Tubal ligation has been touted as a permanent form of birth control, but a new study shows that women are more likely than previously thought to get pregnant after the procedure.
The study, published Tuesday in NEJM Evidence, revealed that 3% to 5% of women in the United States who had their "tubes tied" – as tubal ligation is often referred to – reported unplanned pregnancies. These rates are higher than the less than 1% of women previously reported as getting pregnant after tubal sterilization, another name for the surgery, by the American College of Obstetricians and Gynecologists and other health experts.
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Early research has shown that interest in tubal ligation and in vasectomies in men has risen since the 2022 U.S. Supreme Court decision in Dobbs v. Jackson Women's Health Organization stripped away federal protections for abortions and limited abortion access in many states. A vasectomy is surgery that prevents pregnancy by cutting and sealing off the tubes that carry sperm in men. After a vasectomy, a couple has less than a 1% chance of becoming pregnant, according to the American Pregnancy Association.
"For people who have chosen a 'permanent' method, learning they got pregnant can be very distressing," the study's lead researcher, Dr. Eleanor Bimla Schwarz, said in a release. "It turns out this is, unfortunately, a fairly common experience."
Schwarz, who is chief of the University of California, San Francisco Division of General Internal Medicine at Zuckerberg San Francisco General, said that contraceptive arm implants and intrauterine devices are more reliable forms of contraception than tubal ligation. For a contraceptive implant, a small plastic rod is placed under the skin of the upper arm to release a slow, steady flow of progesterone to pause ovulation. An IUD, another form of long-term, reversible contraception, is a small device inserted into the vagina to prevent pregnancy.
The study looked at data from more than 31,000 women, including 4,184 of whom had had tubal ligations. Findings showed that 2.9% of women who reported having their tubes tied between 2013 and 2015 had gotten pregnant within the first year. The women who were youngest at the time of the surgery had the highest chance of getting pregnant, the researchers found.
People on Medicaid, a joint federal and state program that covers medical costs for some people with limited resources, had no higher chance of getting pregnant than those with private insurance, according to the study.
Nearly 65% of women ages 15 to 49 in the United States use contraception. Rates of contraception use increase with age, with nearly 74% of women 40 to 49 using contraception compared to more than 37% of women ages 15 to 19, according to the Centers for Disease Control and Prevention.