Birth control for men: Works in monkeys, humans next

08 กุมภาพันธ์ 2560

Search for long-term, reversible, non-surgical birth control for men to avoid side-effects that women suffer from birth control pills, coming soon.

HEALTH, MEDICINE & BIRTH CONTROL

Birth control for men: Works in monkeys, humans next

AFP News Agency

A new medical technology that prevents pregnancy long-term and is used by the man, not the woman, will likely be available soon.

A gel squirted into the sperm ducts of male monkeys has been effective at preventing pregnancy.

Male humans may be squirting it into their sperm ducts soon, if their girlfriend or wife insists.

THE SEARCH FOR MALE BIRTH CONTROL

While several birth control options exist for women, the race is on for a non- surgical, long-term and reversible male contraceptive without the negative side effects of hormonal changes that women who use birth control pills often suffer from.

The only short-term solutions available today are condoms, which many people complain interfere with sex, and withdrawal before ejaculation, which comes with a high risk of pregnancy.

VASECTOMY CURRENTLY ONLY LONG-TERM OPTION

Longer term, the sole option is a vasectomy, which involves tying or cutting the sperm conducting tubes called the vas deferens.

This prevents sperm from mixing with seminal fluid ejaculated during sex.

Vasectomies can be reversed in some cases, but the procedure is technically challenging and leads to low rates of fertility.

The YouTube video below describes and explains the medical procedure of the vasectomy:

MONKEYS ANATOMICALLY SIMILAR TO HUMANS: SO MAY WORK IN HUMANS TOO

Researchers in the US are developing a possible alternative to the vasectomy, dubbed Vasalgel, which has proven effective in rabbits and now also in rhesus monkeys -- more closely related and anatomically similar to humans.

Vasalgel is a polymer gel injected directly into the vas deferens, creating a blockage in the tube that transports sperm from the testes out through the penis.

(Source: Parsemus Foundation)

NO BABIES AFTER THE MONKEYS WERE INJECTED

In an experiment at the California National Primate Research Center, 16 adult male monkeys were treated.

They were housed with females, and monitored for up to two years -- covering at least one breeding season per animal.

"Treated males have had no conceptions since Vasalgel injections," the research team wrote in the journal Basic and Clinical Andrology (see here).

PREGNANCY RATE TYPICALLY 80%

Normally, the expected pregnancy rate among females housed with males would have been about 80 percent.

MINIMAL COMPLICATIONS

"The presence of Vasalgel appears to be well tolerated and placement resulted in minimal complications," the researchers wrote.

One monkey of the 16 had symptoms of sperm granuloma, a buildup in the vas deferens which is a common complication in about 60 percent of human vasectomies, they added.

Not yet tested in monkeys, the reversibility of the method was tested in earlier experiments in rabbits, when the gel was successfully flushed out with solution of sodium bicarbonate.

CLINICAL TRIAL IN HUMANS COMING SOON

Preparations are underway for a clinical trial with Vasalgel in humans, said the Parsemus Foundation, a non-profit organisation funding the product's development.

The research has benefits for the monkeys as well, researchers added.

It is ideal to house captive rhesus monkeys in groups for their social welfare, but populations can quickly explode due to high fertility.

And vasectomy in monkeys is more complex than in humans, with many complications.

PROCEDURE WORKED IN EVERY SINGLE MONKEY, WITHOUT EXCEPTION

"We were impressed that this alternative worked in every single monkey, even though this was our first time trying it," said Angela Colagross-Schouten, the project's lead veterinarian.

Basic reproductive health and family planning information: