EXECUTIVE SUMMARY

Concerns about weight gain may be driving contraception choices, new data released by Penn State College of Medicine indicate. Women who are overweight or obese are less likely than women who are not overweight or obese to use the birth control pill and other hormonal contraceptive methods, the research suggests.

  • In the current study, 23% of overweight and 21% of obese women used long-acting reversible contraceptives (LARCs), while 6% of underweight and normal-weight women used LARCs.
  • Previous research indicates that overweight or obese women may be less likely to use oral contraception because of concerns about weight gain. However, a Cochrane Review found available evidence was insufficient to determine the effect of combination contraceptives on weight, and that no large effect was evident.

Concerns about weight gain may be driving contraception choices, new data released by Penn State College of Medicine indicate.1 Women who are overweight or obese are less likely than women who are not overweight or obese to use the birth control pill and other hormonal contraceptive methods, the research suggests.1

Weight is an important issue; more than half (58.5%) of U.S. reproductive age women are overweight or obese.2 Previous research indicates that overweight and obese women may be less likely to use oral contraception or the contraceptive shot, depot medroxyprogesterone acetate (DMPA), because of concerns about weight gain.3 Many women may discontinue hormonal contraception because of weight gain, which increases their risk of unintended pregnancy.4

Review the Research

Cynthia Chuang, MD, MSc, Penn State professor of medicine and public health sciences, and fellow researchers performed the study to see if women’s weight or their perception of weight influenced the type of birth control they used. To do so, they examined demographic and survey data from almost 1,000 privately insured women in Pennsylvania. The scientists determined weight category based on body mass index (BMI).

Chuang says as a women’s healthcare provider, she has always wondered how weight — or perception of weight — may affect birth control choice. Research indicates that weight (and fears of weight gain) affects other medication choices, such as with antidepressants.5

“We were further intrigued after Julia Kohn et al published their article showing that contraceptive method choices differed by obesity status, with obese women more likely to use Tier 1 [implant or IUD] or Tier 3 [condoms, female condoms, fertility-based awareness methods, vaginal sponge, and spermicide],” she states. “While that was a very large data set of nearly 150,000 women, we had more sociodemographic and pregnancy-related variables, as well as questions on weight perception that we thought could help further tease out the relationships between weight and contraceptive method use.”

Researchers found that 23% of overweight and 21% of obese women used LARCs, the most effective forms of birth control. In contrast, just 6% of underweight and normal-weight women used LARCs in the study.1 There also was a trend toward overweight and obese women being more likely to use non-prescription methods such as condoms, withdrawal, and natural family planning, or no method at all. However, these results did not reach statistical significance, researchers note.

Check Patient’s Perspective

In the current study, researchers also evaluated whether perception of weight influenced contraceptive choice. Results indicate that half the women perceived themselves to be overweight, although only about 42% were overweight or obese based on BMI. However, this perception did not appear to influence birth control choice.

“Women may be worried about weight gain when they’re making decisions about birth control, so clinicians need to be aware of that,” Chuang says. “It could be an opportunity to counsel women about LARCs, which are more effective forms of contraception.”

For women who look to use the pill or other combined hormonal methods, a 2014 Cochrane Review concluded that available evidence was insufficient to determine the effect of combination contraceptives on weight, but no large effect was evident. Most studies of different birth control methods reviewed showed no large weight difference.6

Some adolescents may be more susceptible to weight gain with the contraceptive injection. Teens who demonstrate a 5% increase in body weight during the first six months of DMPA use may be at risk for continued weight gain while using this method.7

Providers can help overweight and obese women choose the most effective method. Whether excess weight significantly affects the effectiveness of hormonal contraceptives is not entirely clear; in a Cochrane Review of five studies from 2002 to 2012, only one demonstrated a higher pregnancy risk in obese women using oral contraceptives as compared to their normal-weight counterparts.8 The efficacy of the implant and injectable contraception has not been shown to be affected by patient weight.8

REFERENCES

  1. Bhuva K, Kraschnewski JL, Lehman EB, Chuang CH. Does body mass index or weight perception affect contraceptive use? Contraception 2017;95:59-64.
  2. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adult obesity in the United States, 2011-2012. JAMA 2014;311:806-814.
  3. Venkat P, Masch R, Ng E, et al. Knowledge and beliefs about contraception in urban Latina women. J Community Health 2008;33:357-362.
  4. Schraudenbach A, McFall S. Contraceptive use and contraception type in women by body mass index category. Womens Health Issues 2009;19:381-389.
  5. Zajecka JM. Clinical issues in long-term treatment with antidepressants. J Clin Psychiatry 2000;61(suppl 2):20-25.
  6. Gallo MF, Lopez LM, Grimes DA, et al. Combination contraceptives: Effects on weight. Cochrane Database Syst Rev 2014;4CD003987.
  7. Bonny AE, Secic M, Cromer B. Early weight gain related to later weight gain in adolescents on depot medroxyprogesterone acetate. Obstet Gynecol 2011;117:793-797.
  8. Lopez LM, Grimes DA, Chen M, et al. Hormonal contraceptives for contraception in overweight or obese women. Cochrane Database Syst Rev 2013;4CD008452.