Vaginal versus intramuscular progestogen for prevention of recurrent spontaneous preterm birth: A pragmatic study in a high-risk patient population

OBJECTIVE: To evaluate whether vaginal progestogen (VP) can be substituted for intramuscular (IM) progestogen for the prevention of recurrent spontaneous pre-term delivery in a residency based high-risk obstetric clinic. STUDY DESIGN: Retrospective study comparing delivery <37 weeks in women with a history of spontaneous preterm birth (SPTB) receiving vaginal versus IM progestogen. Outcomes were obtained via electronic medical record. RESULTS: There was no significant difference between the IM (n=36) and VP (n=28) groups for delivery <37 weeks (23.5% vs. 46.4%, p=0.067). A statistically significant increase in the number of additional gestational days compared to their earliest SPTB was seen in individuals with 17α-hydroxyprogesterone caproate (17α-OHP) versus VP (9.0±5.8 days vs. 5.3±6.0 days; p=0.036). There were no differences between the groups for other secondary outcomes. CONCLUSION: Our study supports the use of either VP or 17α-OHP for prevention of SPTB; however, there was an increase in the number of gestational days versus earliest SPTB in the 17α-OHP group.