Phase-rectified signal averaging method to predict perinatal outcome in infants with very preterm fetal growth restriction- a secondary analysis of TRUFFLE-trial by Lobmaier, SM, van Charante, N, Ferrazzi, E, Giussani, DA, Shaw, CJ, Müller, A, Ortiz, JU, Ostermayer, E, Haller, B, Prefumo, F, Frusca, T, Hecher, K, Arabin, B, Thilaganathan, B, Papageorghiou, AT, Bhide, A, Martinelli, P, Duvekot, JJ, van Eyck, J, Visser, GHA, Schmidt, G, Ganzevoort, W, Lees, CC, Schneider, KTM