Methods:
All rounds were conducted using Google Forms, with the first three
rounds occurring within a 24-hour period during the PI meeting. The
first round involved collecting demographic information and obtaining
informed consent. Potential surrogate markers were identified through an
open-ended question.In the second round, participants were presented
with a feedback report that introduced the subsequent phase. The
suggested surrogate markers were categorized as antenatal, maternal,
neonatal, or placental markers, with overlapping variables consolidated.
Each marker was then ranked on a scale from very important (5) to
irrelevant (1), with the option for non-medical scientists to
selectively choose ’no opinion’. The third round involved participants
indicating agreement on marker inclusion. A median score of 5 indicated
inclusion, a median score of 4 indicated potential inclusion, a median
score below 4 indicated exclusion. Consensus was reached when 70%
agreement was achieved. A follow-up online round was conducted after 3
months to confirm the condensed final list of surrogate markers and
identify the measurement instruments to be used, requiring 80%
agreement for consensus.