This is not a diagnosis which is found in medical textbooks, but the reality is that in today's day and age, where men and women live in metropolises and pursue high flying careers, they are not able to spend enough time together – and not having enough sex at the right time results in infertility.
The tragedy is that this is a socially induced medical problem – they would easily be able to have a baby if they had more frequent sex.
This is a common problem amongst people who migrate to the Middle East to earn more money. Because they are able to spend only 1-2 months every year with their wife, they end up not being able to have a baby – and by the time they put this on their priority list, precious time has been wasted.
This is also a problem which plagues migrant labourers who come from UP and Bihar to work in Mumbai, in order to eke out a living.
And this is true for many middle class couples, who spend most of their time community to and fro from work, which means they are often just too tired to be able to have sex when they get back home.
One treatment option is self-insemination. You can read more about this at http://www.drmalpani.com/knowledge-center/articles/selfinsemination