A double-blind, placebo-controlled RCT evaluated the effectiveness of a ginger extract (EV.EXT35) on 120 women with morning sickness before 17th week of gestation.19 Subjects received either 125 mg of ginger extract (equivalent to 1.5 g of dried ginger) or placebo (soy bean oil) 4 times daily for 4 days. No data were reported on the preparation of the ginger extract. Outcomes included
the frequency, duration, and distress caused by the symptoms of nausea, vomiting, and retching. Secondary outcomes included gestational age, birth weight, and occurrence of side effects and adverse effects on pregnancy outcomes such as abortion, stillbirth, congenital abnormalities, and neonatal death. Pregnancy-related symptoms were recorded 24 hours before and during the 4 days of treatment (4 time a day) using the Rhodes Index of Nausea, Vomiting, and Retching (an 8-item,5-point Likert-type tool). The follow-up of the study included 81 women (women from the placebo and ginger groups who were given an 18-day ginger supply following the end of the trial). Outcomes were compared with the general infant population delivered at the Royal Hospital for Women in Sydney. The results showed a significant reduction in nausea experience, occurrence, and distress in the ginger and in the placebo groups. However,
the reduction of nausea scores was significantly higher in the ginger than in the placebo group. Similar results were observed for retching symptoms. There was no significant difference between ginger extract and placebo groups for any of the vomiting symptoms.