An editorial notes that in retrospect, it is likely the initial rationale for hormonal therapy, i.e. the observed fall in pregnancy hormone levels before pregnancy loss was, in fact, a consequence rather than a cause of pregnancy failure and the subsequent enthusiasm for hormonal therapy was driven by overestimation of the incidence of pregnancy loss in the absence of therapy and by reports of seeming success in uncontrolled case series. It suggests the trial of treatment for threatened abortion provides much-needed information regarding both the true risk of pregnancy loss in the absence of treatment and the small, statistically insignificant difference in the incidence of live births between treatment and expectant management in a contemporary context.