Meta-analysis of acustimulation effects on nausea and vomiting in pregnant women.

Objective: We used meta-analysis to examine the effects of acustimulation (AS) on the prevention of nausea and vomiting in pregnant women (NVP).

Methods: Meta-analysis of effects of acustimulations (ie, acupressure, acupuncture, and electrical stimulation [ETS]) on NVP was conducted. Fourteen trials, eight random controlled trials (RCTs), with one RCT having two treatment modalities with four groups, and six crossover controlled trials (N = 1655) published over the last 16 years were evaluated for quality according to the Quality of Reports of Meta-analysis of Randomized Controlled Trials (QUORUM) guidelines. Relative risks (RR) and 95% confidence intervals (CI) were calculated from the data provided by the investigators of the original trials.

Results: Before the treatment, 100% of the women (13 trials, n = 1615 women) were nauseated, but and 96.6% (1599/1655) reported vomiting. After the treatment, compared with the controls, AS (all modalities combined) reduced the proportion of nausea (RR = 0.47, 95% CI: 0.35-0.62, P < .0001) and vomiting (RR = 0.59, 95% CI: 0.51-0.68, P < .0001). Acupressure methods applied by finger pressure or wristband reduced NVP. The ETS method was also effective in reducing NVP. However, the acupuncture method did not show effects on reducing NVP. There was a placebo effect when compared with controls in reducing nausea (three trials, RR = 0.63, 95% CI: 0.39-1.02, P = .0479) and vomiting (five trials, RR = 0.67, 95% CI: 0.50-0.91, P = .0084).

Conclusions: This meta-analysis demonstrates that acupressure and ETS had greater impact than the acupuncture methods in the treatment of NVP. However, the number of acupuncture trials was limited for pregnant women, perhaps because it is impossible to self-administer the acupuncture and thus inconvenient for women experiencing NVP as chronic symptoms.