Safety and efficacy of contraception--Why should the obese woman be any different?

Pharmacokinetics of oral levonorgestrel and ethinylestradiol in women after Roux-en-Y gastric bypass surgery

BACKGROUND

Most patients undergoing Roux-en-Y gastric bypass (RYGB) are women in reproductive age. It is not known if bariatric surgery affects the pharmacokinetics of oral contraceptives.

OBJECTIVES

The primary objective was to evaluate ethinylestradiol (EE) and levonorgestrel (LNG) absorption in women undergoing RYGB, compared with nonoperated controls matched by age and body mass index (BMI). A secondary objective was to assess whether the time since surgery and BMI in the postoperative period influenced the absorption parameters.

SETTING

University hospital, Brazil.

METHODS

This study was designed to compare the maximum plasma concentration (C_max), the time to the peak plasma level (T_max), the area under the curve (AUC_0-8 and AUC_0-∞) after a single dose of a combined oral contraceptive with 0.03 mg EE and 0.15 mg LNG among 20 women after RYGB and 20 controls. Blood samples were obtained for 8 hours.

RESULTS

The mean LNG AUC_0-8 and LNG AUC_0-∞ were higher in RYGB group (P = .048 and P = .004, respectively). We found a positive correlation for LNG AUC_0-8 (P = .045) and AUC_0-∞ (P = .004) and the time since surgery, and we found a negative correlation for LNG C_max (P = .018), AUC_0-8 (P = .003), and AUC_0-∞ (P = .001) and BMI.

CONCLUSION

No significant differences were found in oral EE pharmacokinetics. The operated group showed higher mean LNG AUC_0-8 and AUC_0-∞ but it was not considered clinically significant. The present study suggests that RYGB may not affect EE and LNG absorption.

Contraceptive Care of Obese Women

Importance

In the United States, 27% of reproductive-aged women are overweight, and 35% are obese. Until recently, contraceptive research excluded women greater than 130% of their ideal body weight. Gaps in data limit evidence-based decision making for effective contraceptive counseling and management in this rapidly growing population.

Objectives

The aims of this summary are to review the benefits, adverse effects, and risk factors associated with contraceptive methods in obese women, with special attention to effectiveness, and provide contraceptive management and counseling recommendations for best clinical practice.

Evidence Acquisition

We performed a thorough search of PubMed for current literature, including original research articles, review articles, and guidelines on contraceptive counseling and management in obese women in the United States. We reviewed the body of evidence with special attention to studies published since recent Cochrane and systematic reviews on this topic.

Conclusions

Contraceptive use is safer than pregnancy, especially for obese women who have increased pregnancy risks. Baseline health is compromised by obesity, but contraceptive risks remain low. Long-acting, reversible contraceptive methods offer superior effectiveness, minimal risk, and numerous noncontraceptive benefits across body mass index groups. No substantial evidence supports ineffectiveness of any method in obese women except oral emergency contraception and the patch. Pharmacokinetic changes of obesity associated with other oral methods do not seem to result in clinically significant declines in effectiveness. Future contraceptive efficacy studies should include obese women to better discuss their contraceptive needs.

Relevance

This review is beneficial for all providers caring for reproductive-aged women wanting to avoid unintended pregnancy.

Pregnancy Intention and Contraceptive Use among Women by Class of Obesity: Results from the 2006-2010 and 2011-2013 National Survey of Family Growth

OBJECTIVE

Conflicting research findings on the association of obesity and pregnancy intention may be due to their collective definition of obesity at a body mass index of 30 kg/m² or greater. However, obese women with a BMI of 40 kg/m² or greater may be both behaviorally and clinically different from obese women with a lower BMI. This study reexamines this relationship, stratifying by class of obesity; the study also explores variations in contraceptive use by class of obesity given their potential contribution to the incidence of unintended or unwanted pregnancy.

METHODS

This study combined data from the 2006 through 2010 and 2011 through 2013 US National Survey of Family Growth. Pregnancy intention (intended, mistimed, unwanted) and current contraceptive use (no method, barrier, pill/patch/ring/injection, long-acting reversible contraceptive, sterilization) were compared across body mass index categories: normal (18.5-24.9 kg/m kg/m²), overweight (25.0-29.9), obese class 1 (30.0-34.9 kg/m²), class 2 (35.0-39.9 kg/m²), and class 3 (≥40 kg/m², severe obesity). Weighted multinomial logistic regressions were refined to determine independent associations of body mass index class and pregnancy intention, as well as contraceptive method, controlling for demographic, socioeconomic, and reproductive factors.

RESULTS

Body mass index data were available for 9,848 nonpregnant, sexually active women who reported not wanting to become pregnant. Women with class 3 obesity had significantly greater odds of mistimed (adjusted odd ratio [aOR], 1.67; 95% confidence interval [CI], 1.02-2.75) or unwanted (aOR, 1.96; 95% CI, 1.15-3.32) pregnancy compared with normal weight women. Women with class 2 or 3 obesity were more likely to not be using contraception (aOR, 1.53-1.62; 95% CI, 1.04-2.29). Although women with class 2 obesity were more likely to be using long-acting reversible contraceptive methods and sterilization over short-acting hormonal methods (aOR, 1.67; 95% CI, 1.08-2.57; aOR, 2.05; 95% CI,1.44-2.91), this association was not observed among women with class 3 obesity.

CONCLUSIONS

Women with class 3 obesity are at greater risk of unintended pregnancy and are less likely to be using contraception than normal weight women. Whether these findings are related to patient and/or provider barriers that are not as visible among women with class 1 and class 2 obesity warrants further investigation.

Contraception and the obese woman

PURPOSE

Obesity has reached epidemic rates among U.S. women of reproductive age, many of whom want to use contraception. However, some forms of contraception can have adverse effects on an obese woman's health. This article explores risks of contraception available in the United States and provides clinical recommendations for use by obese women.

DATA SOURCES

Information was compiled by reviewing the scientific literature on contraception and female obesity using CINAHL, MEDLINE, PubMed search engines.

CONCLUSIONS

The evidence is largely supportive of combined oral contraceptive (COC) use in carefully screened obese women without known risks factors for cardiovascular disease. The efficacy of COCs may be slightly reduced in obese women because of increased body mass. Other types of hormonal contraceptives have varying safety and efficacy reports when used by obese women. Intrauterine devices do not have reduced efficacy nor increased risks for obese women but insertion may be more difficult. Obesity has no effect on efficacy of barrier methods of contraception.

IMPLICATIONS

Clinicians should conduct a careful history and physical exam with selected supporting laboratory tests when considering prescription of hormonal contraceptives for obese women. Obese women require health counseling to carefully follow directions for contraceptive use to avoid unintended pregnancy.

Obesity and oral contraceptives: a clinician's guide

Obesity and unintended pregnancy are two of the major health epidemics we are currently facing worldwide. Patient education is a clinician's greatest tool in combating both epidemics but many clinicians may be uncomfortable with counselling and prescribing contraception for obese women. Overall, the prevention of unintended pregnancy in obese women far outweighs any risk associated with oral contraceptive use. This review aims to provide the clinician with a practical guide to the use of oral contraceptive pills in obese women.

Concepts of contraception for adolescent and young adult women with chronic illness and disability

Sexual behavior is common in adolescents and young adults with or without chronic illness or disability, resulting in high levels of unplanned pregnancy and STDs. Individuals with chronic illness or disability should not receive suboptimal preventive health care. These individuals have a need for counseling regarding issues of sexuality and contraception. Sexually active adolescent and young adult women can be offered safe and effective contraception if they wish to avoid pregnancy. Women with chronic illnesses and disabilities who are sexually active should also be offered contraception based on their specific medical issues. Condoms are also recommended to reduce STD risks. Table 36 summarizes basic principles of contraception application for specific illnesses, which have been identified since the release of the combined OC in 1960. Clinicians should also consider the noncontraceptive benefits of this remarkable and life-changing technology that allows all reproductive age women to improve their lives, including those with chronic illnesses and disabilities.