More than half the female population of the United States is overweight or obese. Thirty-two percent of women aged 20–39 and 40% of women aged 40–59 are obese.1 One-third of adolescent females aged 12–19 are overweight and obese, with 20% qualifying as obese.1 Overweight and obese women are no less likely to be sexually active and therefore at risk of pregnancy than normal-weight women.2 Adolescent females in the higher-weight categories have a higher risk of unintended pregnancy than their normal-weight peers due to lower self-esteem and less confidence negotiating condom and contraception use.2
Obesity increases several maternal and fetal risks associated with pregnancy, including gestational diabetes, preeclampsia, fetal macrosomia, emergency cesarean section, and stillbirth. In addition, pregnancy can exacerbate pregestational comorbidities such as hypertension, diabetes, and obesity. Obese women should plan their pregnancies to optimize their health and minimize maternal and fetal complications.
Until recently, however, obese women have been excluded from contraception trials, in which participants are generally limited to within 130% of their ideal body weight.2 Therefore, health care providers experience difficulty counseling their obese patients about the safety and efficacy of contraception methods available in the United States.
For the purposes of this chapter, the World Health Organization (WHO) body mass index (BMI) classification system is used.3 A BMI of 30 kg/m2 is considered obese (Table 27-1).
TABLE 27-1World Health Organization BMI Classificationa |Favorite Table|Download (.pdf) TABLE 27-1 World Health Organization BMI Classificationa
|Weight Classification ||BMI (kg/m2) |
|Underweight ||<18.5 |
|Normal weight ||18.5–24.99 |
|Overweight ||25–29.99 |
|Obese ||≥30 |
| Class I obese ||30–34.99 |
| Class II obese ||35–39.99 |
| Class III obese ||≥40 |
The contraception options available in the United States are listed in Table 27-2 along with their pregnancy rates with perfect use (efficacy), typical use (effectiveness), and continuation at 1 year. All methods are more effective than no method. However, as sterilization, intrauterine devices (IUDs), and the subdermal contraceptive implant do not require patient compliance to work properly, their pregnancy rates with typical use approach perfect use pregnancy rates. Both the American Congress of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics recommend intrauterine devices and the subdermal contraceptive implant as first-line contraceptives for women of all ages as they are long-acting, reversible contraceptive (LARC) methods.4,5 Their effectiveness is as high as that of sterilization without being permanent. The Medical Eligibility Criteria tables produced by the Centers for Disease Control and Prevention (CDC) provide assistance in determining which methods are appropriate for obese patients (Table 27-3). Methods in category 1 do not have any restrictions. Current evidence indicates the benefits of methods in category 2 ...