The Effect of Aromatherapy on Nausea and Vomiting during Pregnancy: A Systematic Review and Meta -Analysis

Background Most pregnant women suffer from nausea and vomiting during pregnancy (NVP) as one of the common discomforts compelling women to increasingly turn to herbal medications for help, including lemon inhalation aromatherapy as investigated in the current systematic review and meta-analysis. We aimed to evaluate the effect of aromatherapy on relieving nausea and vomiting during pregnancy. Materials and Methods In the present study, electronic sources in English (Medline [via PubMed], Scopus, Web of Science, and Cochrane Library); and databases in Persian (SID and Magiran) were systematically searched without any time constraints until February 10, 2018. Following keywords were used to find research articles related to the effect of aromatherapy on the NVP: (Nausea OR Vomiting) AND (Aromatic therapy OR Essential oil OR Essential oils OR Fragrance OR Fragrant oil OR Fragrant oils OR Scent OR Alternative Medicine OR Complementary Medicine) AND (Pregnancy). Results Four studies were included in systematic review. The results of this study reported that aromatherapy with lemon compared to placebo improves the severity of nausea and vomiting in pregnant women, but Mentha and Peppermint oil alone or in combination with lavender, showed no significant improvement. There was no significant difference between the placebo and aromatherapy groups regarding total score of nausea and vomiting among pregnant women at the third day (standardized mean difference [SMD] = -0.347; 95% Confidence Interval [CI]: -0.980 to 0.287; P=0.284, heterogeneity; I2=72%; P=0.054). Conclusion Aromatherapy did not show any beneficial effect on nausea and vomiting among pregnant women. Only aromatherapy with lemon oil can be beneficial.