Experts say having MORE sex with your partner can mean a healthier pregnancy

Good news: research has suggested that having more sex before you conceive can actually lead to a healthier pregnancy.

It all comes down to the way women's bodies have evolved over time, and how the immune system works.

Research shows that women who have regular sex with the same partner for at least three months before conceiving have less risk of developing preeclampsia.

Preeclampsia is a condition that can lead to serious complications, including growth problems for the unborn child, and in rare cases can be life threatening for the mother.

Professor Sarah Robertson from the University of Adelaide explained in The Conversation how the two are connected.

'Preeclampsia is more common when there has been limited sexual contact with the father before pregnancy is conceived, and is associated with insufficient establishment of immune tolerance in the mother,' she wrote.

The key factor seems to be the length of time couples had been having regular sex before conception, according to statistics of the rate of preeclampsia in pregnant women. 

'Women with less than three months sexual activity with the conceiving partner had a 13 per cent chance of preeclampsia, more than double the average occurrence,' Professor Robertson explained.

'Among the few women who conceived on the first sexual contact with the father, the chance of preeclampsia was 22 per cent, three times higher than the average. Low birth weight babies were also more common in this group.'

Other studies have shown that it's not just natural pregnancies that benefit from regular sex, with couples going through IVF having higher chance of conceiving if they are also having penetrative sex.

'A study of Australian and Spanish couples showed intercourse in the days just before or just after embryo transfer boosted pregnancy rates by 50 per cent.' Professor Robertson said.

Scientists aren't entirely sure why the immune system has such a close link to reproduction, but believe it may have something to do with women's bodies detecting genetic traits.