By Caroline Ryan
BBC News, Prague
Sending in the clowns can significantly increase the chances that fertility treatment will be a success, Israeli researchers have found.
Tricks were used to relax patients
The team looked at women undergoing embryo transfers, where an IVF embryo is put into the womb.
Just over a third of women entertained by a clown conceived, compared to 19% of a group who were not, a European fertility conference heard.
Experts said helping patients relax was the key to increasing conception rates.
The research was carried out by Dr Shevach Friedler at the Assaf Harofeh Medical Centre in Zerifin.
Dr Friedler, who attended a movement and mime school in France before he entered the medical profession, said he knew fertility patients became stressed - and that laughter could reduce stress.
And he pointed out that clowns were often used to help children who were in hospital feel better.
The team studied 186 women aged 25 to 40 over 10 months, all of whom were undergoing embryo transfer treatment.
Half were simply given the treatment and nothing else.
However, the other group were entertained by a clown for up to 15 minutes as they recuperated in bed after the treatment.
Of the 93 who did not receive the "clown-treatment", just 18 fell pregnant, compared to 33 of the 93 who did.
Dr Friedler said the team had needed to devise an adult-friendly clown: "A clown with a red nose is fine for children, but we had to invent a new character for these adult women."
The character they devised was a chef called Shlomi Algussi, who uses magic tricks and jokes to make women laugh.
Dr Friedler said: "The response form the women was wonderful."
But he added it was not something all clinics would be able to introduce.
"For medication, you can get the patient to pay, but who is going to pay for clowns?"
Dr Mark Hamilton, chairman of the British Fertility Society, said: "Humour is recognised as an antidote to stress, although it is not prescribed on the NHS.
"But clinicians need to be sensitive to the effects of emotions and the psychological pressures on couples.
"It's an important part of care which should be part of medical practice."