Methods	Clinical trial.
Participants	225 pregnant women in the first and 2nd trimesters of pregnancy
Interventions	Thiethylperazine 30 mg daily. Placebo.
Outcomes	Therapeutic response: good, fair, poor. No information on time-point of evaluation(s)
Notes	The patients were not told they were taking part in a trial.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	Not described.
Allocation concealment?	Unclear	Staff reported to be blind to group allocation - not described how
Blinding? Change in grade of nausea or vomiting at second visit compared to first	Yes	The staff of the clinic did not know which of the 2 apparently similar tables the patient would receive Double-blind trial.
Incomplete outcome data addressed? Change in grade of nausea or vomiting at second visit compared to first	Yes	High attrition: 45 (20% of 225, 19 from treatment group, 26 from placebo group) were not included in the analysis because of failure to return for assessment, transfer to another hospital or failure to take the tablets (breakdown by reason not given). Results about therapeutic response reported for 180 patients (but 8 from treatment group and 8 from placebo group were not classified “because of equivocal evidence, intercurrent illness or abortion”), results for fetal outcome reported for 147 patients
Free of selective reporting?	Yes	All outcomes reported.
Free of other bias?	Yes