Obstetrics and Contraceptive Issues

Modern American society is awash in calorie-dense but nutritional poor food. Our fast-food lifestyle has contributed to an epidemic of obesity. More than two thirds of adults in the United States are now either obese or overweight.[1] Because metabolic health is a direct signal of the adequacy of the environment, it is not surprising that complications of obesity affect reproductive health.

Many clinicians dismiss reproductive concerns for obese women as trivial in comparison with other health issues. However, there are complex effects of obesity on reproductive health and lasting intergenerational effects when pregnancy occurs. Reviews in this issue focus on sexual behavior, contraceptive counseling, pregnancy complications, and the effects of obesity on fetal development and programming that influence adult health.[2] [3] [4] [5] Although much has been written about the association of obesity with anovulation and polycystic ovarian syndrome, most obese women are fertile.[6] Kaneshiro reviews data from the National Survey of Family Growth, Behavioral Risk Factor Surveillance System, and the Pregnancy Risk Assessment Monitoring System that demonstrate the sexual behavior of obese women is similar to that of nonobese women.[2] Interactions between obesity and poverty complicate and confound the observed relationships. There is no difference in the overall prevalence of contraceptive use between obese and nonobese women, but obese women are less likely to use oral contraceptives and more likely to undergo sterilization procedures. No difference was noted in most types of sexual behavior for women of different body weights.

There is far greater clarity on the issues surrounding obesity and pregnancy; obesity makes pregnancy high risk.[4] Marshall and Spong[4] detail how the physiological challenges of pregnancy are exacerbated by obesity and the manner in which these changes lead to overt disease. In particular, obesity greatly increases the risk of diabetes in pregnancy and magnifies the already elevated risk of venous thromboembolism (VTE). Obese women are also at much higher risk of complications during vaginal delivery and have higher rates of cesarean delivery. Obesity leads to a greater chance of complications from surgery and anesthesia. In addition, obese women are at greater risk of spontaneous abortion and stillbirth, and also of maternal death.

Although it makes sense for all women to carefully consider if, when, and how often to become pregnant, this is particularly true for obese women. Preconception counseling can improve outcomes through identification of baseline disease states such as hypertension and diabetes. Frias and Grove[5] describe the physiological changes of obesity in pregnancy and detail how these exaggerate the inflammatory state characteristic of the metabolic syndrome. Not only does this increase the risk of pregnancy complications, it directly affects the developing fetus, increasing the incidence of childhood obesity and adult cardiovascular disease and diabetes. Elegant experiments in the nonhuman primate have demonstrated that improving metabolism through dietary changes can reduce the inflammatory state associated with obesity and reduce the likelihood of pregnancy complications and adverse fetal programming.[5]

Just as in normal weight women, effective contraception is the key to healthy pregnancies. Although the sexual behaviors of obese and nonobese women are similar, obese women require additional contraceptive counseling regarding the interaction between obesity and the risks of both pregnancy and hormonal contraception. The review by Edelman and Jensen[3] puts these risks in context. The principal risk of estrogen-containing combined hormonal contraception is venous thrombosis. Although obese women have a higher baseline risk of VTE compared with normal weight women (∼2.4 fold), use of a combined hormonal method increases the risk 24-fold in contrast to an only 4- to 5-fold increase in nonobese users.[7] Fortunately, the absolute risk of VTE with hormonal contraception is lower than the risk observed in pregnancy.[4] Furthermore, the availability of highly effective and well-tolerated estrogen-free progestin-only hormonal methods provides clinicians and women with options to the combined pill, patch, and ring. The Centers for Disease Control and Prevention and the World Health Organization have published detailed guidelines for contraceptive initiation and continuation that address medical complications such as obesity.[8]

Although some studies support a slightly higher failure rate in obese women using combined oral contraceptives, it is important to keep in mind that the most important aspect of contraceptive failure is incorrect use, not method failure. In addition to high efficacy, long-acting reversible methods such as the levonorgestrel intrauterine system offer several advantages to obese women including a reduction in menstrual bleeding. However, it is important to keep in mind that obese women with symptoms of androgen excess might benefit more from the ovarian androgen suppression of a combined oral contraceptive if they are otherwise healthy.

All clinicians who care for obese reproductive age women should bring up the discussion of family planning during routine health-care encounters. The reviews in this issue demonstrate that the impact of an unintended pregnancy in an obese woman is far reaching and costly. Specialists in family planning can assist with the counseling regarding contraception in medically complicated obese women.

• References

• 1 Flegal KM, Carroll MD, Kit BK, Ogden CL. Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999–2010. JAMA 2012; 307 (5) 491-497
• 2 Kaneshiro B. Contraceptive use and sexual behavior in obese women. Semin Reprod Med 2012; 30 (6) 457-462
• 3 Edelman AB, Jensen JT. Obesity and hormonal contraception: safety and efficacy. Semin Reprod Med 2012; 30 (6) 477-483
• 4 Marshall NE, Spong CY. Obesity, pregnancy complications, and birth outcomes. Semin Reprod Med 2012; 30 (6) 463-469
• 5 Frias AE, Grove KL. Obesity: A Transgenerational problem linked to nutrition during pregnancy. Semin Reprod Med 2012; 30 (6) 470-476
• 6 Cole JA, Norman H, Doherty M, Walker AM. Venous thromboembolism, myocardial infarction, and stroke among transdermal contraceptive system users. Obstet Gynecol 2007; 109 (2 Pt 1) 339-346
• 7 van Hylckama Vlieg A, Helmerhorst FM, Vandenbroucke JP, Doggen CJ, Rosendaal FR. The venous thrombotic risk of oral contraceptives, effects of oestrogen dose and progestogen type: results of the MEGA case-control study. BMJ 2009; 339: b2921
• 8 Centers for Disease Control and Prevention. U.S. medical eligibility criteria for contraceptive use, 2010. MMWR Recomm Rep 2010; 59 (RR-4) 1-86