June 20, 2011 -- Intrauterine devices (IUDs) and implantable contraceptives may not be popular, but they are among the most reliable contraceptive methods available.
"IUDs and implants should be considered first-line contraceptives for a majority of women," says Eve Espey, MD, MPH, an associate professor of obstetrics and gynecology at the University of New Mexico in Albuquerque. She co-authored a paper on these choices in the American Congress of Obstetricians and Gynecologists' Practice Bulletin.
Still, these methods have never really caught on among women for several reasons, including concern about side effects such as pelvic infections. Fewer than 6% of women in the U.S. used IUDs between 2006 and 2008.
The majority of unintended pregnancies among contraceptive users occur because of inconsistent or incorrect contraceptive use, and this is where implants and IUDs stand out from the pack. They are maintenance-free, which means there is virtually no margin of error, she says.
There are two IUDs available in the U.S. Both are small, T-shaped devices made of flexible plastic that are inserted into the uterus during a routine doctor's visit. ParaGard IUD contains copper and is effective for 10 years. Mirena contains a small amount of the hormone progestin and is effective for five years. Both devices prevent a fertilized egg from attaching to the uterine wall. The copper IUD also interferes with the sperm's ability to move through the uterus and into the fallopian tubes.
"These both have a tremendous safety record and well-known acceptability by patients," she says. Espey says she checks the copper IUD after five to 10 years.
"If Mirena fails, you will go back to regular, heavy menstrual period, so it may be obvious," she says.
Implanon is a single-rod contraceptive implant that inserted under the skin of the upper arm that releases the hormone progestin over a three year period. "You can feel it, so I don't recommend a lot in the way of checking," she says.