Respiratory transition at birth involves rapidly clearing fetal lung liquid and preventing efflux back into the lung whilst aeration is established. We have developed a sustained inflation (SI_OPT) individualized to volume-response and a dynamic tidal positive end-expiratory pressure (open lung volume, OLV) strategy that both enhance this process. We aimed to compare the effect of each with a group managed with PEEP of 8 cmH₂O and no recruitment manoeuvre (No-RM), on gas exchange, lung mechanics, spatiotemporal aeration and lung injury in 127±1d preterm lambs. Forty-eight fetal-instrumented lambs exposed to antenatal steroids were ventilated for 60 min after applying the allocated strategy. Spatiotemporal aeration and lung mechanics were measured with electrical impedance tomography (EIT) and forced-oscillation respectively. At study completion, molecular and histological markers of lung injury were analyzed. Mean (SD) aeration at the end of the SI_OPT and OLV groups was 32 (22) and 38 (15) mL/kg, compared to 17 (10) mL/kg (180s) in the No-RM (p=0.024, one-way ANOVA). This translated into better oxygenation at 60 min (p=0.047; two-way ANOVA) resulting from better distal lung tissue aeration in SI_OPT and OLV. There was no difference in lung injury. Neither SI_OPT nor OLV achieved homogeneous aeration. Histological injury and mRNA biomarker upregulation were more likely in the regions with better initial aeration, suggesting volutrauma. Tidal ventilation or a SI achieve similar aeration if optimized, suggesting that preventing fluid efflux after lung liquid clearance is at least as important as fluid clearance during the initial inflation at birth.