone would recognize as a medical problem, such as diabetes or a broken leg. However, one of the most widely prescribed medical treatments is contraception. But what "medical problem" do you diagnose in order to prescribe contraception?
People in institutional settings (locked hospitals, homes for the developmentally disabled, etc.) are, of course, sexually active. The doctors that care for them must provide contraception to prevent pregnancy - usually injected hormone contraception. The surprising (to me) diagnosis you most commonly see on the chart of an institutionalized patient, when a doctor is prescribing contraception to her, is "unwanted fertility." Fertility is something we think of as healthy - but doctors may diagnose "unwanted fertility" as a medical problem for which contraception is the preferred treatment.
I think this is an interesting solution, although the diagnosis is often, strictly speaking, a fiction, as many female residents of group homes and such will tell you they definitely want to get pregnant - what is really meant is that the patient's fertility is unwanted by her guardian.
A similar diagnostic possibility is necessary in the case of the rational suicide. A diagnosis of "unwanted life" could form the basis for the provision of lethal means of suicide that require a prescription, without requiring general legalization of the lethal drugs. The diagnostic criteria might even include more than just a wish to die - requirements might include that the wish be persistent (repeated requests over a period of time), that it not be accompanied by (or motivated by) delusions, and that the wish to die be clear and unambiguous.
Although I do not think there is a moral right to procreate (for anyone), I am concerned with the use of the "unwanted fertility" diagnosis against the expressed wishes of patients, even though these patients would likely not be able to care for any children borne by them. It is a convenient solution, but it stretches the truth a bit. This worry is even more important in the analogous "unwanted life" case. The "unwanted life" diagnosis would never be appropriate in cases where the life of the subject is unwanted by someone other than himself (his guardian, say) rather than unwanted by the subject of the diagnosis. Likewise, if a person met the criteria for the "unwanted life" diagnosis, despite having some sort of mental illness as defined by the DSM-IV, it would be inappropriate for his wish to be denied because others disagreed with his wish to die.