Study designs of evaluations included in the review
Randomised controlled trials (RCTs) of satisfactory methodological quality.
Specific interventions included in the review
Either continuous wave or pulsed-wave umbilical Doppler, given from week 20 onwards in cases of high-risk pregnancy.
Participants included in the review
Women with high-risk pregnancies. These were defined as those at risk of delayed intra-uterine development, pre-eclampsia, arterial hypertension requiring treatment, or suspicion of chronic foetal distress.
Outcomes assessed in the review
The primary outcome assessed was perinatal mortality. Additional outcomes included: antenatal hospital admission; induction of labour or Caesarean section; foetal distress during labour; emergency Caesarean during labour; Apgar scores at 1 and 5 minutes; neonatal admission and artificial ventilation; perinatal death; and monitoring of foetal heart beat, ultrasound monitoring, and Doppler monitoring during pregnancy.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.