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Does Viagra affect fertility?

Men whose ability to engage in intercourse depends on using Viagra could understandably believe that, thanks to the drug’s properties that allow for more frequent sex, their chances of conceiving a child have proportionally increased. But different studies examining that very issue have resulted in conflicting conclusions.

A 2017 Chinese meta-analysis published in the journal Urology suggests that erectile dysfunction drugs known as phosphodiesterase type 5 – or PDE5 inhibitors, which include Viagra, Cialis, and Levitra – could be helpful to men with poor sperm quality.

The analysis, which encompassed 11 different studies covering 1,317 male subjects, found that taking PDE5 inhibitors boosted the number of well-swimming (motile) sperm as well as those of normal shape (morphology). These factors play an important part in determining how effectively a sperm can swim to fertilize an egg. Which, in turn, plays a major role in whether you can successfully impregnate your partner.

According to a Men’s Health review of the study, researchers also found that “chronic administration” of the little blue pills appeared to better improve sperm-quality metrics than merely taking the drugs as needed. The analysis also indicated that men with healthy sperm who took erectile dysfunction drugs didn’t demonstrate any increase in sperm quality.

The study concluded, “Oral PDE5 inhibitors treatment could modestly increase the sperm motility and morphology in infertile men”. And even though that observation sounds encouraging, “modest” is still a far cry from “robust” or “significant”.

In fact, a few years before the Chinese meta-analysis, researchers from Queen’s University in Belfast, Northern Ireland, announced that results from test tube experiments showed that taking Viagra could reduce fertility in men.

Research team member David Glenn told New Scientist that, while Viagra is sometimes used to speed up the production of a sperm sample from men who have difficulty providing one without the drug, men should nonetheless reconsider their use of Viagra.

The team collected 45 semen samples from men working with fertility clinics and gave 50 percent Viagra while 50 percent were used as a control. Within a quarter of an hour, sperm in men who’d been given Viagra began swimming faster, an effect that lasted for a little more than 2 hours.

At that point, nearly 80 percent of those sperm were deemed completely “reacted,” which refers to the process by which the head of the sperm produces digestive enzymes that break down the outer shell of an egg.

That’s not necessarily such bad news for the absolutely fastest swimming sperm, which can reach an egg in as little as 45 minutes. Many sperm, however, can take upwards of 12 hours to reach the fallopian tubes. Given that it generally takes about 30 minutes for Viagra to become effective, users would need to cultivate the speediest possible sperm to stand a decent chance of reaching the egg before becoming fully reacted, and therefore spent.

The Belfast researchers noted that their findings backed up previous work that they’d conducted on mice who, when given Viagra before mating with females, produced 40 percent fewer embryos than those in a control group. Cultured embryos were also less likely to survive.

Then there’s this to muddy the waters even more: According to a Canadian pharmacy blog, which quoted a 1994 study, prolonged sexual abstinence of at least 7 days affected all sperm parameters, with volume and count increasing as swimming ability and shape decreased in quality.

Thus, the blog noted, sildenafil-based drugs like Viagra can have a positive effect on fertility by increasing the frequency of sexual intercourse.

Which brings us back to where we started.

Given the amount of conflicting research about the effects of Viagra on male fertility, an obvious scenario presents itself as an attractive compromise: If the drug isn’t necessary for a man to engage in intercourse, he could collect his sperm for preservation, untainted by Viagra, and freeze them for future possible use.

Even if Viagra doesn’t factor into a man’s needs at present or in the foreseeable future, taking steps to protect his assets before its use becomes desirable or necessary could provide the best way for preserving healthy sperm.

The worst mistake a man could make would be to put off what can be preserved today in the hope that a wonder drug will somehow save the day – especially one that, like Viagra, has already been on the market for 20 years.

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