To assess the efficacy alternative medicine in the treatment of nausea and vomiting of pregnancy (NVP), three major databases of PubMed, Cochrane Library and Scopus were systematically searched since inception until January 14 2019 to investigate the effects of herbal medicines on NVD. The quality assessment of studies was performed according to Jadad scale. All studies showed that ginger had a positive effect on nausea in pregnant women. Unlike others studies, one study reported that ginger was not beneficial to the treatment of vomiting. Herbal medicines such as matricaria chamomilla, elettaria cardamomum, pomegranate and spearmint syrup, lemon provide safe and effective medical alternatives for treating pregnant women with mild to moderate NVD. The results suggested that ginger were more effective than vitamin B, but at the dose of 35-500 mg ginger, vitamin B6 and ginger had identical effect. However, over a longer treatment period (60 days), vitamin B6 was proved to be more effective than ginger. The same effect was observed in the comparison of quince and vitamin B6 as well as ginger and doxylamine plus pyridoxine. Mentha did not generated a positive effect on nausea and vomiting. However, this finding should be considered in the light of the above limitations.IMPACT STATEMENTWhat is already known on the subject? Previous systematic reviews have shown the superiority of ginger over the placebo. Lemon, chamomile and Mentha have been found to be more effective than the placebo.What do the results of this study add? This systematic review confirmed the results of previous systematic reviews in a larger sample size. Ginger was more effective than vitamin B, but at the dose of 35-500 mg ginger, vitamin B6 and ginger had identical effect. However, over a longer treatment period (60 days), vitamin B6 was proved to be more effective than ginger.What are the implications of these findings for clinical practice and further research? Matricaria chamomilla, elettaria cardamomum, pomegranate and spearmint syrup, lemon and ginger can be recommended to pregnant women for alleviation of NVP.
Keywords: Herbal medicine; nausea; phytoestrogen; pregnant women; systematic review; vomiting.