Medical practitioners attending the conference were told they should check on the sexual wellbeing of the parents of young children.

It has been estimated that at least a third of couples develop serious, long-lasting psychosexual disturbances after the birth of their first child.

Sexual anthropologist Bella Ellwood-Clayton, who was invited to speak at the conference, said it could take years for couples to resume their normal sex lives. ''Rather than setting the bar for six weeks, I think it's more likely to set at six years,'' she said.

Dr Ellwood-Clayton said pre-existing sexual problems in couples tended to worsen after the birth of their first child and were at their most pronounced three to four years later.

''It's really important that somebody knows that a lower libido is what the couple is going to be dealing with for a few years because it might not come as such a momentous shock for the couple. I think it's important for people in the medical profession to take more of an active role in discussing the sexual side of pregnancy of birthing and of new parenting and for them to routinely inquire about couples' sexual wellbeing.''

Dr Ellwood-Clayton said a loss of sexual desire in women after childbirth could be linked to a range of factors, including post-delivery discomfort, exhaustion, postnatal depression, being overwhelmed with new responsibilities and body image issues.

Men could also be traumatised by watching their partners experience labour.

''There's this myth of ever-lasting passionate monogamy when in all likelihood it is natural for us during the life course to go through periods of having a lower libido,'' she said, ''and I think that should be perfectly accepted and fine.

''But we have these enormous expectations and also a very real issue is two people have different desires in a relationship and some people's sexual needs aren't being fulfilled. That is often the cause of relationship breakdown and I think that's reflected in our current divorce rate of 40 per cent.''

The problem was considered serious enough to be placed on the agenda of the annual scientific meeting of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists in Canberra this week.