Challenges in Using Progestin to Prevent Singleton Preterm Births: Current Knowledge and Clinical Advice

Preterm birth is the leading cause of infant morbidity and mortality in children younger than 5 years old and accounts for approximately 35% of newborn deaths worldwide. The use of progestogen therapy for prevention of preterm birth has been one of the most controversial topics in modern obstetrics. Progestogens can be classified as natural or synthetic. Progesterone is a natural progestogen while progestins such as 17-alpha-hydroxyprogesterone caproate (17OHP-C) are synthetic steroid hormones. Evidence supporting the use of progestogens varies by formulation and populations studied. After more than a decade, the US Food and Drug Administration has withdrawn accelerated approval of 17OHP-C for the prevention of recurrent preterm birth in pregnant individuals with a singleton gestation. With this decision, there is no current FDA-approved treatment for prevention of spontaneous preterm birth. In this review, we provide a historical context behind the rise and fall of 17OHP-C clinical application, highlight the challenges behind the data supporting progestogen use, and offer suggestions on how to make an impact on preterm birth moving forward.