(1002) Incidence of Recurrent Preterm Birth in the US after FDA Withdrawal of 17-OH-Progesterone

Objective: For >10 years, 17-OH-progesterone (17-OH-P) was prescribed to reduce the risk of recurrent spontaneous preterm birth. In 2023, its FDA approval was withdrawn due to a lack of demonstrated efficacy. The objective of this study was to examine population changes in the incidence of recurrent preterm birth after the FDA withdrawal.

Study Design: We performed a pre-post study using cross-sectional US natality data. Patients with a history of preterm birth and who delivered a singleton, live birth after 20 weeks of gestation were included. FDA withdrawal of approval for 17-OH-P was in April 2023. The pre-period was from 09/2022-03/2023, and the post-period from 09/2023-03/2024; both periods were the same length and comprised the same calendar months. Births from 04/2023-08/2023 were excluded to avoid patients who potentially discontinued 17-OH-P mid-pregnancy. We examined the incidence of recurrent preterm birth < 37 and< 34 weeks of gestation; results were stratified by race and ethnicity and reported for groups with ≥100 individuals in the denominator. Chi-square tests were used for comparison.

Results: There were 16,088 deliveries in the pre-period and 16,534 in the post-period. There were no significant differences in the incidence of preterm birth < 37 weeks (26.7 vs. 26.4%, p=0.54) or < 34 weeks (6.7 vs 6.7%, p=1.00) between the pre- and post-periods. When stratified by race, there was no significant increase in preterm births in the post-period among any of the racial and ethnic groups (Figure).

Conclusion: When comparing the periods immediately before and after the FDA withdrawal of its approval for 17-OH-P, there were no apparent national differences in the incidences of recurrent preterm birth overall or among racial and ethnic groups. Future studies using individual patient-level data with more granular details on the etiologies for prior preterm births and accounting for other changes related to recurrent preterm birth management (e.g., vaginal progesterone use) will be important in understanding the population impacts of this major practice change.