The FDA's report of its study of women using contraceptives:
Combined Hormonal Contraceptives (CHCs) and the Risk of Cardiovascular Disease Endpoints
We conclude that the study results add to the small body of literature which shows that the NGMN transdermal patch is associated with higher risk of VTEs relative to standard CHC pills and provides another positive finding to the increasing body of evidence linking DRSP to increased risk of VTE relative to standard low-dose
CHC pills. DRSP was associated with higher risk of ATE in new users overall with this finding restricted to women in the 35-55 years age group only. The finding of increased risk of VTE with the ETON vaginal ring relative to standard CHCs is new and raises concern but needs to be replicated in other studies.