Randomization and Masking
Following completion of written informed consent and baseline assessments, participants were randomized to MT plus standard care or standard care alone during NICU using a computer-generated randomization list with ratio 1:1, in block sizes of 2 or 4 varying randomly, stratified by site, using an online system (Sealed Envelope Ltd). Only the first-born infant of multiple pregnancies was included and randomized, while multiple-birth siblings received a corresponding intervention for ethical reasons. Before discharge home, participants were randomized a second time to postdischarge MT or standard care in a 1:1 ratio using the aforementioned procedures. It was not possible to mask participants, clinicians, or data collectors due to nature of the intervention and outcome measures.