Saracoglu 1999.

Methods	Randomisation: randomisation method unknown.
Participants	Women seen at Perinatology Unit. Country: Turkey. 400 women randomised.
Interventions	Women randomised to fetal acoustic stimulation group were monitored for at least 5 minutes. A vibratory acoustic stimulation was applied to the maternal abdomen in the region of the fetal head and activated for 1 second up to 4 times.
Outcomes	Primary outcome: FHR reactivity. This was defined by the presence of 2 accelerations of 15 bpm and of at least 15 seconds' duration within a 20‐minute period. Non‐reactivity was defined as 40 minutes without the reactive criterion.
Notes	A fetal acoustic stimulator (Model 146; Corometrics, Wallingford, CT;75 Hz, 74 db) was used, and FHR was recorded with a fetal heart monitor (Model 115; Corometrics). The report by Saracoglu 1998 only provided data in abstract form and these were inadequate. There was no reply despite various attempts to contact the authors. The abstract was subsequently published in full (Saracoglu 1999) and the published paper (Saracoglu 1999) is included in this review.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	The study participants were randomly selected from patients applying to the unit. However, the assignment to acoustic stimulation or NST does not appear to be randomised ("divided equally").
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No information provided.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Follow‐up: 100%.
Selective reporting (reporting bias)	Low risk	All outcomes in the methods section have been reported on.
Other bias	Unclear risk	No information provided.