Williams 2003

Methods	Randomised controlled study ‐ block randomisation (block of 4 and 6). Individual women.
Participants	Women with high‐risk pregnancies ‐ singletons (IUGR 7%, hypertension 10%, diabetes 11%, prolonged pregnancy 43%, decreased fetal movements 22%). GA > 32 weeks. N = 1360 women.
Interventions	Intervention: umbilical artery Doppler: if Doppler normal then women seen twice a week; if equivocal then amniotic fluid index done; if abnormal then proceeded to induction/delivery within 24 hours. Comparison: electronic FHR with NST: twice a week; Kulbi score (5 components). If equivocal (Kulbi = 6) identified then assessment of amniotic fluid volume; if abnormal (Kulbi = 4) identified  then induction/delivery within 24 hours.
Outcomes	Primary outcome: incidence of CS for fetal distress in labour (non reassuring FHR). Secondary outcome: total CS, Apgar score 1 and 5 min, the incidence of stillbirth, the presence of meconium, and the incidence of transfer to the NICU with severe neonatal morbidity.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number table with a variable block size of 4 and 6.
Allocation concealment (selection bias)	Unclear risk	Sequentially numbered opaque envelopes although no information as to whether they were sealed. “...envelopes were kept in a locked drawer that was accessible only to the unit clerk. The envelops was opened by the nurse/sonographer in the presence of the patient”.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding women and/or staff in these trials was not generally feasible.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding women and/or staff in these trials was not generally feasible.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Describe any loss of participants to follow‐up at each data collection point: no final outcome data were available for 16 women (10 in NST group and 6 in Doppler group).                                                        Describe any exclusion of participants after randomisation: 4 women were assigned in error and did not have the identified high‐risk condition ‐ removed from further analysis ‐ 1356 women in study. Was the analysis ITT? “once assigned randomly to particular group, the patient remained in that group for any subsequent assessment that took place in that pregnancy".
Selective reporting (reporting bias)	Unclear risk	All the outcomes have been reported but we have not assessed the trial protocol.
Other bias	Low risk	If the study was stopped early, explain the reasons: study not stopped early for benefit. Describe any baseline in balance: this seems fine. Describe any differential diagnosis: this seems alright.

AEDF: absent end diastolic flow AEDV: absent end diastolic velocity

AN: antenatal BPD: bronchopulmonary dysplasia BPP: biophysical profile CS: caesarean section CTG: cardiotocography EDV: end diastolic velocities FHR: fetal heart rate GA: gestational age ITT: intention‐to‐treat IUFD: intrauterine fetal death IUGR: intrauterine growth retardation IVH: intraventricular haemorrhage min: minute NEC: necrotising enterocolitis NICU: neonatal intensive care unit NS: not significant NST: non‐stress test PTL: preterm labour PROM: preterm rupture of membranes RCT: randomised controlled trial RDS: respiratory distress syndrome SD: standard deviation SGA: small‐for‐gestational age US: ultrasound vs: versus