We randomly allocated women 1:1:1 , with randomly sized blocks and stratified by participating centre and gestational age ( < 29 weeks vs 29 weeks ) , to three timing of delivery plans , which differed according to antenatal monitoring strategies : reduced cardiotocograph fetal heart rate STV ( CTG STV ) , early DV changes ( pulsatility index > 95th percentile ; DV p95 ) , or late DV changes ( A wave [ the deflection within the venous waveform signifying atrial contraction ] at or below baseline ; DV no A ) .