The safest maximum time a woman can keep her contraceptive implant or hormonal intrauterine device in place, as set out by the US regulator, the FDA, may be too cautious, suggest early findings from a study that is tracking the continued effectiveness of the methods against pregnancy beyond remove-by dates.
The researchers at the Washington University School of Medicine in St. Louis, MO, say that hormonal intrauterine devices (IUDs or “coils”) and contraceptive implants (matchstick-sized, flexible plastic rods inserted into the arm) “remain highly effective one year beyond their approved duration of use.”
The results are published online ahead of print in the Obstetrics & Gynecology journal, and come from an analysis of 500 of the intended 800 women to be enrolled in the study.
The recommended duration of use approved by the Food and Drug Administration (FDA) is:
- 3 years for contraceptive implants
- 5 years for hormonal IUDs.
But the implants in the study, Implanon and Nexplanon, and the IUD, Mirena, have all given reliable contraceptive performance in the study for a further year.
In this initial analysis, none of the 237 women continuing to rely on implants has become pregnant beyond the remove-by date.
There has been one pregnancy among the 263 women continuing to rely on hormonal IUDs, although this contraceptive success rate, say the researchers, is in keeping with that seen when there is compliance with the maximum recommended use for 5 years.
The study will continue to monitor the devices’ contraceptive efficacy for up to 3 years beyond the recommended deadlines for their removal.
Co-author Dr. Colleen McNicholas, assistant professor of obstetrics and gynecology at the Washington University School of Medicine, outlines the potential implications of the research:
“This research is important because extended use of these devices will reduce cost to both the individual and insurer and improve convenience for women, who can delay removal and re-insertion.”
When the women enrolled into the study they were all aged between 18 and 45 years. Informed of the risk of pregnancy by setting aside the FDA’s advice, their contraceptives had to be within 6 months of expiry dates.
Other studies have also tested IUD and implant endurance beyond established limits – the researchers say earlier work by the World Health Organization and European researchers has shown that they may be effective for longer.
Senior author Dr. Jeffrey Peipert believes in the benefit to the population of such findings. The professor of obstetrics and gynecology at the medical school says:
“The longer a contraceptive method is effective, the bigger the impact it can have.
“In the long term, this work has the potential to change how we provide contraceptive methods around the world and can enable women to control their reproductive health and family size.”
Leading gynecologists in the US, however, from the American Congress of Obstetricians and Gynecologists (ACOG), say that, while there is an increasing use of the long-acting reversible contraceptive methods, implants and intrauterine devices are still receiving relatively low take-up in America.
“In part, high-unintended pregnancy rates in the US may be the result of relatively low use of long-acting reversible contraceptive methods, specifically the contraceptive implant and intrauterine devices.”
The picture on the use of modern contraceptives is worse elsewhere, however. Earlier this week, medical scientists working for the World Health Organization reported that a low take-up of methods such as hormonal IUDs across 35 low-income to middle-income countries is responsible for 9 in 10 unwanted pregnancies.
Unreliable “traditional” methods were prevalent instead, such as having sex outside the most fertile part of the month. See: ’15 million unwanted pregnancies’ created by low contraception.