Please take some time to read this article.
Short version: Timed sex can lead to issues with men's libido and the researchers don't recommend more than a few months of timed sex. Some men also are more prone to erectile disfunction and straying after prolonged timed sex.
"Any couple trying for a baby is told that timing is everything. But pressure to perform when their partner is at her most fertile drives men away, according to research.
One in ten men has had an affair because of the pressure of rigorously timed sessions, while four out of ten claimed it made them impotent.
More than 400 men took part in the study, which found the pressure to conceive a baby caused men acute stress.
Fertility experts routinely tell couples to time intercourse to coincide with the window when a woman is ovulating. There are even highly sensitive devices designed to help couples work out – down to the minute – when she is at her most fertile.
But as the number of timed sex sessions increased so did the men’s level of stress, according to the research carried out in South Korea. None of the men in the study had ever had sexual problems.
The finding supports several previous studies showing that men who are under stress produce less testosterone, which has an effect on their libido.The authors suggested couples should be made aware of these risks and attempt timed sessions for no longer than three months at a time, with breaks for a few months in between.
Timed intercourse seems to impose a substantial degree of stress on male partners, inducing erectile dysfunction and, in some cases, causing them to seek extramarital sex,’ they wrote in the Journal Of Andrology. Andrology is the branch of medicine concerned with diseases in men, especially the reproductive organs.
They added: ‘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.’ All the couples in the study had been trying to conceive naturally for a year.
The authors noted that having 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’. They believe that higher levels of cortisol, the stress hormone, being produced by the body was to blame for lower testosterone.
Professor Allan Pacey, a senior lecturer in andrology at the University of Sheffield, said: ‘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.
‘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.’
Professor Pacey, also chairman of the British Fertility Society, added: ‘If couples are having regular sex two or three times a week, they will hit the fertile window.’
In the UK the age limit for free IVF treatment is to be raised to
42. Currently only women up to 39 are allowed three free rounds of NHS fertility treatment. Draft guidelines being put out for consultation by the rationing body Nice could allow 8,000 more women in their early 40s to benefit. At present they have to pay up to £5,000 per treatment."
Summary taken from this post on the Infertility board on thebump.com