SAN DIEGO – Obese women with a body mass index of 40 or greater are more likely to experience expulsion of levonorgestrel IUDs than women with lower BMI, according to findings from a retrospective cohort study.
Women with class III obesity (a BMI of 40 or greater) had a 3.06-times higher odds of expulsion (95% confidence interval, 1.69-5.57) with a levonorgestrel IUD, compared with a control group of women with a BMI of less than 35,, of the University of Hawaii at Manoa, Honolulu, reported at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists.
Dr. Saito-Tom and her colleagues looked at other potential IUD complications, including infection, perforation, and pregnancy. Women with class III obesity also had a higher rate of all complications combined at 24%, compared with 10% among women with class I obesity.
Although complications were higher for more severely obese women, there were no differences between BMI groups in difficulty with insertion (P = .59) or 12-month continuation (P = .69).
The study was unique because it included a diverse ethnic population, with 36% Native Hawaiian/Pacific Islander women and 31% Asian women.
The study wasn’t powered to identify the reasons for greater expulsion in obese women, but some theories include that the IUD could be more difficult to place in larger women without adequate instrumentation or exam tables. Women with class III obesity also tend to have higher rates of heavy menstrual bleeding, which could be driving expulsion, Dr. Saito-Tom said.
However, the results should not deter physicians from placing hormonal IUD in these women, she said. While the expulsion rate was higher than seen generally, it is still an effective method for most obese women. “That’s much more beneficial than discouraging patients,” Dr. Saito-Tom said.
Physicians should continue to educate patients about the benefits of long-acting reversible contraceptives and encourage all patients to utilize them, regardless of their weight, she said.
Dr. Saito-Tom reported having no relevant financial disclosures. One of her colleagues reported grant support from Merck and being a consultant for UpToDate.