I read with interest your “Editors’ Choice” article, a review on “Progesterone for pre-term birth prevention: an evolving intervention.”

Although the authors state that their concise review was restricted only to more recent data (since 2000), they also state that “there is still considerable uncertainty surrounding how progesterone actually works, indication for its use…” The review then essentially concludes that, empirically, progesterone, when used prophylactically, leads to significant reduction of preterm birth and low birthweight. No attempt was made to advance a theory of a possible mechanism of action of the physiologic evidence of this progesterone effect. In the 1960s and 1970s, Csapo et al published several original research papers and comprehensive reviews on the pathophysiologic effect of preterm labor and the potential of treating it with progesterone. A man, who spent a lifetime and a distinguished career on the very subject that was reviewed here, should have been acknowledged in the bibliography of this otherwise useful retrospective.