The researchers from University of Hong Kong compared the effects of real and placebo acupuncture on pregnancy rates given on the day of embryo transfer in 370 patients.
They found that placebo acupuncture after IVF treatment was associated with significantly higher overall pregnancy rate than real acupuncture.
They found that the overall pregnancy rate for placebo acupuncture was 55.1 pct, compared to 43.8 pct for the real acupuncture.
"We found a significantly higher overall pregnancy rate following placebo acupuncture when compared with that of real acupuncture," Dr Ernest Hung Yu Ng, Associate Professor in the Department of Obstetrics and Gynaecology at the University of Hong Kong (People's Republic of China).
"In addition, there was a trend towards higher rates of clinical pregnancy, ongoing pregnancy, live birth and embryo implantation in the placebo acupuncture group, although the differences did not reach statistical significance," he added.
The authors suggest that placebo acupuncture may not act as an inert control for real acupuncture, and that it may be having a real effect.
Placebo acupuncture seems to be more effective as the measurements for the receptivity of the uterus and the levels of patient stress changed significantly for both the real and control groups after the women had received the real or placebo acupuncture
During the study, the researchers used a placebo needle that looked identical to a real acupuncture needle, but which was blunt and retracted into the handle of the needle when pressed on the skin, while still giving the appearance and sensation of entering the skin.
A trained acupuncturist applied the placebo to the same acupuncture points as for the real acupuncture.
"Placebo acupuncture is similar to acupressure and therefore is good enough to improve the pregnancy rate. Or else, it's possible that real acupuncture may, in some way, reduce the pregnancy rate of acupuncture.
"So far there is no evidence that real acupuncture would adversely affect IVF outcomes because, in a previous meta-analysis of several acupuncture studies, the pregnancy rate was higher in the acupuncture groups than in the control groups.
"Further studies should be conducted to compare placebo or non-invasive acupuncture and controls without acupuncture," Ng added.
Infertile patients can suffer from high levels of stress and anxiety, which can adversely affect the outcome of IVF.
Dr Ng said: "We found a significant decrease in serum cortisol concentration and the anxiety level following placebo and real acupuncture. Reduction in stress in both groups may also contribute to a better pregnancy rate following placebo and real acupuncture," he added.