epicts the inclusion of participants in the final analysis; 5 690 participants were recruited into the SCOPE study at 14–16 weeks (STROBE Statement: S1 Table). Forty-eight participants (0.8%) were lost to follow-up and 14 (0.2%) were ineligible after recruitment. Nineteen (0.3%) of the 5 628 remaining participants did not have a booking haemoglobin and were excluded, resulting in a final study population of 5 609 participants at 14–16 weeks. Without adjustment to the measured haemoglobin, 103 (1.8%) of the participants were anaemic; 125 (2.2%) were found to be anaemic after adjusting for cigarette smoking.