Is neonatal injury more likely outside of a 30-minute decision-to-incision time interval for cesarean delivery?

Not according to this study. For Category 1 and 2 deliveries occurring within (vs outside) 30 minutes, there was a higher likelihood of overall 5-minute Apgar score less than 7 (odds ratio [OR] 3.10; 95% confidence interval [CI] 1.93–4.96) and umbilical artery pH level less than 7.10 (OR 3.40; 95% CI 2.38–4.87). For Category 1 deliveries only, no difference was found in Apgar scores or umbilical artery pH levels.

Tolcher M, Johnson RL, El-Nashar SA, West CP. Decision-to-incision time and neonatal outcomes: A systematic review and meta-analysis. Obstet Gynecol. 2014;123(3):536–548.