The myth around resting after for sex for conception is being questioned

London - The long-held belief that if you want to improve your chances of conception you should lie with your knees up after making love is a myth, scientists say.

Fertility clinics have for years recommended that women stay immobile with their knees in the air after artificial insemination. But the study found little difference in conception rates between patients who followed this advice and those who got up immediately. There was even evidence that getting up improves pregnancy chances.

Scientists say the same should be true of women seeking to conceive naturally.

Researchers from the VU University Medical Centre in Amsterdam studied 479 women undergoing fertility treatment. Half the women had to stay immobile for 15 minutes in bed after artificial insemination, on their backs with their knees in the air and feet flat on the bed.

The other half were asked to get up and carry on with their daily activities.

The researchers found that after a total course of treatment – which in some cases included six cycles of intrauterine insemination (IUI) – 32 per cent who rested with their knees up got pregnant. Of those who were ‘immediately mobilised’ after sex, 43 per cent became pregnant.

Study author Dr Jouke van Rijswijk, who presented her research to the European Society for Human Reproduction and Embryology in Helsinki, said: ‘In our opinion, immobilisation after IUI has no positive effect on pregnancy rates, and there is no reason why patients should stay immobilised after treatment.’

A previous Dutch study also recommended 15 minutes of lying down but Dr van Rijswijk said: ‘We also know from other studies that sperm cells can reach the fallopian tube five minutes after insemination and that they can survive for several days in the womb.

‘Why should bed rest affect that? There’s no biological explanation for a positive effect of immobilisation. We believe our results in such a large randomised trial are sufficiently strong to render the recommendation for bed rest obsolete.’

Daily Mail