The OrthoEvra patch and the NuvaRing both provide combinations of ultrapotent progestins with EE. Both patch and ring provide almost constant low levels of the contraceptive steroids that are less than the peak levels seen with OCs. Both offer greater convenience to the user, which improves compliance. The patch has a surface area of 20 cm2. It delivers a daily dose of 150 μg norelgestromin, the active metabolite of norgestimate, and 20 μgof EE. The patch is worn for 1 week then replaced with a new patch for 7 days, continuing for 3 consecutive weeks followed by a week with no patch. The patch was compared with a multiphasic OC containing levonorgestrel 50 to 125 μg,and 30to40 μg EE (Triphasil) in a randomized trial of 1,417 women (122). The overall and method failure Pearl indices were 1.24 and 0.99 pregnancies per 100 woman-years in the patch group and 2.18 and 1.23 in the OC group, respectively, numerically less in the patch group but not statistically significant. Patch users had more breakthrough bleeding or spotting in the first two cycles, but thereafter this did not differ from OC users. Patch users reported more breast discomfort, dysmenorrhea, and abdominal pain than the OC users, but other adverse events were uncommon and did not differ. Perfect compliance was reported for 88.2% of patch users’ cycles versus 77.7% of the pill users’ cycles (p <.001). Pregnancy risk with the patch appears to be higher for women weighing more than 90 kg.
The NuvaRing is 54 mm in outer diameter and has a cross section of 4 mm. It delivers daily doses of 120 μgof etonogestrel, the active metabolite of desogestrel, with 15 μgof EE, and thus is the lowest estrogen combination hormonal method available in the United States. The soft, ﬂexible ring is worn in the vagina for 3 weeks, and then removed for 1 week, after which time a new ring is inserted. If inserted on the first day of menstruation, no back up method of contraception is needed. It can be inserted on days 2 to 5 and used with a backup method such as condoms for the first week. In a pharmacokinetic study comparing the ring with a combination OC containing 150 μgof desogestrel and 30 μgof EE, maximum blood levels of EE with the ring were about one-third of those seen with the OC, and the etonogestrel level was about 40% of that produced by the OC. Despite these findings, ovulation was inhibited in all women studied (213). Women wearing the ring are reported to have fewer days of irregular bleeding or spotting than women taking an OC with 150 μgof levonorgestrel and 30 μgof EE (214). A large study found a total pregnancy rate of 1.18 (95% CI, 0.73–1.80) per 100 woman-years and 0.77 (0.37–1.40) pregnancies per 100 woman-years with perfect use (214). Some women prefer to remove the ring for intercourse, although this is not necessary. It should be reinserted within 3 hours to avoid loss of efficacy.