stopped drinking. Around week 32 of gestation, women were asked about their average weekday and weekend alcohol consumption, from which weekly alcohol intake was derived. However, attrition was high (41%) and the format of this variable was different from the other alcohol drinking variables at previous time-points, and therefore it was not used in formal association analyses. Drinking patterns were assessed in a separate question, included in the questionnaires at week 18 of gestation, which asked about the number of days in the previous 4 weeks that the mother had consumed at least 4 units of alcohol [defined as ‘binge drinking’ occasions for the purpose of this study (71)]]. Response categories were 0, 1–2, 3–4, 5–10 or ≥10 days. For the analyses, consuming at least 4 units of alcohol on one or more days around week 18 was considered ‘binge drinking during pregnancy’. Drinking cessation at various time-points was defined as non-drinking at those time-points, for women who were drinking before the index pregnancy.
