maternal nipple pain, perceptions of adequacy of milk
supply, introduction of alternative foods, satisfaction with
infant feeding, maternal feelings about breastfeeding in
public, and details about expressing and breast pump
use (to be reported separately). We also asked about
maternal return to paid employment, when women
planned to or actually restarted work or study. The question
used to elicit the primary outcome was ‘In the last
24 hours, how have you been feeding your baby?’
A range of mutually exclusive options were available for
the interviewer to code the answer appropriately, and
this classification allowed us to analyse outcomes as ‘any
breast milk’, ‘only breast milk’, ‘breastfeeding only at the
breast’, ‘giving any EBM’, ‘giving only formula’, ‘giving
any solids’, and any combination of these. Although
interviews were conducted as near as possible to
6 months postpartum, where this did not occur, and if
breastfeeding had already ceased, other questions
ensured we were able to ascertain the age of the infant
when any and only breast milk feeding ceased, and what
milk the baby was actually receiving at 6 months. Anyone
who had answered the survey prior to 26 completed
weeks postpartum was removed from the analysis, and
for those who answered at 27 weeks or later, feeding at
6 months was assumed to be breast milk feeding if the
infant was still breast milk feeding at the time of the
survey.