Comparison of Intrauterine Devices
Pregnancy rate at 1 year of use | 0.4% | 0.2% | 0.2–0.6% | — |
Cumulative pregnancy rate for maximum duration of use | 1.0% | 0.9–1.4% | 0.5–1.1% | < 2% at 12 years |
Reversibility | Rapid | Rapid | Rapid | Rapid |
Standard duration | 3 years | 5 years | 8 years | 10 years* |
Changes in bleeding | Irregular bleeding Amenorrhea at 1 year: 6% | Irregular bleeding Amenorrhea at 1 year: 12% | Irregular bleeding Amenorrhea at 1 year: 20% | No change in cyclical nature of cycles |
Mean monthly blood loss | — | 5 mL (at 6 months of use) | 5 mL (at 6 months of use) | 50‒80 mL |
Additional benefits | — | — | May be used to treat heavy menstrual bleeding, chronic pelvic pain, or endometriosis | May be used as emergency contraception Nonhormonal |
Adverse effects | Minimal: Headache, spotting, breast tenderness, nausea (which usually resolves within 6 months) | Same as for the 3-year IUD | Same as for the 3-year IUD | More severe menstrual cramps (usually relieved by nonsteroidal anti-inflammatory drugs [NSAIDs]) and heavier flow |
Primary mechanism of action | Thickens cervical mucus and prevents fertilization | Same as for the 3-year IUD | Same as for the 3-year IUD | |
* Evidence supports use for 12 years. | ||||