(C-062) Utilization of hormonal contraceptives during the postpartum period in the FDA Sentinel System

Background: Risk of venous thromboembolism (VTE) is high in the immediate postpartum period. Hormonal contraceptive (HC) use is associated with an increased risk of VTE. Thus, postpartum women are generally advised not to start a combined hormonal contraceptive (CHC) earlier than 4 weeks postpartum if not breastfeeding. Recommendations for timing of initiating progestin-only contraceptive (POC) postpartum vary by products. Few studies have explored the timing of HC initiation in the postpartum period.

Objectives: Our objective is to describe the utilization pattern of HC initiation in the postpartum period among women in the FDA Sentinel System.

Methods: We included women with a livebirth or stillbirth delivery who initiated HCs within the 12-month postpartum period in 6 data partners in the Sentinel Distributed Database, which include 4 commercial health plans, Medicaid, and Medicare in the U.S., from January 2012 to January 2024. We examined the initiation of HCs, which included CHCs (oral, patch, and vaginal ring) and POCs (oral, intrauterine system [IUS], depot-medroxyprogesterone acetate [DMPA], and subcutaneous implant) within 12-month postpartum. The index date was defined as the date of delivery (live or stillbirth), with no history of previous deliveries within the past 12 months.

Results: We identified 344,929 women who initiated CHC and 819,703 who initiated POC in the 12-month postpartum period. The majority of initiated CHCs were oral pills (83.8%), followed by vaginal ring (8.6%) and patch (7.6%). Overall, less than 2.5% of women started CHCs within 4 weeks postpartum (1.7%, 0.9%, 1.6%, 2.4% within each of the first 4 weeks, respectively). CHC start peaked in week 7 (18.9%). Timing and patterns of initiation were consistent among CHC types. For POCs, the most initiated type was oral pills (46.8%), followed by IUS (29.5%), implant (12.0%), and DMPA (11.7%). About 6% of total POC users started during the first postpartum week with the majority using oral pills (79.0%) or an implant (10.7%). Thereafter, initiation fell below 3% through week 4. All POC starts, except IUS, had similar patterns and peaked in week 7 (20.7%). Initiation of IUS was less than 1% through week 4 and peaked in week 7 (17.4%).

Conclusions: Our data showed that the frequency of HC initiation within the first 4 weeks postpartum is generally low. However, by week 7, approximately 44% of women had started CHC and 53% had initiated POC. Further study is needed to characterize the risk of VTE in the immediate postpartum period (0 – 4 weeks) for specific type of HCs after birth in the U.S. population.