Family planning methods from which the male partner could choose were limited to coitus interruptus, condoms and vasectomy. But recently, other strategies are being explored that are not yet consolidated but have very promising prospects.
Research in female hormonal contraception has a relatively short history, as the first product marketed for this purpose dates back to 1959, but it is far ahead of male contraception and more limited by the difficulty of finding substances that inhibit sperm production without seriously affecting sexual desire and erectile capacity.
Let’s review the classic methods of male contraception and the novelties of the most modern methods.
– Coitus interruptus, a method already described both in the Bible and in the Muslim tradition, consists in withdrawing the penis from the vagina before ejaculation. It is attributed to be about 80% effective. The aspects that lower the effectiveness of the method are that it is not always possible or convenient to control exactly the moment of ejaculation, and that the presence of spermatozoa in the pre-seminal fluid that is secreted during sexual intercourse before ejaculation has been described.
– The first condoms have been documented since ancient times and were made from animal intestines. Materials have evolved infinitely and nowadays they are manufactured with latex or synthetic polymers that do not contain latex for allergic people, which allow to make a very thin sheath that is placed on the erect penis before penetration and that acts as a barrier to avoid contact with female secretions and collects the contents of the ejaculate, thus combining the contraceptive capacity with the prevention of sexually transmitted diseases.
– Vasectomy: definitive surgical method relatively simple to perform, in which under local anesthesia the vas deferens is sectioned, a small tube easily located under the skin of the scrotum, which is the one that leads the sperm from the testicle to the urethra. With this duct obstructed the sexual function is not limited in any aspect, the ejaculation is preserved intact, simply the ejaculated liquid does not contain spermatozoa. It has a definitive purpose, although its reversal can be attempted by re-splicing the ends of the sectioned duct, although it is a complex intervention and not always with good results.
– In relation to vasectomy, research lines have been developed with substances that act mechanically obstructing the vas deferens, currently there are two drugs called RISUG® and VasalGel™, which injected into the vas deferens, act as a “plug” that curiously can be dissolved by injecting other substances “solvents” making this method reversible, showing an effectiveness of 100% in laboratory animals.
– Another cheap and reversible mechanical method has also been proposed that certain frequency ranges of ultrasound applied to the scrotum can reduce sperm motility and viability. It has been shown to be effective in animals and is a line of research in humans.
– The “male pill”: In advanced stages of study there are two substances, DMAU and 11β-MNTDC, which can be administered orally causing a significant reduction in the concentration of spermatozoa in the ejaculate, which recover after discontinuation of treatment. The rationale for their usefulness is as follows: Sperm production is stimulated by two hormones (LH and FSH) secreted by a small gland at the base of the brain, the pituitary gland. These substances, DMAU and 11β-MNTDC, bind to the progesterone and androgen receptors of the pituitary gland fooling it into believing that hormone levels are already present and thus the pituitary gland stops doing its job of producing LH and FSH interfering with sperm production.
There are currently clinical trials underway evaluating these drugs, which will have to be adjusted in doses and routes of administration, and their safety and side effects will have to be analyzed, which are basically, to a greater or lesser degree: decreased libido, erectile dysfunction, weight gain, acne and negative oscillations in cholesterol values. All of them are important side effects, but let us keep in mind that they are the same as those of female hormonal contraception.
– Finally, there are lines of research with multiple enzymatic chemical substances that inhibit or interfere in the sperm synthesis chain, or in their viability or motility, which have demonstrated their effectiveness but whose safety in humans will have to be carefully evaluated. These studies are very promising because this change in the contraceptive strategy with non-hormonal substances makes it possible to avoid interference in the hormonal balance of the organism, which is very delicate.
The results are very positive, and further research is needed, but it seems possible that in the near future interesting, varied and safe methods will be available so that men can also take responsibility for contraceptive measures.
Dr. Garcia Montaner