Widespread Birth Control Use Potentially Associated with Serious Intestinal Complications

Two women faced life-threatening situations when their contraceptive implants moved into their abdominal areas, causing a severe condition known as bowel strangulation.

The individuals had been using ring-shaped intrauterine devices (IUDs) for more than three decades, surpassing the approved duration of up to ten years for such devices.

At 61 and 73 years old, both women had not undergone the recommended device removal. They sought medical attention after experiencing symptoms including abdominal pain, nausea, and vomiting.

Medical examinations revealed that the IUDs had gradually penetrated the uterine wall, which tends to thin with age, eventually migrating into the abdominal cavity.

Within the abdomen, the IUDs formed a hazardous loop, ensnaring sections of the small intestine and restricting blood flow, leading to tissue necrosis. Surgeons were required to excise as much as two feet of intestine to resolve the issue.

While IUDs are generally safe, complications, though rare, can be serious. The risk goes up when devices are left in after menopause because the shrinking uterus makes perforation more likely.

The two cases, reported by surgeons in China, occurred within six months of each other. The authors suggested this ‘cluster’ may signal a growing problem as populations age and more women live for decades with retained IUDs. 

Ring-shaped IUDs are used by 40 to 50 million women globally. They are an older form of the devices and less common in the US because they tend to cause problems later in life. 

More than 50 million women worldwide use ring-shaped IUDs, but for two of them, it led to emergency gastrointestinal surgery (stock)

Their blunt shape means they migrate more slowly than the sharper T-shaped IUDs used today.

Ring-shaped IUDs are also rigid and do not flex with the uterus. After menopause, as the uterus shrinks, the stiff ring can slowly wear through the thinning uterine wall over many years.

Once it escapes into the abdomen, a loop of intestine can slip through its hollow center and become trapped, cutting off blood flow and requiring emergency surgery.

In contrast, modern T-shaped IUDs are flexible and rarely cause this. If they migrate, they are more likely to directly puncture an organ rather than create a trap for the bowel.

While IUDs are generally safe and effective, the risk of serious complications rises significantly when devices are left in place after menopause because of the thinning of the uterine wall. 

One case study published in the American Journal of Case Reports details a 61-year-old woman who arrived at the emergency department complaining of severe abdominal pain, bloating, nausea and vomiting over the previous day.  

A CT scan revealed that her ring-shaped IUD had migrated out of her uterus and into her abdomen.

There, a loop of her small intestine had slipped through the ring’s center and become strangulated, cutting off its blood supply.

Surgeons rushed her to the operating room and found 30 centimeters, roughly 12 inches, of dead bowel. 

They removed the dead tissue and reconnected the healthy ends.

Just months later, a 73-year-old woman visited the same hospital with similar symptoms – nausea, vomiting and lower abdominal pain that had worsened over two days. 

Her CT scan told the same story as the first patient’s: a migrated ring IUD with a loop of intestine trapped inside. This time, surgeons found 50cm, or 20 inches, of dead bowel that had to be removed.

Both women recovered well after their surgeries.

A CT scan showing proper placement of an IUD in the pelvic cavity, left, and a CT scan showing the migration of the IUD to the abdominal cavity

A CT scan of one of the patient’s abdominal cavities shows her IUD had migrated from her pelvic cavity

IUDs work primarily by stopping sperm from reaching or fertilizing an egg, preventing pregnancy. 

Hormonal IUDs release a small amount of progesterone-like hormone that thickens cervical mucus, making it hard for sperm to enter the uterus, and thins the uterine lining, so a fertilized egg is less likely to implant.

Copper IUDs release copper ions, which are toxic to sperm, preventing fertilization.

Most IUDs are safe and effective for three to 10 years, depending on the type, and can be removed at any time.

Complications with IUDs are rare overall, affecting less than one to five percent of users. The most frequent issue is device expulsion, where the IUD slips out of place. This happens in about three to 11 percent of women over five years.

Far more concerning is uterine perforation — when the IUD pushes through the uterine wall. This is exceedingly rare, occurring in only one to two out of every 1,000 insertions; that is less than 0.2 percent.

While IUDs are highly effective at preventing pregnancy, if a pregnancy does occur with an IUD in place, there is a slightly higher chance it could be ectopic, meaning outside the uterus, though the absolute risk remains extremely low.

For the vast majority of women, IUDs are a safe and reliable form of birth control.