Methods	Randomised.
Participants	1360 patients.
Interventions	Doppler testing versus non-stress testing.
Outcomes	Incidence of caesarean delivery for fetal distress, neonatal morbidity
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“Consenting patients were assigned randomly.” “Each envelope contained an allocation that had been determined with the use of a random number table with a variable block size of 4 and 6”.
Allocation concealment (selection bias)	Low risk	“Randomization was performed by opening sequentially numbered opaque envelopes.” “The nurse/sonaographer approached the unit clerk to obtain the next envelope in sequence. Envelopes were kept in a locked drawer that was accessible only to the unit clerk.”
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	16 patients were lost to follow up - reasons not reported. 4 patients were assigned randomly in error and did not have the identified high-risk condition and were removed from further analysis. Analysis occurred for 1340 women out of 1360 enrolled - minimal loss
Selective reporting (reporting bias)	Low risk	All prespecified outcomes appear to have been fully reported
Other bias	Low risk	There were no significant differences that were identified in the maternal demographic data - apart from a higher incidence of induction in the Doppler group for abnormal testing (31 women vs 13 women)

FHR: fetal heart rate

ICU: intensive care unit

NICU: neonatal intensive care unit

VAS/mFBP: vibroacoustic stimulation with mock stimulation