Objective: The purpose of this study was to identify the effect of early cessation of 17-alpha-hydroxyprogesterone caproate (17P) on the incidence of spontaneous recurrent preterm delivery (PTD).
Study design: Retrospective analysis of data from women who were enrolled for outpatient 17P administration between January 2004 and May 2006 included women with previous PTD and current singleton pregnancy who were beginning weekly 17P injections (250 mg intramuscularly) at 16-20.9 weeks. The study group was comprised of patients who were electively terminating 17P at <32.0 weeks and who delivered >10 days from the last injection. The control group consisted of patients who received weekly 17P injections until PTD or 36.9 weeks of gestation. The primary study outcome was the rate of recurrent spontaneous PTD.
Results: Study group patients were significantly more likely to have spontaneous recurrent PTD at <37 weeks of gestation (48.1% vs 33.3%; P = .011), at <35 weeks of gestation (30.9% vs 14.0%; P < .001), and at <32 weeks of gestation (16.0% vs 7.0%; P = .020).
Conclusion: Early cessation of 17P treatment is associated with an increased risk for spontaneous recurrent PTD.