Perhaps not always, but it may help women who are going through in-vitro fertilization.
In a study of 219 women undergoing IVF published in Fertility and Sterility, an Israeli team led by Shevach Friedler found that the odds of success were greater among women who were entertained by a professional "medical clown" just after the embryos were transferred to their wombs.
Overall, 36% became pregnant, as compared to 20% of women who'd had a comedy-free recovery after the transfer procedure.
Friedler said he got the idea for the study after reading about the potential physiological impact of laugher as a "natural anti-stress mechanism."
"Patients suffering from infertility undergoing IVF are incredibly stressed," said Friedler, who is based at Assaf Harofeh Medical Center in Zrifin, Israel, in an email to Reuters Health.
"So I thought that this intervention could be beneficial for them at the crucial moments after embryo transfer."
To test the idea, the research team had a medical clown visit their fertility clinic
periodically over one year. Of the 219 women in the study, half underwent embryo transfer on a day the clown was at the clinic.
During recovery from the procedure, each woman had a 15-minute visit from the clown, who performed a specific routine created by Friedler - who has studied movement and mime - and a colleague.
The researchers found that, compared to women who came to the clinic on a "non-clown" day, those who'd had a laugh were more than twice as likely to become pregnant, when other factors such as age, type of infertility and the number of embryos transferred, were taken into account.
Friedler said more studies were needed to see if other stress-reducing techniques might be useful, noting that it wasn't clear if the clown intervention had actually worked to curb stress. Researchers also don't know what role emotional stress might play in IVF success.
So-called "clown care" has long been used at medical centers in Israel, the United States, Canada, Europe and Australia, usually in children's hospitals. Israel's University of Haifa also recently launched a degree program in "medical clowning".
Friedler said that if studies at other centers back up his findings, fertility clinics elsewhere might take up the tactic.
"After all, this is one of the least hazardous interventions in our field," he said. Do you believe that laughter can help IVF?