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Abstract
This report describes the long-term follow-up of 376 women who received NORPLANTR implants in the period October 1974 through May 1979. One-hundred-and-ten subjects
received replacement implants after variable lengths of use of the first set.
The average levonorgestrel plasma levels declined steadily through eight years of
use of NORPLANTR capsules (r = −.937). Values were 0.35 ng/ml, 0.29 ng/ml and 0.22 ng/ml at treatment
years 1, 5 and 8, respectively. Levonorgestrel plasma levels after replacement with
a second set of implants were similar to those observed after the first insertion,
either when placed in the same site as the first set or in a different area.
Nineteen pregnancies occurred during 18,530 woman-months of use of the first set of
implants, eleven of them during years 6 through 8 of treatment. The Pearl Index for
the first 5 years of NORPLANTR implants use was 0.63. No pregnancy has occurred in 4194 woman-months observed during
treatment with a second set of capsules.
Fifty-six women (14.9%) out of 376 acceptors of the first implant and 10 (9.1%) out
of 110 acceptors of the replacement implants were terminated for other medical reasons,
mainly bleeding problems and side effects commonly associated with hormonal contraception.
Two women died while using NORPLANTR implants, one of a cardiac arrest after surgery for a gallbladder disease and one
because of endocranial hypertension originating from the rupture of an aneurism of
the median cerebral artery.
The bleeding pattern observed in the three months after NORPLANTR capsules replacement was similar to that observed in the 90 days before replacement
and different from that experienced by the same women in the first 90 days of implant
use. This finding can be interpreted as an indicator of adaptive changes experienced
by the target organs during long-term continuous administration of levonorgestrel.
The prompt recovery of fertility after removal of NORPLANTR implants suggests that these changes are reversible.
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References
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Article info
Publication history
Accepted:
July 1,
1987
Received:
April 22,
1987
Footnotes
*This work was undertaken as part of the contraceptive development program sponsored and coordinated by the International Committee for Contraceptive Research of The Population Council, Inc., New York, New York.
Identification
Copyright
© 1987 Geron-X, Inc. Published by Elsevier Inc.
