Obesity and contraception: Metabolic changes, risk of thromboembolism, use of emergency contraceptives, and role of bariatric surgery

Rates of obesity are increasing worldwide. Due to the medical consequences of obesity, routine health care like family planning becomes complicated. Conflicting data exists regarding efficacy of hormonal contraceptives in obese women, while little data on efficacy of emergency contraception in obese women exists. Much of what is available suggests lower serum hormonal levels in obese women with little effect on ovulation inhibition. Contraceptive steroids can cause a number of deteriorating metabolic changes, particularly in obese women; whether these changes are clinically significant is unknown. Venous thromboembolic risk is increased with both obesity and use of hormonal contraceptives; however the question remains if the risk is additive or multiplicative. Bariatric surgery can lead to digestive changes which may affect absorption of contraceptive hormones. While long acting reversible contraceptives may be the best option in the post operative obese patient, little data, beyond a simple recommendation to avoid pregnancy for at least one year, exists to help guide appropriate contraceptive choice.