Randomization
Participants were randomly assigned using opaque, sealed envelopes, stratified by gestational age (24 0/7 to 27 6/7 weeks or ≥28 0/7 weeks) and type of pregnancy (singleton or twin pregnancy). The allocation sequence was based on computer-generated pseudorandom numbers (permuted blocks of varying length). The research team opened envelopes in the theater immediately before the cesarean delivery. The randomization result was then announced to the entire team during the team time-out prior to the start of the surgery.