TABLE 3

Contraceptive methods currently rated ‘very effective’

Type of contraception	How it works	Failure rate^a	Advantages	Disadvantages
Female sterilization	Either the tubes are tied and then cut, or a coil is inserted into the tubes	< 1%	Permanent; no further medicines or procedures required to prevent pregnancy	Reversal is seldom successful and is expensive; imaging is required to confirm occlusion of tubes; coils take 3–4 months to be fully effective
Male sterilization (vasectomy)	Interruption or occlusion of the male tubes	< 1%	Safer, less costly, and shorter recovery time than tubal ligation	Reversal is not always successful; does not work immediately: 3–4 months required with frequent sperm testing
Implant	Contains a progestin hormone; implanted in the upper arm, slowly releases hormone into the body and lasts 3 years	< 1%	Provides highly effective, prolonged contraception without estrogen; fertility returns rapidly after removal of the rod	Unscheduled bleeding is common; implants can be difficult to remove, and infection or scarring can occur at the insertion/removal site
Intrauterine device (IUD)	2 types: hormonal (progestin, lasting 3–5 years) and nonhormonal (copper, lasting at least 10 years)	< 1%	Highly effective, long-acting; fertility returns within 1 month (copper IUD) or 1 year (progestin IUD)	Possible uterine perforation (rare, ≤ 1 in 1,000), expulsion of the IUD, increased risk of pelvic infection in the first 20 days after insertion