BOSTON (Reuters Health) - Implanting an intrauterine device (IUD) in the womb immediately after an abortion, instead of waiting 2 to 6 weeks, poses few risks to the woman, according to a new study.
Placing the IUD immediately increases the chance -- but only slightly -- that it will fall out within 6 months, the new study of 575 women has concluded.
Switching to immediate insertion "could prevent more than 70,000 unintended pregnancies annually in the United States," the research team, led by Dr. Paula Bednarek of the Oregon Health and Science University in Portland, notes in the June 9 New England Journal of Medicine.
But federal law discourages that practice among low-income women covered by the Title X program. The requirement that no federal money be used for abortion services effectively blocks clinics from giving those women any kind of contraceptive on the same day and in the same facility where their abortion is performed, Bednarek told Reuters Health.
The study was designed to see if IUDs, implanted immediately after an abortion or miscarriage, would remain in place. The study also gauged the risk of infection or tears of the uterus. All the volunteers had been pregnant for 5 to 12 weeks.
The IUDs were bought by the Susan Thompson Buffett Foundation, which paid for the study, an arrangement that avoided the federal restrictions.
Six months after insertion, the researchers found, IUDs had been expelled in 5 percent of the 258 women who had received an immediate insertion, compared to less than 3 percent of the 226 volunteers who had been required to wait. About four-fifths of the expulsions occurred within the first 2 months.
By that 6-month mark, more than 90 percent of the women who had immediately gotten their IUD were still using it, versus about three quarters who received a delayed insertion.
Five pregnancies occurred in the delayed insertion group, all among women who never received their IUD. There were no pregnancies in the immediate insertion group.
Side effects were rare in both groups. There were no tears due to IUDs, and five pelvic infections were reported in each group.
IUDs, which cost several hundred dollars plus whatever a doctor charges to insert them, generally have low failure and complication rates. While one in 11 first-time contraceptive pill users become pregnant in their first year, the first-year failure rate with an IUD is less than one in 100.
But the devices are underused, primarily because women have heard about the serious problems caused by the Dalcon Shield IUD in the 1970s, said Bednarek. That case led to stricter testing for the devices.
The new study, known as PAIR (for Post-Aspiration IUD Randomization), used either Bayer HealthCare Pharmaceuticals' Mirena levonorgestrel-released IUD or Teva Pharmaceuticals' ParaGard T380A copper IUD.
The researchers also found that if a woman expelled one IUD, she often expelled a replacement.
Among the 13 women in the immediate-insertion group who lost one device, seven asked for a replacement and five had expelled the second IUD by the 6-month mark.
"That's something we'd like to understand," Bednarek said.
There were six expulsions among women who got a delayed insertion; none requested a second IUD.
Heavier women were more likely to expel their IUDs, a finding that surprised researchers. "It wasn't a strong risk," said Bednarek, "but it was the only association we noticed in this study."
Thirty percent of the women in the delayed-insertion group never came back for their IUDs at all.
Immediate insertion "will prevent unintended pregnancies," said Bednarek. "It's more convenient, it's less expensive, it's less painful all around, it's good for the individual and it's good for society. We just need to create a system that makes it more doable."
SOURCE: bit.ly/jN66la N Engl J Med 2011.