IS case 523: Contraceptive vaginal ring
Imaging Sciences URMC 2010
Publication Date: 2010-09-10
Patient is a 30-year-old female with abdominal pain.
Incidental combined contraceptive vaginal ring.
Contraceptive vaginal ring
A combined contraceptive vaginal ring is a once a month contraceptive device. It is made from the copolymer evatane in which two hormones, ethinyl estradiol (EE) 2.7 mg, and etonogestril (ENG) 11.7 mg, are equally dispersed. 15 μg EE and 120 μg ENG are released daily into the vaginal epithelium. The advantage of a vaginal contraceptive is that it is absorbed by the vagina, avoiding hepatic first pass metabolism. The soft, flexible, and transparent ring is inserted into the vagina for three weeks at a time then removed for one hormone-free week of withdrawal bleeding. The vaginal ring, NuvaRing®, has comparable contraceptive efficacy to oral contraceptives. Adverse effects are rare but include breast tenderness, nausea, headache, vaginitis, leucorrhea, irregular bleeding, and possible risk for thromboembolism. The ring infrequently falls out.
Contraceptive vaginal rings are typically radiolucent and undetectable on radiographs (Fig. 3). On CT, they are well defined, circular, and lucent compared to the surrounding tissues (Fig. 2). Devices measure 54 mm in diameter and 4 mm in thickness. A radiologist should be aware of this device to avoid mistaking it for a foreign body and to look for potential complications such as malposition or impaction. A vaginal ring contraceptive can be differentiated from a pessary, used for uterine prolapse, as a pessary is usually radiodense on radiographic studies and can be seen on plain film radiographs.
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- Roumen FJ. Review of the combined contraceptive vaginal ring, NuvaRing. Ther Clin Risk Manag. 2008 Apr;4(2):441-51. PMID: 18728840