Obesity and contraception: emerging issues.

Obesity is increasing in prevalence worldwide. Obese women are at similar risk of unintended pregnancy as normal weight women, although limited data are available on the effects of obesity on the efficacy of contraception. Conflicting data exist regarding efficacy of oral contraceptives in obese women, although trends of oral contraceptive failure are no higher than compared with those of normal weight women. The risk of venous thromboembolism is increased with obesity, and this risk may be additive when using a combined hormonal method. Bariatric surgery can lead to increased fertility; postoperative recommendations include avoiding pregnancy in the first year. Contraceptive use patterns in these women are largely unknown. Surgeons need greater awareness of the need for use of effective long-acting methods, and consensus guidelines need to be established.