Birth Control Implant Moves From Woman's Arm to Her Lung, Doctors Warn Vigorous Exercise Is a Risk Factor

Doctors have described the rare case of a woman who underwent surgery after a contraceptive implant moved from her arm to her lung.

An unnamed woman visited her doctor because she had experienced abnormal bleeding from her vagina for three months, according to the case report published in BMJ Case Reports.

The 31-year-old was otherwise healthy, had never had surgery, and had no family history of a condition that might explain her condition. She had also had regular menstrual cycles, and had used the Implanon NXT contraceptive for eight years. Doctors inserted an implant into her arm in 2010, then again in 2013, and once again in 2017.

She was referred to a gynecologist to take out the implant in the hope it would fix her bleeding. But when staff examined her arm, they realized it wasn't there.

The woman then underwent an ultrasound. The image showed the implant was sitting to the left of her chest. An x-ray revealed more: the piece of plastic had become lodged in the lower lobe of her left lung. Medics next had to work out whether it was in one of her vessels, or in the lung tissue. A CT scan confirmed the object was in the lower left vessel of her lung.

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A stock image of a woman holding her arm. The contraceptive implant is inserted in the upper arm. Getty

Doctors decided the woman needed surgery to remove the rogue implant.

Surgeons carried out video-assisted thoracoscopic surgery (VATS), a minimally invasive procedure where a small hole is made in the chest wall. A camera and surgical instruments are inserted into the opening, and medics can see inside the body using a video monitor.

The woman's surgery went smoothly, and she didn't suffer any complications. After four days in hospital, she was sent home. Doctors gave her the all-clear at a check-up, as her wounds were healing well and her lungs were functioning normally.

"Migration of an Implanon to the lung is very rare, with few cases described in literature," wrote the doctors who treated the woman.

If the implant is inserted deeply, it can enter the venous system and then the pulmonary arterial system, warned the doctors. Exercising vigorously appears to increase the risk of vascular migration, they said.

Contraceptive implants are thin rods that are inserted into the skin of the upper arm.

Dr. Nancy Fang, a gynecologist who specializes in contraception at Columbia University, stressed to Newsweek it is rare for an implant to move, citing a recent study suggesting the plastic has migrated to the lung in as few as 1 per 100,000 women.

Fang rejected the idea that vigorous exercise can move the implant to the lung.

"Special training is required to place contraceptive implants and careful placement prevents the complications described here. Exercise with an implant is safe and will not lead to other health problems," she said. "Deep placement, not exercise, is connected to migration of the implant to the lung."

By sitting in the arm, the rod lets off progestins—the synthetic form of the female reproductive hormone progesterone. This stops a woman ovulating, and thickens the mucus from the cervix making it harder for sperm to pass through to the womb and fertilize an egg. As such, the implant provides 99 percent protection against pregnancy.

Depending on the implant, the devices last from three to five years. They can be removed at any time to restore the patient's fertility.

This article was updated to correct the name of the journal in which the study was published, and updated with comment from Dr. Nancy Fang.