new methods for male contraception
of Surgery and Experimental Research,Faculty of Medicine, Cairo University,
Asian J Androl 1999 Dec; 1: 161-167
AbstractThe methods devised for male contraception are meagre. In the current communication, we review 3 recently developed methods applied for male contraception: testicular suspension, polyester-induced azoospermia and prolactin injection. The testicle was suspended in the superficial inguinal pouch close to the scrotal neck using 2 methods: stitch and ball. The azoospermic effect of the polyester sling seems to be due to 1) creation of electrostatic field across the intrascrotal structures, and 2) disordered thermoregulation. Prolactin administration, as a contraceptive method is efficient and safe and has the potential to be developed as a male contraceptive. The effect of the above mentioned 3 methods is reversible. These methods, especially testicular suspension and polyester suspensors, are simple and easily applicable and were well acceptable by the subjects.
1 IntroductionMany effective methods of contraception have been devised for women while men have as yet not received enough attention in this respect. Most commonly used are withdrawal, the condom, and vasoligation. Although the latter is an effective male contraceptive method, yet the high incidence of permanent infertility and the surgical risk are limiting its use on a large international scale. Androgen, alone[2,3] or combined with progesterone, did not prove to be an efficient method of contraception. For this reason, the search for a reliable, reversible and safe method for male contraception continues. The current communication gives a brief report on three new methods for male contraception: testicular suspension, polyester-induced azoospermia, and prolactin injections.
2 Testicular suspension
of the fields of search is the vulnerability of spermatogenesis to thermal
insult[6-9]. In a preceding experimental study on dogs,
the testicles of the animals were suspended in the superficial inguinal
pouch for one year and then released. During testicular suspension, the
semen quality deteriorated to the effect that by the 12th month, 80% of
the test dogs were azoospermic. This was accompanied
by a significant drop in serum testosterone, an increase of serum prolactin
and the failure of dog mating to accomplish pregnancy. Three months after
release of suspension, the sperm character and hormonal assay became normalized
and mating produced
pregnancy. Based upon these results, a simple, safe, reliable and reversible
method of male contraception is developed.
procedure was carried out in 28 male volunteers. The testicles were suspended
in the superficial inguinal pouch close to the scrotal neck using the
technique of stitch suspension in 15 and of ball suspension in 13 subjects.
testicle is suspended close to the scrotal neck in the superficial inguinal
pouch which lies between the external oblique and the deep layer of the
superficial fascia over the inguinal canal. With the subject in the supine
position, the skin at the scrotal neck is infiltrated with 5 mL 1% xylocaine.
While the left hand places and holds the testicle in the described location,
2 to 300 silk stitches are taken between the skin and the tunics of the
testicle so as to keep the testicle in this position.
The technique is carried out on both testicles. A suspensory sling
for support is worn for 3 weeks, whereas the stitches are removed 2 weeks
postoperatively. The procedure is performed on an outpatient basis.
suspensory sling consisting of a non-stretchable fabric is prepared separately
for each subject to fit snugly around the individual scrotum. The so-called
ball suspensor contains 2 compartments, each having a
ball (made of textile and filled with cotton) of the size of the testicle
fixed to its bottom.
The ball suspensor is applied to the scrotum; the testicles are elevated
to the scrotal neck. They are managed manually to lie in the superficial
inguinal pouch, overlying the balls. The subjects are instructed how to
apply the sling on
their own. The ball suspensor is worn day and night and replaced by
a fresh one only when it becomes loose or soiled.
the 12 months of testicular suspension, the proper location of the testicles
at the scrotal neck as well as their size and consistency are checked
every 15 days. Rectal and intratesticular temperature and the semen are
examined once a month.
A testicular biopsy is taken six months after suspension. The testicle
size, temperature and biopsy, and semen as well as serum testosterone,
FSH, LH, and prolactin were examined before and during the testicular
suspension period and after suspension release. Sexual intercourse was
practised during testicular
suspension and after release, but not during the first 3 months into suspension.
ball suspension is reversed by simple discontinuation. To release stitch
suspension, the skin at the scrotal neck is infiltrated with 5 mL
of 1% xylocaine. Through a skin incision of 1 to 1.5 cm over the suspended testicle,
the adhesions that have developed between the testicle and the
scrotal skin are cut by blunt and sharp dissection. The testicle is then
drawn down to lie in the most dependent part of the scrotum. The contralateral
testicle is released
in the same way. The procedure is carried out at the outpatient clinic.
suspension, the sperm count dropped to severe oligozoospermia. Pregnancy
did not occur. There was a significant decrease in serum testosterone
and an increase in prolactin.
The mean difference between rectal and testicular temperature
in the pre-suspension period was (30.2) while in post-suspension was
(1.10.1) (P<0.001) Testicular biopsy showed degeneration
of seminiferous tubules.
Six months after testicular release, sperm count, rectal-testicular temperature
difference and serum hormone levels returned to normal. The testicular
biopsy showed normal spermatogenesis. Pregnancy occurred.
studies since the beginning of this century have established the vulnerability
of spermatogenesis to relatively small increases in testicular temperature[6-9].
Moore[6,7], performing experimental cryptorchidism in the guinea
pig, observed a complete dissolution of cells of the seminiferous tubules,
except the Sertoli elements, within a period of 2 weeks. The testicles
became smaller and never returned to a spermatogenic function as long
as they remained in the abdomen. Re-locating the testicle, which showed
residual spermatogenia, back into the
scrotum resulted in the return of a normal spermatogenic function[7-9].
Likewise, testicular grafts in rats produced spermatozoa only when attached
to the inside walls of the scrotum, but failed to do so in any other locality
outside the scrotum.
Damage of the spermatogenic function of the testicle by artificial cryptorchidism
was produced in the rat[8,9], rabbit, dog,
and sheep and by scrotal insulation in the ram
and bull. Experiments were done to demonstrate the thermoregulatory
function of the scrotum as well as the damaging effect of heat on the
testicles. Thus, elevation of testicular temperature by dry[6,17]
or wet[18,19] heat induced extensive degeneration and loss
of spermatogenic tissues.
testicle has a thermoregulatory apparatus which regulates the scrotal-rectal temperature
relationship and keeps it constant in reaction to environmental temperature
of this mechanism inhibits spermatogenesis and leads to infertility[22,24,25].
of the testicle in the superficial inguinal pouch led to diminished spermatogenesis.
This seems to be due to disordered thermoregulation resulting from 2 factors:
(a) testicular fixation and (b) high testicular position.
fixation results in loss of testicular motility in reaction to changes
in environmental temperature[20-24]. The testicle loses its
thermoregulatory function, and its temperature remains constant despite
environmental temperature variations.
the location of the testicle high in the inguinal pouch close to the warm
abdomen has elevated its temperature to the effect that the testicular-rectal
temperature difference recorded values below normal. The constantly and
significantly elevated testicular temperature seems to be responsible
for the diminished spermatogenesis. The semen showed diminished sperm
count and motility with an increase in abnormal sperm forms, such that
by the end of the 12th month into suspension 68% of the subjects were
azoospermic and 32% severely oligozoospermic. Six months after release
of suspension the semen quality was normalized.
is noteworthy that the sperm count reduction after testicular suspension
was more manifest in stitch than in ball suspension, although the difference
was insignificant. Accordingly, the increase in the sperm count after
suspension release occurred earlier in ball than in stitch suspension.
The difference in results between the 2 suspension procedures, albeit
insignificant, could be related to the
invariably firm position of the stitch-suspended testicle which unlike
the unfixed ball-suspended
testicle remains unaffected by the subject's movements in
his daily activities.
suspension was accompanied with a significant decrease in serum testosterone
and an increase in serum prolactin. These hormone levels were normalized
after suspension release. The testicular biopsy showed tubular degenerative
changes during suspension, which recovered after release.
The above mentioned results point to a deleterious effect of testicular suspension on the testicular function and its restoration after suspension release. The role of these testicular changes in contraception was tested. Pregnancy did not occur during the suspension period. During the first 3 post-suspension months, sexual intercourse was not practiced because the changes in the testicular function were not adequate yet to guard against pregnancy. After release of testicular suspension, one third of the wives conceived in the first 6 months post-release, and the remaining two thirds in the following 8 months.
is worth mentioning that fetal anomalies were not encountered during pregnancy
or after delivery. Furthermore, there were no abortions during the study period.
3 Polyester-induced azoospermia
issue we investigated recently is the vulnerability of spermatogenesis
to polyester (polyethylene terphthalate) contained in textile products[26-28].
An earlier study showed that dogs when made to wear polyester
underpants had a diminished sperm count which was reversible when the
pants were removed. In contrast, dogs wearing cotton pants showed insignificant
semen changes. A human study revealed that polyester underpants worn by
men generated an electrostatic field that traversed the scrotum and
seemed to affect the testicle and/or the epididymis, leading to diminished
spermatogenesis. Textiles worn by 33 volunteers in 3
equal groups during 18 months produced insignificant changes in testicular
temperature and serum reproductive hormones. In the first
group of 11 subjects who wore polyester underpants, 4 showed a significantly
decreased sperm count and testicular degenerative changes by the 14th
month; these changes were reversed after
the underpants had been removed. In the second polyester-cotton mix group of
11 subjects, only 1 volunteer became oligospermic 16 months into the pants-wearing
period; the sperm count was normalized after removal of the underpants.
In the third group of 11 wearing cotton only, insignificant changes in
the semen character appeared.
The results of these studies led to conclude that polyester fabrics have a depressive effect on the spermatogenesis and that this effect was reversible on removal of the pants. It further appeared that this effect is related to the electrostatic charges generated by the polyester fabrics and creating an electrostatic field across the testicle and/or the epididymis.
was therefore surmised to use polyester-containing textiles as a contraceptive
tool for men. The
contraceptive effect of a polyester sling applied
to the scrotum was studied in 14 men who wore a polyester suspensor
for 12 months.
suspensory sling consisted of polyester fabric and was fashioned for the
scrotum to lie within it (Figure 1).
Variable sizes of the sling were made to suit the scrotum and slung to
the waist of the subject by a belt attached to the suspensor. The belt
was tied so that the suspensor elevated the testicles towards the abdomen.
The suspensor was used day and night and was changed when soiled. Follow-up
investigations comprised periodic check of semen character, testicular
size, rectal-testicular temperature difference, serum reproductive hormones,
and testicular biopsy. The electrostatic potentials generated by friction
between the polyester
suspensor and the scrotal skin were determined. Female partners used contraceptives
until the men became azoospermic. After 12 months, the suspensor was abandoned
and the aforementioned investigations were performed again.
1. Scrotal sling (from Shafik).
the suspensor-wearing period, all men became azoospermic after (139.620.8)
days (data expressed in the means), with decreases in both testicular
volume (P<0.05) and rectal-testicular temperature difference
(P<0.001). Serum reproductive hormones showed no significant
Seminiferous tubules revealed degenerative changes. No pregnancy
occurred during this period. The
polyester suspensor generated electric potentials (366.430.5) V/cm2
by day and (158.313.6) V/cm2 by night.
In the period after the suspensor was abandoned, the sperm concentration returned to the pre-test level in a mean period of (156.614.8) days. Likewise, the testicular volume and rectal-testicular temperature difference were normalized. In 5 couples the women conceived as they had planned.
study demonstrates that the ensheathing of the scrotum in
a polyester suspensor has induced azoospermia in all of the 14 volunteers
and that this azoospermia is reversible following the release of the suspensor,
and the wives of 5 of the volunteers became pregnant according to plan.
the study shows that electrostatic potentials are generated from the polyester
sling and the opposing scrotal skin as a result of friction between the
two surfaces. They are higher during daytime rather than at night, due probably
to the higher temperatures prevailing during the day. The electrostatic
charges and consequently the potentials are directly proportional to the
temperature: the higher the temperature, the more charges are generated.
Azoospermic effect of the polyester sling
azoospermic effect of the polyester sling seems to be related to two factors[26-28]:
the electrostatic field effect and the disordered thermoregulatory effect.
The electrostatic field effect
between the scrotal skin and the polyester sling creates a negative charge
on the inner surface of the sling and a positive
one on the scrotal skin facing the sling (Figure
2). An equal but opposite charge to the one on the inner sling aspect
occurs on the outer sling surface. The result is that the outer surface
of the scrotal sac facing the sling will have a number of positive charges.
The latter produces induced charges with negative sign on the other surface
of the scrotal sac. Eventually, equal but opposite charges are created
on the two aspects of the scrotal sac: the one in contact with the sling
and the other away from it (Figure
2). These opposite charges will produce an electrostatic field
extending from one aspect of the scrotum toward
the other through the scrotal sac[26-28]. The electrostatic field
traversing the scrotal contents would disturb the testicles and/or epididymis
leading to diminished spermatogenesis.
2. Diagrammatic illustration of the electrostatic potentials created
on the polyester suspensor
and the scrotal sac. The electrostatic field is demonstrated (from Shafik).
polyester suspensor leads to spermatogenic depression
also by disturbing the testicular thermoregulatory mechanism. The suspensor
induces disturbed thermoregulation by two mechanisms. Firstly, it fixes the
two testicles to the effect that they cannot move in reaction to changes
in the environmental
temperature[13,14]. Secondly, it slings the two testicles
up towards the warm abdomen, thus increasing the testicular temperature
with a resulting decrease in the rectal-testicular temperature difference.
The testicular temperature may as well affect the frequency of the electrostatic
potentials generated on the scrotal skin. As mentioned earlier, the higher
the temperature, the more charges are generated. Thus, with the temperature
of the testicles increasing as a result of their being close to the warm
abdomen, the generated electrostatic charges increase, and their possible
injurious effect on the intrascrotal structures
would consequently be increased. In all volunteers a decrease in the rectal-testicular
temperature difference during the period when the polyester suspensor
was worn, was recorded. However, the temperature difference returned to
the pre-test value after the suspensor was released.
Polyester sling as a contraceptive tool
4 Prolactin Injection
our contribution to the search for a safe, effective, convenient and reversible
contraceptive method, we have taken advantage of the properties of prolactin
(PRL) to try its use as a male contraceptive method.
is a protein hormone secreted by the anterior pituitary gland. Its secretion
seems to be inhibited by a PRL release-inhibiting hormone which may be
dopamine[30,31]. Hyperprolactinemia has been found in infertile
patients with oligo-
Furthermore, lactational hyperprolactinemia seems to be decisive
for maintaining lactational amenorrhea which is known to have a contraceptive
The method was tested in dogs: 14 test and 14 control. The dogs in the test group were injected with ovine PRL in a dose of 600 g/kg of body weight weekly for 6 months. During this period, the testicles, semen, reproductive hormones, renal function, and serum sodium and potassium were examined periodically. Testicular biopsy was obtained 3 and 6 months from PRL administration. These investigations were repeated during the 6 months following withdrawal of the drug.
sperm count dropped gradually with a decrease in sperm motility and an
increase in abnormal forms, and azoospermia was reached within 3 months
after PRL administration.
Testicular biopsy showed degenerated seminiferous tubules. Reproductive
hormones, renal function as well as serum sodium and potassium revealed
insignificant change (P>0.05). Dog mating during the period
of PRL administration
produced no pregnancy. Three months after drug withdrawal, the sperm count
was normalized and mating produced pregnancy; the offspring showed no
Our study demonstrates that PRL inhibits spermatogenesis. The sperm inhibition started about 2 weeks after PRL administration, approached azoospermia in 6 weeks and reached azoospermia in all the dogs within 3 months. The diminished sperm density was accompanied by decreased motility and increased abnormal forms of sperm. These changes in the spermiogram were accompanied with degenerative changes in seminiferous tubules and continued to the end of the 6-month period of PRL administration. Meanwhile, no significant changes were encountered in renal function or in the serum levels of sodium and potassium. Glycosuria was not detected which would indicate that the carbohydrate metabolism had not been affected. The reproductive hormones showed insignificant changes at 3 and 6 months after PRL administration. It does not exclude the possibility that gonadotropin and testosterone secretion may be suppressed if they have been assessed at an early date of PRL injection. After 3 months of PRL administration, pregnancy did not occur despite repeated inseminations.
months after drug withdrawal, 85.7% of the dogs had a normal spermiogram. Five
months from withdrawal, all dogs had a normal semen character and produced pregnancy
with healthy offsprings in all of the 9 inseminated bitches. These results
demonstrate the effectiveness of PRL in inducing reversible spermatogenic
depression without lasting changes in serum reproductive hormones or renal
and libido would thus not be affected because serum testosterone levels
are not affected.
has been reported that PRL and growth hormones can produce renal retention
of water, sodium and
potassium that persists for 12 to 18 hours after PRL administration[34,35].
In our study, no significant changes could be detected in these
could be due to the fact that the injections were spaced weekly.
The cause of the anti-spermatogenic action of PRL is so far unknown. Reproductive hormones were not measured frequently enough to determine the effect of any suppression of gonadotropin secretion. In addition, the spermatogenic depression could be due to a direct action of PRL on the testicle. The degenerated seminiferous tubules may provide indirect evidence for this possibility; a direct relationship between the two events, PRL administration and testicular injury, could however not be verified in our study but is a point that calls for further investigation.
results of the present study demonstrate that PRL has the potential to
be developed as a male contraceptive, which is reversible.
The method is simple and has no complication.
The only disadvantage to date is that the drug is administrated
by injection. Nonetheless
it seems to have the potential for paving the
way to a prolactin pill as an efficient contraceptive method for males.
Ross JA, Hong S, Huber
DH. Voluntary sterilization: an international fact book. New York Association
for Voluntary Surgical Contraception; 1985.
to Prof. Ahmed Shafik. Dept. of Surgery and Experimental Research, Faculty
of Medicine, Cairo University, 2 Talaat Harb Street, Cairo, Egypt.