While many couples trying to conceive are often told that timing is everything, new findings confirm that pressure on men from having to “perform” on cue when their partner is ovulating and at her most fertile state can result in impotence and even adultery.

The latest findings, published in Journal of Andrology, found that after six months of “timed-intercourse” at least four out of 10 men report suffering erectile dysfunction or impotence, and one in 10 men report having an affair because of the pressure of the rigorously timed sessions.

The study consisted of 439 men who had no previous episode of erectile or ejaculatory dysfunction and who were attempting to achieve natural conception for more than a year.

Timed intercourse, the most basic treatment for failure to achieve pregnancy, usually involves regular visits and ultrasounds to predict the time of ovulation and determine the optimal times when couples should have sex to conceive.

However South Korean researchers who set out to determine the impact of impending timed intercourse on the psychological well-being and behavior of male partners, which they say is an area that has not been thoroughly investigated, warn couples about the downsides of this type of fertility treatment.

Researchers found that the pressure to conceive a baby led to acute stress in male participants, and as the number of timed intercourse incidences increased, so did the number of erectile dysfunction cases, extramarital sex and men reporting that they avoided having sex with their partner at the allotted time.

“It is clear that the greater instances of timed intercourse trials, the more incidences of erectile dysfunction and extramarital sex and the greater the desire to avoid sex with the intended partner,” the authors wrote.

Findings from the latest study also support several previous studies that showed that men who are stressed produce less testosterone, which negatively affected their libido.

Scientists explained that needing to sleep with their partner at a specific time “becomes a burden and is carried out as a job to be done, which imposes further stress,” which leads the body to produce greater levels of stress hormone cortisol which leads to lower production of testosterone.

“Physicians and clinicians should acknowledge the potential harmful effects of timed intercourse on men. Furthermore, both female and male partners should also be cautioned about the increased possibilities of erectile dysfunction and extramarital sex as the number of incidents of TI increases,” the authors wrote.

"Stress and anxiety are commonly thought to be detrimental to sexual function, and in the present study, as the number of incidents of timed intercourse increased, the number of men experiencing erectile dysfunction also increased," researchers wrote.

Researchers recommended that couples wanting to conceive naturally through timed intercourse should take a break after three months before trying the method again.

“I’m glad someone has studied this, as the single biggest concern for men – usually when their partner is not in the room – is that they really find it a struggle when their partners are obsessed with timing,” said Professor Allan Pacey, a senior lecturer in andrology at the University of Sheffield, according to Daily Mail.

“While it is useful for couples to be aware of the fertile window, obsessing about it is not helpful at all. Men are being phoned up at three in the afternoon and told that the green light is on and they have to come home immediately,” he said.