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Abstract
Attempts were made to collect several samples of cervical mucus in each of thirty-three
cycles of women using NORPLANTR subdermal implants, in seven cycles from NORPLANT-2 rod users, and in 33 control
cycles.
The attempts to collect a mucus sample were successful on 20 of 77 and 7 of 14 occasions
in NORPLANTR capsule and rod users, respectively, due to the scanty amount and stickiness found
in the majority. All 59 attempts in control subjects were successful. The distance
travelled by the fastest sperm and by the bulk of spermatozoa through the cervical
mucus ![Math Eq]()
was assessed after 10 min of incubation with a normal semen sample. The best score
for each cycle was considered for the comparison between treated and control cases.
Sperm penetration was greatly impaired in mucus samples of implant users with penetration
by the fastest sperm exceeding 10 mm in only two instances and exceeding 20 mm in
none. In 30 of 33 control samples, the fastest sperm travelled 21 mm or more and in
28, the bulk of spermatozoa travelled further than 10 mm. Unsuccessful attempts to
collect mucus and poor sperm migration were observed in NORPLANTR implant users even when circulating estradiol levels were comparable to those seen
in the late follicular phase of the normal menstrual cycle. These results suggest
that the principal mechanism by which NORPLANTR implants prevent pregnancy is by interference of sperm migration through cervical
mucus.
was assessed after 10 min of incubation with a normal semen sample. The best score
for each cycle was considered for the comparison between treated and control cases.
Sperm penetration was greatly impaired in mucus samples of implant users with penetration
by the fastest sperm exceeding 10 mm in only two instances and exceeding 20 mm in
none. In 30 of 33 control samples, the fastest sperm travelled 21 mm or more and in
28, the bulk of spermatozoa travelled further than 10 mm. Unsuccessful attempts to
collect mucus and poor sperm migration were observed in NORPLANTR implant users even when circulating estradiol levels were comparable to those seen
in the late follicular phase of the normal menstrual cycle. These results suggest
that the principal mechanism by which NORPLANTR implants prevent pregnancy is by interference of sperm migration through cervical
mucus.To read this article in full you will need to make a payment
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References
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- Anovulation, inadequate luteal phase and poor sperm penetration in cervical mucus during prolonged use of NorplantR implants.Contraception. 1985; 31: 261-272
- Long-term reversible contraception with levonorgestrel-releasing SilasticR rods.Am. J. Obstet. Gynecol. 1984; 148: 1006-1013
- Contraceptive drug delivery via subdermal implants.in: Lemberger L. Reidenberg M.M. Proceedings of the Second World Conference on Clinical Pharmacology and Therapeutics. American Society for Pharmacology and Experimental Therapeutics, Maryland1984: 650-660
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Article info
Publication history
Accepted:
July 28,
1987
Received:
May 26,
1987
Identification
Copyright
© 1987 Published by Elsevier Inc.
