NuvaRing vs. the Pill
Nuvaring has the same contraceptive efficacy as the Pill with lower systemic estrogen exposure, more consistent serum estrogen levels and better cycle control, but more local adverse events resulting in higher discontinuation rates.*
A review of twelve randomized controlled trials comparing the combined contraceptive vaginal ring (NuvaRing) and the [30-μg] combined oral contraceptive pill (Pill) found that:
1. Systemic exposure to estrogen with NuvaRing was approximately 50% of that for the Pill (15 μg EE per day vs. 30 μg EE per pill).
(Unfortunately, the influence of the lower EE exposure with the [NuvaRing] on lipid metabolism and coagulation factors remains unknown, as no RCTs between [NuvaRing] and the [Pill] on these important metabolic parameters have yet been published.)
2. Despite the lower systemic exposure to EE, the incidence of estrogen-related adverse events such as breast tenderness, headache and nausea was not significantly different between both treatment modalities.
3. No apparent differences between both methods were found in blood pressure changes, body weight changes or decreasing rates of PMS and dysmenorrhea [pain] complaints.
4. Contraceptive efficacy during the first year of use was excellent and comparable between NuvaRing and the Pill. (This finding should be interpreted with caution, of course, as it is not predictive of the long-term contraceptive results.)
5. Better cycle control with NuvaRing than with the Pill.
6. The vaginal route of hormone administration was associated with higher incidences of local adverse events such as leukorrhea [discharge], vaginal discomfort, vaginitis and ring-related events comprising foreign body sensation, coital problems and expulsions than the oral route.
7. Discontinuation rates due to local and ring-related adverse events were higher in the NuvaRing groups than in the Pill groups.
8. Incidences of serious adverse events were low and comparable in both groups. (However, the number of participants in the studies was too small and the duration of the studies too short to provide any reliable information on the incidence of infrequent but serious adverse events like thromboembolism.)
9. Both NuvaRing and the Pill were found to be highly acceptable methods of contraception.
10. Compared with women not using hormonal contraception, both women using NuvaRing and the Pill reported a global improvement of sexual function.
[*quote slightly modified for clarity]