Study: Implantable Contraceptives Work
Analysis Shows the Birth Control Method Is Effective in Preventing Pregnancy
WebMD News Archive
July 18, 2007 -- Implantable contraceptives are highly effective for
preventing pregnancy and seem to be well tolerated by the women who use them, a
review of the research shows.
The combined analysis included nine studies comparing different implantable
contraceptives. More than four out of five women who participated in the
studies had the implants for two years or longer, suggesting that they were
satisfied with the birth control method.
The most common side effect with the implants was irregular menstrual
bleeding, with cessation of periods increasing with duration of use.
"Menstrual disturbances are common, and these side effects should be
explained to women before the implant is inserted so that women can make an
informed choice about their contraceptive strategy," says researcher Jo
Power of London's Margaret Pyke contraceptive center.
Implantable Contraceptives in the U.S
Implantable contraception has had a rocky history in the U.S and was not
even an option for women in this country for several years before 2006.
Exactly one year ago, the FDA approved Implanon, a matchstick-sized implant
that delivers a steady dose of the hormone progestin to prevent pregnancy for
up to three years.
Implanon is inserted by a doctor under the skin of the upper arm, and it can
be removed at any time.
The single-rod delivery system for Implanon is designed to minimize the risk
of the removal problems that plagued the first implantable contraceptive to
become available in North America, Wyeth Pharmaceutical's Norplant.
Approved for sale in the U.S. in 1990, Wyeth stopped marketing the
contraceptive here a decade later due to quality-control issues and a rash of
lawsuits by women who said they were injured when having Norplant's six rods
Wyeth also market's a two-rod implantable contraceptive outside the U.S. --
sold as Jadelle -- but has no plans to introduce it here, a company spokeswoman
The newly published research review, conducted for the independent, health
practices analysis group Cochrane Collaboration, found all three implantable
contraceptives to be very effective for preventing pregnancy, but there were
some differences between them.
Not surprisingly, the one-rod Implanon and two-rod Jadelle proved to be
quicker to implant and remove from the body than the six-rod Norplant.
Menstrual bleeding irregularities were common with all three implants, but
Implanon users were twice as likely as Norplant users to have complete
cessation of periods after two years of use.