The results of clinical trials involving monkeys as test subjects have created excitement about the possibility that male contraceptive jab could be on the horizon in the future.
Apparently more effective than the pill, ‘Vasalgel’ has the same end effect as vasectomy, however the jab should be reversible if the man decides he wants to have children at a later point, with a second injection in theory working to dissolve the gel plug.
The premise involves the injecting of gel into the vas deferens – the tube responsible for moving sperm from the testicles to the urethra – in order to block it.
Currently, men only have two main methods of contraception – either wear a condom to catch the sperm, which some men are bizarrely still reluctant to do, or under a vasectomy operation (sterilisation), whereby the two tubes that carry sperm from a man’s testicles to the penis are cut, blocked or sealed.
Over 10,000 men have vasectomies each year in England and it is considered a more ‘permanent’ solution of contraceptive. It is possible to have a vasectomy reversed, although the procedure does not guarantee success. If a reversal is performed within 10 years of your vasectomy, the success rate stands at about 55%, but then drops to 25% if your reversal is carried out over 10 years after the vasectomy.
As contraception options for males have not really altered in a century, the new injectable gel could be a worldwide success, and alleviate some of the pressure off women to prevent pregnancy.
A previous jab that was looked into that used hormones to prevent sperm production, was discovered to induce too many side effects including depression and muscle pain, resulting in 20 men withdrawing from a 12 month clinical trial.
However, a team of researchers at The University of California tested the new Vasalgel on 16 adult male monkeys, 10 of whom were already fathers.
They assessed the monkeys for a week following the injection and were then released back into their enclosure and joined up with some fertile females.
Mating occurred, but interestingly not a single female monkey became pregnant over the duration of the study, including two full breeding periods for some of the monkeys.
There were very little in the way of side effects, but one monkey did require an operation as the injection damaged one of his tubes. For not one female monkey to fall pregnant in the two years of the study though will be deemed a huge success.
The next stage now will be human trials, and it could be tested in people as early as 2018.
Professor Adam Balen, chair of the British Fertility Society, said: “This is an interesting technique that achieves a reversible “vasectomy” by blocking the passage of sperm with a substance that later can be flushed out.
“If free of side effects, then this novel approach has the potential for great promise as a male contraceptive. It is essential to know that the reversibility remains, irrespective of the duration of use.”
Fertility expert Allan Pacey, professor of andrology at the University of Sheffield, said there could be a ‘worldwide market’ for an effective male contraceptive.
He added: “The idea of trying to replace the traditional method of vasectomy by inserting a gel into the tube which carries sperm from the testicles to the penis at ejaculation is not a new one.
“However, we haven’t seem much progress in developing the idea in recent years, so this study is a useful step in the right direction.”